Dr. Omkaram Nalamasu Profile

Dr. Omkaram Nalamasu

CTO at Applied Materials Inc

SPIE Involvement:

Author

Publications (38)

Proceedings Article | 30 March 2021 Presentation

Applied Materials: The Path to Production: Enabling the Next Generation of Photonic Devices with Materials Engineering

Omkaram Nalamasu

Proceedings Volume 11764, 117640B (2021) https://doi.org/10.1117/12.2597456

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Proceedings Article | 24 August 2001 Paper

Base additives for use in a single layer 193-nm resist based upon poly(norbornene/maleic anhydride/acrylic acid/tert-butyl acrylate)

Francis Houlihan, Donna Person, Omkaram Nalamasu, Ilya Rushkin, Ognian Dimov, Elsa Reichmanis

Proceedings Volume 4345, (2001) https://doi.org/10.1117/12.436912

KEYWORDS: Lithography, Hassium, Chemically amplified resists, Polymers, Chromophores, Information operations, Picosecond phenomena, Standards development, Calcium, Nomenclature

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Proceedings Article | 24 August 2001 Paper

Lithographic behavior of carboxylate-based dissolution inhibitors and the effect of blending

Francis Houlihan, Zhenglin Yan, Elsa Reichmanis, Gary Dabbagh, Kevin Bolan, Omkaram Nalamasu, Ilya Rushkin, Ognian Dimov

Proceedings Volume 4345, (2001) https://doi.org/10.1117/12.436904

KEYWORDS: Lithography, Polymers, Molecules, Solids, Semiconducting wafers, Image resolution, Silicon films, Prototyping, Chemically amplified resists, Analog electronics

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Proceedings Article | 5 July 2000 Paper

High-density lithography using attenuated phase-shift mask and negative resist

Stanley Pau, Raymond Cirelli, Kevin Bolan, Allen Timko, John Frackoviak, Pat Watson, Lee Trimble, James Blatchford, Omkaram Nalamasu

Proceedings Volume 4000, (2000) https://doi.org/10.1117/12.389015

KEYWORDS: Photomasks, Photoresist materials, Phase shifts, Lithography, Binary data, Manufacturing, Critical dimension metrology, Printing, Microelectronics, Integrated circuits

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Proceedings Article | 23 June 2000 Paper

Modeling chemically amplified resists for 193-nm lithography

Ebo Croffie, Mosong Cheng, Andrew Neureuther, Francis Houlihan, Raymond Cirelli, James Sweeney, Gary Dabbagh, Pat Watson, Omkaram Nalamasu, Ilya Rushkin, Ognian Dimov, Allen Gabor

Proceedings Volume 3999, (2000) https://doi.org/10.1117/12.388300

KEYWORDS: Diffusion, Data modeling, FT-IR spectroscopy, Chemically amplified resists, Semiconducting wafers, Absorbance, Photolysis, Polymers, Lithography, Interfaces

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Proceedings Article | 23 June 2000 Paper

Model study by FT-IR and 13C NMR of the interaction of poly(norbornene-alt-maleic anhydride) and its derivatives with select cholate dissolution inhibitors or with select iodonium and sulfonium phot

Gary Dabbagh, Francis Houlihan, Ilya Rushkin, Richard Hutton, Omkaram Nalamasu, Elsa Reichmanis, Zhenglin Yan, Arnost Reiser

Proceedings Volume 3999, (2000) https://doi.org/10.1117/12.388265

KEYWORDS: Distributed interactive simulations, Clouds, Polymers, Hydrogen, FT-IR spectroscopy, Spectroscopy, Medium wave, Photoresist materials, Bismuth, Silver

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Proceedings Article | 23 June 2000 Paper

Mechanism of single-layer 193-nm dissolution inhibition resist

Zhenglin Yan, Francis Houlihan, Elsa Reichmanis, Omkaram Nalamasu, Arnost Reiser, Gary Dabbagh, Richard Hutton, Dan Osei, Jose Sousa, Kevin Bolan

Proceedings Volume 3999, (2000) https://doi.org/10.1117/12.388275

KEYWORDS: Ions, Polymers, Clouds, Polymer thin films, Switches, Medium wave, Molecules, Imaging systems, Spectroscopy, Hydrogen

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Proceedings Article | 23 June 2000 Paper

Dissolution properties of cycloolefin-maleic-anhydride-based resist resins

Ilya Rushkin, Francis Houlihan, Janet Kometani, Richard Hutton, Omkaram Nalamasu, Elsa Reichmanis, Ognian Dimov, Arturo Medina, Ulrike Varlemann, Allen Gabor, T. Sarrubi, Murrae Bowden

Proceedings Volume 3999, (2000) https://doi.org/10.1117/12.388305

KEYWORDS: Polymers, Polymerization, Lithography, Molecules, Standards development, Photoresist processing, Dry etching, Resistance, Printing, Modulation

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Proceedings Article | 26 July 1999 Paper

Depth of focus enhancement for 193-nm window lithography with subresolution assist features

Pat Watson, Armen Kroyan, Raymond Cirelli, H. Maynard, James Sweeney, Fred Klemens, G. Timp, Omkaram Nalamasu

Proceedings Volume 3679, (1999) https://doi.org/10.1117/12.354345

KEYWORDS: Etching, Lithography, Scanning electron microscopy, Oxides, Lithographic illumination, Critical dimension metrology, SRAF, Photoresist processing, Printing, Semiconducting wafers

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Proceedings Article | 26 July 1999 Paper

Effects of subresolution assist features on depth of focus and uniformity of contact windows for 193-nm lithography

Armen Kroyan, Pat Watson, Raymond Cirelli, Omkaram Nalamasu, Frank Tittel

Proceedings Volume 3679, (1999) https://doi.org/10.1117/12.354377

KEYWORDS: SRAF, Lithography, Lithographic illumination, Computer simulations, Optical proximity correction, Tolerancing, Scanning electron microscopy, Critical dimension metrology, Environmental sensing, Photomasks

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Proceedings Article | 11 June 1999 Paper

Toward the ultimate storage device: the fabrication of an ultrahigh-density memory device with 193-nm lithography

Raymond Cirelli, J. Bude, William Mansfield, G. Timp, Fred Klemens, Pat Watson, Gary Weber, James Sweeney, Francis Houlihan, Allen Gabor, Fred Baumann, M. Buonanno, G. Forsyth, D. Barr, T. Lee, C. Rafferty, Richard Hutton, Allen Timko, J. Hergenrother, Elsa Reichmanis, Lloyd Harriott, S. Hillenius, Omkaram Nalamasu

Proceedings Volume 3678, (1999) https://doi.org/10.1117/12.350213

KEYWORDS: Etching, Photomasks, Lithography, Diffusion, Semiconducting wafers, Phase shifts, 193nm lithography, Photoresist materials, Silicon, Chemically amplified resists

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Proceedings Article | 11 June 1999 Paper

Model study by FT-IR of the interaction of select cholate dissolution inhibitors with poly(norbornene-alt-maleic anhydride) and its derivatives

Gary Dabbagh, Francis Houlihan, Ilya Rushkin, Richard Hutton, Omkaram Nalamasu, Elsa Reichmanis, Allen Gabor, Arturo Medina

Proceedings Volume 3678, (1999) https://doi.org/10.1117/12.350155

KEYWORDS: Polymers, Hydrogen, FT-IR spectroscopy, Absorption, Molecules, Molecular interactions, Spectroscopy, Polymer thin films, Fourier spectroscopy, Lithography

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Proceedings Article | 11 June 1999 Paper

Resist outgassing as a function of differing photoadditives

Francis Houlihan, Ilya Rushkin, Richard Hutton, Allen Timko, Omkaram Nalamasu, Elsa Reichmanis, Allen Gabor, Arturo Medina, Sanjay Malik, M. Neiser, Roderick Kunz, Deanna Downs

Proceedings Volume 3678, (1999) https://doi.org/10.1117/12.350209

KEYWORDS: Lithography, Chromophores, Photolysis, NOx, Polymers, Diffusion, Quartz, Electron beam lithography, Deep ultraviolet, Ultraviolet radiation

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Proceedings Article | 11 June 1999 Paper

New polymers for 193-nm single-layer resists based on substituted cycloolefins/maleic anhydride resins

Ilya Rushkin, Francis Houlihan, Janet Kometani, Richard Hutton, Allen Timko, Elsa Reichmanis, Omkaram Nalamasu, Allen Gabor, Arturo Medina, Sydney Slater, Mark Neisser

Proceedings Volume 3678, (1999) https://doi.org/10.1117/12.350241

KEYWORDS: Polymers, Lithography, Etching, Polymerization, Plasma etching, Silicon, Resistance, Ultraviolet radiation, Plasma, Argon

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Proceedings Article | 11 June 1999 Paper

Optimization of 193-nm single-layer resists through statistical design

Allen Gabor, Ognian Dimov, Arturo Medina, Mark Neisser, Sydney Slater, Ruey Wang, Francis Houlihan, Raymond Cirelli, Gary Dabbagh, Richard Hutton, Ilya Rushkin, James Sweeney, Allen Timko, Omkaram Nalamasu, Elsa Reichmanis

Proceedings Volume 3678, (1999) https://doi.org/10.1117/12.350205

KEYWORDS: Polymers, Lithography, Binary data, Distributed interactive simulations, Etching, Resistance, Photomasks, Diffusion, Silicon, Semiconducting wafers

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Proceedings Article | 18 December 1998 Paper

Subresolution assist feature tolerences for contact windows using 193-nm lithography

Armen Kroyan, Pat Watson, Raymond Cirelli, Omkaram Nalamasu, Anthony Novembre, Frank Tittel

Proceedings Volume 3546, (1998) https://doi.org/10.1117/12.332873

KEYWORDS: SRAF, Lithography, Photoresist processing, Optical proximity correction, Critical dimension metrology, Scanning electron microscopy, Image processing, Lithographic illumination, Tolerancing, Reticles

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Combining assist features with appropriate off-axis illumination conditions can significantly improve depth of focus and uniformity of critical dimensions of contact windows. It is known that sub-resolution assist features modify the environment of isolated features in a fashion that they appear dense. In recent years the impact of assist features was mostly studied for gate-level lithography. In this paper the placement and dimension control of assist features for contact windows are examined and analyzed using 193 nm lithography in conjunction with a state-of-the-art single layer resist. Our study is primarily done for 160 nm contact windows, and it is based on experimental data obtained from critical dimension measurements with varying focus, exposure dose, and in different environments. Along with optical proximity corrections we use off-axis illumination technique which increases depth of focus of contact windows and improves the overall process latitude. Specifically for this study we have designed a test photomask with different geometries and pattern densities of contact windows with and without assist features to be used at 193 nm wavelength. To study the proximity effects, different sizes of assist features were used as well as the distances of assists from the main feature were varied. The results have shown that while increasing the process latitude for the primary feature using assist slots in combination with off-axis illumination, the resist thickness and contrast are limiting the assist feature dimensions that can be used. Assist features appear to significantly increase critical dimension uniformity of the contact windows when using both conventional and off-axis illumination techniques, and they dramatically increase the common exposure dose latitude for contact windows with densities from near-isolated to dense, decreasing the proximity effects. Assist feature technique combined with quadrupole illumination demonstrates about 0.3 micron improvement in depth of focus for every type contact window pattern used.

Proceedings Article | 29 June 1998 Paper

New variable-transmission illumination technique optimized with design rule criteria

Raymond Cirelli, Masis Mkrtchyan, Pat Watson, Lee Trimble, Gary Weber, David Windt, Omkaram Nalamasu

Proceedings Volume 3334, (1998) https://doi.org/10.1117/12.310739

KEYWORDS: Lithographic illumination, Carbon, Photomasks, Fiber optic illuminators, Lithography, Quartz, Diffraction, Transmittance, Tolerancing, Software development

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Proceedings Article | 29 June 1998 Paper

Recent advances in increasing the thermal flow resistance of acetal derivatized polyhydroxystyrene deep-UV matrix resins

Janet Kometani, Francis Houlihan, Allen Timko, Omkaram Nalamasu, Elsa Reichmanis, Sharon Heffner, Mary Galvin-Donoghue

Proceedings Volume 3333, (1998) https://doi.org/10.1117/12.312466

KEYWORDS: Polymers, Lithography, Solids, Resistance, Ion exchange, Lithium, Deep ultraviolet, Liquids, Scanning electron microscopy, Matrices

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Proceedings Article | 29 June 1998 Paper

193-nm single-layer photoresists based on alternating copolymers of cycloolefins: the use of photogenerators of sulfamic acids

Francis Houlihan, Janet Kometani, Allen Timko, Richard Hutton, Raymond Cirelli, Elsa Reichmanis, Omkaram Nalamasu, Allen Gabor, Arturo Medina, John Biafore, Sydney Slater

Proceedings Volume 3333, (1998) https://doi.org/10.1117/12.312462

KEYWORDS: Diffusion, Lithography, Scanning electron microscopy, Polymers, Photoresist materials, Solids, Crystals, Semiconducting wafers, Chemically amplified resists, Sodium

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Proceedings Article | 29 June 1998 Paper

Positive-tone processing of plasma-polymerized methylsilane (PPMS)

Gary Dabbagh, Richard Hutton, Raymond Cirelli, Elsa Reichmanis, Anthony Novembre, Omkaram Nalamasu

Proceedings Volume 3333, (1998) https://doi.org/10.1117/12.312398

KEYWORDS: Oxygen, Plasma, Etching, Polymers, Plasma etching, Image processing, Diffusion, Lithography, Infrared spectroscopy, Refractive index

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Proceedings Article | 29 June 1998 Paper

Subresolution assist feature and off-axis illumination optimization for 200- and 240-nm contact windows using 248-nm lithography

Pat Watson, Raymond Cirelli, Allen Timko, Omkaram Nalamasu, Carl Lockstamphor, Steven Berger, Neil Bassom, Ganesh Sundaram

Proceedings Volume 3334, (1998) https://doi.org/10.1117/12.310743

KEYWORDS: Lithographic illumination, Photomasks, Optical proximity correction, Scanning electron microscopy, SRAF, Lithography, Mask making, Manufacturing, Photoresist processing, Optical calibration

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Proceedings Article | 7 July 1997 Paper

Overview of photoacid generator design for acetal resist systems

Francis Houlihan, Omkaram Nalamasu, Elsa Reichmanis, Allen Timko, Ulrike Varlemann, Thomas Wallow, N. Bantu, John Biafore, Thomas Sarubbi, Pasquale Falcigno, H. Kirner, Norbert Muenzel, Klaus Petschel, Hans-Thomas Schacht, Reinhard Schulz

Proceedings Volume 3049, (1997) https://doi.org/10.1117/12.275848

KEYWORDS: Lithography, Quantum efficiency, Absorbance, Polymers, Microelectronics, Chemically amplified resists, Semiconducting wafers, Chromophores, Silver, Chemistry

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Proceedings Article | 7 July 1997 Paper

Recent advances in 193-nm single-layer photoresists based on alternating copolymers of cycloolefins

Francis Houlihan, Thomas Wallow, Allen Timko, E. Neria, Richard Hutton, Raymond Cirelli, Omkaram Nalamasu, Elsa Reichmanis

Proceedings Volume 3049, (1997) https://doi.org/10.1117/12.275856

KEYWORDS: Polymers, Resistance, Photoresist materials, Lithography, Standards development, Analog electronics, Deep ultraviolet, Spectroscopy, Solids, Scanning electron microscopy

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Proceedings Article | 7 July 1997 Paper

Design and process of a new DUV ARCH3 resist

N. Bantu, Brian Maxwell, Arturo Medina, Thomas Sarubbi, Medhat Toukhy, Hans-Thomas Schacht, Pasquale Falcigno, Norbert Muenzel, Klaus Petschel, Francis Houlihan, Omkaram Nalamasu, Allen Timko

Proceedings Volume 3049, (1997) https://doi.org/10.1117/12.275833

KEYWORDS: Polymers, Photoresist materials, Deep ultraviolet, Lithography, Photoresist processing, Chemistry, Photoresist developing, Scanning electron microscopy, Glasses, Resolution enhancement technologies

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Proceedings Article | 14 June 1996 Paper

Evaluation of cycloolefin-maleic anhydride alternating copolymers as single-layer photoresists for 193-nm photolithography

Thomas Wallow, Francis Houlihan, Omkaram Nalamasu, Edwin Chandross, Thomas Neenan, Elsa Reichmanis

Proceedings Volume 2724, (1996) https://doi.org/10.1117/12.241834

KEYWORDS: Lithography, Photoresist materials, Distributed interactive simulations, Optical lithography, Resistance, Etching, Polymers, Silicon, Carbon, Deep ultraviolet

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Proceedings Article | 9 June 1995 Paper

Structural design of ketal and acetal blocking groups in two-component chemically amplified positive DUV resists

Carlo Mertesdorf, Norbert Muenzel, Heinz Holzwarth, Pasquale Falcigno, Hans-Thomas Schacht, Ottmar Rohde, Reinhard Schulz, Sydney Slater, David Frey, Omkaram Nalamasu, Allen Timko, Thomas Neenan

Proceedings Volume 2438, (1995) https://doi.org/10.1117/12.210382

KEYWORDS: Polymers, Carbon, Deep ultraviolet, Lithography, Structural design, Glasses, Oxygen, Analog electronics, Diffusion, Staring arrays

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Proceedings Article | 19 May 1995 Paper

Electron-beam and x-ray lithographic characteristics of the optical resist ARCH

Anthony Novembre, Regine Tarascon-Auriol, Omkaram Nalamasu, Linus Fetter, Kevin Bolan, Chester Knurek, Norbert Muenzel, Heinz Holzwarth

Proceedings Volume 2437, (1995) https://doi.org/10.1117/12.209189

KEYWORDS: X-rays, Lithography, X-ray lithography, Deep ultraviolet, Electron beam lithography, Photoresist processing, Semiconducting wafers, Photomasks, Scanning electron microscopy, X-ray optics

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