Dr. Tsutomu Shoki Profile

Dr. Tsutomu Shoki

at HOYA Corp

SPIE Involvement:

Author

Publications (28)

Proceedings Article | 30 September 2021 Presentation

EUV attenuated phase shift mask: development and characterization of mask properties

Ikuya Fukasawa, Yohei Ikebe, Takeshi Aizawa, Tsutomu Shoki, Takahiro Onoue

Proceedings Volume 11855, 118550N (2021) https://doi.org/10.1117/12.2606239

Read Abstract +

SPIE Journal Paper | 1 September 2017

Investigation of alternative absorbers for extreme ultraviolet mask blanks

Yohei Ikebe, Hirofumi Kozakai, Tsutomu Shoki, Takahiro Onoue

JM3, Vol. 16, Issue 04, 041006, (September 2017) https://doi.org/10.1117/12.10.1117/1.JMM.16.4.041006

KEYWORDS: Reflectivity, Extreme ultraviolet, Nickel, Photomasks, Diffusion, Interfaces, Etching, Extreme ultraviolet lithography, Lithography, Thin films

Read Abstract +

Proceedings Article | 23 October 2015 Paper

Film loss-free cleaning chemicals for EUV mask lifetime elongation developed through combinatorial chemical screening

Jaehyuck Choi, Jinsu Kim, Jeff Lowe, Davide Dattilo, Soowan Koh, Jun Yeol Choi, Uwe Dietze, Tsutomu Shoki, Byung Gook Kim, Chan-Uk Jeon

Proceedings Volume 9635, 96350C (2015) https://doi.org/10.1117/12.2197226

KEYWORDS: Extreme ultraviolet, Carbon, Photomasks, Extreme ultraviolet lithography, Ruthenium, Industrial chemicals, Particles, Scanning probe microscopy, Mask cleaning, Pellicles

Read Abstract +

EUV masks include many different layers of various materials rarely used in optical masks, and each layer of material has a particular role in enhancing the performance of EUV lithography. Therefore, it is crucial to understand how the mask quality and patterning performance can change during mask fabrication, EUV exposure, maintenance cleaning, shipping, or storage.

SPM (Sulfuric acid peroxide mixture) which has been extensively used for acid cleaning of photomask and wafer has serious drawback for EUV mask cleaning. It shows severe film loss of tantalum-based absorber layers and limited removal efficiency of EUV-generated carbon contaminants on EUV mask surface.

Here, we introduce such novel cleaning chemicals developed for EUV mask as almost film loss free for various layers of the mask and superior carbon removal performance. Combinatorial chemical screening methods allowed us to screen several hundred combinations of various chemistries and additives under several different process conditions of temperature and time, eventually leading to development of the best chemistry selections for EUV mask cleaning.

Recently, there have been many activities for the development of EUV pellicle, driven by ASML and core EUV scanner customer companies. It is still important to obtain film-loss free cleaning chemicals because cleaning cycle of EUV mask should be much faster than that of optic mask mainly due to EUV pellicle lifetime. More frequent cleaning, combined with the adoption of new materials for EUV masks, necessitates that mask manufacturers closely examine the performance change of EUV masks during cleaning process.

We have investigated EUV mask quality changes and film losses during 50 cleaning cycles using new chemicals as well as particle and carbon contaminant removal characteristics. We have observed that the performance of new chemicals developed is superior to current SPM or relevant cleaning chemicals for EUV mask cleaning and EUV mask lifetime elongation.

SPIE Journal Paper | 1 April 2013 Open Access

Improvement of defects and flatness on extreme ultraviolet mask blanks

Tsutomu Shoki, Masato Ootsuka, Minoru Sakamoto, Tatsuo Asakawa, Ryuuji Sakamoto, Hirofumi Kozakai, Kazuhiro Hamamoto, Takahiro Onoue, Toshihiko Orihara, Osamu Maruyama, Jun-Ichi Horikawa

JM3, Vol. 12, Issue 02, 021008, (April 2013) https://doi.org/10.1117/12.10.1117/1.JMM.12.2.021008

KEYWORDS: Extreme ultraviolet, Inspection, Polishing, Photomasks, Extreme ultraviolet lithography, Glasses, Defect inspection, Silicon, Molybdenum, Wafer-level optics

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 14 March 2012 Paper

Development of fiducial marks on EUV blanks for defect mitigation process

Takahiro Onoue, Kazuhiro Hamamoto, Toshihiko Orihara, Osamu Maruyama, Tsutomu Shoki, Junichi Horikawa

Proceedings Volume 8322, 832226 (2012) https://doi.org/10.1117/12.919745

KEYWORDS: Fermium, Extreme ultraviolet, Frequency modulation, Photomasks, Lithography, Inspection, Extreme ultraviolet lithography, Ruthenium, Ion beams, Electron beams

Read Abstract +

Proceedings Article | 26 March 2011 Paper

Printability and inspectability of defects on the EUV mask for sub-32nm half pitch HVM application

Sungmin Huh, In-Yong Kang, Sang-Hyun Kim, Hwan-seok Seo, Dongwan Kim, Jooon Park, Seong-Sue Kim, Han-Ku Cho, Kenneth Goldberg, Iacopo Mochi, Tsutomu Shoki, Gregg Inderhees

Proceedings Volume 7969, 796902 (2011) https://doi.org/10.1117/12.879384

KEYWORDS: Inspection, Photomasks, Extreme ultraviolet, Wafer inspection, Semiconducting wafers, Defect detection, Defect inspection, Extreme ultraviolet lithography, Manufacturing, Particles

Read Abstract +

SPIE Journal Paper | 1 April 2010

Thin-absorber extreme-ultraviolet lithography mask with light-shield border for full-field scanner: flatness and image placement change through mask process

Takashi Kamo, Yuusuke Tanaka, Toshihiko Tanaka, Iwao Nishiyama, Osamu Suga, Tsukasa Abe, Tadahiko Takikawa, Hiroshi Mohri, Tsutomu Shoki, Youichi Usui

JM3, Vol. 9, Issue 02, 023005, (April 2010) https://doi.org/10.1117/12.10.1117/1.3378154

KEYWORDS: Photomasks, Etching, Extreme ultraviolet lithography, Image processing, Multilayers, Photoresist processing, Photovoltaics, Lithography, Extreme ultraviolet, Coating

Read Abstract +

Proceedings Article | 20 March 2010 Paper

Improvement of total quality on EUV mask blanks toward volume production

Tsutomu Shoki, Masaru Mitsui, Minoru Sakamoto, Noriyuki Sakaya, Masato Ootsuka, Tasuto Asakawa, Takeyuki Yamada, Hideaki Mitsui

Proceedings Volume 7636, 76360U (2010) https://doi.org/10.1117/12.849363

KEYWORDS: Extreme ultraviolet, Polishing, Inspection, Extreme ultraviolet lithography, Photomasks, Annealing, Reflectivity, Coating, Mask making, Ruthenium

Read Abstract +

Proceedings Article | 30 September 2009 Paper

Thin absorber EUVL mask with light-shield border for full-field scanner: flatness and image placement change through mask process

Takashi Kamo, Yuusuke Tanaka, Toshihiko Tanaka, Osamu Suga, Tsukasa Abe, Tadahiko Takikawa, Hiroshi Mohri, Tsutomu Shoki, Youichi Usui

Proceedings Volume 7488, 748818 (2009) https://doi.org/10.1117/12.829873

KEYWORDS: Photomasks, Etching, Image processing, Extreme ultraviolet lithography, Multilayers, Photoresist processing, Scanners, Coating, Optical lithography, Lithography

Read Abstract +

Proceedings Article | 11 May 2009 Paper

Evaluation of an e-beam correction strategy for compensation of EUVL mask non-flatness

Kevin Orvek, Jaewoong Sohn, Jin Choi, Roxann Engelstad, Sudharshanan Raghunathan, John Zimmerman, Thomas Laursen, Yoshitake Shusuke, Tsutomu Shoki

Proceedings Volume 7379, 73790Q (2009) https://doi.org/10.1117/12.824267

KEYWORDS: Photomasks, Scanners, Semiconducting wafers, Extreme ultraviolet lithography, Finite element methods, Extreme ultraviolet, Polishing, Distortion, Overlay metrology, Optical alignment

Read Abstract +

Proceedings Article | 17 October 2008 Paper

EUVL practical mask structure with light shield area for 32nm half pitch and beyond

Takashi Kamo, Hajime Aoyama, Toshihiko Tanaka, Osamu Suga, Tsukasa Abe, Tadahiko Takikawa, Naoya Hayashi, Tsutomu Shoki, Youichi Usui, Morio Hosoya

Proceedings Volume 7122, 712227 (2008) https://doi.org/10.1117/12.801576

KEYWORDS: Photomasks, Etching, Reflectivity, Extreme ultraviolet lithography, Multilayers, Photoresist processing, Coating, Extreme ultraviolet, Lawrencium, Lithography

Read Abstract +

Proceedings Article | 30 October 2007 Paper

Recent performance of EUV mask blanks with low-thermal expansion glass substrates

Tsutomu Shoki, Takeyuki Yamada, Shouji Shimojima, Yuuki Shiota, Mitsuharu Tsukahara, Kesahiro Koike, Hiroaki Shishido, Osamu Nozawa, Toshiyuki Sakamoto, Morio Hosoya

Proceedings Volume 6730, 673015 (2007) https://doi.org/10.1117/12.748369

KEYWORDS: Extreme ultraviolet, Polishing, Reflectivity, Photomasks, Extreme ultraviolet lithography, Glasses, Inspection, Silicon, Molybdenum, Defect inspection

Read Abstract +

Proceedings Article | 20 October 2006 Paper

Process development for EUV mask production

Tsukasa Abe, Akiko Fujii, Shiho Sasaki, Hiroshi Mohri, Naoya Hayashi, Tsutomu Shoki, Takeyuki Yamada, Osamu Nozawa, Ryo Ohkubo, Masao Ushida

Proceedings Volume 6349, 63493G (2006) https://doi.org/10.1117/12.692519

KEYWORDS: Etching, Reflectivity, Extreme ultraviolet, Photomasks, Silicon, Photoresist processing, Scanning electron microscopy, Dry etching, Defect inspection, Inspection

Read Abstract +

Proceedings Article | 23 March 2006 Paper

Phase defect observation using an EUV microscope

Kazuhiro Hamamoto, Yuzuru Tanaka, Takahiro Yoshizumi, Yasuyuki Fukushima, Hideaki Shiotani, Noriyuki Sakaya, Morio Hosoya, Tsutomu Shoki, Takeo Watanabe, Hiroo Kinoshita

Proceedings Volume 6151, 615119 (2006) https://doi.org/10.1117/12.655430

KEYWORDS: Extreme ultraviolet, Microscopes, Photomasks, Multilayers, X-ray optics, X-rays, Extreme ultraviolet lithography, Inspection, EUV optics, Glasses

Read Abstract +

Proceedings Article | 6 May 2005 Paper

Development of low damage mask making process on EUV mask with thin CrN buffer layer

Mitsuhiro Kureishi, Ryo Ohkubo, Morio Hosoya, Tsutomu Shoki, Noriyuki Sakaya, Hideo Kobayashi, Osamu Nozawa, Yoh-ichi Usui, Osamu Nagarekawa

Proceedings Volume 5751, (2005) https://doi.org/10.1117/12.598613

KEYWORDS: Etching, Extreme ultraviolet, Multilayers, Reflectivity, Silicon, Photomasks, Atomic force microscopy, Dry etching, Scanning electron microscopy, Transmission electron microscopy

Read Abstract +

Proceedings Article | 17 December 2003 Paper

Fabrication of programmed phase defects on EUV multilayer blanks

Takeru Kinoshita, Tsutomu Shoki, Hideo Kobayashi, Ryo Ohkubo, You-Ichi Usui, Morio Hosoya, Noriyuki Sakaya, Osamu Nagarekawa

Proceedings Volume 5256, (2003) https://doi.org/10.1117/12.517836

KEYWORDS: Multilayers, Extreme ultraviolet, Transmission electron microscopy, Defect inspection, Atomic force microscopy, Inspection, Glasses, Photomasks, Silicon, Coating

Read Abstract +

Proceedings Article | 28 August 2003 Paper

Pattern inspection of EUV mask using an EUV microscope

Takeo Watanabe, Tsuneyuki Haga, Tsutomu Shoki, Kazuhiro Hamamoto, Shintaro Takada, Naoki Kazui, Satoshi Kakunai, Harushige Tsubakino, Hiroo Kinoshita

Proceedings Volume 5130, (2003) https://doi.org/10.1117/12.504240

KEYWORDS: Photomasks, Extreme ultraviolet, Extreme ultraviolet lithography, Microscopes, Inspection, Scanning electron microscopy, Multilayers, Mask making, Dry etching, Surface roughness

Read Abstract +

Proceedings Article | 28 August 2003 Paper

Exposure contrast of an EUV mask

Morio Hosoya, Tsutomu Shoki, Takeru Kinoshita, Noriyuki Sakaya, Osamu Nagarekawa

Proceedings Volume 5130, (2003) https://doi.org/10.1117/12.504072

KEYWORDS: Reflectivity, Multilayers, Extreme ultraviolet, Extreme ultraviolet lithography, Photomasks, Silicon, Optical simulations, Chromium, Molybdenum, Ruthenium

Read Abstract +

Proceedings Article | 1 August 2002 Paper

Process development of 6-in EUV mask with TaBN absorber

Tsutomu Shoki, Morio Hosoya, Takeru Kinoshita, Hideo Kobayashi, Youichi Usui, Ryo Ohkubo, Shinichi Ishibashi, Osamu Nagarekawa

Proceedings Volume 4754, (2002) https://doi.org/10.1117/12.477007

KEYWORDS: Reflectivity, Extreme ultraviolet, Multilayers, Photomasks, Silicon, Chromium, Ion beams, Glasses, Etching, Inspection

Read Abstract +

Proceedings Article | 25 August 1999 Paper

Progress in SiC membrane for x-ray mask

Tsutomu Shoki, Akinori Kurikawa, Takamitsu Kawahara, Tadashi Sakurai

Proceedings Volume 3748, (1999) https://doi.org/10.1117/12.360243

KEYWORDS: Silicon carbide, X-rays, Low pressure chemical vapor deposition, Photomasks, Polishing, Semiconducting wafers, Chemical vapor deposition, Surface finishing, Prototyping, X-ray lithography

Read Abstract +

Proceedings Article | 7 July 1997 Paper

Scattered-light alignment system using SiC mask for x-ray lithography

Tsutomu Miyatake, Masaoki Hirose, Tsutomu Shoki, Ryo Ohkubo, Kuniaki Yamazaki

Proceedings Volume 3048, (1997) https://doi.org/10.1117/12.275780

KEYWORDS: Optical alignment, Photomasks, Semiconducting wafers, Silicon carbide, X-rays, Objectives, X-ray lithography, Autoregressive models, Light scattering, Opacity

Read Abstract +

Proceedings Article | 24 July 1996 Paper

Study on x-ray irradiation stability of absorber materials for x-ray masks by stress measurement

Kinya Ashikaga, Shinji Tsuboi, Yoshio Yamashita, Shinji Sugihara, Yoshio Gomei, Tsutomu Shoki, Yoichi Yamaguchi, Tsuneaki Ohta

Proceedings Volume 2793, (1996) https://doi.org/10.1117/12.245200

KEYWORDS: X-rays, Tantalum, Photomasks, Silicon, Semiconducting wafers, Silicon carbide, Oxygen, Electron beams, Photoresist processing, Sputter deposition

Read Abstract +

Proceedings Article | 24 July 1996 Paper

Characteristics of Ta4B/SiC x-ray mask blanks

Ryo Ohkubo, Tsutomu Shoki, Hideaki Mitsui, Noromichi Annaka, Yoichi Yamaguchi

Proceedings Volume 2793, (1996) https://doi.org/10.1117/12.245215

KEYWORDS: Etching, Chromium, Silicon carbide, Sputter deposition, Xenon, Polishing, X-rays, Argon, Photomasks, Dry etching

Read Abstract +

Proceedings Article | 3 July 1995 Paper

Study of SiC x-ray mask distortion induced by backetching receding subtractive fabrication process

Shinji Tsuboi, Tsutomu Shoki, Tsuneaki Ohta, Hiroshi Okuyama, Kinya Ashikaga, Yoshio Yamashita, Ryo Ohkubo, Yoichi Yamaguchi, Hiroshi Hoga

Proceedings Volume 2512, (1995) https://doi.org/10.1117/12.212773

KEYWORDS: Silicon carbide, Photomasks, Distortion, Silicon, Semiconducting wafers, X-rays, Glasses, Mask making, Lithography, Electron beams

Read Abstract +

Proceedings Article | 3 July 1995 Paper

Amorphous stuctured Ta4B absorber on SiC membrane for x-ray mask

Tsutomu Shoki, Ryo Ohkubo, Gregory Wells, Yoichi Yamaguchi, Kuniaki Yamazaki, Franco Cerrina

Proceedings Volume 2512, (1995) https://doi.org/10.1117/12.212815

KEYWORDS: Silicon carbide, Annealing, X-rays, Tantalum, Photomasks, Sputter deposition, X-ray lithography, Argon, Silicon, Semiconducting wafers

Read Abstract +

Proceedings Article | 3 November 1994 Paper

Optical properties of polycrystalline -SiC membrane for x-ray mask

Tsutomu Shoki, Yoichi Yamaguchi, Noromichi Annaka, Isao Amemiya

Proceedings Volume 2254, (1994) https://doi.org/10.1117/12.191943

KEYWORDS: Silicon carbide, Transmittance, Polishing, Refractive index, Optical properties, X-rays, Surface roughness, Annealing, Surface finishing, Photomasks

Read Abstract +

Proceedings Article | 13 May 1994 Paper

Synchrotron irradiation stability of x-ray masks utilizing stress-free W-Ti absorbers and SiC membranes

Hiroshi Okuyama, Yoshio Yamashita, Kenji Marumoto, Hideki Yabe, Yasuji Matsui, Yoichi Yamaguchi, Tsutomu Shoki, Hiroyuki Nagasawa

Proceedings Volume 2194, (1994) https://doi.org/10.1117/12.175799

KEYWORDS: Silicon carbide, X-rays, Photomasks, Distortion, Sputter deposition, Semiconducting wafers, X-ray optics, Electron beams, Refractive index, Antireflective coatings

Read Abstract +

Proceedings Article | 24 June 1993 Paper

Properties of thin SiC membrane for x-ray mask

Tsutomu Shoki, Hiroyuki Nagasawa, Hiroyuki Kosuga, Yoichi Yamaguchi, Noromichi Annaka, Isao Amemiya, Osamu Nagarekawa

Proceedings Volume 1924, (1993) https://doi.org/10.1117/12.146526

KEYWORDS: Silicon carbide, Transmittance, Protactinium, X-rays, Radium, Polishing, Reactive ion etching, Surface roughness, Transparency, Semiconducting wafers

Read Abstract +