1999 Fiscal Year Final Research Report Summary
Study of short-wavelength intersubband luminescence in nitride semiconductors
| Project/Area Number |
09650054
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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 |
Applied optics/Quantum optical engineering
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| Research Institution | Osaka Prefecture University |
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Principal Investigator |
MORIMORO Keizo Osaka Pref. Univ. RIAST, Assistant Prof., 先端科学研究所, 講師 (50100219)
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| Co-Investigator(Kenkyū-buntansha) |
SUGIURA Hideo NTT Optoelectronics Lab., Chief Researcher, 光エレクトロニクス研究所, 主幹研究員
KAWAMURA Yuichi Osaka Pref. Univ. RIAST, Associate Prof., 先端科学研究所, 助教授 (80275289)
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| Project Period (FY) |
1997 – 1999
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| Keywords | GaN / III-V nitride / MOCVD / MOVPE / inter-subband transition / quantum well |
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| Research Abstract |
We have investigated a method for obtaining the large lateral growth rate in GaN films grown directly on the AlィイD22ィエD2OィイD23ィエD2(0001) substrate by two-flow metalorganic vapor phase epitaxy, in which one main flow carries a reactant gas parallel to the substrate and the other subflow carries an inactive gas nearly perpendicular to the substrate. The large normal hexagonal-like pyramid growth is obtained under the optimum angle of the subflow tube. The optimum angle is about 1 °inclination from vertical to the direction of the nozzle of the main flow. The very small inclination of subflow tube from the optimum angle gives a large influence on the morphology of GaN : (1) A tilt of 0.05 ° gives a small distorted hexagonal-like pyramid morphology, (2) a tilt of 0.3 gives three-dimensional island growth, and (3) a tilt of 0.7 gives no growth on the center of the substrate. This result indicates that the lateral growth rate is the largest at the optimum angle. Any direction of the tilt gives the similar results on the center of the substrate. The morphology off the center depends on the direction of the tilt. GaN grow more on the narrower direction between the brim of subflow tube and the substrate. The above result is obtained under the condition of the main flow speed of 45 cm/s and subflow speed of 20 cm/s. The optimum angle depends on the main flow speed, subflow speed, pressure, and so on. The reactant gas drains out along the substrate to all directions under the optimum arrangement, which contributes to higher decomposition rate of NHィイD23ィエD2 and leads to the large lateral growth rate.
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Research Products
(4 results)
