| Co-Investigator(Kenkyū-buntansha) |
KUDOU Tomohiro Department of Information and Communication Engineering, Associate Researcher, 情報通信工学科, 助教授 (90225160)
HAYAMA Kiyoteru Kumamoto National College of Technology, Department of Electronic Engineering,, Associate Researcher, 電子工学科, 助教授 (00238148)
OHYAMA Hidenori Kumamoto National College of Technology, Department of Electronic Engineering, Professor, 電子工学科, 教授 (80152271)
HAKATA Tetusya Department of Electronic Control, Associate Researcher, 電子制御工学科, 助教授 (60237899)
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| Research Abstract |
In these days when the use of nuclear reactors, high-energy particle accelerators and artificial satellites expands, the development of semiconductor devices, which can normally operate in a radiation-rich environment, is extensively taking place everywhere. In the project, the degradation of the electrical performance and the generated lattice defects in InGaAs devices, subjected to 1-MeV electrons, 1-MeV fast neutrons, 20-MeV protons and 20-MeV alpha rays, were investigated as a function of fluence and radiation source.
The main conclusions which can be made from the research project :
1. The degradation of the electrical performance of InGaAs devices increases with increasing radiation fluence, while it decreases with increasing germanium content.
2. After irradiation, electron capture levels are observed in InGaAs epitaxial layers which are probably related with a Ga interstitial complex. The electron capture levels, which act as generationrecombination center, are mainly responsible for the degradation of device performance.
3. The electron capture levels induced in Si-doped Ino.49Gao.5lP donor layer of InGaAs HEMT (High Electron Mobility Transistor) are thought to be mainly responsible for the decrease of the drain current and effective mobility due to the donor removal/ 4. The damage coefficient for proton irradiation is nearly the same as for neutron irradiation and is about three orders of magnitude larger than that for electron irradiation. This difference is due to the' different number of knock-on atoms, which is correlated with the difference of mass and the possibility of nuclear collisions for the formation of lattice defects.
5. The degraded performance and induced deep levels recover by thermal annealing.
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