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With an increasing number of power plants operated in excess of their original design service life an early recognition of critical material degradation in components will gain importance. Many years of reactor safety research allowed for the identification and development of electromagnetic NDE methods which detect precursors of imminent damage with high sensitivity, at elevated temperatures and in a radiation environment. Regarding low-alloy heat-resistant steel grade WB 36 (1.6368, 15NiCuMoNb5), effects of thermal and thermo-mechanical aging on mechanical-technological properties and several micromagnetic parameters have been thoroughly studied. In particular knowledge regarding the process of copper precipitation and its acceleration under thermo-mechanical load has been enhanced. Whilst the Cu-rich WB 36 steel is an excellent model material to study and understand aging effects related to neutron radiation without the challenge of handling radioactive specimens in a hot cell, actually neutron-irradiated reactor pressure vessel materials were investigated as well. The neutron fluence experienced and the resulting shift of the ductile-brittle transition temperature were determined electromagnetically, and it was shown that weld and base material can be distinguished from the cladded side of the RPV wall. Low-cycle fatigue of the austenitic stainless steel AISI 347 (1.4550, X6CrNiNb18-10) has been characterized with electromagnetic acoustic transducers (EMATs) at temperatures of up to 300 °C. Time-of-flight and amplitude of the transmitted ultrasound signal were evaluated against the number of load cycles applied and observed as an indication of the imminent material failure significantly earlier than monitoring stresses or strains.

Backside sample preparation is a well known method to help circumvent undesired effects and artifacts in the analysis of a sample or device structure. However it remains challenging in the case of thin layers analysis since only a fraction of the original sample must remain while removing all of the substrate and maintaining a smooth and flat surface suitable for analysis. Here we present a method adapted to the preparation of ultra thin layers grown on pure Si substrates. It consists in a mechanical polishing up to a few remaining microns, followed by a dedicated wet etch. This method can be operated in a routine fashion and yields an extremely flat and smooth surface, without any remaining Si from substrate. It therefore allows precise analysis of the layers of interests with various characterization techniques.

Silicon's intersection with biology is a premise inherent in Moore's prediction. Distinct from biologically inspired molecular logic and storage devices (more Moore) are the integration of solid state electronic devices with the soft condensed state of the body (more than Moore). Developments in biomolecular recognition events per sq. cm parallel those of Moore's Law. However, challenges continue in the area of “More than Moore”. Two grand challenge problems must be addressed—the biocompatibility of synthetic materials with the myriad of tissue types within the human body and the interfacing of solid state micro‐ and nano‐electronic devices with the electronics of biological systems. Electroconductive hydrogels have been developed as soft, condensed, biomimetic but otherwise inherently electronically conductive materials to address the challenge of interfacing solid state devices with the electronics of the body, which is predominantly ionic. Nano‐templated interfaces via the oriented immobilization of si...

For the analysis of certified semiconducting Al0.7Ga0.3As/GaAs superlattices and photovoltaic samples, we used new generations Auger nano‐probes such as the JEOL JAMP‐9500F Field emission Microprobe and the PHI‐700 Xi system. These nano‐probes are generally used for the chemical analysis of complex nano‐structures at the deca‐nanometric scale. In this paper, we first used both systems for the determination of the surface composition of an Al0.7Ga0.3As/GaAs reference sample. In that, we studied the impact of surface topography on the Auger analysis. Secondly, we used both systems for chemical analysis of photovoltaic samples. Here, we investigated the in‐depth chemical composition, in particular the a‐Si:H (n)/ZnO/Al and ITO/a‐Si:H (p) interfaces, after a specific cross‐section preparation. However, limitations such as image drift due to acoustic vibration and heating effects due to continuous bombardment of energetic electrons at the same point are still a big challenge for quick, routine analysis.

Directed self‐assembly (DSA) of block copolymers (BCPs) is a technology that combines lithographically defined physical or chemical features to guide self‐assembled polymers to create features smaller than those possible with conventional lithography. To the semiconductor industry DSA represents a possible lithography solution below 22–16 nm node where the targeted line edge roughness (LER) is 1.4 nm or less. This LER requirement presents a challenge for DSA to become a viable lithography solution. Hitherto the LER of DSA block copolymers was measured mostly using SEM and AFM, hence the results represent only the top surface characteristics. In addition, the observed LER using SEM or AFM is often greater than 1.3 nm. The purpose of this work is to demonstrate the use of transmission X‐ray scattering to quantify LER as well as the critical dimensions in BCP patterns created with the DSA technique. Experimental results from poly(styrene‐b‐methyl methacrylate) copolymer line gratings with 23 nm half pitch will be presented and the theoretical developments needed to extract LER from X‐ray scattering will also be discussed.

This paper presents an overview of imec's R&D addressing the challenges of CMOS scaling towards the 10 nm node and its outlook beyond. In addition to the relentless geometrical shrinks, opportunities to further increase nanoelectronic system functionality and performance by co‐integration and chip stacking technologies combined with emerging MEMS and optoelectronic technologies will be presented.

Off‐axis electron holography has been used to measure the strain and the dopant fields in semiconductor specimens that have been prepared for examination by focused ion beam milling. By using the electrical and mechanical stability of the FEI Titan TEM, electron holograms have been acquired for long time periods which leads to active dopant and strain maps with excellent signal to noise ratios. We show that the position of the electrical junction can be measured in these devices specimens with a spatial resolution of 1 nm. In addition, we demonstrate that dark field electron holography and nanobeam electron diffraction can be used to quantitatively measure the strain in a range of specimens from 10‐nm‐thick SiGe layers, SiGe recessed source and drain transistors and CESL pMOS devices. In addition, the evolution of strain during the silicidation process has been observed in SiGe device specimens.

We describe the development of electrical test methods to evaluate damage that determines reliability in advanced, small‐scale conductors, including damascene copper and aligned carbon nanotube networks. Rapid thermal cycling induced during high‐current AC stressing provides a means for measuring lifetimes associated with cyclic plasticity and/or diffusive damage in damascene copper. The specific type of damage that develops depends on the line geometry and the nature of the stress state induced within the lines during cycling. Voids form in both fully passivated and partially passivated lines under high levels of hydrostatic tension. Dislocation activity takes place in partially passivated lines in the presence of high shears. High‐current DC stressing provides a means for evaluating the fabrication quality of aligned carbon nanotube (CNT) networks, in what we believe to be the first lifetime degradation tests of such materials. While classic electromigration is unlikely in nanocarbon, we observed through resistance changes two forms of degradation that we believe are tied to the nanotube packing and resulting conduction path density through the network: a gradual build‐up of damage, and a more abrupt, unpredictable form of damage accumulation, which may be linked to sudden changes in network morphology due to stressing.

As a non‐contact, in‐line monitoring technique for stress/strain and crystallinity of Si, epitaxial Si1−xGex/Si and implanted Si, a polychromator‐based, high resolution, multi‐wavelength Raman spectroscopy system was evaluated. Three major spectral lines at 457.9, 488.0 and 514.5 nm from a multi‐wavelength Ar ion laser were used as the excitation source for virtual depth profiling of material properties. Si stress/strain and Ge content were accurately measured from ultra thin (>5 nm) epitaxial Si1−xGex/Si. Crystalline stress value of C‐implanted Si and stress change before and after annealing were also successfully characterized. High resolution, multi‐wavelength μ‐Raman spectroscopy is shown to be a very promising non‐contact, in‐line characterization technique for nanoelectronic materials.

Despite its limitations, like the low through put, Atomic force microscopy (AFM) is in common use in the semiconductor industry for surface geometry characterization. Recent development in optical profilometry, Index Corrected Topography (ICT), further expands the technique by analysis of the collected interferograms to extract films parameters (thickness, for instance) and surface topography. This model based technique delivers literally complete information (e.g. topography, roughness, filmstack properties) of measured structure with sub‐micron lateral resolution and angstrom vertical resolution. The approach is a strong asset since it allows contact less topography measurement of wafer surfaces.In this paper we will show how this specific metrology can meet the aforementioned stringent requirements. The comparison with both the AFM and the spectroscopic ellipsometry will be presented.

Plasma assisted Atomic Layer Deposition Al2O3 samples were studied using an approach of complementary metrology using Ellipsometry, X‐Ray Reflectivity, Atomic Force Microscopy, and Total Reflection X‐Ray Fluorescence. For modeling the samples, an interfacial rough SiO2 layer has to be assumed. The excellent linearity of the ALD process was used to cross check Ellipsometry and X‐Ray Reflectivity. In contrast to Ellipsometry, X‐Ray Reflectivity showed a residual surface layer, identified as chlorine contaminated layer by TXRF. The samples are shown to be ideal candidates for calibration of X‐ray fluorescence as the Al signal linearly depends on the film thickness or ALD cycles. Furthermore, the impact of self‐absorption of thick layers for TXRF was shown by the samples.

Future generations of CMOS technology require aggressive scaling of SOI and BOX layer thickness. This will pose significant challenges for SOI specific metrology. Future requirements for layer thickness measurements, LPD inspection, electrical and structural characterization of SOI stack are discussed. Possible directions for future development of appropriate techniques are proposed.

The semiconductor manufacturing industry is now facing serious challenges in achieving defect detection rates with acceptable throughput and accuracy. With conventional bright‐field and dark‐field inspection methods now at their limits, it has become essential to explore alternative optical methods such as angle‐resolved scatterfield microscopy, 193 nm short wavelength solutions, and coherent illumination. In this paper we evaluate new optical technologies capable of extending high throughput defect inspection beyond the 22 nm node. We investigate source optimization for angle and polarization resolved illumination, measurement wavelengths down to 193 nm and interference microscopy using electromagnetic simulations and laboratory apparatus. Illumination engineering techniques recently developed at the National Institute of Standards and Technology (NIST), based on a bright‐field optical platform, are applied to signal‐based defect analysis of features with dimensions well below the measurement wavelength. A key to this approach is tailoring the illumination as a function of angle and polarization to targets of interest.

Leakage current distributions of high‐k dielectric thin films (8 nm HfSixOy and 5 nm ZrO2) were measured by tunneling atomic force microscopy (TUNA). In contrast to the thick HfSixOy film, where grains and grain boundaries can be seen by TUNA topography maps, ZrO2 films show no topography roughness. But large leakage current fluctuations can be seen for both dielectrics by TUNA current images. Higher leakage currents were found to flow through the grain boundaries of both analyzed high‐k dielectric films. Furthermore, local current voltage (I‐V) characteristics could successfully be measured precisely localized at grains and at grain boundaries, respectively, of the ZrO2 film. The obtained local I‐V curves showed significant differences between grains and grain boundaries, respectively. In the case of the ZrO2 film, the leakage current through the grain boundaries was up to 8 times larger than that through the grains at a substrate voltage of −3.5 V.

The presented method based on the Surface Photo Voltage effect has become an important ion implant characterization technique due to its high sensitivity and non‐contact nature. It is shown that the method can be applied to characterize critical areas of ion implant process, such as source‐drain and source‐drain extension, both before and after annealing step. In the paper we demonstrate the sensitivity of the method to the dopant/implant dose variations in both the source‐drain and halo implant regions.

Therma‐Probe® (TP) is widely used in the semiconductor industry for the Statistical Process Control (SPC) monitoring of the various ion implantation steps included in the Complementary Metal Oxide Semiconductor process. This fully optical, hence non‐destructive and fast, pump‐probe technique measures the probe laser reflectance (DC reflectance) as well as the pump‐laser‐induced changes in probe reflectance (AC reflectance, also called TW signal). In this paper, we report on the latest advances in the use of TP for the monitoring of ultra‐shallow junctions both before and after annealing of the implanted layers.

Photoreflectance (PR), using a uv (374 nm) diode laser probe beam, and Raman spectroscopy, using a multi‐wavelength Ar+ laser coupled to a high‐resolution multi‐wavelength spectrometer, were used to characterize the strain relaxation of Si top layers grown on a graded and relaxed SiGe buffer stack with a final Ge concentration of 20%. The Si top layer thicknesses ranged from 1.6 to 18 nm. Considerable radial variation in the strain relaxation was seen in all sampled wafers, highlighting the need for rapid, local strain characterization. Strong correlation between shift in the Si layer dielectric response, measured by uv‐PR, and the Si top layer strain, measured by Raman, is reported.

Spectroscopic ellipsometry (SE) is utilized to measure optical, structural and chemical properties of advanced semiconductor materials. In the case of very thin metal films, the correlation between thickness dependent optical properties and the free electron relaxation time is traced to the change in grain size. Low‐κ dielectric materials were characterized to extract the chemical (molecular bond vibration and carbon content), porous (pore volume fraction and pore size), and mechanical (coefficient of thermal expansion and Young's modulus) properties. SE was also employed to measure the bandgap of high‐κ dielectric thin films and the glass transition temperature of EUV photoresists and under layers. The percentage of curing in adhesive bonding layers used in 3D interconnects and the stress in strain engineered III‐nitride thin films were measured via infrared SE. SE is also an excellent method of measuring thin Silicon on Insulator materials. The shift in transition energies of the critical points in extremely thin silicon‐on‐insulators (ETSOI) were measured using direct space analysis.

High‐resolution X‐ray diffraction (HRXRD) is an established technique for the characterization and metrology of epitaxial thin‐films. However, its use by the silicon semiconductor industry has been limited due to the stringent reliability, spot‐size and throughput requirements for in‐line measurement of product wafers. We have developed a new X‐ray metrology tool (called the JVX 7200) that meets these demands. The tool features a novel HRXRD channel that provides composition, relaxation and thickness information for SiGe and Si:C epitaxial films. It also combines an enhanced X‐ray reflectivity (XRR) channel to provide complementary thickness, density and roughness information on SiGe as well as other front‐end of line (FEOL) films, such as those found in high‐k gate/metal gate (HKMG) stacks. We describe the principles and capabilities of both the HRXRD and XRR channels and provide a comparison with conventional X‐ray systems. Representative data are presented to highlight the capabilities of the new tool.

Extreme ultraviolet (EUV) lithography is the successor to optical lithography and will enable advanced patterning in semiconductor manufacturing processes down to the 8 nm half pitch technology node and beyond. However, before EUV can successfully be inserted into high volume manufacturing a few challenges must be overcome. Central among these remaining challenges is the requirement to produce “defect free” EUV masks. Mask blank defects have been one of the top challenges in the commercialization of extreme ultraviolet (EUV) lithography. To determine defect sources and devise mitigation solutions, detailed characterization of defects is critical. However, small defects pose challenges in metrology scale‐up. SEMATECH has a comprehensive metrology strategy to address any defect larger than a 20 nm core size to obtain solutions for defect‐free EUV mask blanks. SEMATECH's Mask Blank Development Center has been working since 2003 to develop the technology to support defect free EUV mask blanks. Since 2003, EUV mask blank defects have been reduced from 10000 of size greater than 100 nm to about a few tens at size 70 nm. Unfortunately, today's state of the art defect levels are still about 10 to 100 times higher than needed. Closing this gap requires progress in the various processes associated with glass substrate creation and multilayer deposition. That process development improvement in turn relies upon the availability of metrology equipment that can resolve and chemically characterize defects as small as 30 nm. The current defect reduction efforts at SEMATECH have intensively included a focus on inspection and characterization. The facility boasts nearly $100M of metrology hardware, including an FEI Titan TEM, Lasertec M1350 and M7360 tools, an actinic inspection tool, AFM, SPM, and scanning auger capabilities. The newly established Auger tool at SEMATECH can run a standard 6‐inch mask blank and is already providing important information on sub‐100 nm defects on EUV blanks. Complementary to Auger analysis, TEM provides ultimate resolution in the defect imaging of sub‐nanometer structures. Crystalline and phase information generated by this metrology technique also indicates the sources of defects. SEMATECH's TEM capability is further equipped with energy dispersive X‐ray spectroscopy (EDS) and electron energy loss spectroscopy (EELS), which provide higher analytical power than similar techniques in traditional secondary electron microscopy (SEM). This paper will describe SEMATECH's comprehensive effort to develop robust inspection of EUV mask defects. We will discuss the development of hardware and procedures for inspecting particles 70 nm and smaller. This paper will also outline challenges in the metrology of current defects on EUV mask blanks and metrology issues that arise with increasingly smaller defects.

Potential challenges with managing mechanical stress and the consequent effects on device performance for advanced 3D through‐silicon‐via (TSV) based technologies are outlined. The paper addresses the growing need in a simulation‐based design verification flow capable to analyze a design of 3D IC stacks and to determine across‐die out‐of‐spec variations in device electrical characteristics caused by the layout and through‐silicon‐via (TSV)/package‐induced mechanical stress. The limited characterization/measurement capabilities for 3D IC stacks and a strict “good die” requirement make this type of analysis critical for the achievement of an acceptable level of functional and parametric yield and reliability. The paper focuses on the development of a design‐for‐manufacturability (DFM) type of methodology for managing mechanical stresses during a sequence of designs of 3D TSV‐based dies, stacks and packages. A set of physics‐based compact models for a multi‐scale simulation to assess the mechanical stress across the device layers in silicon chips stacked and packaged with the 3D TSV technology is proposed. A calibration technique based on fitting to measured stress components and electrical characteristics of the test‐chip devices is presented. A strategy for generation of a simulation feeding data and respective materials characterization approach are proposed, with the goal to generate a database for multi‐scale material parameters of wafer‐level and package‐level structures. For model validation, high‐resolution strain measurements in Si channels of the test‐chip devices are needed. At the nanoscale, the transmission electron microscopy (TEM) is the only technique available for sub‐10 nm strain measurements so far.

Si/SiGeC superlattices are used in the construction of new generation devices such as multichannel transistors. The incorporation of C in the SiGe layers allows for a better control of the strain and the Ge content. However the formation of β‐SiC clusters during annealing at high temperature limits the thermal stability of the alloy. It leads to a strong modification of the strain due to the reduction of the substitutional carbon content. Here, we investigated the behavior of Si/SiGeC superlattices that have been annealed using different characterization techniques: dark‐field electron holography for the evaluation of strain; infrared spectroscopy and ToF‐SIMS for the determination of the composition. It was found that after annealing at 1050 °C, the reduction of the substitutional C proportion leads to a recovery of the perpendicular strain in the superlattice. It was also proposed that the local arrangement of C atoms in a third nearest neighbor configuration is an intermediary step during the formation...

In this work, we report a series of Kelvin Force Microscopy (KFM) measurements, suitable to observe the topography and the contact potential difference (CPD) distribution of the following stack: CdTe/CdS/ITO/glass. The sample is prepared by mechanical polishing after cleavage to decrease the roughness. In order to have a better understanding of the charge transport inside the solar cell and to vary the Fermi level pinning effect, different bias are applied to the sample. The CPD variations with different bias on cross‐section in dark condition are presented. We observe the reverse bias widens the CdTe/CdS depletion region. Under illumination, electron and holes are generated near the interface and varies the CPD distribution. Additionally, the chemical composition of each layer has been investigated by nano‐Auger electron spectroscopy (AES). We observe the interdiffusion at the CdTe/CdS interface and determine the composition of the active layers to be CdTe/CdS0.7Te0.3.

The IEC technical committee 113 “Nanotechnology standardization for electrical and electronic products and systems” develops standards to be used in the electrotechnical industry. These standards will address all stages in the life cycle of nano‐enabled electrotechnical products. The focus of the standardization activities is on products whose performance is inherently related to the use of nanomaterials and nanoprocesses. Examples of product groups addressed are nano‐enabled batteries, photovoltaic cells, lightning devices and printed electronics. Currently, the committee concentrates on nanomanufacturing processes and quality management.

This paper collects the results of a study aimed to investigate the impact of organic contamination on the electrical properties of the silicon oxide and of the silicon oxide‐silicon interface. Some wafers were contaminated by immersion in solution of diethylphthalate (DEP) in solvent. The wafers were then oxidized to perform surface recombination velocity measurements by Elymat, and capacitors were fabricated for capacitance vs. voltage and capacitance vs time measurements. In addition, the interface state density was measured by the MOS‐DLTS technique and the gate oxide integrity was evaluated by constant current stress. Elymat measurements of surface recombination velocity show that surface recombination velocity is increased by organic contamination. From the point‐of‐view of the intrinsic properties of the silicon oxide‐silicon interface, MOS‐DLTS showed the most significant effects. These measurements allowed identifying a band of interface states located around Ev +0.1 eV as related to organic cont...

In order to reach high levels of transistor performance, it is desirable to increase electrical conductivity of the device. An efficient way to enhance carrier mobility in the conduction channel is to generate strain in the structure using process‐induced stress. To achieve that, stress engineering of the contact etch stop layer (CESL), an amorphous hydrogenated silicon nitride film deposited by plasma enhanced chemical vapour deposition on top of the metal oxide semiconductor assembly, is widely used since it is a low‐cost technique. Indeed, this film possesses an intrinsic stress that can be set from tensile (σ = 1.6 GPa) to compressive (σ = −3.0 GPa) depending on deposition conditions. From an electrical point of view, strain induced in the silicon channel can lead to an increase of carrier mobility as high as 8–10% which in turn increases Ion/Ioff and decreases switching time of the transistor. Usually, strain induced in the channel is very low (0.1–0.3%), making quantitative measurements challenging....

Scanning Electron Microscopy (SEM) has been a mainstay of critical dimension (CD) metrology since the inception of integrated microelectronics, due to its inherent high resolution capability and relative ease of interpretation. However, as device dimensions continue to shrink, and non‐planar devices become integrated into process flows (e.g., finFETs), the need to identify and develop successor technologies becomes essential. Here, we report progress on the development of two innovative technologies proposed for CD measurement, and assess their viability for high volume manufacturing applications. Finally, we describe recent efforts to extend the life of conventional CD‐SEM.Small Angle X‐ray Scattering (SAXS) also offers Angstrom‐level resolution, is non‐destructive, and requires no additional preparation steps. Performed in either transmission or reflection mode, this method is particularly suitable for arrayed structures and non‐planar devices. Whereas direct imaging methods provide a complete description of a single measurement site, SAXS probes a comparatively large area containing many sites, and effectively provides information on feature dimensions and the statistical variations within the sampled. The chief limitation to implementing CD‐SAXS is throughput, gated by x‐ray source brilliance. Conventional x‐ray tube and rotating anode sources do not have the correct combination of brightness and stability required to obtain rapid, consistent measurements. Recent innovations in x‐ray source technology, including plasma and liquid metal based sources, have shown promise for making CD‐SAXS a viable HVM method.Scatterometry methods offer yet another attractive approach. Advances in the optical components and simulation software enable one to obtain most of the sixteen components of the Mueller Matrix for each wavelength of light instead of the typical Ψ and Δ. This is great importance when measuring highly anisotropic 3D scatterometry test structures.Finally, it is worth considering the efforts to extend the life of CD‐SEM. A series of advances such as drift correct frame averaging and 3D Monte Carlo models that improve metrology for nanoscale features are all under consideration. These improvements push CD‐SEM resolution closer to its theoretical limits. Additionally, the use of contrast transfer functions (CTFs) as an improved means for achieving tool matching and assessing tool performance, is considered. When an image is collected from an ideal test specimen, such as a high resolution Fresnel Zone Plate or a pseudo‐random dot array, the CTF can be used as a measure of the fidelity with which specimen topography is represented in the recorded signal, as a function of spatial frequency. Tuning SEM parameters to manipulate the CTF provides a richer feedback mechanism than simply using nominal resolution and signal‐to‐noise ratio.

The silicidation reaction between a titanium metal film, capped by a TiN layer, and a boron‐implanted silicon substrate has been analyzed by Atom Probe Tomography. Two different thicknesses of titanium metal film were considered to study the process of silicidation and subsequent effects on the redistribution of the dopants. The concentration depth profiles determined by atom probe tomography and secondary ion mass spectrometry depict an additional amorphous TiSix phase for the thicker Ti film in contrast to a fully silicided TiSi2 layer for the thin one. The experimental data shows lower solubility of boron in TiSi2 in comparison to the amorphous TiSix phase. Additionally, boron accumulation at the interface between the TiSi2 and the TiN capping layer is observed. The atom probe study clearly reveals boron precipitates at interfaces between TiSi2 and Si substrate or TiN capping layer. These precipitates can be identified either to a stoichiometric ratio of TiB2 or TiB correlated to the size of the indivi...

The imaging of surfaces using the PhotoElectron Emission Microscopy (PEEM) technique has recently received considerable interest, mainly thanks to the use of high brilliance synchrotron radiation which facilitates the study of surface properties and chemical selectivity. By inserting a transfer lens in the optical column of a high transmission and full energy‐filtering PEEM, it is possible to image the back focal plane, named k‐PEEM imaging mode. Hence, the corresponding image shows the angular distribution of the emitted photoelectrons for a given kinetic energy. By varying the kinetic energy, the complete energy filtering provides full 2D cuts of the band structure in reciprocal space. In this paper, we present the principles and the capabilities of this new imaging mode, and compare it to the standard ARPES technique. Then, we present results obtained on a model sample: Ag(100), and on a technological sample, epitaxial graphene on SiC(0001), highlighting the potential of this new imaging mode for the spatially resolved characterization of the electronic structure of monocrystalline materials in devices.

The measurement of Ag, Pt and Au on wafer surfaces was addressed by a liquid phase chemical collection coupled to ICPMS analysis. Three chemistries were evaluated from intentionally contaminated wafers in the E12 to E15 at/cm2 concentration range. Different modes of voluntary wafer contamination allowed us to consider both the chemical form of the contaminant (i.e. ionic and metal forms) and its localization (i.e. on the surface and included in the oxide layer). Diluted HNO3 was used for Ag collection on the wafer surface allowing a collection efficiency (CE) higher than 90%. Regarding Pt and Au, diluted aqua regia and diluted HF/aqua regia were used. The first solution leads to a good collection of Au and Pt on the wafer surface (CE >90%) and is inefficient for contamination included in the oxide layer while the second one addresses the two cases with collection rates higher than 94%. Finally, detection limits of few E10 at/cm2 were determined showing the relevance of the technique implemented.

The detrimental effects of metallic on certain key electrical parameters of silicon devices mandates the use of state‐of‐the‐art characterization and metrology tools as well as appropriate control plans. Historically, this has been commonly achieved in‐line on monitor wafers through a combination of Total Reflectance X‐Ray Fluorescence (TXRF) and post anneal Surface Photo Voltage (SPV). On the other hand, VPD (Vapor Phase Decomposition) combined with ICP‐MS (Inductively Coupled Mass Spectrometry) or TXRF is known to provide both identification and quantification of surface trace metals at lower detection limits. Based on these considerations the description of an advanced monitoring scheme using SPV, TXRF and automated VPD ICP‐MS is described.

The dielectric constant of dielectric films used in on‐chip interconnect stacks of microelectronic products is controlled by the deposited material for low‐k and by the incorporation of porosity/voids for ultra‐low‐k (ULK) materials. The porosity has a significant and direct influence on the mechanical and interfacial properties of these materials. Pore volume fraction and spatial distribution have a detrimental impact on the material stiffness and fracture toughness, film adhesion, sensitivity to CMP and device mechanical reliability during other processing steps. The nanomechanical testing of low‐k films—namely nanoindentation and nanoscratch measurements—allows an indirect characterization of the porosity of a ULK film. These tests can resolve variations with nanometer scale spatial resolution as well as changes of porosity of the material as a function of film thickness, all of which significantly impact the mechanical reliability of the device.

At the same time as research in 3D TSV technology is advancing quickly, the analytical techniques used in the evaluation of 3D stacks must also advance in capability. Microscopy techniques for which silicon is opaque such as scanning acoustic microscopy (SAM) and confocal infrared (IR) microscopy are capable of inspecting the interface between bonded wafer pairs, while high resolution X‐ray computed tomography (XCT) is used to detect voids in TSVs. With nano‐XCT, voids in copper TSVs with sub‐100 nm size can be visualized. For more detailed failure characterization, a target Focused Ion Beam (FIB) cross‐section through the localized region of interest (defect) and subsequent scanning electron microscopy (SEM) imaging is proposed. Currently, the most important requirement is to reduce the so‐called time‐to‐data, e. g. for defect localization using nano‐XCT and for cross‐section characterization.

Supported by the European Commission and EURAMET, a consortium of 10 participants from national metrology institutes, universities and companies has started a joint research project with the aim of overcoming current challenges in optical scatterometry for traceable linewidth metrology. Both experimental and modelling methods will be enhanced and different methods will be compared with each other and with specially adapted atomic force microscopy (AFM) and scanning electron microscopy (SEM) measurement systems in measurement comparisons. Additionally novel methods for sophisticated data analysis will be developed and investigated to reach significant reductions of the measurement uncertainties in critical dimension (CD) metrology. One final goal will be the realisation of a wafer based reference standard material for calibration of scatterometers.

We have demonstrated high resolution focused ion beams based on a magneto‐optical trap ion source (MOTIS), which takes advantage of the ultra cold temperatures of laser cooled atoms to produce high brightness, low emittance ion beams. We have created focused beams of both Cr+ and Li+ and present secondary electron micrographs obtained with these beams, demonstrating a focal spot size as low as 27 nm at a beam energy of 2 keV. This work shows that the MOTIS can be a useful source for focused ion beams that will open new opportunities for applications in materials characterization and metrology.

Through‐focus scanning optical microscopy (TSOM) is a relatively new method that transforms conventional optical microscopes into truly three‐dimensional metrology tools for nanoscale to microscale dimensional analysis. TSOM achieves this by acquiring and analyzing a set of optical images collected at various focus positions going through focus (from above‐focus to under‐focus). The measurement resolution is comparable to what is possible with typical light scatterometry, scanning electron microscopy (SEM) and atomic force microscopy (AFM). TSOM method is able to identify nanometer scale difference, type of the difference and magnitude of the difference between two nano/micro scale targets using a conventional optical microscope with visible wavelength illumination. Numerous industries could benefit from the TSOM method—such as the semiconductor industry, MEMS, NEMS, biotechnology, nanomanufacturing, data storage, and photonics. The method is relatively simple and inexpensive, has a high throughput, provides nanoscale sensitivity for 3D measurements and could enable significant savings and yield improvements in nanometrology and nanomanufacturing. Potential applications are demonstrated using experiments and simulations.

The recent advance in lithography process leads to microelectronics compound size reduction. As a direct consequence, micro roughness should not be negligible compared to critical dimension. That is why a novel approach has been developed using an angle resolved scatterometer to quantify roughness value.In order to compare and validate results from scattering measurement, a multiscale analysis will be performed with AFM measurement. Based on theory and numerical models, validation of this technique is performed.

Today 3D integration based on TSV's is a well accepted approach to further improve Integrated Circuits in terms of miniaturization, performance, power consumption and heterogeneous integration. However, 3D integration comes with the introduction of many new processes and materials that may affect behavior and reliability of the overall system. Therefore, there is a strong demand for physical characterization and failure analysis and more explicitly, also for tools and techniques that allow for easy chip access and navigation to the site of interest and that can provide physical information at the nanometer scale within a large field of view.In the framework of the European project JEMSIP‐3D, a novel plasma‐FIB platform has been developed and evaluated by the project partners. This new platform has been characterized in terms of mill rates, resolution and ion assisted CVD kinetics and effective methods have been developed to suppress the curtaining that may appear on X‐sections due to variations in materia...

Reduced uncertainty in the thermonuclear rate of the {sup 33}S(p,{gamma}){sup 34}Cl reaction would help to improve our understanding of nucleosynthesis in classical nova explosions. At present, models are generally in concordance with observations that nuclei up to roughly the calcium region may be produced in these explosive phenomena; better knowledge of this rate would help with the quantitative interpretation of nova observations over the S-Ca mass region, and contribute towards the firm establishment of a nucleosynthetic endpoint. As well, models find that the ejecta of nova explosions on massive oxygen-neon white dwarfs may contain as much as 150 times the solar abundance of {sup 33}S. This characteristic isotopic signature of a nova explosion could possibly be observed through the analysis of microscopic grains formed in the environment surrounding a nova and later embedded within primitive meteorites. An improved {sup 33}S(p,{gamma}){sup 34}Cl rate (the principal destruction mechanism for {sup 33}S in novae) would help to ensure a robust model prediction for the amount of {sup 33}S that may be produced. Finally, constraining this rate could confirm or rule out the decay of an isomeric state of {sup 34}Cl(E{sub x} = 146 keV, t{sub 1/2} = 32 m) as a source formore » observable gamma-rays from novae. We have performed several complementary experiments dedicated to improving our knowledge of the {sup 33}S(p,{gamma}){sup 34}Cl rate, using both indirect methods (measurement of the {sup 34}S({sup 3}He,t){sup 34}Cl and {sup 33}S({sup 3}He,d){sup 34}Cl reactions with the Munich Q3D spectrograph) and direct methods (in normal kinematics at CENPA, University of Washington, and in inverse kinematics with the DRAGON recoil mass separator at TRIUMF). Our results will be used with nova models to facilitate comparisons of model predictions with present and future nova observables.« less

The CD-SEM has been the tool of choice for the imaging and metrology of semiconductor devices for the past three decades but now, with critical dimensions at the nanometer scale, electron beam instruments can no longer deliver adequate performance. A scanning microscope using a He+ ion beam offers superior resolution and depth of field, and provides enhanced imaging contrast. Device metrology performed using ion beam imaging produces data which is comparable to or better than that from a conventional CD-SEM although there are significant differences in the experimental conditions required and in the details of image formation. The charging generated by a He+ beam, and the sample damage that it can cause, require care in operation but are not major problems.

A vertical nanowire tunnel field effect transistor (TFET) and a bit cost scalable (BICS) flash memory are characterized by electron tomography. The optimum measurement conditions are investigated by comparison of the 3D reconstructions obtained with different specimen geometries and different image modes. The few nm thick layers of both devices are clearly observed on the 3D reconstructions, showing the high resolution of this technique and its importance for the analysis of nanodevices.

The shrinking trend in semiconductor technologies is challenging the available instrumentation for mechanical characterization of thin films. Colored Picosecond Acoustics (APiC), a non‐destructive and non‐contact laser technology, enables the measurements of mechanical parameters of complex thin films stacks. In this paper we present the technology and report on results obtained on standard materials.

In this paper three electrical methods for SiC resistivity measurement are discussed. The primary method is based on the Elastic Material Probe (EM‐Probe) or Elastic Probe CV (ECV). Also we discuss the specifics of the advanced Mercury CV (MCV) and Spreading Resistance (SRP) techniques. Measurement results of 4H‐SiC Epitaxial samples are presented, showing a good correlation between various methods.

Resistive switching memory (also known as RRAM for resistive random access memory) is considered a promising candidate for the next‐generation nonvolatile memories. This paper summarizes the electrical characterization methodologies for RRAM performance evaluation and the investigation of resistive switching mechanisms. Some unique issues in RRAM measurements are discussed, including polarity, forming, and switching control. Product‐oriented RRAM characterization needs to consider yield, failure mechanisms, and reliability issues, which has only began to be addressed by the RRAM research community.

We used azimuthally‐resolved spectroscopic Mueller matrix ellipsometry to study a periodic silicon line structure with and without artificially‐generated line edge roughness (LER). Grating profiles were determined from multiple azimuthal configurations, focusing the incident beam into a 60 μm spot. We used rigorous numerical modeling, taking into account the finite numerical aperture and determining the profile shape using a four trapezoid model for the line profile. Data obtained from the perturbed and unperturbed gratings were fit using the same model, and the resulting root‐mean‐square error (RMSE) values were compared. The comparison shows an increase in RMSE values for the perturbed grating that can be attributed to the effects of LER.

In the present paper we extend Fourier‐Scatterometry by the use of the coherent properties of white light for the characterization of sub‐wavelength periodic gratings of photosensitive material structured by two‐photon polymerization. Our goal is a fast and precise optical characterization of periodical gratings of sub 100 nm size. The investigated structures include gratings produced by two‐photon polymerization of photosensitive material and typical semiconductor test gratings. A Fourier‐Scatterometer has been set up using a white light source and also additionally a reference‐branch for white‐light‐interference (WLI). A sensitivity comparison between Fourier‐Scatterometry and WLI‐Scatterometry is presented.

In this paper, we present a spectroscopic Mueller matrix ellipsometry measurement of a silicon line grating with nominal pitch of 600 nm and line width 100 nm. An uncertainty analysis is performed on the measurement results. The results are compared to critical dimension atomic force microscopy (CD‐AFM) measurements. Except for one of the gratings, the CD‐AFM and scatterometry measurements lie within each other's uncertainties.