2007 Fiscal Year Final Research Report Summary
Radiation damage mechanism of advanced semiconductor materials and devices
| Project/Area Number |
17560054
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Engineering fundamentals
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| Research Institution | Kumamoto National College of Technology |
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Principal Investigator |
SHIGAKI Kazuasda Kumamoto National College of Technology, Department of Electronics Engineering, Associated Professor (50044722)
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| Co-Investigator(Kenkyū-buntansha) |
OHYAMA Hidenori Kumamoto National College of Technology, Department of Electronics Engineering, Professor (80152271)
HAYAMA Kiyoteru Kumamoto National College of Technology, Department of Electronics Engineering, Associated Professor (00238148)
KUDOU Tomohiro Kumamoto National College of Technology, Department of General, Associated Professor (90225160)
TAKAKURA Kenichiro Kumamoto National College of Technology, Department of Electronics Engineering, Associated Professor (70353349)
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| Project Period (FY) |
2005 – 2007
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| Keywords | radiation damage / electron / proton / SiC transistor / SOI transisor / induced lattice defect / recovery |
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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 SOI (Silicon on Insulator) MOS (Metal Oxide Semiconductor) FETs, SiC transistors and SiGe diode, subjected to 1-MeV electrons, and 20-MeV protons, were investigated as a function of fluence, fluence rate and radiation source.
The main conclusions which can be made from the research project :
1. The degradation of the electrical performance of semiconductor devices increases with increasing radiation fluence, while it decreases with increasing germanium content.
2. After irradiation, electron capture levels are observed in SiC epitaxial layers which are probably related with a B interstitial complex. The electron capture levels, which act as generation-recombination center, are mainly responsible for the degradation of device performance.
3. The electron capture levels induced in B-doped SiC epitaxial layers of SiC transistor are thought to be mainly responsible for the decrease of the drain current and effective mobility due to the donor removal together with leakage current by interface damage
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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