Takashi Sakurada
Sumitomo Electric Industries
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Publication
Featured researches published by Takashi Sakurada.
IEEE Transactions on Electron Devices | 2000
Shigeru Nakajima; Masaki Yanagisawa; Eiji Tsumura; Takashi Sakurada
The effect of MESFET structure on the frequency dispersion of drain conductance (g/sub d/) was examined, It was found that a shorter gate length, lower buried p-layer concentration, lower sheet resistance of n/sup +/ layer, and thinner active layer thickness are effective in suppressing the frequency dependent g/sub d/. These phenomena are explained by the presence of deep traps in the depletion layer between the semi-insulating substate and active layer. We also show that the cross-point change of eye-pattern for density of input signal in logic ICs is due to frequency dependent g/sub d/ The cross-point change between mark ratio of 1/8 and 7/8 shows a linear relationship with gd/sub RF//gd/sub dc/ (the ratio of the drain conductance at RF and dc input), These results indicate that an optimized device structure with g/sub d/ small frequency dispersion can be used to realize high-speed and high quality logic ICs.
international conference on indium phosphide and related materials | 2003
K. Hashio; Noriyuki Hosaka; S. Fujiwara; Takashi Sakurada; R. Nakai; N. Hara; Y. Tsusaka; J. Matsui
Recent progress of high speed optical communication systems have been increasing the fabrication scale of devices, such as HBTs and OEICs. These devices will require semi-insulating Fe-doped InP substrates that are larger in diameter (4-inch) and higher in quality to improve device performance and reduce costs. With the growth of larger diameter InP crystals the increase of dislocation densities becomes critical. Though a boat growth method is the most appropriate for achieving low dislocation density, the boat growth of InP is difficult because of twinning issues. Therefore, most previous efforts have adopted a < 111 >-orientation to prevent twinning. However, this type of orientation is not suitable for the production of [100] substrates. SEI has succeeded in developing 4-inch Fe-doped InP substrates that are higher in quality using our VB (Vertical Boat) technique.
24th Annual Technical Digest Gallium Arsenide Integrated Circuit (GaAs IC) Symposiu | 2002
Tomohiro Kawase; Noriyuki Hosaka; Katushi Hashio; Masato Matsushima; Takashi Sakurada; Ryusuke Nakai
Macroscopic and microscopic uniformity in 4-inch InP substrates has been significantly improved by new developments in SEIs Vertical Boat (VB) technique. In this paper, we report improvements, in etch-pit density (EPD) distribution, micro-resistivity profiles, and photoluminescence (intensity and 4.2K spectra), for 4-inch InP VB in comparison to both VCZ (SEI proprietary Vapor pressure controlled Chockralski) and commercially available VGF substrates.
international conference on indium phosphide and related materials | 2001
Takashi Sakurada; Makoto Kiyama; Shigeru Nakajima; Masami Tatsumi
Rapid thermal annealing (RTA) is useful for shallow channel device fabrication because of suppression of dopant diffusion. However, short RTA sequence easily causes slip formation due to thermal stress during the process, which is more serious in the case of larger diameter wafers. We investigated at what point slip generated during RTA by monitoring temperature distribution within a wafer and successfully suppress slip formation by introducing a waiting step in the cooling process while maintaining the high cooling rate and the abrupt doping profile.
Archive | 2006
Shin Hashimoto; Makoto Kiyama; Tatsuya Tanabe; Kouhei Miura; Takashi Sakurada
Archive | 2008
Takashi Sakurada
Archive | 2005
Makoto Kiyama; Takuji Okahisa; Takashi Sakurada
Archive | 2006
Shin Hashimoto; Makoto Kiyama; Takashi Sakurada; Tatsuya Tanabe; Kouhei Miura; Tomihito Miyazaki
Archive | 2007
Tomoki Uemura; Takashi Sakurada; Shinsuke Fujiwara; Takuji Okahisa; Koji Uematsu; Hideaki Nakahata
Archive | 2009
Michimasa Miyanaga; Keisuke Tanizaki; Issei Satoh; Hideaki Nakahata; Satoshi Arakawa; Yoshiyuki Yamamoto; Takashi Sakurada