Kiyoharu Nakao
Komatsu Limited
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Featured researches published by Kiyoharu Nakao.
23rd Annual International Symposium on Microlithography | 1998
Tatsuo Enami; Osamu Wakabayashi; Toshihiro Nishisaka; Natsushi Suzuki; Takashi Nire; Hakaru Mizoguchi; Hiroaki Nakarai; Hirokazu Tanaka; Tatsuya Ariga; Kouji Shio; Takeshi Okamoto; Ryoichi Nodomi; Hitoshi Tomaru; Kiyoharu Nakao
We present the performance and durability of the newest model of the KrF excimer laser for microlithography KLES-G10K. The laser achieves 10 W of output power with 0.7 pm bandwidth at 1000 Hz with newly developed solid state pulsed power module and the high precise narrowing module. The durability of laser tube achieves 5 billion pulses with the new radio frequency preionization scheme, which reduces consumption of fluorine gas and maintenance of laser tube drastically.
XIV International Symposium on Gas Flow, Chemical Lasers, and High-Power Lasers | 2003
Hakaru Mizoguchi; Ryoichi Nohdomi; Tatsuya Ariga; Kazuaki Hotta; Kiyoharu Nakao; Koichi Kasuya
The roadmap of semiconductor fabrication predicts that the semiconductor market will demand 65 nm node devices from 2004/2005. Therefore, an Ultra-Line-Narrowed F2 laser for dioptric projection systems has been developed under the ASET project of “The F2 Laser Lithography Development Project”. The target of this project is to achieve a F2 laser spectral bandwidth below 0.2 pm (FWHM) and an average power of 25 W at a repetition rate of 5 kHz. The energy stability (3-sigma) target is less than 10%. Simultaneously, it is also required to establish the technology of evaluating the optical performance. An Oscillator-Amplifier arrangement at 2 kHz was developed as a first step of an Ultra-Line-Narrowed F2 laser system. With this laser system, we achieved the basic study of the synchronization technology for line narrowing operation using two system arrangements: MOPA (Master Oscillator/Power Amplifier) and Injection Locking. Based on this experience we have developed the 5 kHz system. With the 5 kHz Line-Narrowed Injection Locking system, we have achieved a spectral bandwidth of <0.2 pm with an output energy of >5 mJ and a pulse to pulse energy stability of <10%. The feasibility of a 5 kHz Ultra-Line-Narrowed F2 Laser for Dioptric Projection Systems has been demonstrated.
Proceedings of SPIE, the International Society for Optical Engineering | 1999
Tatsuo Enami; Masaki Nakano; Takayuki Watanabe; Ayako Ohbo; Tsukasa Hori; Takashi Ito; Toshihiro Nishisaka; Akira Sumitani; Osamu Wakabayashi; Hakaru Mizoguchi; Hiroaki Nakarai; Naoto Hisanaga; Takeshi Matsunaga; Hirokazu Tanaka; Tatsuya Ariga; Syouich Sakanishi; Takeshi Okamoto; Ryoichi Nodomi; Takashi Suzuki; Yuichi Takabayashi; Hitoshi Tomaru; Kiyoharu Nakao
In the semiconductor industry, it is one of the most important issues to reduce manufacturing cost of the semiconductor device by increasing throughput. We have succeeded in the development of the high repetition rate excimer laser technology, and obtained the prospect of low CoO of the laser device. In this paper, we present the performance and advanced technologies of the newest model of the KrF excimer laser for microlithography; KLES-G20K. The laser achieves 20 W of output power with 0.6 pm bandwidth at 2 kHz. The pulse to pulse energy stability, 3 sigma is less than 6 percent and integrated energy stability is within +/- 0.4 percent. By our estimation, more than 50 percent of CoO of the laser device is cut by adopting developed machine compared to a present one.
Second International Symposium on Laser Precision Microfabrication | 2002
Hiroshi Komori; Tatsuya Ariga; Hidenori Watanabe; Takahito Kumazaki; Naoki Kitatochi; Kotaro Sasano; Yoshifumi Ueno; Toshihiro Nishisaka; Ryoichi Nohdomi; Kazuaki Hotta; Hakaru Mizoguchi; Kiyoharu Nakao
The Association of Super-Advanced Electronics Technologies (ASET) started The F2 Laser Lithography Development Project in March 2000, to clarify solutions of base F2 lithography technologies. In this project, we are developing an ultra line-narrowed F2 laser light source for exposure tools tat are employing dioptric projection optics. We have developed an intermediate engineering injection- locking laser system that has an oscillator laser and an amplifier to study the feasibility of an ultra line-narrowed F2 laser. A spectral bandwidth of <0.2pm (FWHM) at a repetition rate of 1000Hz and an average power of 14W has been achieved with this laser system. The laser output performance dependence on the relative delay between oscillator laser and amplifier is also measured.
SPIE's 27th Annual International Symposium on Microlithography | 2002
Yasuaki Fukuda; Seiji Takeuchi; Takashi Aoki; Hiroyuki Nagasaka; Soichi Owa; Fumika Yoshida; Youichi Kawasa; Keiji Egawa; Takehito Watanabe; Ikuo Uchino; Akira Sumitani; Kiyoharu Nakao
Purging and reduction of out-gassing are very important issues that need to be treated in order to realize F2 laser lithography system. Several methods of purging are tried and out-gases from metals, O-rings, lubricants, and an adhesive are analyzed. Metal surfaces mainly release oxygen and water independent of surface roughness, Ni plating, or elements. Other substances are not detected by API-MS or GC-MS. Since O-rings are indispensable to make gas-tight structures, several kinds of O-rings made of fluoro-compounds are tested. Black fluoro-rubber o-ring, O-ring F, is recommended from the view of organic out-gassing but Teflon-based fluoro-elastomer, O-ring A, is a good candidate in terms of the water out-gassing. Greases emit a large amount of out-gases even when the samples are not irradiated by 157 nm laser. As an adhesive, Adhesive A is recommended because of the fact that it does not release as much organic and inorganic compounds which may absorb 157 nm laser light. Finally preliminary demonstration using a model exposure system is performed to obtain purging time for several cases.
26th Annual International Symposium on Microlithography | 2001
Yasuaki Fukuda; Seiji Takeuchi; Takashi Aoki; Soichi Owa; Fumika Yoshida; Youichi Kawasa; Akira Sumitani; Keiji Egawa; Takehito Watanabe; Kiyoharu Nakao
Purging and contamination are two important issues that need to be treated in order to realize F2 laser lithography system. For the purpose of developing gas-purging and chemically clean technologies, we designed and constructed an experimental set-up. It is used for the study of purging and out-gassing evaluation in order to obtain useful data for development of exposure system. Preliminary experiments showed that purging condition has a strong effect on the residual oxygen and water concentration in the final gas-replaced atmosphere. And we have found that the amount of out-gas depends on the surface finish method of the material used through analyses of impurity gas examination with or without laser irradiation.
Archive | 2002
Kiyoharu Nakao; Yoshifumi Ueno
26th Annual International Symposium on Microlithography | 2001
Tatsuya Ariga; Hidenori Watanabe; Takahito Kumazaki; Naoki Kitatochi; Kotaro Sasano; Yoshifumi Ueno; Toshihiro Nishisaka; Ryoichi Nohdomi; Kazuaki Hotta; Hakaru Mizoguchi; Kiyoharu Nakao
SPIE's 27th Annual International Symposium on Microlithography | 2002
Takanori Nakaike; Osamu Wakabayashi; Toru Suzuki; Hakaru Mizoguchi; Kiyoharu Nakao; Ryoichi Nohdomi; Tatsuya Ariga; Naoki Kitatochi; Takashi Suganuma; Takahito Kumazaki; Kazuaki Hotta; Masaki Yoshioka
Archive | 2011
Kiyoharu Nakao; Yoshifumi Ueno; 清春 中尾; 能史 植野