This PDF file contains the front matter associated with SPIE Proceedings Volume 7767, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing.

One of the important challenges in nanoscale manufacturing is the construction of simultaneously patterned three dimensional structures, materials and devices. Since we live in a three dimensional world, such capabilities are needed to fully realize the capabilities of nanotechnology. We describe self-assembly processes based on utilizing intrinsic stress and inducing grain coalescence (extrinsic stress) in thin metal films that can be used to curve or fold lithographically patterned two dimensional (2D) panels into 3D structures. We discuss the use of intrinsic chromium (Cr) stresses and extrinsic stresses based on induced grain coalescence in tin (Sn) based structures with varying material composition to create a variety of lithographically patterned curved and polyhedral structures.

Optical digital-imaging techniques offer a fast, high-resolution, and wide-range metrology capability for measuring semi-transparent and transparent polymer-based devices during manufacture. This work presents novel instrumentation for in-process statistical control and metrology capable of measuring a complete macroscale part (~25 mm) down to its microscale features (~50 μm). The high speed 2.5D profilometer has generated contour plots with 0.4 μm lateral and 1 μm vertical resolution. The instrument has an estimated data rate of 8 million 3D data points per second, approximately 270 times faster than conventional white light interferometry.

We describe a method of detecting nanometer-level gap and tip/tilt alignment between a focusing zone plate mask and a silicon substrate using interferometric-spatial-phase-imaging (ISPI). The zone plate mask is used to generate submicrometer focused light spot to induce silicon nanowire growth in a CVD process. ISPI makes use of diffracting fringes from gratings and checkerboards fabricated on the mask to determine the correct gapping distance for the focusing zone plates. The method is capable of detecting alignment inside a gas-flow chamber with variable pressure.

The wear of atomic force microscope (AFM) tips is a critical issue in the performance of probe-based metrology and nanomanufacturing processes. In this work, diamond-like carbon (DLC) was coated on Si AFM tips using a plasma ion implantation and deposition process. The mechanical integrity of these DLC-coated tips was compared to that of uncoated silicon tips through systematic nanoscale wear testing over scan distances up to 0.5 meters. The wear tests consisted of a combination of contact-mode AFM scanning, transmission electron microscopy, and pull-off force measurements. Power spectral density analysis of AFM measurements acquired on structured samples was used to evaluate the imaging performance of the tips. The results show that Si tips are prone to catastrophic failure in self-mated contacts under typical scanning conditions. In contrast, DLC-coated tips demonstrate little to no measurable wear under adhesive forces alone, and exhibit stress-dependent gradual wear under external loads of ~22 and 43 nN.

Metrology and control of critical dimensions (CD) are the keys to the nanotechnology success. Modern nanotechnology and nanometrology are largely based on knowledge earned during the last 10-20 years of semiconductor technology development. Semiconductor CD metrology entered the nanotechnology age in the late 1990's. Work on 130 nm and 90 nm node technologies led to the conclusion that precision is an insufficient metric for metrology quality assessment. Other components of measurement uncertainty (MU) must be considered: (i) sample-to-sample measurement bias variation, (ii) sampling uncertainty and (iii) sample variation induced by probe-sample interaction. The first one (sample dependent systematic error) is common for "indirect" and model-based CD metrologies such as top-down and cross-sectional scanning electron microscopy (SEM) and optical scatterometry (OCD). Unless special measures are taken, bias variation of CDSEM and OCD could exceed several nanometers. Variation of bias and, therefore, MU can be assessed only if reference metrology (RM) is employed. The choice of RM tools is very limited. The CD atomic force microscope (AFM) is one of a few available RM tools. The CDAFM provides sub-nanometer MU for a number of nanometrology applications. Significant challenges of CDAFM remain: (a) probe finite dimensions are limiting characterization of narrow high-aspect spaces; (b) probe flexibility complicates positioning control; (c) probe apex sharpness limits 3D AFM resolution; (d) lifetime of atomically sharp probes is too short; (e) adsorbates change properties and dimensions of nanometer-sized objects considerably, etc. We believe that solutions for the problems exist. In this paper we discuss role of RM in nanometrology, current RM choices, challenges of CDAFM, and potential solutions.

NIST has introduced a new standard for dimensional metrology and the calibration of the scanning electron microscope (SEM) scale identifi ed as Reference Material (RM) 8820. RM 8820 was primarily intended to be used for calibrating the X and Y scale (or magnifi cation) in SEMs but, can be used for an many other purposes. Essentially, all laboratory microscopes can be calibrated to this same artifact. The NIST pattern is only one part of a very large array of test structures that were designed for various dimensional metrology purposes useful to semiconductor production technologies. These and other purposes, discussed in the presentation, RM 8820 can also be used on/in any other type of microscope, such as optical and scanning probe microscopes and for scatterometry measurements.

This paper presents an evaluation of e-beam assisted deposition and welding of conductive carbon nanotube (c-CNT) tips for electrical scanning probe microscope measurements. Variations in CNT tip conductivity and contact resistance during fabrication were determined as a function of tip geometry using tunneling AFM (TUNA). Conductive CNT tips were used to measure 2D dopant concentration as a function of annealing conditions in BF₂-implanted samples.

A simple method for measuring a step-height sample is presented with the heterodyne central fringe identification technique and a precision translation stage. This method can accurately point out the zero optical path difference position such that the optical path lengths of two arms of the interferometer are absolutely equivalent. Thus, the two surfaces of the step-height sample can be identified sequentially with the translation stage. The displacement of the translation stage is equal to the step-height of the test sample. The feasibility of the technique is demonstrated. The measurable range is not limited by the coherence length of the light source. The measurement accuracy depends on the uncertainties of the heterodyne central fringe identification method and the translation stage. In our setup, we have a 100 mm measurable range and a 4 nm uncertainty. The wavelength stability of the light source has a minor effect on the measurement.

Digital holographic microscopy (DHM) is utilized for quantitative phase contrast microscopy in optical testing of reflective or transparent specimens and allows altering the focus numerically by propagating the complex wave. Especially for compensation of deformations or displacements and for long-term investigations of living cells, a reliable region selective numerical readjustment of the focus is of particular interest in digital holographic microscopy. Since this method is time consuming, a Halton point set with low discrepancy has been chosen. By this, the effective axial resolution can be enhanced numerically by post processing of complex wave fronts without narrowing the field of view leading to a loss of information around the focus plane by blurring. The concept of numerical parametric lenses is another key feature in DHM and used to correct aberrations in the reconstructed wave front caused by the setup. To reduce the number of parameters for parametric lenses, the polynomial basis by Forbes is applied for the needs of DHM. Both numerical approaches have been characterized and adapted to the requirements of DHM. The applicability is demonstrated by results of investigations of engineered surfaces and biological cells.

Linear variable filter (LVF) spectrometers represent an interesting group of low cost spectral monitoring systems for procedural or condition monitoring systems. Such highly integrated, miniaturized spectral devices are promising components for the design of rugged, portable and shock resistant monitoring systems. Among others, detection of chemical substances and their corresponding concentrations in fluids is possible by analyzing the characteristic absorption bands. Using this spectral device for lubricant condition monitoring a certain quality of spectra is essential for revealing the change of their properties over lifetime. The focus of this work is to evaluate the useability of a low cost chip-size wavelength interrogator having a 256 elements pyroelectric detector array combined with a linear variable filter. Therefore, simulations were performed to specify the maximum resolution and to compare it to real world measurement data in the petrochemical domain. The influence of a different number of detector elements per array (e.g. 64 / 128) on the maximum spectral resolution is calculated and compared to measured data. An ideal system design is presented and the limits of such interrogators with respect to infrared spectral monitoring are indicated.

The spectral responsivity of detectors is commonly measured through the comparison with a reference detector and an optical system that provides monochromatic radiation. Such systems are designed to provide narrow bandwidth monochromatic radiation whose optical flux is generally low. These levels of optical flux are not enough to excite photopic instruments whose spectral response has to be measured. In this work we propose an optical arrangement with enough optical flux to realize such measurements. The system consists of a color temperature calibrated lamp which is the reference. The monochromatic separation is realized with a transmittance grating. The spectral distribution at the plane of the instrument is calculated, it is practically the same that the lamp except for the level of irradiance. The spectral response measured is corrected by the bandwidth of the system. Experimental results are presented and the noise-to-signal level reached in the system is discussed.

We present a new optical technique using complete Mueller polarimetry in the back focal plane of a microscope objective to characterize the overlay defects in microelectronics industry. Exploiting the fundamental symmetries in the physics of periodic structures and polarized light and the redundancies in the angle-resolved images we prove that it is possible to measure overlay by this fast and non-destructive technique. The simulations of the one-dimensional structures have shown that the values of a chosen criterion exploiting the off-diagonal coefficients symmetries are proportional to the values of overlay defects and can reach 0.25 for a 25nm defect. The accuracy of the polarimeter used for this application becomes even more critical because it is directly linked to the overlay measurement. Beside the redundancies in the acquired data, the angular resolution allows us also to decouple the information along X and Y directions in the Fourier space. Due to this the overlay defect can be characterized and decomposed with respect to these two axes. We show that the proposed new technique is sensitive to both magnitude and sign of the shift. Thus, Mueller polarimetry in the Fourier space (MPFS) offers more parameters for the process quality control compared with conventional spectroscopic ellipsometry (SE). It means that MPFS should be more efficient than SE for the overlay characterization in microelectronic industry.

3D metrology systems are used to examine and qualify micro- and nano-manufacturing techniques and further for reverse engineering of micro- and nanostructures. For this purpose the generation of capable and reliable 3D-coordinates in large numbers is essential. Combining classical triangulation with a new technique of calibrating measurement labels results in high rates of reliable 3D metrology data. The triangulation setup consists of a stereomicroscope mounted on a 5-axis-gantry to generate all necessary points of view. Measurement labels are projected through one stereomicroscopeport and their positions are localized through the second port. Providing the calibration rule is determined, the measurement system assigns each localized position to an absolute coordinate. For registration purposes measurement labels are projected on a semitransparent mirror. Localizing measurement labels simultaneously with an observation and a calibration camera in connection with the working distance, defines the calibration rule. By modifying the working distance between calibration camera and stereomicroscope, the measurement volume is scanned. The grid of the calibration camera chip acts as a measurement standard for the measurement labels. This approach features the spatial registration of a huge amount of measurement labels covering the measurement volume in short time without building up the optical model of the imaging.

The in-situ measurements for continuously rolling optical films by the chromatic confocal apparatus have been successfully achieved by the authors. The apparatus presented here consists of chromatic confocal to avoid the vibrations caused by the roller machine while working. Without the need of the vertical z axis scan, chromatic confocal can give instant thickness measurements. Therefore, the apparatus possesses the characters of high resolution and fast response. We believe that this system can highly monitor and improve the yield rate in production lines.

Efficient and dependable characterization methods of magnetic-plasmonic nanostructures are essential towards the implementation of new nanoscale materials in magneto-optical applications. Surface magneto-optic Kerr effect (SMOKE) is a powerful characterization technique, because of its simplicity and high sensitive to even monolayer thick magnetic materials. It relies on the measurement of polarization and absorption changes of reflected light in the presence of a magnetic field. While SMOKE has been applied in the past to investigate the magnetic information of continuous films, there is little work on applying it to characterize arrays of nanoparticles with variable magnetic and optical properties. Here, we have used it to investigate the magnetic behavior of nanoparticle arrays made by nanosecond pulsed laser self-organization. This technique produces an array of single-domain magnetic nanoparticles with size-dependent magnetic orientation. Nanoparticle arrays of Co and Ni were prepared on SiO₂ substrates. SMOKE measurements were performed for a variety of different particle sizes and material. Systematic differences in saturation and coercivity were observed for the different samples. These results demonstrated that SMOKE is a reliable technique to rapidly characterize the magnetic behavior of nanoparticle arrays.

Pyrometer calibration is a common task in most radiometry labs. When measurements are made in a wide range of temperatures, it is necessary to use different blackbody radiators to cover the whole interval. A problem that arises with this is the lack of concordance in the signals measured by the pyrometer when taken from different radiators. In a recent publication, Fourier theory is applied to measure the temperature of inhomogeneous objects, particularly periodic objects¹. Those results are used to measure the temperature of the coil filament of a reference lamp (in a range from 300 K to 3300 K, approximately), considering the filament as a periodic object, which is modeled with a simple functions arrangement. Measurement verification is also presented by comparing our calculations to the experimental data of the lamp's temperature.

Comparison goniometer, precision autocollimator, can be used to measure parallelism or angular error. If the size of the work piece to be measured is larger than the aperture of the objective lens, the measurement can not be carried through, because a part of work piece can't be observed. A new technique, called overlapping measurement technique, is proposed. The work piece will be moved, and two adjacent measurements must have an intercross. The relationship between the readings of the autocollimator and the angular error has been deduced. A program written in VC++6.0 will be used to process the measurement data.

We have achieved a simple and precise frequency stabilization technique for commercially available 1mW, 850nm vertical cavity surface emitting laser (VCSEL) based on optical heterodyne beat frequency control by introducing two sets of frequency stabilized VCSEL's with Fabry-Perot resonator (FPR) as frequency discriminator. The stabilized VCSEL's were quite similarly fabricated with each other, in which the electrical negative feedback was supplied for stabilization. We have also detected optical heterodyne beat between these two VCSEL's by adjusting the locking frequency of each VCSEL. Thus, we have further reduced the frequency fluctuations from these stabilized VCSEL's by controlling their feedback current so that the variation in the optical beat frequency should be minimized. As a result, we have successfully suppressed the amount of optical beat frequency fluctuations within 2MHz at measuring time of 1 sec. That is, the attained Allan variance is within the order of 10^-9. In this work, we have achieved simple and inexpensive and precise frequency stabilization for 850nm VCSEL by optical heterodyne beat frequency control, which is quite applicable to nanomanufacturing.

Dimensional measurements of microstructures with uncertainties below 50nm require both nanopositioning and nanomeasuring machines (NPMMs) as well as appropriate microprobes. This paper introduces a novel 3-D tactile microprobe system developed at the Ilmenau University of Technology, Institute of Process Measurement and Sensor Technology, and contains an analysis of its metrological characteristics. This microprobe system uses a silicon membrane to induce the measurement force and to operate as the damping system for the stylus. This damping is entirely brought about by internal friction. An optical detection system measures the deflection of the membrane and thus of the stylus. The optical detection system uses a single laser beam, focused on the backside of the silicon membrane. The reflected beam is split, with one part being used to measure the tilt about the x- and y-axes and the other part being fed back into an interferometer for deflection measurement in the z-direction. Thus, the deflection of the membrane can be measured with sub-nanometre resolution. An NPMM was used to analyse the metrological characteristics of the microprobe system and to calibrate it. This paper focuses on a detailed analysis of the three-dimensional reproducibility for point measurements by obtaining and evaluating a directional response pattern. This pattern is then compared to the behaviour of other microprobe systems. Furthermore, the work shows that the microprobe system can be applied successfully to scanning measurements and satisfactory results obtained. These results indicate that the microprobe system is well-suited for universal measurement tasks in dimensional metrology.

Digital holographic microscopy (DHM) is utilized for quantitative phase contrast microscopy in optical testing of reflective or transparent specimens and allows altering the focus numerically by propagating the complex wave. Especially for compensation of deformations or displacements and for long-term investigations of living cells, a reliable region selective numerical readjustment of the focus is of particular interest in digital holographic microscopy. Since this method is time consuming, a Halton point set with low discrepancy has been chosen. By this, the effective axial resolution can be enhanced numerically by post processing of complex wave fronts without narrowing the field of view leading to a loss of information around the focus plane by blurring. The concept of numerical parametric lenses is another key feature in DHM and used to correct aberrations in the reconstructed wave front caused by the setup. To reduce the number of parameters for parametric lenses, the polynomial basis by Forbes is applied for the needs of DHM. Both numerical approaches have been characterized and adapted to the requirements of DHM. The applicability is demonstrated by results of investigations of engineered surfaces and biological cells.