Prof. Roger H. French Profile

Prof. Roger H. French

Kyocera Professor at Case Western Reserve Univ

SPIE Involvement:

Author

Publications (42)

Proceedings Article | 18 September 2018 Presentation

Degradation analysis of polyamide-based backsheets in field photovoltaic modules under different climatic conditions (Conference Presentation)

Yadong Lyu, Andrew Fairbrother, Jae Hyun Kim, Xiaohong Gu, Michael Kempe, Liang Ji, Kent Whitfield, Kenneth Boyce, Adam Hauser, Greg O’Brien, Scott Julien, Kai-Tak Wan, Yu Wang, Laura Bruckman, Roger French

Proceedings Volume 10759, 107590F (2018) https://doi.org/10.1117/12.2325843

KEYWORDS: Climatology, Climate change, Solar cells, Oceanography, Spectroscopy

Read Abstract +

Proceedings Article | 23 August 2017 Paper

Degradation of photovoltaic backsheet materials under multi-factor accelerated UV light exposures

Addison Klinke, Abdulkerim Gok, Silas Ifeanyi, Roger French, Laura Bruckman

Proceedings Volume 10370, 1037004 (2017) https://doi.org/10.1117/12.2274108

KEYWORDS: Solar cells, Ultraviolet radiation, Humidity, Statistical modeling, FT-IR spectroscopy, Absorbance, Infrared spectroscopy, Polymers, Analytics, Photovoltaics

Read Abstract +

Proceedings Article | 23 August 2017 Paper

Characterizing the weathering induced changes in optical performance and properties of poly(ethylene-terephthalate) via MaPd:RTS spectroscopy

Devin Gordon, Lin DeNoyer, Corey Meyer, Noah Sweet, David Burns, Laura Bruckman, Roger French

Proceedings Volume 10370, 1037005 (2017) https://doi.org/10.1117/12.2274113

KEYWORDS: Positron emission tomography, Ultraviolet radiation, Light scattering, Spectroscopy, Solar cells, UV optics, Reflection, Refraction, Optical properties, Air contamination

Read Abstract +

Proceedings Article | 23 August 2017 Paper

Model development of degradation of PV modules backsheet with locating place of module

Yu Wang, Andrew Fairbrother, Sebastien Merzlic, Scott Julien, Lucas Fridman, Camille Loyer, Amy Lefebvre, Gregory O'Brien, Xiaohong Gu, Liang Ji, Kenneth Boyce, Michael Kempe, Kai-tak Wan, Roger French, Laura Bruckman

Proceedings Volume 10370, 103700L (2017) https://doi.org/10.1117/12.2274209

KEYWORDS: Solar cells, Climatology, FT-IR spectroscopy, Photovoltaics, Humidity, Positron emission tomography, Spectroscopy

Read Abstract +

Proceedings Article | 23 August 2017 Paper

Degradation analysis of field-exposed photovoltaic modules with non-fluoropolymer-based backsheets

Andrew Fairbrother, Scott Julien, Kai-Tak Wan, Liang Ji, Kenneth Boyce, Sebastien Merzlic, Amy Lefebvre, Greg O'Brien, Yu Wang, Laura Bruckman, Roger French, Michael Kempe, Xiaohong Gu

Proceedings Volume 10370, 1037003 (2017) https://doi.org/10.1117/12.2272488

KEYWORDS: Photovoltaics, Solar cells, Polymers, Reliability, Optical inspection, Colorimetry, Raman spectroscopy, Infrared spectroscopy

Read Abstract +

The selection of polymeric materials utilized in photovoltaic (PV) modules has changed relatively little since the inception of the PV industry, with ethylene-vinyl acetate (EVA), polyethylene terephthalate (PET), and fluoropolymer-based laminates being the most widely adopted primary components of the encapsulant and backsheet materials. The backsheet must serve to electrically insulate the solar cells and protect them from the effects of weathering. Due to continued downward pressure on cost, other polymeric materials are being formulated to withstand outdoor exposure for use in backsheets to replace either the PET film, the fluoropoymer film, or both. Because of their relatively recent deployment, less is known about their reliability and if they are durable enough to fulfill the ≥25 year warranties of current PV modules. This work presents a degradation analysis of field-exposed modules with polyamide- and polyester-based backsheets. Modules were exposed for up to five years in different geographic locations: USA (Maryland, Ohio), China, and Italy. Surface and cross-sectional analysis included visual inspection, colorimetry, glossimetry, and Fourier-transform infrared spectroscopy. Each module experienced different types of degradation depending on the exposure site, even for the same material and module brand. For instance, the polyamide-based backsheet experienced hairline cracking and greater yellowing and chemical changes in China (Changsu, humid subtropical climate), while in Italy (Rome, hot-summer Mediterranean climate) it underwent macroscopic cracking and greater losses in gloss. Spectroscopic studies have permitted identification of degradation products and changes in polymer structure over time. Comparisons are made to fielded modules with fluoropolymer-based backsheets, as well as backsheet materials in accelerated laboratory exposures. Implications for qualification testing and service life prediction of the non-fluoropolymer-based backsheets are discussed.

Proceedings Article | 2 November 2016 Presentation

Cross-correlation of backsheet degradation between real-world exposed modules and accelerated exposures of backsheet materials (Conference Presentation)

Laura Bruckman, Roger French, Yu Wang, Michael Kempe, Amy Lefebvre, Xiaohong Gu, Liang Ji, Kai-Tak Wan, Christopher Flueckiger

Proceedings Volume 9938, 993805 (2016) https://doi.org/10.1117/12.2238162

KEYWORDS: Data modeling, Solar cells, Atmospheric modeling, Climatology, Performance modeling, Polymers, Meteorology, Data acquisition, Feature selection, Nondestructive evaluation

Read Abstract +

Proceedings Article | 26 September 2016 Presentation + Paper

Characterizing the weathering induced haze formation and gloss loss of poly(ethylene-terephthalate) via MaPd:RTS spectroscopy

Devin Gordon, Abdulkerim Gok, Corey Meyer, Cara Fagerholm, Noah Sweet, Lin DeNoyer, Laura Bruckman, Roger French

Proceedings Volume 9938, 99380I (2016) https://doi.org/10.1117/12.2238295

KEYWORDS: Positron emission tomography, Air contamination, Spectroscopy, Ultraviolet radiation, Optical properties, Scattering, Refraction, Data modeling, Light scattering, Statistical modeling

Read Abstract +

Proceedings Article | 23 September 2015 Paper

A data science approach to understanding photovoltaic module degradation

Nicholas Wheeler, Abdulkerim Gok, Timothy Peshek, Laura Bruckman, Nikhil Goel, Davis Zabiyaka, Cara Fagerholm, Thomas Dang, Christopher Alcantara, Mason Terry, Roger French

Proceedings Volume 9563, 95630L (2015) https://doi.org/10.1117/12.2209204

KEYWORDS: Solar cells, Confocal microscopy, Photovoltaics, Electroluminescence, Positron emission tomography, Raman spectroscopy, Microscopy, Data modeling, Diagnostics, Corrosion

Read Abstract +

Proceedings Article | 8 October 2014 Paper

Optical properties of PV backsheets: key indicators of module performance and durability

Thomas Felder, William Gambogi, James Kopchick, R. Scott Peacock, Katherine Stika, T. John Trout, Alexander Bradley, Babak Hamzavytehrany, Abdulkerim Gok, Roger French, Oakland Fu, Hongjie Hu

Proceedings Volume 9179, 91790P (2014) https://doi.org/10.1117/12.2062063

KEYWORDS: Optical properties, Solar cells, FT-IR spectroscopy, Ultraviolet radiation, Positron emission tomography, Spectroscopy, Chemical analysis, Photovoltaics, Polymers, Oxidation

Read Abstract +

Proceedings Article | 8 October 2014 Paper

Thermal performance of microinverters on dual-axis trackers

Mohammad Hossain, Timothy Peshek, Yifan Xu, Liang Ji, Jiayang Sun, Alexis Abramson, Roger French

Proceedings Volume 9179, 91790J (2014) https://doi.org/10.1117/12.2061235

KEYWORDS: Solar cells, Photovoltaics, Temperature metrology, Capacitors, Data analysis, Reliability, Statistical analysis, Data modeling, Field effect transistors, Thermal modeling

Read Abstract +

Proceedings Article | 24 September 2013 Paper

Photovoltaic lifetime and degradation science statistical pathway development: acrylic degradation

Laura Bruckman, Nicholas Wheeler, Ian Kidd, Jiayang Sun, Roger French

Proceedings Volume 8825, 88250D (2013) https://doi.org/10.1117/12.2024717

KEYWORDS: Photovoltaics, Analytics, Ultraviolet radiation, Absorption, Polymethylmethacrylate, Solar cells, Statistical analysis, Absorbance, Solar concentrators, Standards development

Read Abstract +

Proceedings Article | 24 September 2013 Paper

Degradation of transparent conductive oxides: mechanistic insights across configurations and exposures

Heather Lemire, Kelly Peterson, Samuel Sprawls, Kenneth Singer, Ina Martin, Roger French

Proceedings Volume 8825, 882502 (2013) https://doi.org/10.1117/12.2024691

KEYWORDS: Transparent conductors, Air contamination, Oxides, Photovoltaics, Solar energy, Sun, Solar cells, Tin, Humidity, Optical properties

Read Abstract +

Proceedings Article | 25 March 2013 Paper

GaN microdomes for broadband omnidirectional antireflection for concentrator photovoltaics

Lu Han, Matthew McGoogan, Tyler Piedimonte, Ian Kidd, Roger French, Hongping Zhao

Proceedings Volume 8620, 862016 (2013) https://doi.org/10.1117/12.2002864

KEYWORDS: Gallium nitride, Reflectivity, Silica, Reflection, Antireflective coatings, Polarization, Photovoltaics, Etching, Finite-difference time-domain method, Reactive ion etching

Read Abstract +

SPIE Journal Paper | 19 November 2012

Photodegradation in a stress and response framework: poly(methyl methacrylate) for solar mirrors and lens

Myles Murray, Laura Bruckman, Roger French

JPE, Vol. 2, Issue 1, 022004, (November 2012) https://doi.org/10.1117/12.10.1117/1.JPE.2.022004

KEYWORDS: Ultraviolet radiation, Polymethylmethacrylate, Photovoltaics, Absorbance, Solar energy, Solar radiation, Mirrors, Absorption, Lamps, Solar cells

Read Abstract +

Proceedings Article | 16 October 2012 Paper

Degradation of back surface acrylic mirrors for low concentration and mirror-augmented photovoltaics

Myles Murray, Laura Bruckman, Devin Gordon, Samuel Richardson, Greg Reinbolt, Mark Schuetz, Roger French

Proceedings Volume 8472, 847205 (2012) https://doi.org/10.1117/12.930102

KEYWORDS: Mirrors, Ultraviolet radiation, Photovoltaics, Scattering, Reflectivity, Humidity, Light scattering, Corrosion, Optical transfer functions, Aluminum

Read Abstract +

Proceedings Article | 19 September 2011 Paper

Design and performance of a low-cost acrylic reflector for a ~7x concentrating photovoltaic module

Kara Shell, Scott Brown, Mark Schuetz, Robert Davis, Roger French

Proceedings Volume 8108, 81080A (2011) https://doi.org/10.1117/12.897763

KEYWORDS: Compound parabolic concentrators, Mirrors, Prototyping, Reflectors, Ray tracing, Reflectivity, Aluminum, Receivers, Ultraviolet radiation, Silver

Read Abstract +

Proceedings Article | 13 September 2011 Paper

Solar radiation durability framework applied to acrylic solar mirrors

Myles Murray, Devin Gordon, Scott Brown, Wei-Chun Lin, Kara Shell, Mark Schuetz, Sean Fowler, Jim Elman, Roger French

Proceedings Volume 8112, 811203 (2011) https://doi.org/10.1117/12.893827

KEYWORDS: Mirrors, Ultraviolet radiation, Photovoltaics, Polymethylmethacrylate, Solar cells, Solar radiation, Absorbance, Polymers, Neodymium, Optical properties

Read Abstract +

SPIE Journal Paper | 1 July 2009

Fluid-photoresist interactions and imaging in high-index immersion lithography

Hoang Tran, Eric Hendrickx, Frieda Van Roey, Geert Vandenberghe, Roger French

JM3, Vol. 8, Issue 03, 033006, (July 2009) https://doi.org/10.1117/12.10.1117/1.3224950

KEYWORDS: Microfluidics, Water, Microfluidic imaging, Semiconducting wafers, Immersion lithography, Crystals, Liquids, Quartz, Printing, Lithography

Read Abstract +

SPIE Journal Paper | 1 April 2009

Index of refraction of high-index lithographic immersion fluids and its variability

Min Yang, Simon Kaplan, Roger French, John Burnett

JM3, Vol. 8, Issue 02, 023005, (April 2009) https://doi.org/10.1117/12.10.1117/1.3124189

KEYWORDS: Refraction, Water, Refractive index, Prisms, Thermal optics, Lithography, Microfluidics, Absorbance, Temperature metrology, Immersion lithography

Read Abstract +

SPIE Journal Paper | 1 July 2008

Optical properties of Teflon^® AF amorphous fluoropolymers

Min Yang, Roger French, Edward Tokarsky

JM3, Vol. 7, Issue 03, 033010, (July 2008) https://doi.org/10.1117/12.10.1117/1.2965541

KEYWORDS: Atrial fibrillation, Absorption, Absorbance, Optical properties, Refractive index, Refraction, Polymers, Silicon, Data modeling, Silicon films

Read Abstract +

Proceedings Article | 12 March 2008 Paper

High-index immersion fluids enabling cost-effective single-exposure lithography for 32 nm half pitches

Roger French, Hoang Tran, Doug Adelman, Nyrissa Rogado, Mureo Kaku, Michael Mocella, Charles Chen, Eric Hendrickx, Freida Van Roey, Adam Bernfeld, Rebekah Derryberry

Proceedings Volume 6924, 692417 (2008) https://doi.org/10.1117/12.772105

KEYWORDS: Semiconducting wafers, Absorbance, Silicon, Water, Microfluidics, Lithography, Liquids, Contamination, Double patterning technology, Extreme ultraviolet

Read Abstract +

Proceedings Article | 26 March 2007 Paper

High-index immersion lithography with second-generation immersion fluids to enable numerical aperatures of 1.55 for cost effective 32-nm half pitches

R. French, V. Liberman, H. Tran, J. Feldman, D. Adelman, R. Wheland, W. Qiu, S. McLain, O. Nagao, M. Kaku, M. Mocella, M. Yang, M. Lemon, L. Brubaker, A. Shoe, B. Fones, B. Fischel, K. Krohn, D. Hardy, C. Chen

Proceedings Volume 6520, 65201O (2007) https://doi.org/10.1117/12.712234

KEYWORDS: Water, Absorbance, Microfluidics, Refractive index, Immersion lithography, Diffractive optical elements, Contamination, Scanners, Computational fluid dynamics, Absorption

Read Abstract +

Proceedings Article | 15 March 2006 Paper

Second generation fluids for 193nm immersion lithography

Roger French, Weiming Qiu, Min Yang, Robert Wheland, Michael Lemon, Aaron Shoe, Doug Adelman, Michael Crawford, Hoang Tran, Jerald Feldman, Steve McLain, Sheng Peng

Proceedings Volume 6154, 615415 (2006) https://doi.org/10.1117/12.656626

KEYWORDS: Microfluidics, Refractive index, Immersion lithography, Microfluidic imaging, Water, Absorbance, Transparency, Lithography, 193nm lithography, Optical lithography

Read Abstract +

SPIE Journal Paper | 1 July 2005

Imaging of 32-nm 1:1 lines and spaces using 193-nm immersion interference lithography with second-generation immersion fluids to achieve a numerical aperture of 1.5 and a k₁ of 0.25

Roger French, Harry Sewell, Min Yang, Sheng Peng, Diane McCafferty, Weiming Qiu, Robert Wheland, Michael Lemon, Louis Markoya, Michael Crawford

JM3, Vol. 4, Issue 03, 031103, (July 2005) https://doi.org/10.1117/12.10.1117/1.2039953

KEYWORDS: Refractive index, Water, Oscillators, Absorption, Absorbance, Lithography, Immersion lithography, Microfluidics, Microfluidic imaging, Glasses

Read Abstract +

Proceedings Article | 12 May 2005 Paper

Second generation fluids for 193 nm immersion lithography

Sheng Peng, Roger French, Weiming Qiu, Robert Wheland, Min Yang, Michael Lemon, Michael Crawford

Proceedings Volume 5754, (2005) https://doi.org/10.1117/12.606448

KEYWORDS: Water, Oscillators, Refraction, Absorption, Absorbance, Microfluidics, Immersion lithography, Optical lithography, Lithography, Microfluidic imaging

Read Abstract +

Proceedings Article | 28 May 2004 Paper

157-nm pellicles for photolithography: mechanistic investigation of the deep-UV photolysis of fluorocarbons

Kwangjoo Lee, Steffen Jockusch, Nicholas Turro, Roger French, Robert Wheland, Michael Lemon, Andre Braun, Tatjana Widerschpan, Paul Zimmerman

Proceedings Volume 5377, (2004) https://doi.org/10.1117/12.534381

KEYWORDS: Fluorine, Photolysis, Pellicles, Ultraviolet radiation, FT-IR spectroscopy, Liquids, Polymers, Oxygen, Deep ultraviolet, Optical lithography

Read Abstract +

Proceedings Article | 28 May 2004 Paper

Immersion fluid refractive indices using prism minimum deviation techniques

Roger French, Min Yang, Michael Lemon, Ron Synowicki, Greg Pribil, Gerald Cooney, Craig Herzinger, Steven Green, John Burnett, Simon Kaplan

Proceedings Volume 5377, (2004) https://doi.org/10.1117/12.537727

KEYWORDS: Prisms, Refractive index, Liquids, Vacuum ultraviolet, Water, Thermal optics, Refraction, Immersion lithography, Nitrogen, Environmental sensing

Read Abstract +

SPIE Journal Paper | 1 January 2004

Transparent fluids for 157-nm immersion lithography

Roderick Kunz, Michael Switkes, Roger Sinta, Jane Curtin, Roger French, Robert Wheland, Chien-Ping Kao, Michael Mawn, Lois Lin, Paula Wetmore, Val Krukonis, Kara Williams

JM3, Vol. 3, Issue 01, (January 2004) https://doi.org/10.1117/12.10.1117/1.1637366

KEYWORDS: Absorption, Immersion lithography, Liquids, Absorbance, Vacuum ultraviolet, Microfluidics, Water, Carbon monoxide, Oxygen, Chemical analysis

Proceedings Article | 12 June 2003 Paper

Single-layer fluoropolymer resists for 157-nm lithography

Michael Crawford, William Farnham, Andrew Feiring, Jerald Feldman, Roger French, Kenneth Leffew, Viacheslav Petrov, Weiming Qiu, Frank Schadt, Hoang Tran, Robert Wheland, Fredrick Zumsteg

Proceedings Volume 5039, (2003) https://doi.org/10.1117/12.485206

KEYWORDS: Absorbance, Polymers, Etching, Silicon, Resistance, Absorption, Fluorine, Lithography, Infrared radiation, Photoresist materials

Read Abstract +

Proceedings Article | 30 July 2002 Paper

Behavior of candidate organic pellicle materials under 157-nm laser irradiation

Andrew Grenville, Vladimir Liberman, Mordechai Rothschild, Jan Sedlacek, Roger French, Robert Wheland, Xun Zhang, Joe Gordan

Proceedings Volume 4691, (2002) https://doi.org/10.1117/12.474604

KEYWORDS: Pellicles, Oxygen, Lamps, Polymers, Reticles, Semiconducting wafers, Absorption, Laser irradiation, Absorbance, Polymer thin films

Read Abstract +

Proceedings Article | 30 July 2002 Paper

157-nm pellicles: polymer design for transparency and lifetime

Roger French, Robert Wheland, Weiming Qiu, M. Lemon, Gregory Blackman, Xun Zhang, Joe Gordon, Vladimir Liberman, A. Grenville, Roderick Kunz, Mordechai Rothschild

Proceedings Volume 4691, (2002) https://doi.org/10.1117/12.474605

KEYWORDS: Polymers, Pellicles, Absorbance, Transparency, Absorption, Quantum efficiency, Optical lithography, Lithography, Molecular lasers, Vacuum ultraviolet

Read Abstract +

The introduction of 157 nm as the next optical lithography wavelength has created a need for new soft (polymeric) or hard (quartz) pellicle materials. Pellicles should be > 98% transparent to incident 157 nm light and, ideally, sufficiently resistant to photochemical damage to remain useful for an exposure lifetime of 7.5 kJ/cm2. The transparency specification has been met. We have developed families of experimental Teflon™AF (TAFx) polymers with > 98% transparency which can be spin coated and lifted as micron-scale, unsupported membranes. Still higher transparencies should be possible once optimization of intrinsic (composition, end groups, impurities, molecular weight) and extrinsic (oxygen, absorbed hydrocarbons, contaminants) factors are completed. The measured transparencies of actual pellicle films, however, are affected by many factors other than absorption. Film thickness must be precisely controlled so as to allow operation at the fringe maxima for the lithographic wavelength. Roughness and thickness uniformity are also critical. An important part of our program has thus been learning how to spin membranes from the solvents that dissolve our pellicle candidates. Meeting the durability specification at 157 nm remains a major concern. The 157 nm radiation durability lifetime of a polymer is determined by two fundamental properties: the fraction of 157 nm radiation absorbed and the fraction (quantum efficiency) of this absorbed radiation that results in photochemical darkening. Originally it was assumed that lifetime increases uniformly with increasing transparency. We now have cases where materials with very different absorbances (TAFx4P and 46P) have similar lifetimes and materials with similar absorptions (TAFx46P and 2P) have very different lifetimes. These findings demonstrate the importance of the relative quantum efficiencies as the 157 nm light energy distributes itself along degradative versus non-degradative pathways. In an effort to identify chemical and structural features that control lifetime, we have been studying model molecular materials, some quite similar to the monomer units used to make our pellicle candidates. Several of these models have shown transparencies much higher and lifetimes far longer than our best pellicle candidates to date.

Proceedings Article | 14 September 2001 Paper

Materials design and development of fluoropolymers for use as pellicles in 157-nm photolithography

Roger French, Joseph Gordon, David Jones, M. Lemon, Robert Wheland, Xun Zhang, Fredrick Zumsteg, Kenneth Sharp, Weiming Qiu

Proceedings Volume 4346, (2001) https://doi.org/10.1117/12.435710

KEYWORDS: Pellicles, Absorption, Polymers, Absorbance, Vacuum ultraviolet, Adhesives, Optical lithography, Atrial fibrillation, Spectroscopy, Transparency

Read Abstract +

Proceedings Article | 24 August 2001 Paper

157-nm imaging using thick single-layer resists

Michael Crawford, Andrew Feiring, Jerald Feldman, Roger French, Viacheslav Petrov, Frank Schadt, Robert Smalley, Fredrick Zumsteg

Proceedings Volume 4345, (2001) https://doi.org/10.1117/12.436874

KEYWORDS: Absorption, Absorbance, Etching, Polymers, Lithography, Transparency, Vacuum ultraviolet, Photoresist materials, Scanning electron microscopy, Resistance

Read Abstract +

Proceedings Article | 5 July 2000 Paper

Fluoropolymers for 157-nm lithography: optical properties from VUV absorbance and ellipsometry measurements

Roger French, Robert Wheland, David Jones, James Hilfiker, Ron Synowicki, Fredrick Zumsteg, Jerald Feldman, Andrew Feiring

Proceedings Volume 4000, (2000) https://doi.org/10.1117/12.388988

KEYWORDS: Absorbance, Pellicles, Vacuum ultraviolet, Polymers, Ellipsometry, Thin films, Spectroscopy, Reflectivity, Optical properties, Absorption

Read Abstract +

With the introduction of 157 nm as the next optical lithography wavelength, the need for new pellicle and photoresist materials optimized for this wavelength has produced much activity in optical characterization of thin film materials. Here we focus on ultra transparent fluoropolymers for 157 nm pellicle applications where absorbances below 0.01/micrometers are necessary to achieve transmissions above 98 percent. Transmission-based absorbance/micrometers measurements performed using VUV spectroscopy are characterized by rapid turn-around time, and are essential during the materials design and screening phase of a new materials development program. Once suitable candidate materials families have been identified for development into 157 nm pellicles, VUV ellipsometry becomes essential to model the film structure, characterize the complex index of refraction, and to tune the pellicle's etalon design. Comparison of VUV absorbance measurements of fluoropolymer thin films on CaF₂ substrates with VUV ellipsometry measurements of the same polymers on silicon substrates demonstrates some of the artifacts in, and helps define the accuracy of transmission based absorbance measurements. Fresnel interference fringes can produce transmission oscillations that can lead to underestimation, or even negative values, of the film absorbance. Film thickness nonuniformity can serve to reduce the Fresnel interference fringes, leading to reduce variation in the apparent 157 nm absorbance for micrometers thick films. VUV ellipsometry coupled with Fresnel analysis of the thin film/substrate system formally takes into consideration all of these optical artifacts, while at the same time determining the complex index of refraction of the materials. Using VUV ellipsometry and Fresnel analysis, the absorbance values do not show the large apparent oscillations, the film thickness is directly determined in the measurement, and film microstructure is also modeled. We have identified ultra transparent fluoropolymers which have 157 nm absorbances below 0.01/micrometers . These materials have the appropriate optical properties for use as 157 nm pellicles with greater than 98 percent transmission. This is an important for the development of 157 nm lithography, since the lack of a 157nm pellicle has been identified as a critical path issue.

Proceedings Article | 23 June 2000 Paper

New materials for 157-nm photoresists: characterization and properties

Michael Crawford, Andrew Feiring, Jerald Feldman, Roger French, Mookkan Periyasamy, Frank Schadt, Robert Smalley, Fredrick Zumsteg, Roderick Kunz, Veena Rao, Ling Liao, Susan Holl

Proceedings Volume 3999, (2000) https://doi.org/10.1117/12.388319

KEYWORDS: Etching, Transparency, Resistance, Polymers, Plasma etching, Photoresist materials, Plasma, Photoresist developing, Lithography, Absorption

Read Abstract +

Proceedings Article | 30 June 1999 Paper

Optical superlattices as phase-shift masks for microlithography

Peter Carcia, Roger French, Gillian Reynolds, Greg Hughes, Charlie Torardi, M. Reilly, M. Lemon, C. Miao, David Jones, L. Wilson, Laurent Dieu

Proceedings Volume 3790, (1999) https://doi.org/10.1117/12.351257

KEYWORDS: Photomasks, Etching, Multilayers, Optical lithography, Quartz, Chromium, Transmittance, Superlattices, Optical properties, Reactive ion etching

Read Abstract +

Proceedings Article | 18 December 1998 Paper

TiSi-nitride attenuating phase-shift photomask for 193-nm lithography

Gillian Reynolds, Roger French, Peter Carcia, Charlie Torardi, Greg Hughes, David Jones, M. Lemon, M. Reilly, L. Wilson, C. Miao

Proceedings Volume 3546, (1998) https://doi.org/10.1117/12.332857

KEYWORDS: Etching, Photomasks, Lithography, Quartz, Transmittance, Chemistry, Dry etching, Reactive ion etching, Chromium, Wet etching

Read Abstract +

Proceedings Article | 27 December 1996 Paper

Materials screening for attenuating embedded phase-shift photoblanks for DUV and 193-nm photolithography

Peter Carcia, Roger French, Kenneth Sharp, Jeff Meth, Bruce Smith

Proceedings Volume 2884, (1996) https://doi.org/10.1117/12.262809

KEYWORDS: Deep ultraviolet, Multilayers, Optical properties, Sputter deposition, Photomasks, Composites, Transmittance, Etching, Inspection, Phase shifts

Read Abstract +

Proceedings Article | 22 May 1995 Paper

Metrology of etched quartz and chrome embedded phase shift gratings using scatterometry

Susan Wilson, S. Sohail Naqvi, John McNeil, Herschel Marchman, Blaine Johs, Roger French, Franklin Kalk

Proceedings Volume 2439, (1995) https://doi.org/10.1117/12.209233

KEYWORDS: Photomasks, Quartz, Etching, Diffraction gratings, Phase shifts, Oxides, Scatterometry, Atomic force microscopy, Diffraction, Scatter measurement

Proceedings Article | 7 December 1994 Paper

Chromium-based attenuated embedded shifter preproduction

Franklin Kalk, Roger French, H. Ufuk Alpay, Greg Hughes

Proceedings Volume 2322, (1994) https://doi.org/10.1117/12.195825

KEYWORDS: Phase shifts, Photomasks, Inspection, Etching, Scanning electron microscopy, Photomask technology, Phase shifting, Dry etching, Absorbance, Optical inspection

Read Abstract +