| Project/Area Number |
62850068
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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| Allocation Type | Single-year Grants |
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| Research Field |
電子機器工学
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| Research Institution | Osaka University |
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Principal Investigator |
CHO Yshio ISIR-Sanken, Osaka University, Associate Professor, 産業科学研究所, 助教授 (20029846)
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| Co-Investigator(Kenkyū-buntansha) |
KONDO Kazuo Fujitsu Laboratories, Compound Semiconductor Devices Laboratories, 化合物半導体研究部, 主任研究員
柴富 昭洋 富士通研究所, 化合物半導体研究部, 部長代理
UMEDA Tokuo ISIR-Sanken, Osaka University, Technical Staff, 産業科学研究所, 教務職員 (40142319)
SHIBATOMI Akihiro Fujitsu Laboratories, Compound Semiconductor Devices Laboratories
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| Project Period (FY) |
1987 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥9,000,000 (Direct Cost: ¥9,000,000)
Fiscal Year 1988: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1987: ¥8,000,000 (Direct Cost: ¥8,000,000)
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| Keywords | Ultra High-Speed / Photodetector / HEMT Structure / Multi-Heterojunction / 2-Dimensional Electron Gas layer / ピコ秒 |
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| Research Abstract |
We Summarize here our efforts for the development of high-speed HEMT(High Electron Mobility Transistor) photodetectors in this scientific research. Different mechanisms have been proposed for the photodetection capability of planar FET structures. They are such as usual photocurrent, photovoltaic generation, or photo-induced gate bias voltage change. Although, depending on the operation conditions, these mechanisms either one of these mechanisms might be a major candidate for the photodetection capability, we proposed the direct optically-induced depletion layer modulation mechanism as a major contributor in the high speed case.
Heretofore, using a HEMT structure we could get 18ps (FWHM) response at room temperature and 13ps (FWHM) response at 126 K. For these response measurements a correlation technique with suing two cascade-connected devices was used. These results show the effective contribution of the 2-D electron gas in the HEMT structure, and at the same time, this proves the ef
… More
fectiveness of the photodetection mechanism we proposed.
Since the advent of the idea of OEIC(Opto-Electronic IC), for the photodetectors, high speed as well as high photoresponsivity are required. To achieved a high photoresponsivity, we tried to use a double-heterojunction HEMT(DH-HEMT) as a photodetector.
Observed photoresponse of a single-heterojunction HEMT(SH-HEMT) and a DH-HEMT. In both cases, the incident light power level is the same. From these results, it can be seen that the response amplitude (proportional to the photoresponsivity for the same incident light power) in a DH-HEMT photodetector is 1.7 times larger than that in a SH-HEMT photodetector. For the response speed, no distinct difference can be seen between these two cases. These responses include a sampling oscilloscope response.
In summary, we examined relative responsivity of the HEMT photodetector. Improvement of a factor of 1.m was observed by a double-heterojunction HEMT. This result supports that the direct optically-induced depletion layer modulation contributes substantially to the mechanism producing the photoresponse in GaAs MESFET's. Less
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