This PDF file contains the front matter associated with SPIE Proceedings Volume 8105, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing.

Nanomanufacturing is the fabrication of materials and components with nanoscale features and resolution and their integration into useful engineered systems. Through the precise control of materials and processes at the nanoscale, new features, functional capabilities, and properties, controlled by physics at the nanoscale, may be realized. The challenges for nanomanufacturing are achieving the desired functionality, product quality, process repeatability, production scalability and cost affordability. The ONR Manufacturing Science Program is meeting these challenges though basic research in nano-scale direct digital manufacturing, massively parallel nanoscale processing, and high-throughput (e.g., roll-to-roll) nanofabrication that encourages system-level integration. These concepts along with research examples will be described.

Nanoparticles and products incorporating nanoparticles are a growing branch of nanotechnology industry. They have found a broad market, including the cosmetic, health care and energy sectors. Accurate and representative determination of particle size distributions in such products is critical at all stages of the product lifecycle, extending from quality control at point of manufacture to environmental fate at the point of disposal. Determination of particle size distributions is non-trivial, and is complicated by the fact that different techniques measure different quantities, leading to differences in the measured size distributions. In this study we use both mono- and multi-modal dispersions of nanoparticle reference materials to compare and contrast traditional and novel methods for particle size distribution determination. The methods investigated include ensemble techniques such as dynamic light scattering (DLS) and differential centrifugal sedimentation (DCS), as well as single particle techniques such as transmission electron microscopy (TEM) and microchannel resonator (ultra high-resolution mass sensor).

Contour metrology is one of the techniques used to verify optical proximity correction (OPC) in lithography models. These methods, known as resolution enhancement techniques (RET), are necessary to continue the decrease in integrated circuit feature sizes. Broadly speaking, RET are used to compensate for lithography errors to ensure better image transfer from the mask to the wafer and subsequence processing. Contours extracted from the printed features are used to verify the OPC models. Currently, the scanning electron microscope (SEM) is used to generate and verify the contours. The critical dimension atomic force microscope (CD-AFM), which is being used as a reference instrument in lithography metrology, has been proposed as a supplemental instrument for contour verification. This is mostly due to the relative insensitivity of the CD-AFM to material properties, the three-dimensional data, and the ability to make the instrument traceable to the SI unit of length. However, although the data from the CD-AFM is inherently three dimensional, the planar two-dimensional data required for contour metrology is not easily compared with the top-down AFM data. This is mostly due to the effect of the CDAFM tip and the scanning strategy. In this paper we outline some of the methods for acquiring contour data using the CD-AFM. Specifically, we look at different scanning strategies, tip types, contour extraction methods, and imaging modes. We compare contours extracted using our method to those acquired using the SEM.

In this paper, we explore the sensitivity of three-dimensional atomic force microscopy to incremental variation in the sidewall angle of near-vertical features. Measurement results are presented from a specially constructed wafer with continuous variation in sidewall slope across a range of angles just above and below vertical. This sample was scanned with a variety of both tip shapes and sizes using two different scan modes. From the results, we are able to derive cutoff limits for measuring near-vertical angles using aggressive scanning modes and the relative biases of different modes and tips in measuring a range of sidewall angles. This provides information about the measurement limitations of differing instrument configurations, each configuration consisting of a combination of tip and scan mode and sensitivity demarcated in terms of the ability to detect changes in the slope and relative accuracy of the measurement.

We report high-precision surface-profile metrology using a femtosecond pulse laser as a low-coherence interferometric light source. Unequal-path non-symmetric interferometer is configured to test a large-sized optics with a small reference mirror, which is only feasible through ultra-short mode-locked pulses with repeated periodic temporal coherence and high spatial coherence. The temporal delay between pulses from the reference and the target optics is precisely scanned by tuning the repetition rate of femtosecond pulses. This method enables us to perform high precision surface metrology without parasitic effects by stray reflections and remove all the moving parts in an interferometer.Ab

Scatterometric applications demand strategies for the selection from the various basic scatterometer principles as well as detailed design rules to fit the final optical instrument, the data processing and user interface into the requirements of the application in scope. In recent years we proposed methods based on the optical properties of various basic measurement structures to support the synthesis process for scatterometers, including the decision for the structure itself. In continuation of last years paper on design rules for catadioptric scatterometers the present paper is dedicated to the metrological verification of the proposed design methods for devices with elliptical mirrors in off-axis alignment. Further questions of data processing and analysis, especially the necessary coordinate transformations and calibration procedures will be discussed, practical examples included.

Sub diffraction limited infrared absorption imaging was applied to hemoglobin by coupling IR optics with an atomic force microscope. Comparisons between the AFM topography and IR absorption images of micron sized hemoglobin features are presented, along with nanoscale IR spectroscopic analysis of the metalloprotein.

A major part of future renewable energy will be generated in offshore wind farms. The used turbines of the 5 MW class and beyond, often feature a planetary gear with 1000 liters lubricating oil or even more. Monitoring the oil aging process provides early indication of necessary maintenance and oil change. Thus maintenance is no longer time-scheduled but becomes wear dependent providing ecological and economical benefits. This paper describes two approaches based on a linear variable filter (LVF) as dispersive element in a setup of a cost effective infrared miniature spectrometer for oil condition monitoring purposes. Spectra and design criteria of a static multi-element detector and a scanning single element detector system are compared and rated. Both LVF miniature spectrometers are appropriately designed for the suggested measurements but have certain restrictions. LVF multi-channel sensors combined with sophisticated multivariate data processing offer the possibility to use the sensor for a broad range of lubricants just by a software update of the calibration set. An all-purpose oil sensor may be obtained.

We proposed a novel pH measurement method based on two-photon fluorescence excitation of a dual-wavelength pHsensitive dye combined with scanning near-field optical microscopy (SNOM) that can be used to evaluate mitochondrial activity. Mitochondria produce ATP using a proton concentration (pH) gradient generated between both sides of their inner membrane. Thus, pH distribution around mitochondria can change with time when mitochondria produce ATP. This pH distribution has attracted interest because of its influence on necrotic cell death. Because ATP depletion causes necrotic cell death, measurement of pH distribution around mitochondria is expected to lead to clarification of the mechanism underlying necrotic cell death. However, it is very difficult to accurately measure pH around mitochondria using conventional pH measurement methods. In this study, a dual-wavelength pH-sensitive dye was excited locally using two-photon fluorescence excitation. In addition, collection-mode SNOM was used to avoid reabsorption by collecting the fluorescent light directly from a florescence point. Using this method, we successfully calibrated pH and observed temporal variations in pH after dropwise addition of acid. Moreover, mitochondrial activity was successfully observed based on these pH changes.

Scanning near-field optical microscopy (SNOM) aims at imaging nanostructured samples with sub-wavelength resolution. Tip-enhanced SNOM utilizes the strong local electromagnetic fields near a laser illuminated sharp metal tip to probe the near-field response of the sample. To achieve a clear image contrast, however, this near-field signal needs to exceed the background contribution resulting from simultaneous far-field excitation and far-field detection. For the resolution of tip-enhanced SNOM, the exact localization of the light emission plays a major role. In this work, the nearfield- to-far-field-ratio and the confinement of surface plasmon polaritons is improved for electrochemically etched conical gold tips by structuring them using multiple three-dimensional nanopatterning with a focused ion beam (FIB). For the first time, surface plasmon Bragg reflectors were fabricated all around the tip in a well-defined distance to the tip apex to mimic finite length antenna structures for which more efficient light confinement is expected. The design of the structures, the fabrication strategy, and the characterization of the resulting tips by scanning electron and optical microscopy is discussed. Photoluminescence spectra recorded before and after FIB modification indicate an increase of the light confinement of 60 %.

With semiconductor development processes hitting harder and harder on Moore's law to continuously scale down, high density advanced packaging technologies become a promising alternate route to improve transistor density. Chip integration IO/cm² density jumps quickly by orders from 2D packaging of 10² to wire bonded chip stack of 10³, to TSV of 104~105 and to advanced 3D integration of 10⁵ to 10⁶. Starting with wire bonding and now prevailing with TSV, more and more silicon layers are stacked up in 3D dimension to improve system density. A typical stacked wafer sample has two wafers glued together with patterned area sandwiched in between. Outer surfaces can be polished or unpolished bare silicon surface, or patterned surface.

In this paper a novel common-path laser encoder system for nanopositioning is proposed, that can effectively reduce the environmental disturbance at its lowest level. It has promising potential for nanometer resolution and large range applications. The experimental results of the proposed laser encoder match well with ones of HP5529A for large ranges. The tested results also show that it has the capability of nanometer scale measurement resolution.

Investigating volume scatterometry methods based on short range LIDAR devices for non-static objects we achieved interesting results aside the intended micro-LIDAR: the high speed camera recording of the illuminated scene of an exploding wire -intended for Doppler LIDAR tests - delivered a very effective method of observing details of objects with extremely strong light emission. As a side effect a schlieren movie is gathered without any special effort. The fact that microscopic features of short time processes with high emission and material flow might be imaged without endangering valuable equipment makes this technique at least as interesting as the intended one. So we decided to present our results - including latest video and photo material - instead of a more theoretical paper on our progress concerning the primary goal.

Cavity-enhanced ellipsometry, using nanosecond pulsed lasers and without moving parts, is demonstrated to have submicrosecond time resolution. The ellipsometric phase angles are measured from the Fourier transform of the cavity ring-down experimental signals, with a sensitivity 0.01 degrees. The technique is applied to highly reflective surfaces, including total internal reflection, where the samples are placed within the evanescent wave. The technique can be generalized to broadband sources, such as from supercontinuum generation, allowing spectral resolution of thin films and monolayer samples.

Reflectometry, a simple whole-field curvature measurement system using a novel computer aided phase shift reflection grating method has been improved to certain extend. The similar system was developed from our earlier works on Computer Aided Moiré Methods and Novel Techniques in Reflection Moiré, Experimental Mechanics (1994) in which novel structured light approach was shown for surface slope and curvature measurement. This method uses similar technology but coupled with a novel phase shift system to accurately measure surface profile, slope and curvature. In our previous paper, "Stress Measurement of thin wafer using Reflection Grating Method", the surface curvature and residual stresses were evaluated using the versatility of the proposed system.. The curvature of wafers due to the deposition of backside metallization was evaluated and compared with a commercially stress measurement system from KLA-Tencor. In this paper, some aspects of the work are extended. Our proposed system is calibrated using a reference flat mirror and spherical mirror certified by Zygo Corporation. The mirrors together with the camera calibration toolbox allow the system to acquire measurement accuracy that is demanded by semiconductor industry. Finally, the results obtained from Reflectometry are compared and contrast with results from KLA Tencor System.

In modern field of microelectronics and MEMS, wafer bonding has emerged as an important processing step in wide range of manufacturing applications. During the manufacturing process, even in the modern clean room, small defects result from trapped particles and gas bubbles exist at bonded interface. Defects and trapped particles may exist on the top and bottom of the wafers, or at the interface of bonded wafer pair. These inclusions will generate high stress around debond region at the wafers bonded interface. In this paper, inspection at the bonded interface will be the interest of investigation. Since silicon wafer is opaque to visible light, defect detection at the bonded interface of silicon wafer is not possible. Due to the fact that silicon wafer is transparent to wavelength greater than 1150nm, an Near Infrared Polariscope which has showed some promises on residual stress measurement on silicon devices has been adapted and developed. This method is based on the well known photoelastic principles, where the stress variations are measured based on the changes of light propagation velocity in birefringence material. The results are compared and contrast with conventional Infrared Transmission Imaging tool (IRT) which is widely used to inspect the bonded silicon wafer. In this research, the trapped particles that are not visible via conventional infrared transmission method are identified via the generated residual stress pattern. The magnitude of the residual stress fields associated with each defect is examined qualitatively and quantitatively. The stress field generated at the wafers bonded interface will looks like a 'butterfly' pattern. Wafer pairs Pyrex-Si and Si-Si bonded interface will be examined.