Proceedings Volume 8466

Instrumentation, Metrology, and Standards for Nanomanufacturing, Optics, and Semiconductors VI

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Proceedings Volume 8466

Instrumentation, Metrology, and Standards for Nanomanufacturing, Optics, and Semiconductors VI

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Volume Details

Date Published: 19 October 2012
Contents: 7 Sessions, 22 Papers, 0 Presentations
Conference: SPIE NanoScience + Engineering 2012
Volume Number: 8466

Table of Contents

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Table of Contents

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  • Front Matter: Volume 8466
  • Nanomanufacturing Metrology I
  • Novel Instruments and Improvements I
  • Metrology and Standards
  • Novel Instruments and Improvements II
  • Characterization: Macro, Micro, and Nano I
  • Characterization: Macro, Micro, and Nano II
Front Matter: Volume 8466
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Front Matter: Volume 8466
This PDF file contains the front matter associated with SPIE Proceedings Volume XXXX, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.
Nanomanufacturing Metrology I
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High-rate, roll-to-roll nanomanufacturing of flexible systems
Khershed P. Cooper, Ralph F. Wachter
Since the National Nanotechnology Initiative was first announced in 2000, nanotechnology has developed an impressive catalog of nano-scale structures with building-blocks such as nanoparticles, nanotubes, nanorods, nanopillars, and quantum dots. Similarly, there are accompanying materials processes such as, atomic layer deposition, pulsed layer deposition, nanoprinting, nanoimprinting, transfer printing, nanolithography and nanopatterning. One of the challenges of nanomanufacturing is scaling up these processes reliably and affordably. Roll-to-roll manufacturing is a means for scaling up, for increasing throughput. It is high-speed production using a continuous, moving platform such as a web or a flexible substrate. The adoption of roll-to-roll to nanomanufacturing is novel. The goal is to build structures and devices with nano-scale features and specific functionality. The substrate could be a polymer, metal foil, silk, cloth or paper. The materials to build the structures and multi-level devices could be organic, inorganic or biological. Processing could be solution-based, e.g., ink-jet printing, or vacuum-based, e.g., chemical vapor deposition. Products could be electronics, optoelectronics, membranes, catalysts, microfluidics, lab-on-film, filters, etc. By this means, processing of large and conformal areas is achievable. High-throughput translates into low cost, which is the attraction of roll-to-roll nanomanufacturing. There are technical challenges requiring fundamental scientific advances in materials and process development and in manufacturing and system-integration where achieving nano-scale feature size, resolution and accuracy at high speeds can be major hurdles. We will give an overview of roll-to-roll nanomanufacturing with emphasis on the need to understand the material, process and system complexities, the need for instrumentation, measurement, and process control and describe the concept of cyber-enabled nanomanufacturing for reliable and predictable production.
Metrology and instrumentation challenges with high-rate, roll-to-roll manufacturing of flexible electronic systems
Harish Subbaraman, Xiaohui Lin, Xiaochuan Xu, et al.
In this paper, we discuss the metrology and instrumentation challenges that need to be overcome in order to realize true implementation of roll-to-roll manufacturing of flexible electronic systems. Several metrology and instrumentation challenges involved such as availability of particulate-free high quality substrate, development and implementation of high-speed in-line and off-line inspection and diagnostic tools with adaptive control for patterned and unpatterned material films, development of reliable hardware, etc need to be addressed and overcome in order to realize a successful manufacturing process. Due to extreme resolution requirements compared to print media, the burden of software and hardware tools on the throughput also needs to be carefully determined. Moreover, the effect of web wander and variations in web speed need to accurately be determined in the design of the system hardware and software. Realization of successful metrology and instrumentation by overcoming the challenges for the development of a roll-to-roll manufacturing system for flexible electronic systems opens limitless possibilities for the deployment of high performance flexible electronic components in a variety of applications including communication, sensing, medicine, agriculture, energy, lighting etc.
Metrology challenges for high-rate nanomanufacturing of polymer structures
Joey Mead, Carol Barry, Ahmed Busnaina, et al.
The transfer of nanoscience accomplishments into commercial products is hindered by the lack of understanding of barriers to nanoscale manufacturing. We have developed a number of nanomanufacturing processes that leverage available high-rate plastics fabrication technologies. These processes include directed assembly of a variety of nanoelements, such as nanoparticles and nanotubes, which are then transferred onto a polymer substrate for the fabrication of conformal/flexible electronic materials, among other applications. These assembly processes utilize both electric fields and/or chemical functionalization. Conducting polymers and carbon nanotubes have been successfully transferred to a polymer substrate in times less than 5 minutes, which is commercially relevant and can be utilized in a continuous (reel to reel/roll to roll) process. Other processes include continuous high volume mixing of nanoelements (CNTs, etc) into polymers, multi-layer extrusion and 3D injection molding of polymer structures. These nanomanufacturing processes can be used for wide range of applications, including EMI shielding, flexible electronics, structural materials, and novel sensors (specifically for chem/bio detection). Current techniques to characterize the quality and efficacy of the processes are quite slow. Moreover, the instrumentation and metrology needs for these manufacturing processes are varied and challenging. Novel, rapid, in-line metrology to enable the commercialization of these processes is critically needed. This talk will explore the necessary measurement needs for polymer based nanomanufacturing processes for both step and continuous (reel to reel/roll to roll) processes.
Performances and limitations of Lab-to-Fab strategies for inline optical metrology
E. Nolot, A. André, A. Michallet
Critical to the realization of robust nanomanufacturing is the development of appropriate metrology protocols. In the Lab-to-Fab approach, the key properties of materials and stacks of interest are accurately probed with at-line and off-line characterization tools. These Lab-deduced properties propagate to Fab tools which allow for fast non-destructive measurements on product wafers. For instance, the combination of at-line X-ray reflectometry (XRR) and variable-angle spectroscopic ellipsometry (VASE) allows for determination of highly reliable optical constants that can be implemented on inline spectroscopic ellipsometers and reflectometers so as to achieve automated measurements on product wafers. We will first comment on the need for combined XRR-VASE Lab-to-Fab strategies. Secondly, we will point out some limitations of the Lab to Fab strategies. Even though Lab and Fab analysis are performed on the same sample, the material properties may vary due to oxidation, aging or contamination. Moreover, Lab-to-Fab approach must be implemented carefully since parameters such as thickness and roughness of surface and interfacial layers are not probed identically by X-ray based and optically-based techniques. Lastly, among a set of optically-based tools, the various capabilities relating to instrumental function, spectral range and ability to collect reliable depolarisation and anisotropyrelated data may impact the accuracy of Lab-to-Fab strategy.
In-line control and characterization of nanomaterials synthesis from hyperspectral polarimetric light scattering: an experimental method
Romain Ceolato, Nicolas Riviere, Beatrice Biscans
Control and characterization of nanomaterial synthesis have been a great challenge for years. Onera, The French Aerospace Lab, has developed a fast, in-line and comprehensive characterization method based on the combination of hyperspectral, polarized and angular measurements. In this paper, physical and optical properties are measured to control and characterize nanomaterials synthesis. Based on achieved results, in-line techniques are presented to retrieve physical properties of materials such as aggregates of calcium carbonate precipitates. Original applications will be discussed in various fields as chemical or atmospheric (eg. aerosol characterization) science.
Defect inspection strategies for 14 nm semiconductor technology
Ralf Buengener
This article presents strategies to overcome the defect inspection challenges expected at the 14 nm technology node: Smaller feature and defect sizes will require very sensitive inspections. At the same time the inspection recipes must be stable against inevitable process variation and potentially high defect density going along with new manufacturing methods for nonplanar transistors (FINFETs). The focus is on existing inspection methods and tools such as brightfield and darkfield optical inspection, e-beam inspection and scanning electron microscopy imaging. Examples from 20 nm technology are shown that can be applied to the next node, including: - Choice of the right type of inspection, based on defect type, - complementary inspections at the same step, each being optimized for certain defect types, - smart use of inspection tool features to extend the usefulness of optical inspection, - use of alternative inspections such as e-beam or advanced process inspection, based on technology maturity, - detection of small systematic defects and random defects, - understanding and overcoming the limitations of inspected area vs. sensitivity and throughput, - monitoring inspection recipe performance.
Novel Instruments and Improvements I
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Object-depending artifacts in confocal measurements
F. Mauch, W. Lyda, M. Gronle, et al.
Confocal sensors are well established in optical surface metrology. Especially when measuring rough surfaces, their robustness is widely appreciated. However, it was shown lately that certain object features can produce severe artifacts in confocal measurements that are hard to identify as false measurements. Experimental evidence of these artifacts is given with a measurement of a suitable surface conducted with a chromatic confocal point sensor. Furthermore various simulations are presented that identify a self-imaging property of the surface features as the root of the artifacts. These simulations also pave the way to a more precise yet still intuitive signal model for confocal measurements.
Advances in metrology for the determination of Young's modulus for low-k dielectric thin films
Sean King, George A. Antonelli, Gheorghe Stan, et al.
As the semiconductor nano-electronics industry progresses toward incorporating increasingly lower dielectric constant materials as the inter layer dielectric (ILD) in Cu interconnect structures, thermo-mechanical reliability is becoming an increasing concern due to the inherent fragility of these materials. Therefore, the need for metrologies to assess the mechanical properties and elastic constants of low-k dielectric materials is great. Unfortunately, traditional techniques such as nano-indentation are being increasingly challenged as target low-k ILD thicknesses decrease below 100 nm for sub 16 nm technologies. In this light, we demonstrate the applicability of two new techniques, Brillouin Light Scattering and Contact Resonance Atomic Force Microscopy, for the determination of Young’s modulus for low-k dielectric thin films. We show that these techniques yield values that are in agreement with standard nano-indentation measurements and are capable at film thickness on the order of 100 nm or less.
Blue irradiance intercomparison in the medical field
Antonio F. G. Ferreira Jr.
This work presents the results of a blue irradiance intercomparison among industrial laboratories of medical devices companies. This intercomparison aims to support the metrological issues of medical equipment manufactures regarding the blue irradiance infant phototherapy equipment requirements on the international standard IEC 60601-2-50:2000. The results showed a low agreement of participants’ measurements according to normalized error criterion. The major explanation for this result is associated to an incorrect equipment choice and long recalibration period.
Metrology and Standards
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New reference material for transmission electron microscope calibration
M. N. Filippov, V. P. Gavrilenko, M. V. Kovalchuk, et al.
We propose a new type of reference material as a magnification standard of transmission electron microscope and a scanning transmission electron microscope. The reference material represents a thin cross-section of a silicon relief structure with certified sizes of its elements. It is fabricated using ion milling. Such reference material can be used for high microscope magnifications (by direct observation of the lattice), as well as for moderate magnifications (around 30,000 times).
First steps towards a scatterometry reference standard
Supported by the European Commission and EURAMET, a consortium of 10 participants from national metrology institutes, universities and companies has recently started a joint research project with the aim of overcoming current challenges in optical scatterometry for traceable linewidth metrology and to establish scatterometry as a traceable and absolute metrological method for dimensional measurements. This requires a thorough investigation of the influence of all significant sample, tool and data analysis parameters, which affect the scatterometric measurement results. For this purpose and to improve the tool matching between scatterometers, CD-SEMs and CD-AFMs, experimental and modelling methods will be enhanced. The different scatterometry methods will be compared with each other and with specially adapted atomic force microscopy (AFM) and scanning electron microscopy (SEM) measurement systems. Additionally novel methods for sophisticated data analysis will be developed and investigated to reach significant reductions of the measurement uncertainties in critical dimension (CD) metrology. To transfer traceability to industrial applications of scatterometry an important step and one final goal of this project is the realisation of different waferbased reference standard materials for calibration of scatterometers. The approaches to reach these goals and first design considerations and preliminary specification of the scatterometry standards are presented and discussed.
Multiple-order imaging for optical critical dimension metrology using microscope characterization
Jing Qin, Hui Zhou, Bryan M. Barnes, et al.
There has been much recent work in developing advanced optical metrology applications that use imaging optics for optical critical dimension (OCD) measurements, defect detection, and for potential use with in-die metrology applications. We have previously reported quantitative measurements for sub-50 nm CD dense arrays which scatter only the 0th-order specular diffraction component using angle-resolved scatterfield microscopy. Through angle-resolved and focus-resolved imaging, we now measure OCD targets with three-dimensional scattered fields that contain multiple Fourier frequencies. Experimental sensitivity to nanometer scale linewidth changes is presented, supported by simulation studies. A new, more advanced approach to tool normalization is coupled with rigorous electromagnetic simulations and library based regression fitting that potentially enables OCD measurements with sub-nanometer uncertainties for targets that scatter multiple Fourier frequencies.
Novel Instruments and Improvements II
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Plasmonic-enhanced infrared photoexpansion nano-spectroscopy using tunable quantum cascade lasers
Mid-IR photoexpansion nano-spectroscopy measures spectra of samples on nanoscale by detecting local thermal expansion associated with light absorption using a standard atomic force microscope (AFM). Cantilever deflection is directly proportional to sample absorption. This method results in a simple experimental setup with no optical detectors. We have recently demonstrated that the sensitivity of photoexpansion nano-spectroscopy can be dramatically enhanced by moving the laser pulses repetition frequency in resonance with the mechanical frequency of the AFM cantilever. We were able to produce spectra from ~100 nm thin films using low energy (4 nJ) pulses from a tunable quantum cascade laser (QCL). The spatial resolution, which is determined by thermal diffusion length, has been demonstrated to be better than 50 nm. Sample heating is limited to ~10 mK. Here we present a novel approach to increase both the sensitivity and spatial resolution of photoexpansion nano-spectroscopy. We utilize the plasmonic local-intensity enhancement below a gold-coated AFM tip. We successfully produced high quality vibrational absorption spectra from samples as thin as 10 nm positioned on top of gold-coated silicon substrates. In addition to higher photoexpansion signal, our technique features higher spatial resolution, which is no longer limited by thermal diffusion length but is instead determined by the dimensions of the high-intensity field region below the metal tip, which can be 10 nm or smaller.
Active retroreflector to measure the rotational orientation in conjunction with a laser tracker
O. Hofherr, C. Wachten, C. Müller, et al.
High precision optical non-contact position measurement is a key technology in modern engineering. Laser trackers (LT) can determine accurately x-y-z coordinates of passive retroreflectors. Next-generation systems answer the additional need to measure an object’s rotational orientation (pitch, yaw, roll). These devices are based on photogrammetry or on enhanced retroreflectors. However, photogrammetry relies on camera systems and time-consuming image processing. Enhanced retroreflectors analyze the LT’s beam but are restricted in roll angle measurements. Here we present an integrated laser based method to evaluate all six degrees of freedom. An active retroreflector directly analyzes its orientation to the LT’s beam path by outcoupling laser light on detectors. A proof of concept prototype has been designed with a specified measuring range of 360° for roll angle measurements and ±15° for pitch and yaw angle respectively. The prototype’s optical design is inspired by a cat’s eye retroreflector. First results are promising and further improvements are under development. We anticipate our method to facilitate simple and cost-effective six degrees of freedom measurements. Furthermore, for industrial applications wide customizations are possible, e.g. adaptation of measuring range, optimization of accuracy, and further system miniaturization.
Imaging of short time microscopic scenes with strong light emission: revisited
Cornelius Hahlweg, Wenjing Zhao, Hendrik Vogeler, et al.
In last year’s session we presented some experimental results from investigations on microscopic scenes with strong light emission such as exploding wires, for which we used laser based shadow imaging methods. The present paper is understood as a continuation in two branches. First, we’d like to discuss the fourier optical properties of shadow imaging in comparison with the imaging of the object itself and its far field, showing that the shadowgraph is the link between imaging the real object and scatterometry. Second, we present investigations on gathering high dynamic range short images of short time processes using a completely different approach based on luminescent screens, delivering a decaying image of naturally high dynamic range, which - during decay time- might be converted to a series of single images under adapted conditions.
A large-scale ceramic package of the CMOS image sensor chip for remote sensing application
Chia-Hung Chang, Jer Ling, Shih-Hung Lo, et al.
A CMOS image sensor chip with the ceramic package technique for remote sensing application is presented in this paper. The chip is fabricated using the United Microelectronics Corporation (UMC) 0.18 um CMOS technology and occupies 25 mm x 120 mm of chip area, which is much larger than the conventional ones. Furthermore, a trade-off in sealing of the cover glass faces the gas leak and moisture sorption. The package of the CMOS image sensor chip in space may cause crack, leakage, and deformation. Consequently, a large-scale and specific package is required to meet remote sensing application. The proposed ceramic package comprises a ceramic substrate, a cover glass, a chip seal, a glass seal, and golden lines. The dimension with lead is approximately 155 mm x 60 mm x 7.87 mm, including 76 Pin Grid Array (PGA) at each side. To demonstrate the reliabilities, the sensor with large-scale ceramic package is also analyzed, manufactured, and tested by the thermal shock, vibration, and vacuum tests. Moreover, the Coordinate Measuring Machine (CMM) is employed to measure the common plane of the package. By testing 12 points on the top plane of the package, the measured relatively peak-to-peak variation can be lower than 10 um. A large-scale ceramic package of the CMOS image sensor chip is implemented in this work to achieve the specifications of the remote sensing application in space.
Characterization: Macro, Micro, and Nano I
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Graphene Raman imaging and spectroscopy processing: characterization of graphene growth
Matias G. Babenco, Li Tao, Deji Akinwande
Raman spectroscopy is a widely used metric to characterize the quality of graphene films prepared by exfoliation or synthesis. As research on graphene advances and graphene is grown over large scales, mapping of growth surface and analysis of Raman spectroscopy is necessary to promote metrology, quality quantification, fundamental research and advanced commercial applications. We present a novel data processing program for analysis of Raman spectroscopy, Graphene Raman Imaging and Spectroscopy Processing (GRISP). GRISP is capable of providing accurate statistical data on key features of the Raman spectrum of graphene over large areas, namely 2D, G and D peak intensity and intensity ratios between 2D to G (I2D/IG) and D to G (ID/IG) as well as Full Width at Half-Maximum of the 2D peak (FWHM2D). GRISP can also map processed data to form mapping images and histogram from which growth quality can be easily visualized and quantified. GRISP takes binary or text formatted raw data and can be directly accessed from nanoHUB platform, thus is universal and independent of the apparatus for Raman spectroscopy.
A portable modular optical sensor capable of measuring complex multi-axis strain fields
Weixin Zhao, B. Terry Beck, Robert J. Peterman, et al.
This paper presents a portable optical sensor capable of measuring complex multi-axis strain fields without the need for special surface preparation or stringent sensor-to-surface alignment. The sensor consists of three to four electronic speckle photography (ESP) modules. The design of each modular element is based on a previously developed 5-axis (five degree of freedom) surface displacement measurement technique, and is able to measure two dimensional in-plane surface movement, unaffected by other degrees of freedom (displacement and rotation) movement. Identical modular strain elements are arranged in a Rosette grid layout so that accurate and robust multi-axis surface strain measurement can be achieved. Experiments were conducted to demonstrate the multi-axis strain field measurement capability of this optical sensor by using a test bed that provided a known directional planar strain field, and excellent results were obtained. In particular, experiments have shown that the principle strain can be accurately extracted independent of the orientation of the device. This portable optical sensor will allow precise non-contact measurement of practical complex strain fields such as those encountered in bridge abutments, and portions of beams near critical infrastructure support locations; in other words, wherever plane strains depart from uni-axial behavior. Its unique hand-held portable capability offers distinct advantages over laboratory strain measurement setups, allowing accurate robust non-contact measurements to be achieved even in a harsh field application environment.
Characterization: Macro, Micro, and Nano II
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Non-destructive 3D characterization of microchannels
Ville Heikkinen, Anton Nolvi, Ivan Kassamakov, et al.
Microfluidic devices allow experimentation in smaller space using small amounts of liquid, resulting in improved reaction rates, cheaper equipment, reduced amount of expensive reagents. Very precise channel shape measurements are needed to assure the designed flow pattern. Several 3D imaging devices provide the necessary precision but typically they cannot image inside closed devices. Hence it is difficult to measure the shape of a microfluidic channel without destroying it. We fabricated and investigated samples with different microchannels. Several types of microfluidic channels were prepared in silicon wafer with a subsequent covering by bonding glass wafer on top. Microchannels in polymer have been done using epoxy-type photoresist SU-8. The internal geometry of the channels was measured using a Scanning White Light Interferometer (SWLI) equipped with optics that compensates for the effects of the top glass of the channels. The geometry of the interior of the channels can be measured with a precision similar to surface layer SWLI measurements without destroying the channels.
Optical testing for meter size aspheric optics
Several meter size steep aspheric optics, with aspheric departure ranging from 100μm to 2mm, have been successfully fabricated at the College of Optical Sciences at University of Arizona. Optical metrology systems have been developed for measuring the optical surfaces efficiently and accurately. These systems include laser tracker surface profiler, swing arm optical CMM with different type of sensors, slope measurements with SCOTS, the Software Configurable Optical Test System (SCOTS) and interferometry with computer generated holograms. We summarize the test methods and provide comparison of the relative strengths and weaknesses.
Comparison of refractive indices measured by m-lines and ellipsometry: application to polymer blend and ceramic thin films for gas sensors
Thomas Wood, Judikaël Le Rouzo, François Flory, et al.
Two optical techniques, “m-lines” and spectroscopic ellipsometry, are compared for their suitability for obtaining the wavelength and temperature dispersion of the refractive index of thin film layers used in gas detector devices. Two types of materials often integrated into gas sensors are studied: a polymer organic-inorganic blend deposited by spin-coating typically used in near infra-red waveguides and the ceramic semiconductor SrTi1-xFexO3 (strontium titanate) doped with iron at concentrations x = 0.075 and 0.1 deposited by electron beam deposition. In this paper, we will compare the refractive index dispersion obtained by m-lines and ellipsometry, and comment on the differences between the measured parameters for the two materials. The chromatic dispersion will be represented by a three term Cauchy law. An intuitive method of verifying the measured indices using an integrating sphere and reflexion coefficient modelling techniques will also be demonstrated. Thermo-optic coefficients of the order of -1×10-4/K for both materials are reported, and very low chromatic dispersions are also measured thanks to the high sensitivity of the m-lines technique.