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This presentation discusses a collaborative effort of two Fraunhofer institutes to develop a lithography model that simulates the fabrication of blazed gratings using grayscale lithography. The model is calibrated with experimental data of blazed grating profiles. The complete process of modelling and calibration has been performed using the Research and Development lithography simulator Dr.LiTHO. To emulate the grayscale exposure of blazed gratings in a LED-based micro-image stepper with Dr.LiTHO a thin mask with a linear variation of the mask transmission and corresponding distribution of exposure dose was used. The resulting photoresist profiles are obtained with a standard model for Diazonaphthoquinone (DNQ) photoresistas. The calibration of simulated and experimental profile data of blazed gratings is performed using Dr.LiTHO’s inbuilt optimizer - Pythmea. The difference between experimental and simulated profile shapes is expressed by an areaFit. Minimization of this areaFit versus photoresist parameters and correlation analysis help to identify the most appropriate model parameters. The extendibility of the model to larger ranges of blazed grating pitches and grayscale exposures of other microstructures such as arrays of microlenses is discussed. Selected examples demonstrate the application of the model for the optimization of dose distributions for grayscale exposures to improve obtained profile shapes.

In this work we present a new all-silica coating - polarizer, which is also capable to withstand high density of radiation. In order to demonstrate the versatility of presented approach, several coating designs have been modelled and two of them fabricated together with the full-scale measurements and analysis necessary for polarizers implementation into high power microlaser systems. Two polarizing coatings at the wavelength of 355 nm have been formed using two stepper motors based GLAD system. Afterwards optical and structural analysis have been performed including spectrophotometric, atomic-force microscopy (AFM), scanning electron microscopy (SEM) and optical resistivity measurements.

More-than-Moore approaches to improve system performance have been a hot topic for a more than a decade as a way to maximize the efficiency and increase the bandwidth of high performance computing systems. Fan-Out packaging that realizes submicron Redistribution Lines (RDL) and large die sizes is one technology that can help enable complex heterogeneous integration for applications including Artificial Intelligence (AI) and autonomous driving. For systems requiring large package sizes, Panel Level Packaging (PLP) can offer efficiency and cost advantages over Wafer Level Packaging (WLP). PLP however poses unique technical challenges including the requirement to realize uniform submicron patterning across the entire rectangular panel. To meet this challenge, Canon developed the first patterning exposure tool (stepper) capable of submicron resolution on 500 mm panels. The panel exposure tool is equipped with wide-field projection optics that offer a large 52 mm × 68 mm image field and a 0.24 NA that is optimum for submicron resolution. The stepper also features an updated panel handling system for processing up to 515 × 515 mm panels. In this paper, we will report on our study of fine patterning on rectangular panels using the submicron resolution panel stepper and will introduce technology innovations supporting advanced heterogeneous integration. Our study researched photoresist material performance and slit-coating uniformity challenges we identified through collaboration with resist vendors and slit-coating equipment manufacturers. We will report on the results of our collaborative study and will discuss current and future PLP advantages, challenges and solutions.

In making sensors require multiple processing by using different masks to accomplish, it needs reload and multiple aligning for a wafer in order to make a functional wafer, thus, the consuming for making mask are wasted, and used lamps toxic. In the study, a ULVLED stepper with Programmable LCoS or DLP as mask for multiple process wafer is proposed. By a programmable ultraviolet light-emitting diode (UVLED) array with a collimated lens as a transfer lens forms uniform source, to expose programmable LCoS or DLP as mask by using a 1 to 1 lithographic lens. Sensors and optical binary lens are easily made.

Photoacoustic imaging is a hybrid imaging technique with broad preclinical and clinical applications. Most of the optical-resolution photoacoustic microscopy (PAM) configurations are based on 3D scanning motor to scan the transducer together with the imaged sample or utilizing galvanometer scanning mirrors. In this paper, a novel low-cost linear laser scanning (LLS) system for photoacoustic microscopy is presented. The linear laser scanning system performs the two-dimensional scanning of the beam across a focusing lens. The prototype built for LLS system features a precision machined aluminum base with mounting platforms for optical components to insure proper alignment through the imaging process. The LLS relies on two stepper motors (1.8-degree, 200 steps per revolution) separately actuated, to move two 45-degree mirror mounts set onto high precision linear slides (44.5 mm of travel) which allow the laser beam to be moved across a tissue sample in a 2D axis. The threaded rod which is used to connect the linear slides and mirror assemblies has a travel distance per turn of 1/20.8” meaning for every inch of travel the rod must turn 20.8 times. The mechanical resolution of the system was estimated to be 6 μm. In this system, a pulsed laser diode with a wavelength of peak radiant intensity of 905 nm and output peak power of 220 W with 50 ns pulse width and repetition rate of 10 kHz was utilized as a light source.

CERCO can’t meet the increasingly stringent requirements for the stepper’s optics, but Zeiss isn’t interested in helping.

Herman van Heek and Gijs Bouwhuis create the world’s first wafer stepper. Van Heek is the system architect; Bouwhuis develops the brilliant aligning principle that puts Dutch lithography on the global map in the decades that follow.

As one of Natlab’s section directors, former war refugee Hajo Meyer recognizes the value of the optical precision technology that a few years later will serve as a seedbed for the wafer stepper.

In this work we address the capability of an alternative overlay evaluation method for the entire BEOL-Process of IHP’s standard 0.25 and 0.13 μm SiGe:C BiCMOS technology. A dual lithography platform NIKON® NSR 210D/207D scanners and NIKON® NSR SF-150 i-Line stepper layer crossing and wafer bow related overlay issues will be discussed. Stack alignment marks, which serves the exposure alignment and overlay determination were introduced. A mismatch for overlay (x/y) |mean| + 3σ values below 8 nm between the KLA® ARCHER 100 overlay and both lithography tools could be demonstrated.

In this paper, Canon will report on our most advanced 300 mm i-line stepper, the FPA-5550iZ2. Steppers enjoy an inherent productivity advantage, and Canon has developed solutions that overcome stepper disadvantages to realize an exposure tool with high overlay accuracy and excellent productivity. We will review Canon’s 300 mm i-line steppers evolutions that started in 2001 when our first 300 mm i-line stepper provided only 84 wafer per hour (wph) throughput. In 2018, our latest FPA5550iZ2 has evolved to realize more than 250wph for productivity while maintaining the same base design and almost same footprint. This paper will report the technologies that improve productivity and introduce current and underdevelopment functions that can enhance customer processes.

A Frozen section examination is the conventional intraoperative histology method widely used in cancer surgery for tumor margin assessment. However, this method is necessary to perform complicated process including sectioning and staining, which require approximately 15 minutes. Particularly with the ultraviolet (UV) laser (266 nm), photoacoustic microscopy (PAM) showed the capability to visualize cell nuclei without the time consuming procedures by utilizing superior optical contrast of DNA/RNA at this wavelength, which can be a potential alternative of the frozen section. However, previously developed UV-PAM is limited to be applied in intraoperative scenarios because it has suffered from slow imaging speed because of 2D mechanical scanning with linear stepper motors. To overcome this limitation, we developed a fast UV-PAM system based on a 2-axis waterproof microelectromechanical systems (MEMS) scanner with the specially fabricated optical components for UV light. This MEMS scanner enables to scan 3 × 3 mm2 range and acquire 400 × 400 pixels image within 20 seconds. The measured spatial and axial resolutions of the developed system are 2.2 and 39 μm, respectively. Finally, we acquired the histology-like PA image of the mouse kidney with characteristic tubular structures of kidney epithelial cells. In the mouse brain, distinct microstructures such as hippocampus and dentate gyrus were differentiated with the validation of frozen section sample.

In this paper, we have implemented a 3D content generation simulator based on integration of phase-only spatial light modulator (SLM) and LabVIEW software to develop a holographic stereogram printer that consists of a coherent laser, a spatial light modulator and X-Y translation stage with stepper motors. This content generation platform provides encoding of directional information extracted from rendered perspective images of real or virtual 3D object. There are mainly three parts related to the implementation for holographic stereogram printer. In the first part, “Digital content generation” phaseonly SLM will be applied to the holographic printer system by loading series of perspective 2D images for each holographic elements (hogel). Regarding this part, phase-only SLM can be converted into an amplitude modulator by adjusting the angles of the polarizer. The second part is “Control system” made in LabVIEW based platform for automatic recording of the holographic stereograms which is synthesized from previous part. The third implementation part is “Optical system” for printing of parallax-related hogels on the holographic plate. To check the performance of the developed approach, numerical simulations and optical experiments are implemented. The hogel images are sequentially exposed using the perspective images to form the whole holographic stereogram on the holographic light sensitive material.

We recently proposed a resonator structure to increase the quantum efficiency (QE) of a quantum well infrared photodetector (QWIP). In this detector systematic parameter study, we have selected two active layer thicknesses, three detector sizes, and three doping levels to investigate the Resonator-QWIP characteristics and the EM modeling in a wide range of detector parameters. To achieve the expected performances, the detector geometry must be produced in precise specification. In particular, the height of the diffractive elements (DE) and the thickness of the active resonator must be uniformly and accurately realized to within 0.05 μm accuracy and the substrates of the detectors have to be removed totally to prevent the escape of unabsorbed light in the detectors. To attain these specifications, two optimized inductively coupled plasma (ICP) etching processes are developed to fabricate a number of test detectors. Due to submicron detector feature sizes and overlay tolerance, we use an ASML stepper instead of a contact mask aligner to pattern wafers. The highest QE we found in this study is 64% obtained from a less optimized 30 μm pitch detector with 1.0×1018 cm-3 doping. In generally, the experimental result agrees with the prediction from electromagnetic (EM) modeling, and the R-QWIPs are able to maintain a relatively constant QE as the pixel size shrinks to 6 μm. The present 6 μm pitch R-QWIP FPA can potentially achieve 20 mK NETD at F/1.2 and 12 ms integration time.

Metasurfaces provide a new basis for recasting optical components into thin planar elements, easy to optically align and control aberrations, leading to a major reduction in footprint, system complexity and cost as well as the introduction of new optical functions.1, 2, 3. Their planarity allows for fabrication routes directly in line with conventional processes of the mature integrated circuit (IC) industry.1 I foresee great technological and scientific penetration of CMOS compatible metasurface-based optical components, ranging from metalenses4-6 to novel polarization optics7, 8. Camera modules for high volume applications, such as cell phones, will be the greatest beneficiaries. The technology required to mass produce metasurfaces dates back to the early 1990s, when the feature sizes of semiconductor manufacturing became smaller than the wavelength of light, advancing in stride with Moore’s law. This provides the possibility of unifying two industries: semiconductor manufacturing and lens-making, whereby the same technology used to make computer chips is used to make metalenses and other optical components, based on metasurfaces. A major obstacle for this to happen had to be overcome. With metasurfaces, the data describing large designs are faced with the challenge of enormous file sizes due to having millions or billions of individual microscopic metaelements (necessitated by the subwavelength size criterion) described over macroscopically large device areas. This extremely high data density over large areas generates unmanageably large total file sizes, limiting the fabrication of optical components such as metalenses to sizes no larger than a few millimeters. Using our new scalable metasurface layout compression algorithm (METAC) that exponentially reduces design file sizes (by 3 orders of magnitude for a centimeter diameter lens) and stepper photolithography, we have recently shown the design and fabrication of metalenses with extremely large areas, up to centimeters in diameter and beyond.9 Finally I envision a future of digital optics based on metasurfaces with increased density of optical components and functionalities per metasurface; it is tempting to speculate that an empirical law might govern its growth, akin to Moore’s Law for digital electronics. References: 1. F. Capasso, Nanophotonics DOI: 10.1515/nanoph-2018-0004 (2018) 2. N. Yu et al. Science 334, 333 (2011) 3. N. Yu and F. Capasso Nature Materials 13, 139 (2014) 4. M. Khorasaninejad et al. Science 352, 1190 (2016) 5. M. Khorasaninejad and F. Capasso, Science 358, 8100 (2017) 6. W-T. Chen et al. Nature Nanotechnology (2018) doi:10.1038/s41565-017-0034-6 7. J. P. B. Mueller et al. Physical Review Letters 118, 113901 (2017) 8. J. P. B. Mueller et al. Optica 3, 42 (2016) 9. A. She et al. Optics Express 26, 1573 (2018)

Microwave Kinetic Inductance Detectors (MKIDs) have held promise as the focal plane sensing elements in large-format imaging arrays for over a decade and have now found application in several ground-based instruments. In this presentation, we discuss the first implementation of MKIDs for a suborbital instrument in the Balloon-borne Large Aperture Submillimeter Telescope – The Next Generation (BLAST-TNG), a suborbital imaging array designed to study the role magnetic fields play in star formation and bridge the angular scales between Planck’s low resolution all-sky maps and ALMA’s ultra-high resolution narrow fields. BLAST-TNG is scheduled to launch from Antarctica in December 2018. This experiment will utilize 8 times as many polarization sensitive detectors and will have 16 times greater mapping speed compared to its predecessor BLASTpol. This will also be a demonstration for future MKID instruments for ground based telescopes, e.g. TolTEC arrays on the LMT, as well as proposed space based missions. We have built three, large-format MKID arrays for BLAST-TNG. Each monolithic 100mm diameter array is sensitive to a different waveband centered at 250 micron, 350 micron, or 500 micron; together comprising 3318 individual polarization-sensitive detectors. The detector arrays are read out with high levels of multiplexing, with each microwave feedline addressing between 466 and 938 unique resonators depending on the array. Designing for space-like low photon loads, polarization-sensitivity, different frequency bands, and 275 mK operation all pose unique challenges. We address these challenges by employing feedhorn-coupled, dual-polarization sensitive pixels fabricated from TiN/Ti multilayers that combine high responsivity, high uniformity, low loss, and a tunable superconducting Tc. Here, we present the detailed design and fabrication of these arrays, which includes an optimized quarter wavelength silicon backshort for each band realized by micromachining a silicon on insulator (SOI) wafer, aluminum patching of the TiN/Ti absorbing inductor to increase response and tune the effective optical coupling impedance, and a semi-automated layout scheme to make a stepper-compliant lithography process that tiles identical stepper images across the array and then trims them individually to minimize their frequency scatter and crosstalk. This results in high quality, easily reconfigurable, and uniform arrays of MKIDs. We show measurements that demonstrate high pixel yield, > 98% polarization isolation, and a noise equivalent power (NEP) limited by photon noise at the expected in-flight photon load.

Fiber spectroscopic telescopes are important tools for astronomy research. In spectroscopic telescopes, the positioning of thousands of fibers on the focal plane is a big issue, which is usually solved by some compact structured devices with small-size motors installed. Stepper motors are normal choice for fiber positioner, however, stepper motors’ low efficiency leads to serious heating, so brushless DC motor becomes a more possible option when the fiber positioner is required to be less heating. Moreover, the size of brushless motor is much smaller than stepper motor in same situation. Brushless DC motor are synchronous motors powered by DC electricity via an inverter. Brushless DC motors complete commutating by switching power supply with an inverter, instead of with the help of carbon brush. Because of the absence of Mechanical Structures like carbon brush and slip ring, BLDC Motors can prevent problems like friction that caused by carbon brush. Both brushless DC motors and Steppers are DC synchronous motors, they generally share the same mechanical structures, but they have many different features. Brushless DC motors perform well in acceleration and they are less likely to generate remarkable amount of noise or heat. Steppers is made for position control, but they sometimes step out, what’s more, they generate a lot of heat and noise while running. Brushless DC motors are usually used when high speed and small size are required, while Steppers are used for positioner. If we can use brushless DC motors for position control, in one way, we can solve the stepping out problem of Steppers and managed to achieve higher accuracy and performance control of position, in the other way, circumstances that need small size and low heat and position control, which may have bothered us a lot, may have an convenient economic solution by using BLDC Motors. Although BLDC Motors are not made for position control, but the Mechanical Structure similarity with Steppers make it possible to realize some kind of position control theoretically. By now, there many ways (with sensor and without sensor) to detect the position of the brushless DC motors’ rotor’s position, which make the idea of using BLDC Motors for position control possible in practice. Generally, ways with sensors detect the rotor position by placing a sensor in the motor, and those without sensors usually calculate the rotor position by detect the voltage and current of the motor. This paper presents our efforts in applying sensorless rotor positioning technology in driving the brushless DC motors and in using the method of sensorless positioning to realize position control. During the process of rotor position detection, a three-terminal resistance network of star arrangement and a simple RC filter is used to get the zero-crossing point of the back EMF. The resistance network is used to extract the neutral voltage and the filter can filter high-frequency background and direct current component. The filtered signal’s zero-crossing point is a shift of the back EMF’s zero-crossing point and almost can be directly used as a reference of the rotor position. Pulse-width-modulation is used to make it possible for the driver to adapt to different brushless motors and different torque. For the purpose of inspecting the performance of the technique when used in position control, the brushless DC motor is mounted to an optical fiber positioner to avoid no-load running and to verify the possibility of applying it for small positioner. The detailed control scheme is introduced, the circuit is analyzed and experimental results obtained form position control experiment are shown to estimate the accuracy of the motor. The result of this paper may help to simplify the control of brushless DC motor and improve the performance of brushless DC motor.

Novel wafer stepper by using contact or proximity printing was developed. The ultraviolet region starts right after the violet end of the rainbow. In scientific terms, UV radiation is electromagnetic radiation just like visible light, radar signals and radio broadcast signals. Ultraviolet radiation can be broken down into three bands: UVA, UVB, and UVC. Projection wafer stepper needs use single wavelength as light sources, such as: g-line, i-line, KrF and ArF. The broadband wavelengths of the UVA, UVB and UVC regions: UVA 400 nm - 315 nm, UVB 315 nm - 280 nm, UVC 280 nm - 100 nm can be used for contact or proximity exposure. Wafer stepper without using projection lens, system reliability and manufacturing cost of wafer stepper can be improved by using contact/ proximity method. This novel contact/ proximity wafer stepper can be used for 3DIC, MEMS and bio-chip lithography application by using thin and thick resist.

In the last decades the semiconductor technology has been driven by Moore’s law leading to high performance CMOS technologies with feature sizes of less than 10 nm [1]. It has been pointed out that not only scaling but also the integration of novel components and technology modules into CMOS/BiCMOS technologies is becoming more attractive to realize smart and miniaturized systems [2]. Driven by new applications in the area of communication, health and automation, new components and technology modules such as BiCMOS embedded RF-MEMS, high-Q passives, Sibased microfluidics and InP-SiGe BiCMOS heterointegration have been demonstrated [3-6]. In contrast to standard VLSI processes fabricated on front side of the silicon wafer, these new technology modules additionally require to process the backside of the wafer; thus require an accurate alignment between the front and backside of the wafer. In previous work an advanced back to front side alignment technique and implementation into IHP’s 0.25/0.13 µm high performance SiGe:C BiCMOS backside process module has been presented [7]. The developed technique enables a high resolution and accurate lithography on the backside of BiCMOS wafer for additional backside processing. In addition to the aforementioned back side process technologies, new applications like Through-Silicon Vias (TSV) for interposers and advanced substrate technologies for 3D heterogeneous integration demand not only single wafer fabrication but also processing of wafer stacks provided by temporary and permanent wafer bonding [8-9]. In this work, the non-contact infrared alignment system of the Nikon® i-line Stepper NSR-SF150 for both alignment and the overlay determination of bonded wafer stacks with embedded alignment marks are used to achieve an accurate alignment between the different wafer sides. The embedded field image alignment (FIA) marks of the interface and the device wafer top layer are measured in a single measurement job. By taking the offsets between all different FIA’s into account, after correcting the wafer rotation induced FIA position errors, hence an overlay for the stacked wafers can be determined. The developed approach has been validated by a standard front side resist in resist experiment. After the successful validation of the developed technique, special wafer stacks with FIA alignment marks in the bonding interface are fabricated and exposed. Following overlay calculation shows an overlay of less than 200 nm, which enables very accurate process condition for highly scaled TSV integration and advanced substrate integration into IHP’s 0.25/0.13 µm SiGe:C BiCMOS technology. The developed technique also allows using significantly smaller alignment marks (i.e. standard FIA alignment marks). Furthermore, the presented method is used, in case of wafer bow related overlay tool problems, for the overlay evaluation of the last two metal layers from production wafers prepared in IHP’s standard 0.25/0.13 µm SiGe:C BiCMOS technology. In conclusion, the exposure and measurement job can be done with the same tool, minimizing the back to front side/interface top layer misalignment which leads to a significant device performance improvement of backside/TSV integrated components and technologies.

In the last decades the semiconductor technology has been driven by Moore’s law leading to high performance CMOS technologies with feature sizes of less than 10 nm [1]. It has been pointed out that not only scaling but also the integration of novel components and technology modules into CMOS/BiCMOS technologies is becoming more attractive to realize smart and miniaturized systems [2]. Driven by new applications in the area of communication, health and automation, new components and technology modules such as BiCMOS embedded RF-MEMS, high-Q passives, Sibased microfluidics and InP-SiGe BiCMOS heterointegration have been demonstrated [3-6]. In contrast to standard VLSI processes fabricated on front side of the silicon wafer, these new technology modules require addition backside processing of the wafer; thus an accurate alignment between the front and backside of the wafer is mandatory. In previous work an advanced back to front side alignment technique and implementation into IHP’s 0.25/0.13 μm high performance SiGe:C BiCMOS backside process module has been presented [7]. The developed technique enables a high resolution and accurate lithography on the backside of BiCMOS wafer for additional backside processing. In addition to the aforementioned back side process technologies, new applications like Through-Silicon Vias (TSV) for interposers and advanced substrate technologies for 3D heterogeneous integration demand not only single wafer fabrication but also processing of wafer stacks provided by temporary and permanent wafer bonding [8]. Therefore, the available overlay measurement techniques are not suitable if overlay and alignment marks are realized at the bonding interface of a wafer stack which consists of both a silicon device and a silicon carrier wafer. The former used EVG 40NT automated overlay measurement system, which use two opposite positioned microscopes inspecting simultaneous the wafer back and front side, is not capable measuring embedded overlay marks. In this work, the non-contact infrared alignment system of the Nikon i-line Stepper NSR-SF150 for both the alignment and the overlay determination of bonded wafer stacks with embedded alignment marks are used to achieve an accurate alignment between the different wafer sides. The embedded field image alignment (FIA) marks of the interface and the device wafer top layer are measured in a single measurement job. By taking the offsets between all different FIA’s into account, after correcting the wafer rotation induced FIA position errors, hence an overlay for the stacked wafers can be determined. The developed approach has been validated by a standard back to front side application. The overlay was measured and determined using both, the EVG NT40 automated measurement system with special overlay marks and the measurement of the FIA marks of the front and back side layer. A comparison of both results shows mismatches in x and y translations smaller than 200 nm, which is relatively small compared to the overlay tolerances of ±500 nm for the back to front side process. After the successful validation of the developed technique, special wafer stacks with FIA alignment marks in the bonding interface are fabricated. Due to the super IR light transparency of both doubled side polished wafers, the embedded FIA marks generate a stable and clear signal for accurate x and y wafer coordinate positioning. The FIA marks of the device wafer top layer were measured under standard condition in a developed photoresist mask without IR illumination. Following overlay calculation shows an overlay of less than 200 nm, which enables very accurate process condition for highly scaled TSV integration and advanced substrate integration into IHP’s 0.25/0.13 μm SiGe:C BiCMOS technology. The presented method can be applied for both the standard back to front side process technologies and also new temporary and permanent wafer bonding applications.

This paper focuses on introducing the results of a model using a control system for an optical filter that can be tuned, using a solution that employs both, an elongation control system and a fiber Bragg grating. At the first stage, the optical characterization of the filter was made, then the stepper motors were chosen for the desired wavelength selection with a couple of pulleys which produce the grating elongation and, as a consequence, the wavelength shifting. The pulleys diameters were calculated to produce 0.8 nm shift for each filtering wavelength using a control program.

Lithography equipment is undergoing some of the most significant changes since the introduction of the wafer stepper. The driving force behind these changes is the diffraction limit of optics. The resulting characteristics of new lithography equipment, to contend with the diffraction limit, are discussed. The high cost of lithography equipment has made mix-and-match lithography commonplace. Step-and-scan technology is the wave of the near-future, as a way to contend with the difficulty of manufacturing wide-field lenses. Resist processing equipment will undergoing few changes, but will often be integrated with steppers. Metrology is being stretched to its limits for technologies below 250 nm.

It has been still highly required for cost efficient solution with easy operation for full-automated CD measurement for line width about 500nm up to 5μm on photomask, because it is frequently use such photomask in the process of manufacturing MEMS sensor for IoT and some devices made in BCD (Bipola CMOS DMOS). As reply to such demand in photomask manufacturing field, we try to take a low noise digital camera technology and LED light source for i-line, which are recently developed, into new measuring tool in order to achieve 1nm (3σ) repeatability for line width measurement between 300nm to 10μm. In addition, for the purpose of full-automated operation, it is very important to find where an initial target line in dense pattern. To achieve such auto line detection precisely, we have improved accuracy of high precision stage (20nm as 3σ) and an alignment algorithm of MEMS Stepper to combine with this tool. As for user-friendly interface, Windows based software helps a lot for not only the operation but also recipe creation or edition in Excel. Actually, in the MEMS manufacturing process, there are various photomasks which need to be check and measure frequently therefore various recipe files are also have to be created and edited frequently.. In order to meet such a requirement in photomask management, we try to make it true by mixing old and new techniques together into one system, which comes to fully automated and cost efficient tool with 1nm repeatability in CD measurement.

Currently an analog microscope has a wide distribution in the following fields: medicine, animal husbandry, monitoring technological objects, oceanography, agriculture and others. Automatic method is preferred because it will greatly reduce the work involved. Stepper motors are used to move the microscope slide and allow to adjust the focus in semi-automatic or automatic mode view with transfer images of microbiological objects from the eyepiece of the microscope to the computer screen. Scene analysis allows to locate regions with pronounced abnormalities for focusing specialist attention. This paper considers the method for stitching microbial images, obtained of semi-automatic microscope. The method allows to keep the boundaries of objects located in the area of capturing optical systems. Objects searching are based on the analysis of the data located in the area of the camera view. We propose to use a neural network for the boundaries searching. The stitching image boundary is held of the analysis borders of the objects. To auto focus, we use the criterion of the minimum thickness of the line boundaries of object. Analysis produced the object located in the focal axis of the camera. We use method of recovery of objects borders and projective transform for the boundary of objects which are based on shifted relative to the focal axis. Several examples considered in this paper show the effectiveness of the proposed approach on several test images.

To evaluate the performance of intraocular lenses to treat cataract, an optomechanical eye model was developed. One of the most crucial components is the IOL holder, which should guarantee a physiological representation of the capsular bag and a stable position during measurement sequences. Individual holders are required due to the fact that every IOL has different geometric parameters. A method which allows obtaining the correct dimensions for the holder of a special IOL was developed and tested, by verifying the position of the IOL before and after a measurement sequence. Results of telecentric measurements and MTF measurements show that the IOL position does not change during the displacement sequence induced by the stepper motors of the eye model.

The infrared absorption of SF6 gas is of narrowband and peaks at 10.6μm. This narrow band absorption posts a stringent requirement on the corresponding sensors as they need to collect enough signal from this limited spectral range to maintain a high sensitivity. Resonator-Quantum Well Infrared Photo detectors (R-QWIPs) are the next generation of QWIP detectors that use resonances to increase the quantum efficiency (QE) for more efficient signal collection. Since the resonant approach is applicable to narrowband as well as broadband, it is particularly suitable for this application. We designed and fabricated R-QWIPs for SF6 gas detection. To achieve the expected performance, the detector geometry must be produced according to precise specifications. In particular, the height of the diffractive elements (DE) and the thickness of the active resonator must be uniform, and accurately realized to within 0.05 μm. additionally, the substrates of the detectors must be removed totally to prevent the escape of unabsorbed light in the detectors. To achieve these specifications, two optimized inductively coupled plasma (ICP) etching processes are developed. Due to submicron detector feature sizes and overlay tolerance, we use an ASML stepper instead of a contact mask aligner to pattern wafers. Using these etching techniques and tool, we have fabricated FPAs with 30 μm pixel pitch and 320x256 format. The initial test results showed promising results.

A new special second-generation computer-controlled device has been developed for measuring biomechanical characteristics of the lower part of the spine vertebras L1–L5 [1]. During straining and measurement of the rigidity of the sample as a whole it is also necessary to observe the movement of individual parts of the sample and to measure their mechanical resistances. The measurement of displacement and rotation of individual parts of the studied model was evaluated by optical methods based on the principle of moire interferometry and fast Fourier transform [2]. During this device development and its verification the lumbar samples were replaced with a system of wooden rollers with system discrete rubber pads. The new computer-controlled device containing four stepper motors, four strain gauges and two CCD cameras.

In the process of semicondutcor fabrication the translation of the final product requirements into specific targets for each component of the manufacturing process is one of the most demanding tasks. This involves the careful assessment of the error budgets of each component as well as the sensible balancing of the costs implied by the requirements. Photolithographic masks play a pivotal role in the semiconductor fabrication. This attributes a crucial role to mask error budgeting within the overall wafer production process. Masks with borderline performance with respect to the wafer fabrication requirements have a detrimental effect on the wafer process window thus inducing delays and costs. However, prohibitively strict mask specifications will induce large costs and delays in the mask manufacturing process. Thus setting smart control mechanisms for mask quality assessment is highly relevant for an efficient production flow. To this end GLOBALFOUNDRIES and the AMTC have set up a new mask specification check to enable a smart ship to control process for mask manufacturing. Within this process the mask CD distribution is checked as to whether it is commensurable with the advanced dose control capabilities of the stepper in the wafer factory. If this is the case, masks with borderline CD performance will be usable within the manufacturing process as the signatures can be compensated. In this paper we give a detailed explanation of the smart ship control approach with its implications for mask quality.

A representative range of the rotary mechanisms proposed for use in GMTIFS is described. All are driven by cryogenically rated stepper motors. For each mechanism, angular position is measured by means of eddy current sensors arranged to function as a resolver. These measure the linear displacement of a decentered aluminum alloy target in two orthogonal directions, from which angular position is determined as a function of the displacement ratio. Resolver function and performance is described. For each mechanism, the mechanical design is described and the adequacy of positioning repeatability assessed. Options for improvement are discussed.

High-Throughput Phenotyping (HTP) is a discipline for rapidly identifying plant architectural and physiological responses to environmental factors such as heat and water stress. Experiments conducted since 2010 at Maricopa, Arizona with a three-fold sensor group, including thermal infrared radiometers, active visible/near infrared reflectance sensors, and acoustic plant height sensors, have shown the validity of HTP with a tractor-based system. However, results from these experiments also show that accuracy of plant phenotyping is limited by the system’s inability to discriminate plant components and their local environmental conditions. This limitation may be overcome with plant imaging and laser scanning which can help map details in plant architecture and sunlit/shaded leaves. To test the capability for mapping cotton plants with a laser system, a track-mounted platform was deployed in 2015 over a full canopy and defoliated cotton crop consisting of a scanning LIDAR driven by Arduinocontrolled stepper motors. Using custom Python and Tkinter code, the platform moved autonomously along a pipe-track at 0.1 m/s while collecting LIDAR scans at 25 Hz (0.1667 deg. beam). These tests showed that an autonomous LIDAR platform can reduce HTP logistical problems and provide the capability to accurately map cotton plants and cotton bolls. A prototype track-mounted platform was developed to test the use of LIDAR scanning for High- Throughput Phenotyping (HTP). The platform was deployed in 2015 at Maricopa, Arizona over a senescent cotton crop. Using custom Python and Tkinter code, the platform moved autonomously along a pipe-track at

There has been 43 years of overlay metrology in microlithography, and how did we get here? This presentation covered three areas: stepper metrology improvements, improved correction potential, and extended feedback loop outside stepper. The presenter went on to discuss where we are today In terms of holistic lithography, as well as where we are going with the future of holistic lithography.

The Semiconductor Industry is making continuous progress in shrinking feature size developing technologies and process to achieve < 10 nm feature size. The required Overlay specification for successful production is in the range one nanometer or even smaller. Consequently, materials designed into metrology systems of exposure or inspection tools need to fulfill ever tighter specification on the coefficient of thermal expansion (CTE). The glass ceramic ZERODUR® is a well-established material in critical components of microlithography wafer stepper and offered with an extremely low coefficient of thermal expansion, the tightest tolerance available on market. SCHOTT is continuously improving manufacturing processes and it’s method to measure and characterize the CTE behavior of ZERODUR®. This paper is focusing on the "Advanced Dilatometer" for determination of the CTE developed at SCHOTT in the recent years and introduced into production in Q1 2015. The achievement for improving the absolute CTE measurement accuracy and the reproducibility are described in detail. Those achievements are compared to the CTE measurement accuracy reported by the Physikalische Technische Bundesanstalt (PTB), the National Metrology Institute of Germany. The CTE homogeneity is of highest importance to achieve nanometer precision on larger scales. Additionally, the paper presents data on the short scale CTE homogeneity and its improvement in the last two years. The data presented in this paper will explain the capability of ZERODUR® to enable the extreme precision required for future generation of lithography equipment and processes.

We developed a novel LED projection based direct write grayscale lithography system for the generation of optical surface profiles such as micro-lenses, diffractive elements, diffusors, and micro freeforms. The image formation is realized by a LCoS micro-display which is illuminated by a 405 nm UV High Power LED. The image on the display can be demagnified from factors 5x to 100x with an exchangeable lens. By controlling exposure time and LED power, the presented technique enables a highly dynamic dosage control for the exposure of h-line sensitive photo resist. In addition, the LCoS micro-display allows for an intensity control within the micro-image which is particularly advantageous to eliminate surface profile errors from stitching and limited homogeneity from LED illumination. Together with an accurate calibration of the resist response this leads to a superior low surface error of realized profiles below 80°. Another benefit of the approach is a patterning speed up to 100 cm2/h, which allows fabricating large-scale optics and microstructures in an acceptable time. We present the setup and show examples of micro-structures to demonstrate the performance of the system, namely a refractive freeform array, where the RMS surface deviation does not exceed 0.2% of the total structure depth of 75 μm. Furthermore, we show that this exposure tool is suitable to generate diffractive optical elements as well as freeform optics and arrays with a high aspect ratio and structure depth showing a superior optical performance. Lastly we demonstrate a multi-level diffraction grating on a curved substrate.

As the semiconductor process technology moves into more advanced nodes, design and process induced systematic defects become increasingly significant yield limiters. Therefore, early detection of these defects is crucial. Focus Exposure Matrix (FEM) and Process Window Qualification (PWQ) are routine methods for discovering systematic patterning defects and establishing the lithography process window. These methods require the stepper to expose a reticle onto the wafer at various focus and exposure settings (also known as modulations). The wafer is subsequently inspected by a bright field, broadband plasma or an E-Beam Inspection tool using a high sensitivity inspection recipe (i.e. hot scan) that often reports a million or more defects. Analyzing this vast stream of data to identify the weak patterns and arrive at the optimal focus/exposure settings requires a significant amount of data reduction through aggressive sampling and nuisance filtering schemes. However, these schemes increase alpha risk, i.e. the probability of not catching some systematic or otherwise important defects within a modulation and thus reporting that modulation as a good condition for production wafers. In order to reduce this risk and establish a more accurate process window, we describe a technique that introduces image-and-design integration methodologies into the inspection data analysis workflow. These image-and-design integration methodologies include contour extraction and alignment to design, contour-to-design defect detection, defective/nuisance pattern retrieval, confirmed defective/nuisance pattern overlay with inspection data, and modulation-related weak-pattern ranking. The technique we present provides greater automation, from defect detection to defective pattern retrieval to decision-making steps, that allows for statistically summarized results and increased coverage of the wafer to be achieved without an adverse impact on cycle time. Statistically summarized results, lead to objective assessments of the output; and increased coverage, in turn, leads to a more comprehensive assessment of the impact of each pattern defect and each focus/exposure modulation. Overall, this leads to a more accurate determination of the process window.

Electrophysiological recording of neuronal action potentials from behaving animals requires portable, precise and reliable devices for positioning of multiple microelectrodes in the brain. We propose a semi-automatic microdrive system for independent positioning of up to 8 electrodes (or tetrodes) in a rat (or larger animals). Device is intended to be used in chronic, long term recording applications in freely moving animals. Our design is based on independent stepper motors with lead screws which will offer single steps of ~ μm semi-automatically controlled from the computer. Microdrive system prototype for one electrode was developed and tested. Because of the lack of the systematic test procedures dedicated to such applications, we propose the evaluation of the prototype similar to ISO norm for industrial robots. To this end we designed and implemented magnetic linear and rotary encoders that provided information about electrode displacement and motor shaft movement. On the basis of these measurements we estimated repeatability, accuracy and backlash of the drive. According to the given assumptions and preliminary tests, the device should provide greater accuracy than hand-controlled manipulators available on the market. Automatic positioning will also shorten the course of the experiment and improve the acquisition of signals from multiple neuronal populations.

The design and fabrication of common optical components lithography Lens has been carried out for a 1 to 1 stepper. The specification of lens is fulfilled the 3-D lithography system as 2 micron in resolution for 1 inch x 2.8 inches system. The lens has been sophistically designed by dual path in a triplet to reduce the number of components. A single aspherical surface has been applied to reduce the aberration to diffraction limit in lens. The well-made shapes of lens have been suggested. Then, the fabrication of lens has been in the process. Finally, the optical axis of tolerance optical mechanical mountings for lens system in assembly has been analyzed, and valuable for assembly and fabrication.

Shutters are used to periodically provide a non-uniformity correction (NUC) calibration surface to micro bolometers. Many bolometer applications, such as TWS and DVE, require compact, power efficient actuators. Actuators in these applications, such as bistable solenoids and stepper motors, benefit from complex drive schemes. Consumer electronics products have generated compact, low-cost drive components that can be used to embed complex drives into these shutters. Shutter drives using these components maintain compactness and power efficiency while simplifying interfaces at minimal cost. Recently, several commercially available shutter systems have been created that incorporate embedded microprocessors into shutters usable for NUC correction of micro bolometers.

ISP SYSTEM has developed a range of large aperture electro-mechanical deformable mirrors (DM) suitable for ultra short pulsed intense lasers. The design of the MD-AME deformable mirror is based on force application on numerous locations thanks to electromechanical actuators driven by stepper motors. DM design and assembly method have been adapted to large aperture beams and the performances were evaluated on a first application for a beam with a diameter of 250mm at 45° angle of incidence. A Strehl ratio above 0.9 was reached for this application. Simulations were correlated with measurements on optical bench and the design has been validated by calculation for very large aperture (up to O550mm). Optical aberrations up to Zernike order 5 can be corrected with a very low residual error as for actual MD-AME mirror. Amplitude can reach up to several hundreds of μm for low order corrections. Hysteresis is lower than 0.1% and linearity better than 99%. Contrary to piezo-electric actuators, the μ-AME actuators avoid print-through effects and they permit to keep the mirror shape stable even unpowered, providing a high resistance to electro-magnetic pulses. The MD-AME mirrors can be adapted to circular, square or elliptical beams and they are compatible with all dielectric or metallic coatings.

ISP SYSTEM has developed an electro-mechanical deformable mirror compatible with Ultra High Vacuum environment, suitable for ultra short pulsed lasers. The design of the MD-AME deformable mirror is based on force application on numerous locations. μ-AME actuators are driven by stepper motors, and their patented special design allows controlling the force with a very high accuracy. Materials and assembly method have been adapted to UHV constraints and the performances were evaluated on a first application for a beam with a diameter of 250mm. A Strehl ratio above 0.9 was reached for this application. Optical aberrations up to Zernike order 5 can be corrected with a very low residual error as for standard MD-AME mirror. Amplitude can reach up to several hundreds of μm for low order corrections. Hysteresis is lower than 0.1% and linearity better than 99%. Contrary to piezo-electric actuators, the μ-AME actuators avoid print-through effects and they permit to keep the mirror shape stable even unpowered, providing a high resistance to electro-magnetic pulses. The deformable mirror design allows changing easily an actuator or even the membrane if needed, in order to improve the facility availability. They are designed for circular, square or elliptical aperture from 30mm up to 500mm or more, with incidence angle from 0° to 45°. They can be equipped with passive or active cooling for high power lasers with high repetition rate.

Driven by new applications such as BiCMOS embedded RF-MEMS, high-Q passives, Si-based microfluidics for bio sensing and InP-Si BiCMOS heterointegration [1-4], accurate alignment between back and front side is highly desired. In this paper, we present an advanced back to front side alignment technique and implementation of it into the back side processing module of IHP’s 0.25/0.13 μm high performance SiGe:C BiCMOS technology. Using the Nikon i-line Stepper NSR-SF150, a new infrared alignment system has been introduced. The developed technique enables a high resolution and accurate lithography on the back side of the BiCMOS-processed Si wafers for additional backside processing, such as backside routing metallization. In comparison to previous work [5] with overlay values of 500 nm and the requirement of two-step lithography, the new approach provides significant improvement in the overlay accuracy with overlay values of 200 nm and a significant increase of the fabrication throughput by eliminating the need of the two-step lithography. The new non-contact alignment procedure allows a direct back to front side alignment using any front side alignment mark (Fig. 2), which generated a signal by reflecting the IR light beam. Followed by a measurement of the misalignment between both front to back side overlay marks (Fig. 3) using EVG®NT40 automated measurement system, a final lithography process with wafer interfield corrections is applied to obtain a minimum overlay of 200 nm. For the specific application of deep Si etching using Bosch process, the etch profile angle deviation across the wafer (tilting) has to be considered as well. From experimental data, an etch profile angle deviation of 8 μm across the wafer has been measured (Fig. 7). The overlay error caused by tilting was corrected by optimization and adjustment of the stepper offset parameters. All measurements of back to front side misalignment were performed with the EVG®40NT automated measurement system whereas the deep etch tilting errors were measured with an optical microscope using special vernier scales embedded in the backend-of-line metallization layer (Fig 4 and Fig. 5) of the IHP’s 0.25/0.13 μm SiGe:C BiCMOS technology. By applying the proposed method of back to front side alignment using infrared illumination alignment, the accuracy of backside fabrication processes like deep Si etching can be significantly improved. The developed technique is very promising to shrink the dimensions by minimizing the back to front side misalignment to improve the device performance of backside integrated components and technologies.

It is proposed the development and implementation of a High Speed Resolution Camera instrument. The basic principle of this technique is to take several pictures of short exposure using different filters of an astronomical object of interest . These images are subsequently processed using specialized software to remove aberrations from atmosphere and from the instrument itself such as blur and scintillation among others. In this paper are described electronic and control systems implemented for BERKUT instrument based on FPGA (Field Programmable Gate Array) generated with VHDL description. An UART communication, using serial protocol, is used with a friendly User Interface providing an easy way for the astronomer to choose between different lenses and different filters for capturing the images. All the movements are produced by stepper motors that are driven by a circuit that powers all the electronics. The camera and the lenses are placed into a linear positioner with the help of a stepper motor which give us repeatable movements for positioning these optical components. Besides it is planned to integrate in the same system a pipeline for image data reduction to have one sturdy system that could fulfill any astronomer needs in the usage of this technique. With this instrument we pretend to confirm the Hipparcos catalogue of binary stars besides finding exoplanets. This technique requires more simple optical equipment and it is less sensitive to environmental noise, making it cheaper and provides good quality and great resolution images for scientific purposes. This equipment will be installed on different 1-m class telescopes in Mexico1 and probably other countries which makes it a wide application instrument.

We have shown that the dissolution properties can be successfully modified to improve the line/space profile and LWR of a low diffusion EUV CA resist. The surface roughness is a function of hot spots in the nominally unexposed regions of the resist material. We conjecture that the photoacid hot spots are formed due to DC flare present in the optical train of the exposure system. We also have shown that the PAGs can be further improved for out-of-band radiation (OOB) response. The improvement can be as much as 557% for 193nm exposure, and 838% by 248nm exposure. The improved OOB response leads to better contact hole performance. We also shared our continued improvement in resist witness plate performance with the majority of our resists passing for carbon growth, and all samples passing for non-cleanables. There does appear to be a site-to-site bias which we attribute to differences between e-beam and EUV exposure and/or substrate working distance from the source. Lastly, we show outstanding lithographic process window for 24 nm contact arrays on an NXE 3300 stepper as well as 15 nm half pitch lines and spaces on the PSI interferometric tool.

In lithography, overlay control is getting increasingly complex. Advanced Process Control (APC) is introduced to minimize excursions from the process window for the present exposure. APC uses metrology data of previously exposed wafers, hence, there is always a delay of tens of minutes before the required information is available. This paper proposes the combination of a patterned expose beam and a patterned fluorescent marker on a wafer to generate a fluorescent signal that carries real-time information of the focus and/or position error of the expose pattern with the pattern on the wafer. A practical realization requires some changes to the exposure process, stepper design and reticle lay-out. Firstly, a matched pair of markers on the wafer and reticle is required. Secondly, the generated fluorescent signal must be measured, for example with a (spectrally filtered) photon counter close to the expose area of the wafer. At last, the markers from the previous lithography step shall, after development, be filled with fluorescent material. This deposition requires an additional process step. Photon budget calculations suggest an overlay measurement accuracy of less than a tenth of a nm (real-time).

In recent years, the demand for high sensitivity image sensors has become prominent, in correlation with the reduction of pixel size and higher pixel counts. Sensitivity is especially important for mobile applications and as a result, back side illumination (BSI) structure image sensors are emerging. The spread of BSI image sensors causes new technological challenges in the lithographic process. One of the challenges is related to the wafer distortion created during the bonding and thinning of the wafer. The challenge is to reduce the impact of the wafer distortion on the overlay accuracy, and we propose two unique solutions for this challenge: Extended Advanced Global Alignment (EAGA) and Shot Shape Compensator (SSC). EAGA is an alignment measurement function that can measure the position and shape of all shots on the wafer. SSC is an exposure function that adjusts the shape of exposure shots according to the shape of the underlying layer's shot on the distorted wafer, by controlling both the XY magnification difference and skew component of the projection optical system. In order to realize the SSC system in i-line stepper, Canon has introduced a new compensation mechanism featuring “two-dimensional Alvarez” optical elements. One other challenge is to detect alignment marks located on the back surface of the silicon wafer and for this challenge, Canon has employed a new alignment system using infrared light. In this paper, we will provide detailed descriptions along with exposure results using these solutions. We will also delve into the possibility of additional process applications that can benefit from the enhanced overlay accuracy provided by Canon i-line lithography systems.

Novel wafer stepper by using contact or proximity printing will be developed, using violet LED light source to replace Hg Arc. lamp or laser. Mirror, filter and condenser lens for Hg Arc. Lamp or laser and reduction lens for projection printing can be discarded. Reliability and manufacturing cost of wafer stepper can be improved. Exposure result by using IP3600 resist and wafer stepper with violet LED light source (wave-length 360nm to 410 nm) will be obtained. This novel wafer stepper can be used for 3DIC, MEMS and bio-chip lithography application by using thin and thick resist with sub-micron to 100 micron thickness.

Silicon photomultipliers (SiPMs) are intensely evaluated as a potential replacement of photomultiplier vacuum tubes for several applications. Essential key features are the photon detection efficiency, the dark count rate, the optical crosstalk and the scalability of the active area and the microcell pitch. In order to achieve considerable improvements of these parameters, KETEK has introduced a new manufacturing technology based on 200 mm wafers and 0.35 μ stepper lithography. Important aspects of the well-established and for many years optimized KETEK Silicon Drift Detector technology could be transferred to the SiPM process. Main items of the new technology are a narrow vertical trench around the individual microcells and an impurity getter: the first reduces the optical cross talk and the second the dark count rate by factor two, whereby the potential of this technology is still not maxed out. A further aspect of the new technology is a low parasitic RC-value device concept: The reduction of parasitic RC-values is targeted on a scalability refinement of SiPM devices which is mandatory for active areas above 10 mm 2 . Finally the geometrical fill factor and the light entrance window of the KETEK device has been further improved for which reason a 50 μm cell pitch device with a photon detection efficiency of 60% in the blue range is presented. Beyond that the SiPM devices show an extremely low temperature coefficient of the gain. This is due to an operation at very high overvoltage along with a low temperature coefficient of the break down voltage.

The range-gated laser imaging technology has become a useful technique in many applications in recent years. In order to expand the range of imaging detection and improve the measurement range resolution of the imaging system, we used circular step advance delay sequence for the synchronous control. And we developed a method of using dynamic phase-shift technique in FPGA to improve the precision of the delay in the time sequence, which can make the precision of the delay stepper between the two adjacent frames less than global clock period of the FPGA and approach the limit of FPGA’s operating frequency. That is to say, it can equivalently increase the clock frequency. Then we can effectively improve measurement range resolution of the imaging system. In this paper, we have studied how dynamic phase-shift technique can be equivalent to higher clock frequency and performed some experiments. We presented the structure of dynamic phase-shift technique used to improve the precision of delay in the synchronization control time sequence. And the simulation and experimental results are showed in this paper. The results demonstrate that using dynamic phase-shift technique in FPGA can make the precision of the delay between the ICCD’s trigger pulse and the laser’s trigger pulse reach 1ns, which means the resolution of measurement range can be 0.15m theoretically. The timing control signal with dynamic phase-shift technique designed in this paper can be widely used in range-gated imaging because of its high timing control precision and flexible parameter setting.

Evaluation of lithography process or stepper involves very large quantity of CD measurements and measurement time. In this paper, we report on an application of Scatterometry based metrology for evaluation of EUV photomask lithography. Measurements were made on mask level with Ellipsometric scatterometer for develop-check CD (DCCD) and final check CD (FCCD). Calculation of scatterometer profile information was performed with in-situ library-based rigorous coupled wave analysis (RCWA) method. We characterized the CD uniformity (CDU) and metal film thickness uniformity. OCD results show that high precision CD measurement EUV absorber and resist is possible with this method. A series of simulations were also performed to investigate the feasibility of Ellipsometric scatterometry for various pitches/line CD sizes, down to 11nm half-pitch at 1x magnification. The data showed that Scatterometry provides a nondestructive and faster mean of characterizing mask CD performance for various EUV process generations.

Project lithography has experienced the development of contact, stepper, and step and scan lithography machine. Currently lithography machine has entered the age of twinscan lithography machine. The twinscan lithography machine took advantages of high efficiency and good compatibility, but the focal depth of twinscan lithography machine was only in the nanometer range. In order to guarantee the quality of the exposure, the twinscan lithography machine put forward high request for detecting the map of the wafer surface. Usually, the uniform sampling method and the whole map rebuilding method were used to detect the map of the silicon wafer surface, which is a main cause for the data redundancy. On the other hand, the map reconstructed by this means was not smooth which caused the motor of lithography machine can't response. To avoid these disadvantages, an algorithm for restoring the wafer surface based on B-spline surface reconstruction is proposed in this paper. This method is able to satisfy requirements for the local adaptive refinement, which effectively avoid data redundancy. This method is robust, which means the effect of solving nonlinear problems and inhibiting fuzzy noise is remarkable. The surface reconstructed by this new method is very smooth, which is more suitable for the movement of the motor in lithography machine.

One key technology in mass microchip-production is an optical projection system (wafer stepper) for deep UV photolithography. Modern wafer stepper-optics featuring sub-200nm resolution, consist of 20 to 25 glass elements with a weight of up to 1000 kg including mechanical parts. After the careful glass element-manufacturing, the optical performance of the system is highly influenced by the precise mechanical alignment of all individual lens elements. The imaging quality of such systems is extremely sensitive to alignment errors as they may severely degrade the imaging quality. Therefore, the optical design of a stepper optic has tight tolerances for the alignment in the sub-μm and arc second range. We will present a high resolution optical measurement system that performs non-contact measurements of centering errors of each surface in an assembled optics with a measurement accuracy of 0.1 μm, and it determines the air gap-distances and lens center-thicknesses with a measurement accuracy of 1.0 μm.

The zero expansion glass ceramic ZERODUR® is a well-established material in microlithography in critical components as wafer- and reticle-stages, mirrors and frames in the stepper positioning and alignment system. The very low coefficient of thermal expansion (CTE) and its extremely high CTE homogeneity are key properties to achieve the tight overlay requirements of advanced lithography processes. SCHOTT is continuously improving critical material properties of ZERODUR® essential for microlithography applications according to a roadmap driven by the ever tighter material specifications broken down from the customer roadmaps. This paper will present the SCHOTT Roadmap for ZERODUR® material property development. In the recent years SCHOTT established a physical model based on structural relaxation to describe the coefficient of thermal expansion’s temperature dependence. The model is successfully applied for the new expansion grade ZERODUR® TAILORED introduced to the market in 2012. ZERODUR® TAILORED delivers the lowest thermal expansion of ZERODUR® products at microlithography tool application temperature allowing for higher thermal stability for tighter overlay control in IC production. Data will be reported demonstrating the unique CTE homogeneity of ZERODUR® and its very high reproducibility, a necessary precondition for serial production for microlithography equipment components. New data on the bending strength of ZERODUR® proves its capability to withstand much higher mechanical loads than previously reported. Utilizing a three parameter Weibull distribution it is possible to derive minimum strength values for a given ZERODUR® surface treatment. Consequently the statistical uncertainties of the earlier approach based on a two parameter Weibull distribution have been eliminated. Mechanical fatigue due to stress corrosion was included in a straightforward way. The derived formulae allows calculating life time of ZERODUR® components for a given stress load or the allowable maximum stress for a minimum required life time.