Mr. Tom Coleman Profile

Tom Coleman

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Author

Publications (17)

Proceedings Article | 5 April 2007 Paper

Advanced edge roughness measurement application for mask metrology

Thomas Marschner, Jan Richter, Uwe Dersch, Amit Moran, Ruthy Katz, David Chase, Reuven Falah, Thomas Coleman

Proceedings Volume 6518, 65181R (2007) https://doi.org/10.1117/12.712530

KEYWORDS: Photomasks, Line edge roughness, Computer aided design, Metrology, Signal processing, Critical dimension metrology, Line width roughness, Semiconducting wafers, Edge roughness, Scanning electron microscopy

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Proceedings Article | 5 April 2007 Paper

CAD-based line/space mix-up prevention for reticle metrology

Thomas Marschner, Maik Enger, Frank Ludewig, Reuven Falah, Sergey Latinsky, Ofer Lindman, Thomas Coleman

Proceedings Volume 6518, 65181W (2007) https://doi.org/10.1117/12.712523

KEYWORDS: Computer aided design, Scanning electron microscopy, Photomasks, Metrology, Reticles, Pattern recognition, Binary data, Solid modeling, Semiconducting wafers, Target recognition

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Proceedings Article | 3 February 2000 Paper

Lithography and CD performance of advanced MEBES mask pattern generators

Jan Chabala, Damon Cole, Henry Pearce-Percy, Wayne Phillips, Maiying Lu, Suzanne Weaver, David Alexander, T. Coleman, Charles Sauer, Frank Abboud

Proceedings Volume 3996, (2000) https://doi.org/10.1117/12.377110

KEYWORDS: Photomasks, Lithography, Critical dimension metrology, Printing, Error analysis, Photoresist processing, Metrology, Dry etching, Etching, Charged particle optics

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Proceedings Article | 30 December 1999 Paper

Control methodology of off-target for varying pattern densities with chrome dry etch

Juergen Hochmuth, Guenther Ruhl, Thomas Coleman

Proceedings Volume 3873, (1999) https://doi.org/10.1117/12.373324

KEYWORDS: Etching, Critical dimension metrology, Dry etching, Photoresist processing, Photomasks, Plasma etching, Data modeling, Diffractive optical elements, Plasma, Helium

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Proceedings Article | 23 April 1999 Paper

Investigation of lithography performance using multipass gray (MPG) with MEBES 5000

Robert Dean, David Alexander, Jan Chabala, Thomas Coleman, Caryn Hartglass, Maiying Lu, Charles Sauer, Suzanne Weaver

Proceedings Volume 3665, (1999) https://doi.org/10.1117/12.346222

KEYWORDS: Lithography, Edge roughness, Line edge roughness, Photomasks, Etching, Critical dimension metrology, Optical proximity correction, Dry etching, Printing, Metrology

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Proceedings Article | 18 December 1998 Paper

180-nm mask fabrication process using ZEP 7000, multipass gray, GHOST, and dry etch for MEBES 5000

Maiying Lu, Thomas Coleman, Charles Sauer

Proceedings Volume 3546, (1998) https://doi.org/10.1117/12.332814

KEYWORDS: Etching, Dry etching, Photoresist processing, Critical dimension metrology, Helium, Plasma, Plasma etching, Photomasks, Wet etching, Image processing

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Proceedings Article | 18 December 1998 Paper

Impact of the loading effect on CD control in plasma etching of Cr photomasks using ZEP 7000 resist

Frederick Chen, Wilman Tsai, Scott Chegwidden, S. Yu, Marilyn Kamna, Jeff Farnsworth, Thomas Coleman

Proceedings Volume 3546, (1998) https://doi.org/10.1117/12.332864

KEYWORDS: Etching, Plasma etching, Plasma, Chromium, Photomasks, Critical dimension metrology, Standards development, Metals, Reactive ion etching, Diffractive optical elements

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Proceedings Article | 1 September 1998 Paper

Performance of the ALTA 3500 scanned-laser mask lithography system

Peter Buck, Alex Buxbaum, Thomas Coleman, Long Tran

Proceedings Volume 3412, (1998) https://doi.org/10.1117/12.328807

KEYWORDS: Etching, Photomasks, Lithography, Critical dimension metrology, Photoresist processing, Calibration, Dry etching, Anisotropic etching, Wet etching, Plasma etching

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Proceedings Article | 1 September 1998 Paper

Further advances in electron-beam pattern generation technology for 180-nm masks

Frank Abboud, Charles Sauer, Matthew Vernon, Thomas Coleman, Robert Dean, William Wang, Richard Prior, Maiying Lu, Suzanne Weaver

Proceedings Volume 3412, (1998) https://doi.org/10.1117/12.328815

KEYWORDS: Dry etching, Etching, Photomasks, Critical dimension metrology, Photoresist processing, Lithography, Image processing, Manufacturing, Calibration, Printing

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Proceedings Article | 28 July 1997 Paper

Plasma etching of Cr photomasks: parametric comparisons of plasma sources and process conditions

Chris Constantine, David Johnson, Russell Westerman, Thomas Coleman, Thomas Faure

Proceedings Volume 3096, (1997) https://doi.org/10.1117/12.277267

KEYWORDS: Etching, Chromium, Critical dimension metrology, Oxygen, Diffractive optical elements, Plasma, Scanning electron microscopy, Plasma etching, Photoresist processing, Reactive ion etching

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As device design rules continue to shrink, on-mask Cr structures must experience a corresponding reduction in size. Although 0.25 micrometer design rules require only 1 micrometer Cr features, the use of OPC structures, which may be needed to minimize line foreshortening and corner rounding, necessitate features to be etched into the Cr which are significantly smaller than this. This need, coupled with the demand for reduced CD bias and improved CD uniformities, requires the use of an alternate chrome etch technology. Plasma etching of Cr can be highly anisotropic, greatly reducing the etch under cut which is responsible for the CD bias typically associated with wet etching. Reactive ion etching (RIE) can provide significant enhancements in the capability of replicating micron and sub-micron features, but the Cr etch rate non-uniformity which is typical of this technique can translate into a CD nonuniformity. This is due in part to the relatively high pressure of operation (50 - 100 mTorr which is necessary to reduce the self generated dc voltage And which minimizes the photo resist etch rate. Recently, high density plasma sources, such as inductively coupled plasma (ICP), have become available which have the ability to operate both at low pressures and high plasma density while maintaining a low and controllable dc voltage. The low pressure operation significantly improves the etch rate uniformity and consequently the CD uniformity. In this study a design of experiment (DOE) is used to investigate the parameter space associated with the dry etching of Cr using an ICP source. The responses of Cr etch rate, selectivity to photo resist, CD uniformity and mean CD to target are studied, and from this an optimized parameter space is defined. Within this space the effect of overetch, dc voltage and pattern loading on the CD uniformity are also investigated. The role played by the photo resist profile in determining the Cr etch profile is also studied and preliminary measurements are made to understand the effect of the above parameters on the mask CD bias.

Proceedings Article | 12 February 1997 Paper

Plasma etching of Cr photomasks: optimization of process conditions and CD control

Chris Constantine, David Johnson, Russell Westerman, Thomas Coleman, Thomas Faure, Leonard Dubuque

Proceedings Volume 3236, (1997) https://doi.org/10.1117/12.301179

KEYWORDS: Etching, Chromium, Critical dimension metrology, Plasma etching, Plasma, Oxygen, Scanning electron microscopy, Diffractive optical elements, Atomic force microscopy, Photoresist processing

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As device design rules continue to shrink, on-mask Cr structures must experience a corresponding reduction in size. Although 0.25 micrometer design rules require only 1 micrometer Cr features, the use of OPC structures, which may be needed to minimize line foreshortening and corner rounding, necessitate features to be etched into the Cr which are significantly smaller than this. This need, coupled with the demand for reduced CD bias and improved CD uniformities, requires the use of an alternate chrome etch technology. Plasma etching of Cr can be highly anisotropic, greatly reducing the etch undercut which is responsible for the CD bias typically associated with wet etching. Reactive ion etching (RIE) can provide significant enhancements in the capability of replicating micron and sub-micron features, but the Cr etch rate non-uniformity which is typical of this technique can translate into a CD non-uniformity. This is due in part to the relatively high pressure of operation (50 - 100 mTorr) which is necessary to reduce the self generated dc voltage and which, in turn, minimizes the photo resist etch rate. Recently, high density plasma sources, such as inductively coupled plasma (ICP), have become available which have the ability to operate both at low pressures and high plasma density while maintaining a low and controllable dc voltage. The low pressure operation significantly improves the etch rate uniformity and consequently the CD uniformity. By coupling this ICP plasma source with a non-contact backside photomask handling system and a true multi-station 'cluster tool.' In this study a design of experiment (DOE) is used to investigate the parameter space associated with the dry etching of Cr using an ICP source. The responses of Cr etch rate, selectivity to photo resist, CD uniformity and mean CD to target are studied, and from this an optimized parameter space is defined. Within this space the effect of overetch, dc voltage and pattern loading on the CD uniformity are also investigated. The role played by the photo resist profile in determining the Cr etch profile is also studied, and preliminary measurements are made to understand the effect of the above parameters on the mask CD bias.

Proceedings Article | 12 February 1997 Paper

Comparison of EBR-900 M1 and ZEP 7000 with plasma-etch processing for MEBES 4500S

Thomas Coleman, David Alexander, Maiying Lu

Proceedings Volume 3236, (1997) https://doi.org/10.1117/12.301211

KEYWORDS: Plasma etching, Photoresist processing, Etching, Critical dimension metrology, Plasma, Resistance, Electron beam lithography, Photomasks, Wet etching, Lithography

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Proceedings Article | 27 December 1996 Paper

Plasma etching of Cr films in the fabrication of photomasks: II. a comparison of etch technologies and a first look at defects

Thomas Coleman, Peter Buck, David Johnson

Proceedings Volume 2884, (1996) https://doi.org/10.1117/12.262796

KEYWORDS: Etching, Plasma etching, Plasma, Dry etching, Reactive ion etching, Critical dimension metrology, Chromium, Oxygen, Photomasks, Wet etching

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Proceedings Article | 24 July 1996 Paper

Evaluation of the MEBES 4500 reticle writer to commercial requirements of 250-nm design rule IC devices

Frank Abboud, David Alexander, Thomas Coleman, Allen Cook, Leonard Gasiorek, Robert Naber, Frederick Raymond, Charles Sauer

Proceedings Volume 2793, (1996) https://doi.org/10.1117/12.245233

KEYWORDS: Reticles, Metrology, Calibration, Raster graphics, Composites, Photomasks, Manufacturing, Distortion, Mirror stabilization, Control systems

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Proceedings Article | 8 December 1995 Paper

Plasma etching of chromium films in the fabrication of photomasks

Thomas Coleman, Peter Buck

Proceedings Volume 2621, (1995) https://doi.org/10.1117/12.228216

KEYWORDS: Etching, Oxygen, Dry etching, Plasma etching, Line edge roughness, Critical dimension metrology, Chromium, Wet etching, Photomasks, Photoresist processing

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Proceedings Article | 8 December 1995 Paper

Method to produce a reference grid artifact for matching a MEBES 4500 system to an external reference

Jim DeWitt, Joe Watson, Thomas Coleman, Leonard Gasiorek, Michael Lubin, Robert Naber, William Wang, Keith Wires

Proceedings Volume 2621, (1995) https://doi.org/10.1117/12.228172

KEYWORDS: Metrology, Photomasks, Composites, Image processing, Software development, Phase shifts, Calibration, Lithography, Optical alignment, Reticles

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Proceedings Article | 3 July 1995 Paper

Preliminary methodology investigation of mask pattern fidelity for 250-nm design rules

Thomas Coleman, Charles Sauer, Robert Naber, Henry Chris Hamaker

Proceedings Volume 2512, (1995) https://doi.org/10.1117/12.212810

KEYWORDS: Printing, Photomasks, Manufacturing, Chlorine, Lithography, Visualization, Scanning electron microscopy, Image quality, Quartz, Statistical analysis

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Techniques have been developed that can quickly and accurately measure corner rounding and contact fill as key indicators of pattern fidelity. Using these techniques, we have examined writing variables for their effect on the lithographic quality of 1.0 micrometers contact. A small contact is perhaps the most demanding figure to achieve, so the results shown can be considered the worst case for 4X radicle manufacturing at 250 nm design rules. A MEBES 4500 was used as the writing tool, using PBS resist on quartz masks. Standard printing methods, single-phase printing (SPP) and multiphase printing (2X MPP) were examined. Results indicate that excellent corner rounding results can be achieved with small address sizes, regardless of the writing strategy or the dose used. As expected, larger spot sizes increase the amount of corner rounding, regardless of the address. As the pattern address is increased, judicious choices of spot size reduce potential pattern fidelity loss when imaging small contracts and other fine features. Multiphase printing is a technique that offers advantages to the user. Its use of offset scan voting (OSV) is a significant factor in reducing placement errors. MPP (2X) has an additional advantage of providing higher dosages. This provides flexibility in resist choices and in the selection of a process window. With 2X MPP, the user has a wide range of addresses and spot sizes that will give excellent results. The dynamic range of operating conditions possible with 2X MPP when writing 1.0 micrometers contacts is a reduced subset of those available using SPP, due to the 2X writing grid (output address). Implementation of 2X MPP has been limited on previous MEBES models due to increased write times of multipass writing. The MEBES 4500 data path supports 2X MPP with write times that approximate SPP. The practical operating envelope of both writing strategies are detailed in this paper. Overall, the MEBES 4500 has a large dynamic operating range. When used with a high resolution process, MEBES 4500 provides excellent pattern fidelity to support requirements of 250 nm design rules.

Showing 5 of 17 publications

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