This PDF file contains the front matter associated with SPIE Proceedings Volume 7042, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and the Conference Committee listing.

Nanometrology provides the means to measure and characterize nanometer scale process and product performance and covers an expanse of topics including instrumentation, measurement methods (off-line and in-process applications), and standards. To meet the needs of the emerging integrated manufacturing community it is important that research on scale-up of nanotechnology for high-rate production, reliability, robustness, yield, efficiency and cost issues for manufactured products and services be pursued. To achieve this, new research directions must include a systems approach that encompasses the characterization of instrumentation, three dimensional metrology, and production-hardened metrology. To illustrate the value of metrology and the role of standards to facilitate product realization, a number of National Nanotechnology Initiative (NNI) sponsored workshops have been organized. This paper provides an overview of some key findings and recommendations identified at two nanomanufacturing workshops held in 2004 and 2006 that were focused on metrology, instrumentation, and standards.

The high speed low capacitance probe presented here is a flexible / tailorable tool for internal node testing on Radio Frequency Integrated Circuits (RFIC). The probe utilizes the mutual capacitive coupling between two wires. In this case, a tungsten whisker and the inner conductor of a coaxial cable forms a capacitor, enabling extremely low probing (loading) capacitance. The mutual capacitance which can be modeled to the first order as a lumped element capacitor provides differentiating action. Viewing the derivative of the output signal, rise time and can be observed directly. Through the use of probe calibration and Fourier transforms the probed signal can be re-created. Probe calibration develops a transfer function enabling re-creation of time domain signals.

This paper presents a micromachined silicon membrane type AFM tip designed to move nearly 1µm by electrostatic force. Since the tip can be vibrated in small amplitude with AC voltage input and can be displaced up to 1μm by DC voltage input, an additional piezo actuator is not required for scanning of submicron features. The micromachined membrane tips are designed to have 100 kHz ~ 1 MHz resonant frequency. Displacement of the membrane tip is measured by an optical interferometer using a micromachined diffraction grating on a quartz wafer which is positioned behind the membrane tip.

Many precision measurement techniques (e.g. scanning probe microscopy, optical tweezers) are limited by sample drift. This is particularly true at room temperature in air or in liquid. Previously, we developed a general solution for sample control in three dimensions (3D) by first measuring the position of the sample and then using this position in a feedback loop to move a piezo-electric stage accordingly (Carter et al., Optics Express, 2007). In that work, feedback was performed using a software-based data acquisition program with limited bandwidth (≤ 100 Hz). By implementing feedback through a field programmable gate array (FPGA), we achieved real-time, deterministic control and increased the feedback rate to 500 Hz - half the resonance frequency of the piezo-electric stage in the feedback loop. This better control led to a three-fold improvement in lateral stability to 10 pm (Δf = 0.01-10 Hz). Furthermore, we exploited the rapid signal processing of FPGA to achieve fast stepping rates coupled with highly accurate and orthogonal scanning.

In this paper we discuss a self-calibration technique for a dual-actuated, single-axis nanopositioner and extend ideas from this method to develop a calibration technique for a two-axis system. The proposed methods exploit concepts of measurement transitivity and redundancy that are will established in self-calibration theory. The developed method has been applied to a dual-actuated single-axis nanopositioner equipped with capacitive displacement sensors with a calibration error in the sub-nanometer range. For the two-axis system, the technique uses a right angle prism as an artifact to calibrate two orthogonal axes. Transitivity between the axes is obtained through the use of a redundant or 'dummy' uncalibrated sensor that maintains the hypotenuse of the right angle prism invariant during sets of measurements. Because, the approach relies on the accuracy of the prism, it cannot be considered to be a self-calibration technique. Nevertheless, experiments indicate that it calibrates a two-axis stage to within 1 nm of the prism.

Nanoscale apertures, especially high transmission nanoantennas, have been shown to have great potential for nanolithography as well as near-field measurements. This paper describes a method for mapping the near-field distribution as a function of distance from the aperture surface. The measurements are performed using a home-built near-field optical microscopy (NSOM) with home-made aperture probes. The force distance curve is used to determine the tip-sample distance. The calibrated NSOM system is then used to correlate the collected near-field optical distribution data with the distance from the surface. The in-plane optical images are obtained at a constant height by turning off the vertical position feedback. The experiment results show that this is a potential method to obtain three dimensional optical measurements of nano structures.

Comparison is made for parameters and properties of test objects based on the relief structures with right-angled and trapezoidal profiles, which are used for calibration of scanning electron microscopes (SEMs) and atomic force microscopes (AFMs). Methods of calibration of SEMs and AFMs with help of this test objects are presented. Comparative analysis has shown that trapezoidal structures with large angles of sidewall inclination, created by anisotropic etching of silicon with the (100) orientation of its surface, possess the most universal characteristics. Such structures could be used for development of internationally recognized measures of length in the nanometer range for calibration of SEMs and AFMs.

A method for objective monitoring of the quality of fabrication of test objects with a trapezoidal profile and large angles of inclination of the sidewalls is proposed. The test objects are created by anisotropic etching of silicon. The method is based on the correlation analysis of the results of experiments performed with scanning electron microscopes (SEMs) and atomic force microscopes (AFMs). In the course of such analysis, coefficients of correlation between the test points on the SEM or AFM signals are calculated. These points correspond to the coordinates of the upper and lower bases of trapezoidal protrusions of a test object structure. The closeness of the correlation coefficients to unity is indication of high quality of the created test object.

Due to greater emphasis on precision than accuracy, many of the measurements made in semiconductor fabrication facilities are not traceable to the SI (Systeme International d'Unites or International System of Units) unit of length. However as the feature sizes of integrated circuits decrease and the use of lithography models becomes more prevalent, the need for accuracy cannot be overemphasized. In response, the National Institute of Standards and Technology (NIST) in conjunction with SEMATECH has developed a reference measurement system (RMS) that can be used to provide accurate measurements for inline metrology tools. The RMS is a critical dimension atomic force microscope (CD-AFM) with traceability to the SI meter. In this paper we present a set of strategies for achieving accuracy for different types of measurands within an RMS and examine several important factors when selecting reference instruments. We also present results of a recent evaluation of linewidth and height using two CD-AFMs and a calibrated AFM with displacement interferometry in all three axes. We further look at the stability of tips such as carbon nanotubes.

The extraction of nanoscale dimensions and feature geometry of grating targets using signature-based optical techniques is an area of continued interest in semiconductor manufacturing. In the current work, we have performed angle-resolved scatterometry measurements on grating targets of 180 nm pitch fabricated by electron beam lithography and anisotropic wet etching of (110)-oriented silicon. The use of oriented silicon results in grating lines with nominally vertical sidewalls, with linewidths estimated by scanning electron microscopy (SEM) to be in the sub-50 nm range. The targets were designed to be suitable for both optical scatterometry and small-angle x-ray scattering (SAXS) measurement. As a consequence of the lattice-plane selective etch used for fabrication, the target trenches do not have a flat bottom, but rather have a wide vee shape. We demonstrate extraction of linewidth, line height, and trench profile using scatterometry, with an emphasis on modeling the trench angle, which is well decoupled from other grating parameters in the scatterometry model and is driven by the crystalline orientation of the Si lattice planes. Issues such as the cross-correlation of grating height and linewidth in the scatterometry model, the limits of resolution for angle-resolved scatterometry at the wavelength used in this study (532 nm), and prospects for improving the height and linewidth resolution obtained from scatterometry of the targets, are discussed.

Results of investigations in the field of measurements of geometrical characteristics of the electron beam of a scanning electron microscope (SEM) are presented. Methods for determining the electron beam diameter are developed and tested on various microscopes. Besides, methods for obtaining the dependence of the electron beam diameter on the beam current, the energy of the primary electrons, and the focusing of the beam are also developed. Finally, method for determining the electron density distribution in the electron beam is proposed.

Biomass surrounds us from the smallest alga to the largest redwood tree. Even the largest trees owe their strength to a newly-appreciated class of nanomaterials known as cellulose nanocrystals (CNC). Cellulose, the world's most abundant natural, renewable, biodegradable polymer, occurs as whisker like microfibrils that are biosynthesized and deposited in plant material in a continuous fashion. Therefore, the basic raw materials for a future of new nanomaterials breakthroughs already abound in the environment and are available to be utilized in an array of future materials once the manufacturing processes and nanometrology are fully developed. This presentation will discuss some of the instrumentation, metrology and standards issues associated with nanomanufacturing of cellulose nanocrystals. The use of lignocellulosic fibers derived from sustainable, annually renewable resources as a reinforcing phase in polymeric matrix composites provides positive environmental benefits with respect to ultimate disposability and raw material use. Today we lack the essential metrology infrastructure that would enable the manufacture of nanotechnology-based products based on CNCs (or other new nanomaterial) to significantly impact the U.S. economy. The basic processes common to manufacturing - qualification of raw materials, continuous synthesis methods, process monitoring and control, in-line and off-line characterization of product for quality control purposes, validation by standard reference materials - are not generally in place for nanotechnology based products, and thus are barriers to innovation. One advantage presented by the study of CNCs is that, unlike other nanomaterials, at least, cellulose nanocrystal manufacturing is already a sustainable and viable bulk process. Literally tons of cellulose nanocrystals can be generated each day, producing other viable byproducts such as glucose (for alternative fuel) and gypsum (for buildings).There is an immediate need for the development of the basic manufacturing metrology infrastructure to implement fundamental best practices for manufacturing and in the determination of properties for these for nanoscale materials and the resultant products.

In this study, the effect of the annealing treatment on electrochemical behaviour and the oxide barrier-film thickness of anodized aluminium-magnesium (Al-Mg) alloy was investigated. Electrochemical parameters such as the polarization resistance (R_P), solution resistance (R_Sol), alternating current impedance (Z), and the double layer capacitance (C_dL) of the anodized Al-Mg alloy were determined in sulphuric acid solutions ranged from 0-10% H₂SO₄ by electrochemical impedance spectroscopy (EIS) methods. Then, the oxide film thickness of the anodized Al-Mg alloy was measured from the obtained electrochemical parameters as a function of the sulphuric acid concentration (0-10% H₂SO₄), in the as received sample and annealed sample conditions. The optimum thickness of the oxide film was detected for the as received samples (4.2nm) and for the annealed samples (0.63nm) in sulphuric acid concentrations of 4% and 2% H₂SO₄, respectively. The reason behind the oxide film thickness of the as received samples is greater than the one for the annealed samples, because the former samples are thermodynamically unstable (more chemically active) as compared to the annealed samples.

We present the results of preliminary investigations determining the sensitivity and applicability of a novel x-ray diffraction based nanoscale imaging technique, including simulations and experiments. The ultimate aim of this nascent technique is non-destructive, bulk-material characterization on the nanometer scale, involving three dimensional image reconstructions of embedded nanoparticles and in situ sample characterization. The approach is insensitive to x-ray coherence, making it applicable to synchrotron and laboratory hard x-ray sources, opening the possibility of unprecedented nanometer resolution with the latter. The technique is being developed with a focus on analyzing a technologically important light metal alloy, Al-xCu (where x is 2.0-5.0 %wt). The mono- and polycrystalline samples contain crystallographically oriented, weakly diffracting Al₂Cu nanoprecipitates in a sparse, spatially random dispersion within the Al matrix. By employing a triple-axis diffractometer in the non-dispersive setup we collected two-dimensional reciprocal space maps of synchrotron x-rays diffracted from the Al₂Cu nanoparticles. The intensity profiles of the diffraction peaks confirmed the sensitivity of the technique to the presence and orientation of the nanoparticles. This is a fundamental step towards in situ observation of such extremely sparse, weakly diffracting nanoprecipitates embedded in light metal alloys at early stages of their growth.

This paper (SPIE Paper 70420G) has been retracted by the author and removed from the SPIE Digital Library on 20 October 2009. The original paper was published without the knowledge or consent of other collaborators, for which the author apologizes. As stated in the SPIE Guidelines for Professional Conduct and Publishing Ethics, "SPIE considers it the professional responsibility of all authors to ensure that the authorship of submitted papers properly reflects the contributions and consent of all authors." A serious violation of these Guidelines has occurred, necessitating that the paper be expunged from the conference proceedings.

A novel approach to x-ray diffraction data analysis for non-destructive determination of the shape of nanoscale particles and clusters in three-dimensions is illustrated with representative examples of composite nanostructures. The technique is insensitive to the x-rays coherence, which allows 3D reconstruction of a modal image without tomographic synthesis and in-situ analysis of large (over a several cubic millimeters) volume of material with a spatial resolution of few nanometers, rendering the approach suitable for laboratory facilities.

In this article, we report a technique that can measure the size of silica nanoparticles in a microfluidic Y-Cell. In this technique, silica nanoparticle dispersion and a buffer solution are pumped through a micro-fabricated microfluidic Y-Cell, in which these two solutions form laminar flows and nanoparticles diffuse into the buffer due to the concentration gradient. The diffusion of nanoparticles into buffer causes a refractive index gradient across the boundary between nanoparticle dispersion and buffer. The refractive index gradients at different positions of the boundary can be measured by optical method and this information is used to calculate the nanoparticle diffusion coefficient, which is then used to calculate the nanoparticle size. We have demonstrated this technique with 5nm and 20nm silica nanoparticles. This technique is relatively fast and easy to implement, and proves to be an ideal candidate for inline process monitoring applications where fast and qualitative measurement is desired.