Development of wide-bandgap oxide epitaxial thin films by multi-wavelength excimer laser processing and substrates modification
| Project/Area Number |
15K20988
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Inorganic materials/Physical properties
Crystal engineering
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
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| Project Period (FY) |
2015-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000)
Fiscal Year 2017: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2016: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2015: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
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| Keywords | 室温エピタキシー / ワイドギャップ酸化物半導体 / エピタキシャル薄膜 / エキシマレーザープロセス / 固相結晶化 / 酸化ガリウム / 結晶核形成制御 / バッファ層 / ワイドギャップ半導体 / エキシマレーザーアニーリング / 固相エピタキシー / 薄膜構造解析 / 低温プロセス / 構造解析 / 低温成長 / レーザーアニール / レーザアニール |
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| Outline of Final Research Achievements |
Epitaxial thin films of β-Ga2O3(-201) with optical bandgap of 4.9eV was obtained on a NiO(111)-buffered α-Al2O3(0001) substrate at room-temperature by following approaches; (1) modification of crystal nucleation sites and growth direction on atomically stepped surface of the substrates, (2) reduction of planar lattice mismatch by introduction of a buffer layer, and (3) non-equilibrium solid-phase crystallization by excimer laser processing. The characteristic nucleation at step-edges was experimentally observed, and (111)-planes of rock-salt type crystals were demonstrated as good buffer layers owing to their homogeneous distance of anion and cation planes as well as their planar symmetry and lattice parameter. The morphology of substrates, and the structure of buffer layers were revealed to have impact on epitaxial formation of wide-bandgap oxide semiconductor thin films by excimer laser processing at room-temperature.
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| Academic Significance and Societal Importance of the Research Achievements |
バンドギャップ3～5eVの酸化物薄膜合成において、紫外レーザーによる結晶化エネルギー吸収と配向性結晶成長、面内秩序形成に与えるバッファ層の構造因子を見出し、基板モフォロジーによる核形成サイト制御と初期結晶化過程を実験的に明らかにした。ワイドギャップ酸化物半導体エピタキシャル薄膜の室温合成プロセスに関する基盤的知見を得た。
深紫外の光電子光学や電力工学において重要性を益す高結晶配向性の酸化物半導体薄膜について室温合成を達成し、高温合成と同等の光学特性を得た。透明・大面積・フレキシブルなど新たな付加価値をもつデバイスの将来的実現に貢献する要素技術を創成した。
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Report
(5 results)
Research Products
(34 results)
