| Project/Area Number |
16H04332
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Electronic materials/Electric materials
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| Research Institution | Nara Institute of Science and Technology |
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Principal Investigator |
URAOKA Yukiharu 奈良先端科学技術大学院大学, 先端科学技術研究科, 教授 (20314536)
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| Co-Investigator(Renkei-kenkyūsha) |
Ishikawa Yasuaki 奈良先端科学技術大学院大学, 先端科学技術研究科, 准教授 (70581130)
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥16,770,000 (Direct Cost: ¥12,900,000、Indirect Cost: ¥3,870,000)
Fiscal Year 2018: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000)
Fiscal Year 2017: ¥5,200,000 (Direct Cost: ¥4,000,000、Indirect Cost: ¥1,200,000)
Fiscal Year 2016: ¥7,540,000 (Direct Cost: ¥5,800,000、Indirect Cost: ¥1,740,000)
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| Keywords | 窒化ガリウム / パワー半導体 / 高圧水蒸気処理 / 高信頼性 / MOS接合 / パワーデバイス / 超臨界水 / 界面準位 / ゲート絶縁膜 / 半導体 / MOS / HEMT / 半導体物理 |
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| Outline of Final Research Achievements |
The reaction mechanism of high pressure steam treatment was studied from the physical property evaluation at the SiO2 / GaN interface. As a result, it was revealed that in the SiO2 film, oxygen atoms in the film were replaced by oxygen atoms in the high-temperature high-pressure steam by HPWVA, and distortion of the Si-O-Si bond was relieved. It is believed that these reactions reduce traps due to oxygen vacancy compensation and distortion. At the SiO2 / GaN interface, it was shown that the oxygen atoms in the high temperature and high pressure water vapor reached the interface may inactivate the interface defect by compensating for the nitrogen vacancies and Ga non-bonding hand. In high pressure conditions such as high pressure steam treatment, the diffusion rate is higher than that of other heat treatments, so high pressure steam treatment is effective for reforming oxygen vacancies at the insulating film / semiconductor interface at low temperatures.
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| Academic Significance and Societal Importance of the Research Achievements |
近年，Siに代わるパワー半導体材料として窒化ガリウム(GaN)が期待されている。Siと比較すると，GaNのバンドギャップは約3倍，絶縁破壊電界は約10倍であり，高出力，高耐圧化が可能である。GaN MOS構造の問題点として絶縁膜/半導体界面に存在する電荷トラップが挙げられる。これまでの研究でSiO2/GaN MOS構造において，絶縁膜堆積後の熱処理として高温高圧の水蒸気を用いた高圧水蒸気処理を施すことで電気特性が改善することが明らかになっている。しかしながら，その反応機構は未だに明らかになっていない。そこで本研究では，物性評価からSiO2/GaN界面での高圧水蒸気処理の反応機構を明らかにした。
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