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We have developed a high speed, miniature scanning probe microscope (MSPM) integrated with a Positioning Unit (PU) for accurately positioning the MSPM on a large substrate. This combination enables simultaneous, parallel operation of many units on a large sample for high throughput measurements. The size of the MSPM is 19 × 45 × 70 mm3. It contains a one-dimensional flexure stage with counter-balanced actuation for vertical scanning with a bandwidth of 50 kHz and a z-travel range of more than 2 μm. This stage is mechanically decoupled from the rest of the MSPM by suspending it on specific dynamically determined points. The motion of the probe, which is mounted on top of the flexure stage is measured by a very compact optical beam deflection (OBD). Thermal noise spectrum measurements of short cantilevers show a bandwidth of 2 MHz and a noise of less than 15 fm/Hz1/2. A fast approach and engagement of the probe to the substrate surface have been achieved by integrating a small stepper actuator and direct monitoring of the cantilever response to the approaching surface. The PU has the same width as the MSPM, 45 mm and can position the MSPM to a pre-chosen position within an area of 275×30 mm2 to within 100 nm accuracy within a few seconds. During scanning, the MSPM is detached from the PU which is essential to eliminate mechanical vibration and drift from the relatively low-resonance frequency and low-stiffness structure of the PU. Although the specific implementation of the MSPM we describe here has been developed as an atomic force microscope, the general architecture is applicable to any form of SPM. This high speed MSPM is now being used in a parallel SPM architecture for inspection and metrology of large samples such as semiconductor wafers and masks.

This paper aims at unraveling the mystery of damage in high speed AFMs for 1X node and below. With the device dimensions moving towards the 1X node and below, the semiconductor industry is rapidly approaching the point where existing metrology, inspection and review tools face huge challenges in terms of resolution, the ability to resolve 3D, and throughput. In this paper, we critically asses the important issue of damage in high speed AFM for metrology and inspection of semiconductor wafers. The issues of damage in four major scanning modes (contact mode, tapping mode, non-contact mode, and peak force tapping mode) are described to show which modes are suitable for which applications and which conditions are damaging. The effects of all important scanning parameters on resulting damage are taken into account for materials such as silicon, photoresists and low K materials. Finally, we recommend appropriate scanning parameters and conditions for several use cases (FinFET, patterned photoresist, HAR structures) that avoid exceeding a critical contact stress such that sample damage is minimized. In conclusion, we show using our theoretical analysis that selecting parameters that exceed the target contact stress, indeed leads to significant damage. This method provides AFM users for metrology with a better understanding of contact stresses and enables selection of AFM cantilevers and experimental parameters that prevent sample damage.

With the device dimensions moving towards the 1X node, the semiconductor industry is rapidly approaching the point where 10 nm defects become critical. Therefore, new methods for improving the yield are emerging, including inspection and review methods with sufficient resolution and throughput. Existing industrial tools cannot anymore fulfill these requirements for upcoming smaller and 3D features, since they are performing at the edge of their performance. Scanning probe microscopy (SPM) has the ability to accurately measure dimensions in the micrometer to nanometer scale. Examples of applications are surface roughness, channel height and width measurement, defect inspection in wafers, masks and flat panel displays. In most of these applications, the target area is very large, and, therefore, the throughput of the measurement plays an important role in the final production cost. Single SPM has never been able to compete with other inspection systems in terms of measurement speed, thus has not fulfilled the industry needs in throughput and cost. Further increase of the speed of the single SPM helps, but it still is far from the required throughput and, therefore, insufficient for high-volume manufacturing. Over the past three years, we have developed a revolutionary concept for a multiple miniaturized SPM heads system, which can inspect and measure many sites in parallel. The very high speed of each miniaturized SPM unit allow the user to scan many areas, each with the size of tens of micrometers, in a few seconds. This paper presents an overview of the technical developments and experimental results of the parallel SPM system for wafer and mask inspection.

The main driver for Semiconductor and Bio-MEMS industries is decreasing the feature size, moving from the current state-of-the-art at 22 nm towards 10 nm node. Consequently smaller defects and particles become problematic due to size and number, thus inspecting and characterizing them are very challenging. Existing industrial metrology and inspection methods cannot fulfil the requirements for these smaller features. Scanning probe Microscopy (SPM) has the distinct advantage of being able to discern the atomic structure of the substrate. It can image the 3D topography, but also a variety of material, mechanical and chemical properties. Therefore SPM has been suggested as one of the technologies that can fulfil the future requirements in terms of resolution and accuracy, while being capable of resolving 3D futures. However, the throughput of the current state-of-the-art SPMs are extremely low, as compared to the high-volume manufacturing requirements. This paper presents the development of an architecture[1] for a fully automated high throughput SPM, which can meet the requirements of future process metrology and inspection for 450 mm wafers. The targeted specifications of the concept are 1) inspecting more than 20 sites per wafer, 2) each site with dimension of about 10 × 10 μm2 (scalable to 100 × 100 μm2) and 3) with a throughput of more than 7 wafers per hour, or 70 wafers per hour with a coarse/fine scanning approach. The progress of the high throughput SPM development is discussed and the baseline design of the critical sub-modules and the research issues are presented. © 2013 SPIE.

TNO Science and Industry and MECAL have developed a six degree of freedom vibration isolation system that suppresses both floor vibrations and direct forces on a table top. The achieved reduction of transmissibility and compliance is 40 dB between 1 and 50 Hz in vertical direction, and 30 dB between 1 and 20 Hz in horizontal direction. Key elements of the system are a newly designed absolute vibration sensor, and two solutions to the horizontal tilting problem.