This PDF file contains the front matter associated with SPIE Proceedings Volume 9173, including the Title Page, Copyright information, Table of Contents, Invited Panel Discussion, and Conference Committee listing.

The development of the metrology and standards for advanced manufacturing of cellulosic nanomaterials (or basically, wood-based nanotechnology) is imperative to the success of this rising economic sector. Wood-based nanotechnology is a revolutionary technology that will create new jobs and strengthen America’s forest-based economy through industrial development and expansion. It allows this, previously perceived, low-tech industry to leap-frog directly into high-tech products and processes and thus improves its current economic slump. Recent global investments in nanotechnology programs have led to a deeper appreciation of the high performance nature of cellulose nanomaterials. Cellulose, manufactured to the smallest possible-size (~2 nm x ~100 nm), is a high-value material that enables products to be lighter and stronger; have less embodied energy; utilize no catalysts in the manufacturing, are biologically compatible and, come from a readily renewable resource. In addition to the potential for a dramatic impact on the national economy - estimated to be as much as $250 billion worldwide by 2020 - cellulose-based nanotechnology creates a pathway for expanded and new markets utilizing these renewable materials. The installed capacity associated with the US pulp and paper industry represents an opportunity, with investment, to rapidly move to large scale production of nano-based materials. However, effective imaging, characterization and fundamental measurement science for process control and characterization are lacking at the present time. This talk will discuss some of these needed measurements and potential solutions.

Traceable dimensional measurements of step-height and lateral standards, patterned surfaces, and particles at the nanoscale need of calibrated instruments such as the metrological AFMs. These instruments have onboard capacitive sensors or interferometers to control the relative tip-sample movements. Interferometers provide a direct traceability to the unit of length, at the cost of more complex set-ups. A new interferometer set-up has been developed to monitor tip-sample z-displacements of the instrument in use at INRIM. The interferometer is made of a compact and symmetric arrangement of the optics to fit available room and minimize the metrology loop. Preliminary results are reported together with the analysis of the main error sources of z-displacement measurements.

In atomic force microscopy (AFM) metrology, the scanning tip is a major source of uncertainty. Images taken with an AFM show an apparent broadening of feature dimensions due to the finite size of the tip. An AFM image is a combination of the feature shape, the tip geometry and details of the tip-sample interaction. Here we describe the use of a new multi-feature characterizer for CD-AFM tip, and report initial measurement results. The results are compared with those obtained from the current tip characterizer.

Many advanced manufacturing processes employ scanning electron microscopes (SEM) for on-line critical measurements for process and quality control. This is the third of a series of papers discussing various causes of measurement uncertainty in scanned particle beam instruments, and some of the solutions researched and developed at NIST. Scanned particle beam instruments especially the scanning electron microscope have gone through tremendous evolution to become indispensable tools for many and diverse scientifi c and industrial applications. These improvements have signifi cantly enhanced their performance and made them far easier to operate. But, ease of operation has also fostered operator complacency. In addition, the user-friendliness has reduced the need for extensive operator training. Unfortunately, this has led to the concept that the SEM is just another expensive digital camera or another peripheral device connected to a computer and that all of the issues related to obtaining quality data have been solved. Hence, a person (or company) using these instruments may be lulled into thinking that all of the potential pitfalls have been fully eliminated and they believe everything they see on the micrograph is always correct. But, as described in this and the earlier presentations this may not be the case. The fi rst paper in this series discussed some of the issues related to signal generation in the SEM, including instrument calibration, electron beam-sample interactions and the need for physics-based modelling to understand the actual image formation mechanisms to properly interpret SEM images. The second paper, discussed another major issue confronting the microscopist: specimen contamination and methods of contamination elimination. This third paper, discusses vibration and drift and some useful solutions.

Atom Probe Tomography (APT) is a near-atomic-scale analytical technique which, due to recent advances in instrumentation and sample preparation techniques, is being used on a variety of 3D applications. Total system detection efficiency is a key parameter for obtaining accurate spatial reconstruction of atomic coordinates from detected ions, but experimental determination of efficiency can be difficult. This work explores new ways to measure total system detection efficiency as well as the specimen characteristics necessary for such measurements. Composite specimens composed of a nickel/chromium multilayer core, National Institute of Standards and Technology Standard Reference Material 2135c, encapsulated with silver, silicon, or nickel were used to demonstrate the suitability of this approach for providing a direct measurement of APT efficiency. Efficiency measurements based on this multilayer encapsulated in nickel are reported.

Scanning Microwave Impedance Microscopy (sMIM), a new electrical measurement mode for AFM, has shown significant success in the imaging and characterization of electrical properties at 10's of nm length scales. We review the state of the art, including imaging studies revealing electrical characteristics of novel materials and nanostructures, such as composites, graphene, patterned optical crystals and ferro-electrics. The technique is suited for a variety of metrology applications where specific physical properties are determined quantitatively. Examples include the measurement of dielectric constant (permittivity) and conductivity. These capabilities will be presented, illustrating sensitivity and resolution for dielectric constant, doping levels and capacitance.

Surface profilers and optical interferometers produce 2D maps of surface and wavefront topography. Traditional standards and methods for characterizing the properties of these surfaces use coordinate space representations of the surface topography. The computing power available today in modest personal computers makes it easy to transform into frequency space and apply well-known signal processing techniques to analyze the data. The Power Spectral Density (PSD) function of the surface height distribution is a powerful tool to assess the quality and characteristics of the surface in question. In order to extract useful information about the spectral distribution of surface roughness or mid-spatial frequency error over a particular spatial frequency band, it is necessary to pre-process the data by first detrending the surface figure terms and then applying a window function before computing the PSD. This process eliminates discontinuities at the borders of the profile that would otherwise produce large amounts of spurious power that would mask the true nature of the surface texture. This procedure is now part of a new draft standard that is being adopted by the US OEOSC for analysis of the statistics of optical surface, OP1.005.¹ Illustrations of the usefulness of these procedures will be presented.

Air pockets (APK) occur randomly in Czochralski (Cz) grown silicon (Si) crystals and may become included in wafers after slicing and polishing. Previously the only APK of interest were those that intersected the front surface of the wafer and therefore directly impacted device yield. However mobile and other electronics have placed new demands on wafers to be internally APK-free for reasons of thermal management and packaging yield. We present a novel, recently patented, APK image processing technique and demonstrate the use of that technique, off-line, to improve quality control during wafer manufacturing.

In this work we demonstrate how absolute length measurements by interferometry, as used for regular gauge block calibration, can be applied to measure the dimensional drift behavior of connections joined by gluing or screwing and how these joining techniques are influenced by thermal treatment. While it is common to investigate the intrinsic stability of material samples by repeated length measurements, there exist growing demands in precision engineering to characterize the stability of assemblies, i.e. of joined material pieces. In order to enable investigation of joining techniques representative joints were fabricated by a number of methods as wringing, screwing and gluing. By using gauge block shaped samples as joining parts parallelism and flatness could be achieved which is needed for interferometric length measurements. The stability of the joints has been investigated longitudinally and laterally to the connection interface, and also mutual tilting of the parts was detected by analysis of the phase topographies. With the use of sample joints, the behavior of connection elements used in ultrahigh-precision instruments can now be examined on an accuracy level of about one nanometer. Results of approximately one year of observation show that screwed joints do not exhibit a significant change of length or orientation. They also did not show response to temperature variations of ±10°C, which is different for adhesive joints where dimensional changes of up to 100 nm were observed.

We present a brief overview of using the effective refractive index of colloidal suspensions for characterizing nanoparticles. We focus our analysis on the so-called nanofluids consisting of nanoparticles suspended in a homogenous liquid matrix. Particular attention is paid to the role of the real part of the effective refractive index on sizing the nanoparticles. We then discuss possible ways to measure the real part of the effective refractive index of nanofluids and precautions needed.

Monitoring the presence of nanomaterials in waste water from semiconductor facilities is a critical task for public health organizations. Advanced semiconductor technology allows the fabrication of sensitive piezoelectric-based mass sensors with a detection limit of less than 1.35 ng/cm² of nanomaterials such as nanoparticles of alumina, amorphous silica, ceria, etc. The interactions between acoustic waves generated by the piezoelectric sensor and nanomaterial mass attached to its surface define the sensing response as a shift in the resonant frequency. In this article the development and characterization of a prototype AlN film bulk acoustic resonator (FBAR) are presented. DC reactive magnetron sputtering was used to create tilted c-axis oriented AlN films to generate shear waves which don’t propagate in liquids thus minimizing the acoustic losses. The high acoustic velocity of AlN over quartz allows an increase in resonance frequency in comparison with a quartz crystal microbalance (QCM) and results in a higher frequency shift per mass change, and thus greater sensitivity. The membrane and electrodes were fabricated using state of the art semiconductor technology. The device surface functionalization was performed to demonstrate selectivity towards a specific nanomaterial. As a result, the devices were covered with a “docking” layer that allows the nanomaterials to be selectively attached to the surface. This was achieved using covalent modification of the surface, specifically targeting ZnO nanoparticles. Our functionalization approach was tested using two different types of nanoparticles, and binding specificity was confirmed with various analytical techniques.

Diffractive optical elements offer a great way to control light beyond the capabilities of traditional refractive components. Because of the very small feature sizes, the characterization of diffractive optical elements is challenging. Using current invasive methods, such as scanning electron microscope (SEM) or atomic force microscope (AFM), the measurements are slow and potentially destructive to the element. Employing optical scatterometery, the measurements are not only fast and non-destructive but also integrable to inline control of the fabrication and replication processes. In this work we use scatterometer to determine the dimensional parameters of binary diffractive optical elements and compare the results with the parameters obtained with AFM and SEM.