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Holographic optical elements for the extreme-ultravioletregime

Description: As the development of extreme ultraviolet (EUV) lithography progresses, interest grows in the extension of traditional optical components to the EUV regime. The strong absorption of EUV by most materials and its extremely short wavelength, however, makes it very difficult to implement many components that are commonplace in the longer wavelength regimes. One such component is the diffractive optical element used, for example, in illumination systems to efficiently generate modified pupil fills. Here we demonstrate the fabrication and characterization of EUV binary phase-only computer-generated holograms allowing arbitrary far-field diffraction patterns to be generated.
Date: August 14, 2006
Creator: Naulleau, Patrick P.; Salmassi, Farhad; Gullikson, Eric M. & Anderson, Erik H.
Partner: UNT Libraries Government Documents Department

Soft X-Ray Imaging of spin dynamics at high spatial and temporalresolution

Description: Soft X-ray microscopy provides element specific magnetic imaging with a spatial resolution down to 15nm. At XM-1, the full-field soft X-ray microscope at the Advanced Light Source in Berkeley, a stroboscopic pump and probe setup has been developed to study fast magnetization dynamics in ferromagnetic elements with a time resolution of 70ps which is set by the width of the X-ray pulses from the synchrotron. Results obtained with a 2 {micro}m x 4 {micro}m x 45nm rectangular permalloy sample exhibiting a seven domain Landau pattern reveal dynamics up to several nsec after the exciting magnetic field pulse. Domain wall motion, a gyrotropic vortex motion, and a coupling between vortices in the rectangular geometry are observed.
Date: June 1, 2007
Creator: Mesler, Brooke L.; Fischer, Peter; Chao, Weilun & Anderson, Erik H.
Partner: UNT Libraries Government Documents Department

Towards sub-10 nm resolution zone plates using the overlaynanofabrication processes

Description: Soft x-ray zone plate microscopy has proven to be a valuable imaging technique for nanoscale studies. It complements nano-analytic techniques such as electron and scanning probe microscopies. One of its key features is high spatial resolution. We developed an overlay nanofabrication process which allows zone plates of sub-20 nm zone widths to be fabricated. Zone plates of 15 nm outer zones were successfully realized using this process, and sub-15 nm resolution was achieved with these zone plates. We extend the overlay process to fabricating zone plates of 12 nm outer zones, which is expected to achieve 10 nm resolution. In addition, we have identified a pathway to realizing sub-10 nm resolution, high efficiency zone plates with tilted zones using the overlay process.
Date: January 23, 2008
Creator: Chao, Weilun; Anderson, Erik H.; Fischer, Peter & Kim, Dong-Hyun
Partner: UNT Libraries Government Documents Department

Multilayer Phase-Only Diffraction Gratings: Fabrication andApplication to EUV Optics

Description: The use of phase-only diffractive devices has long played an important role in advanced optical systems in varying fields. Such devices include gratings, diffractive and holographic optical elements, diffractive lenses, and phase-shift masks for advanced lithography. Extending such devices to the increasingly important regime of extreme ultraviolet (EUV) wavelengths, however, is not trivial. Here, we present an effective fabrication and etch process enabling high-resolution patterning of Mo/Si multilayers for use in EUV phase devices, providing another method for fabrication of high numerical aperture diffractive devices or high-resolution EUV phase shift masks.
Date: May 1, 2007
Creator: Salmassi, Farhad; Gullikson, Eric M.; Anderson, Erik H. & Naulleau, Patrick P.
Partner: UNT Libraries Government Documents Department

HSQ double patterning process for 12 nm resolution x-ray zone plates

Description: Soft x-ray zone plate microscopy is a powerful nano-analytic technique used for a wide variety of scientific and technological studies. Pushing its spatial resolution to 10 nm and below is highly desired and feasible due to the short wavelength of soft x-rays. Instruments using Fresnel zone plate lenses achieve a spatial resolution approximately equal to the smallest, outer most zone width. We developed a double patterning zone plate fabrication process based on a high-resolution resist, hydrogen silsesquioxane (HSQ), to bypass the limitations of conventional single exposure fabrication to pattern density, such as finite beam size, scattering in resist and modest intrinsic resist contrast. To fabricate HSQ structures with zone widths in the order of 10 nm on gold plating base, a surface conditioning process with (3-mercaptopropyl) trimethoxysilane, 3-MPT, is used, which forms a homogeneous hydroxylation surface on gold surface and provides good anchoring for the desired HSQ structures. Using the new HSQ double patterning process, coupled with an internally developed, sub-pixel alignment algorithm, we have successfully fabricated in-house gold zone plates of 12 nm outer zones. Promising results for 10 nm zone plates have also been obtained. With the 12 nm zone plates, we have achieved a resolution of 12 nm using the full-field soft x-ray microscope, XM-1.
Date: June 16, 2009
Creator: Chao, Weilun; Kim, Jihoon; Rekawa, Senajith; Fischer, Peter & Anderson, Erik H.
Partner: UNT Libraries Government Documents Department

Resists for next generation lithography

Description: Four Next Generation Lithographic options (EUV, x-ray, EPL, IPL) are compared against four current optical technologies (i-line, DUV, 193 nm, 157 nm) for resolution capabilities based on wavelength. As the wavelength of the incident radiation decreases, the nature of the interaction with the resist changes. At high energies, optical density is less sensitive to molecular structure then at 157 nm.
Date: October 3, 2001
Creator: Brainard, Robert L.; Barclay, George G.; Anderson, Erik H. & Ocola, Leonidas E.
Partner: UNT Libraries Government Documents Department

Stability of modulation transfer function calibration of surface profilometers using binary pseudo-random gratings and arrays with nonideal groove shapes

Description: The major problem of measurement of a power spectral density (PSD) distribution of surface heights with surface profilometers arises due to the unknown Modulation Transfer Function (MTF) of the instruments, which tends to distort the PSD at higher spatial frequencies. The special mathematical properties of binary pseudo-random patterns make them an ideal basis for developing MTF calibration test surfaces. Two-dimensional binary pseudo-random arrays (BPRAs) have been fabricated and used for the MTF calibration of the MicroMap{trademark}-570 interferometric microscope with all available objectives. An investigation into the effects of fabrication imperfections on the quality of the MTF calibration and a procedure for accounting for such imperfections are presented.
Date: March 31, 2010
Creator: Barber, Samuel K.; Anderson, Erik H.; Cambie, Rossana; Marchesini, Stefano; McKinney, Wayne R.; Takacs, Peter Z. et al.
Partner: UNT Libraries Government Documents Department

Binary pseudo-random gratings and arrays for calibration of the modulation transfer function of surface profilometers: recent developments

Description: The major problem of measurement of a power spectral density (PSD) distribution of the surface heights with surface profilometers arises due to the unknown Modulation Transfer Function (MTF) of the instruments. The MTF tends to distort the PSD at higher spatial frequencies. It has been suggested [Proc. SPIE 7077-7, (2007), Opt. Eng. 47 (7), 073602-1-5 (2008)] that the instrumental MTF of a surface profiler can be precisely measured using standard test surfaces based on binary pseudo-random (BPR) patterns. In the cited work, a one dimensional (1D) realization of the suggested method based on use of BPR gratings has been demonstrated. Here, we present recent achievements made in fabricating and using two-dimensional (2D) BPR arrays that allow for a direct 2D calibration of the instrumental MTF. The 2D BPRAs were used as standard test surfaces for 2D MTF calibration of the MicromapTM-570 interferometric microscope with all available objectives. The effects of fabrication imperfections on the efficiency of calibration are also discussed.
Date: July 7, 2009
Creator: Barber, Samuel K.; Soldate, Paul; Anderson, Erik H.; Cambie, Rossana; Marchesini, Stefano; McKinney, Wanye R. et al.
Partner: UNT Libraries Government Documents Department

Fabrication and Optical Measurements of Nanoscale Meta-Materials:Terahertz and Beyond

Description: Recently, artificial meta-materials have been reported [1] that have a negative index of refraction, which allows a homogeneous flat slab of the material to behave as a perfect lens [2], possibly even creating sub-diffraction limited focusing. These novel artificial materials have numerous potential applications in science, technology, and medicine [3], especially if their novel behavior can be extended to the technologically critical near-infrared and visible region. The meta-materials consist of split-ring resonators which provide a negativem, and metal strips which provide a negative e. First steps towards scaling the dimensions of these metamaterials have been recently taken with the fabrication of split-ring resonator structures showing magnetic resonances at about1 THz [4]and 100 THz [5]frequencies.
Date: July 27, 2005
Creator: Martin, Michael C.; Hao, Zhao; Liddle, Alex; Anderson, Erik H.; Padilla, Willie J.; Schurig, David et al.
Partner: UNT Libraries Government Documents Department

Double patterning HSQ processes of zone plates for 10 nm diffraction limitedperformance

Description: In e-beam lithography, fabrication of sub-20 nm dense structures is challenging. While there is a constant effort to develop higher resolution resist processes, the progress of increasing pattern density is slow. For zone plates, consisting of dense lines and spaces, the outermost zone width has been limited to slightly less than 20 nm due to effects such as low aerial image contrast, forward scattering, intrinsic resist resolution, and development issues. To circumvent these effects, we have successfully developed a new double patterning HSQ process, and as a result, we have fabricated zone plates of 10 and 12 nm using the process. We previously developed a double patterning process in which a dense zone plate pattern is sub-divided into two semi-isolated, complementary zone set patterns. These patterns are fabricated separately and then overlaid with high accuracy to yield the desired pattern. The key to success with this process is the accuracy of the overlay. For diffraction-limited zone plates, accuracy better than one-third of the smallest zone width is needed. In our previous work, the zone set patterns were formed using PMMA and gold electroplating, which were overlaid and aligned to the zero-level mark layer with sub-pixel accuracy using our internally developed algorithm. The complete zone plate fabrication was conducted in-house. With this process, we successfully fabricated zone plates of 15 nm outermost zone. Using this zone plate, we were able to achieve sub-15 nm resolution at 1.52 nm wavelength, the highest resolution ever demonstrated in optical microscopy at that time. We attempted to extend the process to fabricating 12 nm and smaller zones. However, the modest PMMA contrast, combined with a relatively large electron beam size compared to the target feature sized limited the process latitude. To overcome this problem, we developed a new overlay process based on high resolution negative ...
Date: January 9, 2009
Creator: Chao, Weilun; Kim, Jihoon; Anderson, Erik H.; Fischer, Peter; Rekawa, Senajith & Attwood, David T.
Partner: UNT Libraries Government Documents Department

Replicated mask surface roughness effects on EUV lithographic pattering and line edge roughness

Description: To quantify the roughness contributions to speckle, a programmed roughness substrate was fabricated with a number of areas having different roughness magnitudes. The substrate was then multilayer coated. Atomic force microscopy (AFM) surface maps were collected before and after multilayer deposition. At-wavelength reflectance and total integrated scattering measurements were also completed. Angle resolved scattering based power spectral densities are directly compared to the AFM based power spectra. We show that AFM overpredicts the roughness in the picometer measurements range. The mask was then imaged at-wavelength for the direct characterization of the aerial image speckle using the SEMATECH Berkeley Actinic Inspection Tool (AIT). Modeling was used to test the effectiveness of the different metrologies in predicting the measured aerial-image speckle. AIT measured contrast values are 25% or more than the calculated image contrast values obtained using the measured rms roughness input. The extent to which the various metrologies can be utilized for specifying tolerable roughness limits on EUV masks is still to be determined. Further modeling and measurements are being planned.
Date: March 11, 2011
Creator: George, Simi A.; Naulleau, Patrick P.; Gullikson, Eric M.; Mochi, Iacopo; Salmassi, Farhad; Goldberg, Kenneth A. et al.
Partner: UNT Libraries Government Documents Department

Actinic EUV mask inspection beyond 0.25 NA

Description: Operating at EUV wavelengths, the SEMATECH Berkeley Actinic Inspection Tool (AIT) is a zoneplate microscope that provides high quality aerial image measurements in routine operations for SEMATECH member companies. We have upgraded the optical performance of the AIT to provide multiple image magnifications, and several inspection NA values up to 0.35 NA equivalent (0.0875 mask-side). We report on the improved imaging capabilities including resolution below 100-nm on the mask side (25 nm, 4x wafer equivalent). EUV reticles are intricate optical systems made from of several materials with wavelength-specific optical properties. The combined interactions of the substrate, multilayer-stack, buffer layer and absorber layer produce a reflected EUV optical field that is challenging to model accurately, and difficult to fully assess without actinic at-wavelength inspection. Understanding the aerial image from lithographic printing alone is complicated by photoresist properties. The AIT is now used to investigate mask issues such as amplitude and phase defect printability, pattern repair techniques, contamination, inspection damage, and mask architecture. The AIT has a 6{sup o} illumination angle, and high-resolution exposure times are typically 20 seconds per image. The AIT operates semi-automatically capturing through-focus imaging series with step sizes as small as 0.1 {micro}m (0.5-0.8 {micro}m are typical), and a step resolution of 0.05 {micro}m. We believe it is the most advanced EUV mask inspection tool in operation today. In the AIT, an EUV image of the mask is projected by a zoneplate lens with high magnification (680-910x) onto a CCD camera. The CCD over-samples the image, providing equivalent pixel sizes down to 15 nm in mask coordinates-several image pixels per resolution element. The original AIT zoneplate specifications were designed to emulate the resolution of a 0.25-NA 4x stepper, and thorough benchmarking analysis of the aberrations, flare, contrast-transfer function, and coherence was published in 2007 [1] (see Fig 1). ...
Date: August 6, 2008
Creator: Goldberg, Kenneth A.; Mochi, Iacopo; Anderson, Erik H.; Rekawa, Seno B.; Kemp, Charles D.; Huh, S. et al.
Partner: UNT Libraries Government Documents Department

Design and fabrication of advanced EUV diffractive elements

Description: As extreme ultraviolet (EUV) lithography approaches commercial reality, the development of EUV-compatible diffractive structures becomes increasingly important. Such devices are relevant to many aspects of EUV technology including interferometry, illumination, and spectral filtering. Moreover, the current scarcity of high power EUV sources makes the optical efficiency of these diffractive structures a paramount concern. This fact has led to a strong interest in phase-enhanced diffractive structures. Here we describe recent advancements made in the fabrication of such devices.
Date: November 16, 2003
Creator: Naulleau, Patrick P.; Liddle, J. Alexander; Salmassi, Farhad; Anderson, Erik H. & Gullikson, Eric M.
Partner: UNT Libraries Government Documents Department

Adding static printing capabilities to the EUV phase-shifting point diffraction interferometer

Description: While interferometry is routinely used for the characterization and alignment of lithographic optics, the ultimate performance metric for these optics is printing in photoresist. Direct comparison of imaging and wavefront performance is also useful for verifying and improving the predictive power of wavefront metrology under actual printing conditions. To address these issues, static, small-field printing capabilities are being added to the extreme ultraviolet (EUV) phase-shifting point diffraction interferometer (PS/PDI) implemented at the Advanced Light Source at Lawrence Berkeley National Laboratory. This Sub-field Exposure Station (SES) will enable the earliest possible imaging characterization of the upcoming Engineering Test Stand (ETS) Set-2 projection optics. Relevant printing studies with the ETS projection optics require illumination partial coherence with {sigma} of approximately 0.7. This {sigma} value is very different from the coherent illumination requirements of the EUV PS/PDI and the coherence properties naturally provided by synchrotron undulator beamline illumination. Adding printing capabilities to the PS/PDI experimental system thus necessitates the development of an alternative illumination system capable of destroying the inherent coherence of the beamline. The SES is being implemented with two independent illuminators: the first is based on a novel EUV diffuser currently under development and the second is based on a scanning mirror design. Here we describe the design and implementation of the new SES, including a discussion of the illuminators and the fabrication of the EUV diffuser.
Date: March 1, 2001
Creator: Naulleau, Patrick; Goldberg, Kenneth A.; Anderson, Erik H.; Batson, Phillip; Denham, Paul; Jackson, Keith et al.
Partner: UNT Libraries Government Documents Department

Experimental analysis of high-resolution soft x-ray microscopy

Description: The soft x-ray, full-field microscope XM-1 at Lawrence Berkeley National Laboratory's (LBNL) Advanced Light Source has already demonstrated its capability to resolve 25-nm features. This was accomplished using a micro zone plate (MZP) with an outer zone width of 25 nm. Limited by the aspect ratio of the resist used in the fabrication, the gold-plating thickness of that zone plate is around 40 nm. However, some applications, in particular, biological imaging, prefer improved efficiency, which can be achieved by high-aspect-ratio zone plates. We accomplish this by using a bilayer-resist process in the zone plate fabrication. As our first attempt, a 40-nm-outer-zone-width MZP with a nickel-plating thickness of 150 nm (aspect ratio of 4:1) was successfully fabricated. Relative to the 25-nm MZP, this zone plate is ten times more efficient. Using this high-efficiency MZP, a line test pattern with half period of 30 nm is resolved by the microscope at photon energy of 500 eV. Furthermore, with a new multilayer mirror, the XM-1 can now perform imaging up to 1.8 keV. An image of a line test pattern with half period of 40 nm has a measured modulation of 90%. The image was taken at 1.77 keV with the high-efficiency MZP with an outer zone width of 35 nm and a nickel-plating thickness of 180 nm (aspect ratio of 5:1). XM-1 provides a gateway to high-resolution imaging at high energy. To measure frequency response of the XM-1, a partially annealed gold ''island'' pattern was chosen as a test object. After comparison with the SEM image of the pattern, the microscope has the measured cutoff of 19 nm, close to the theoretical one of 17 nm. The normalized frequency response, which is the ratio of the power density of the soft x-ray image to that of the SEM image, is shown in ...
Date: September 6, 2001
Creator: Chao, Weilun; Anderson, Erik H.; Denbeaux, Gregory; Harteneck, Bruce; Pearson, Angelic L.; Olynick, Deirdre et al.
Partner: UNT Libraries Government Documents Department

Design, fabrication, and characterization of high-efficiency extreme ultraviolet diffusers

Description: As the development of extreme ultraviolet (EUV) lithography progresses, interest grows in the extension of traditional optical components to the EUV regime. The strong absorption of EUV by most materials and its extremely short wavelength, however, makes it very difficult to implement many components that are commonplace in the longer wavelength regimes. One such example is the diffuser often implemented with ordinary ground glass in the visible light regime. Here we demonstrate the fabrication of reflective EUV diffusers with high efficiency within a controllable bandwidth. Using these techniques we have fabricated diffusers with efficiencies exceeding 10% within a moderate angular single-sided bandwidth of approximately 0.06 radians.
Date: February 19, 2004
Creator: Naulleau, Patrick P.; Liddle, J. Alexander; Salmassi, Farhad; Anderson, Erik H. & Gullikson, Eric M.
Partner: UNT Libraries Government Documents Department

Calibration of the modulation transfer function of surface profilometers with binary pseudo-random test standards: expanding the application range

Description: A modulation transfer function (MTF) calibration method based on binary pseudo-random (BPR) gratings and arrays [Proc. SPIE 7077-7 (2007), Opt. Eng. 47, 073602 (2008)] has been proven to be an effective MTF calibration method for a number of interferometric microscopes and a scatterometer [Nucl. Instr. and Meth. A616, 172 (2010)]. Here we report on a further expansion of the application range of the method. We describe the MTF calibration of a 6 inch phase shifting Fizeau interferometer. Beyond providing a direct measurement of the interferometer's MTF, tests with a BPR array surface have revealed an asymmetry in the instrument's data processing algorithm that fundamentally limits its bandwidth. Moreover, the tests have illustrated the effects of the instrument's detrending and filtering procedures on power spectral density measurements. The details of the development of a BPR test sample suitable for calibration of scanning and transmission electron microscopes are also presented. Such a test sample is realized as a multilayer structure with the layer thicknesses of two materials corresponding to BPR sequence. The investigations confirm the universal character of the method that makes it applicable to a large variety of metrology instrumentation with spatial wavelength bandwidths from a few nanometers to hundreds of millimeters.
Date: March 14, 2011
Creator: Yashchuk, Valeriy V.; Anderson, Erik H.; Barber, Samuel K.; Bouet, Nathalie; Cambie, Rossana; Conley, Raymond et al.
Partner: UNT Libraries Government Documents Department

Magnetic soft x-ray microscopy-imaging fast spin dynamics inmagnetic nanostructures

Description: Magnetic soft X-ray microscopy combines 15nm spatial resolution with 70ps time resolution and elemental sensitivity. Fresnel zone plates are used as X-ray optics and X-ray magnetic circular dichroism serves as magnetic contrast mechanism. Thus scientifically interesting and technologically relevant low dimensional nanomagnetic systems can be imaged at fundamental length and ultrafast time scales in a unique way. Studies include magnetization reversal in magnetic multilayers, nanopatterned systems, vortex dynamics in nanoelements and spin current induced phenomena.
Date: June 1, 2007
Creator: Fischer, Peter; Kim, Dong-Hyun; Mesler, Brooke L.; Chao, Weilun; Sakdinawat, Anne E. & Anderson, Erik H.
Partner: UNT Libraries Government Documents Department

Performance of actinic EUVL mask imaging using a zoneplatemicroscope

Description: The SEMATECH Berkeley Actinic Inspection Tool (AIT) is a dual-mode, scanning and imaging extreme-ultraviolet (EUV) microscope designed for pre-commercial EUV mask research. Dramatic improvements in image quality have been made by the replacement of several critical optical elements, and the introduction of scanning illumination to improve uniformity and contrast. We report high quality actinic EUV mask imaging with resolutions as low as 100-nm half-pitch, (20-nm, 5x wafer equivalent size), and an assessment of the imaging performance based on several metrics. Modulation transfer function (MTF) measurements show high contrast imaging for features sizes close to the diffraction-limit. An investigation of the illumination coherence shows that AIT imaging is much more coherent than previously anticipated, with {sigma} below 0.2. Flare measurements with several line-widths show a flare contribution on the order of 2-3% relative intensity in dark regions above the 1.3% absorber reflectivity on the test mask used for these experiments. Astigmatism coupled with focal plane tilt are the dominant aberrations we have observed. The AIT routinely records 250-350 high-quality images in numerous through-focus series per 8-hour shift. Typical exposure times range from 0.5 seconds during alignment, to approximately 20 seconds for high-resolution images.
Date: August 20, 2007
Creator: Goldberg, Kenneth A.; Naulleau, Patrick P.; Barty, Anton; Rekawa,Senajith B.; Kemp, Charles D.; Gunion, Robert F. et al.
Partner: UNT Libraries Government Documents Department

Characterization of electron microscopes with binary pseudo-random multilayer test samples

Description: Verification of the reliability of metrology data from high quality x-ray optics requires that adequate methods for test and calibration of the instruments be developed. For such verification for optical surface profilometers in the spatial frequency domain, a modulation transfer function (MTF) calibration method based on binary pseudo-random (BPR) gratings and arrays has been suggested [Proc. SPIE 7077-7 (2007), Opt. Eng. 47(7), 073602-1-5 (2008)} and proven to be an effective calibration method for a number of interferometric microscopes, a phase shifting Fizeau interferometer, and a scatterometer [Nucl. Instr. and Meth. A 616, 172-82 (2010)]. Here we describe the details of development of binary pseudo-random multilayer (BPRML) test samples suitable for characterization of scanning (SEM) and transmission (TEM) electron microscopes. We discuss the results of TEM measurements with the BPRML test samples fabricated from a WiSi2/Si multilayer coating with pseudo randomly distributed layers. In particular, we demonstrate that significant information about the metrological reliability of the TEM measurements can be extracted even when the fundamental frequency of the BPRML sample is smaller than the Nyquist frequency of the measurements. The measurements demonstrate a number of problems related to the interpretation of the SEM and TEM data. Note that similar BPRML test samples can be used to characterize x-ray microscopes. Corresponding work with x-ray microscopes is in progress.
Date: September 17, 2010
Creator: Yashchuk, Valeriy V; Conley, Raymond; Anderson, Erik H; Barber, Samuel K; Bouet, Nathalie; McKinney, Wayne R et al.
Partner: UNT Libraries Government Documents Department

Calibration of the modulation transfer function of surface profilometers with binary pseudo-random test standards: Expanding the application range

Description: A modulation transfer function (MTF) calibration method based on binary pseudo-random (BPR) gratings and arrays [Proc. SPIE 7077-7 (2007), Opt. Eng. 47(7), 073602-1-5 (2008)] has been proven to be an effective MTF calibration method for a number of interferometric microscopes and a scatterometer [Nucl. Instr. and Meth. A 616, 172-82 (2010]. Here we report on a significant expansion of the application range of the method. We describe the MTF calibration of a 6 inch phase shifting Fizeau interferometer. Beyond providing a direct measurement of the interferometer's MTF, tests with a BPR array surface have revealed an asymmetry in the instrument's data processing algorithm that fundamentally limits its bandwidth. Moreover, the tests have illustrated the effects of the instrument's detrending and filtering procedures on power spectral density measurements. The details of the development of a BPR test sample suitable for calibration of scanning and transmission electron microscopes are also presented. Such a test sample is realized as a multilayer structure with the layer thicknesses of two materials corresponding to BPR sequence. The investigations confirm the universal character of the method that makes it applicable to a large variety of metrology instrumentation with spatial wavelength bandwidths from a few nanometers to hundreds of millimeters.
Date: July 26, 2010
Creator: Yashchuk, Valeriy V; Anderson, Erik H.; Barber, Samuel K.; Bouet, Nathalie; Cambie, Rossana; Conley, Raymond et al.
Partner: UNT Libraries Government Documents Department

Characterization of electron microscopes with binary pseudo-random multilayer test samples

Description: We discuss the results of SEM and TEM measurements with the BPRML test samples fabricated from a BPRML (WSi2/Si with fundamental layer thickness of 3 nm) with a Dual Beam FIB (focused ion beam)/SEM technique. In particular, we demonstrate that significant information about the metrological reliability of the TEM measurements can be extracted even when the fundamental frequency of the BPRML sample is smaller than the Nyquist frequency of the measurements. The measurements demonstrate a number of problems related to the interpretation of the SEM and TEM data. Note that similar BPRML test samples can be used to characterize x-ray microscopes. Corresponding work with x-ray microscopes is in progress.
Date: July 9, 2010
Creator: Yashchuk, Valeriy V; Conley, Raymond; Anderson, Erik H.; Barber, Samuel K.; Bouet, Nathalie; McKinney, Wayne R. et al.
Partner: UNT Libraries Government Documents Department