2001 Fiscal Year Final Research Report Summary
Improvement of GaN epi-layer quality and reduction of dislocation density by selective growth method using buried metal
| Project/Area Number |
12650308
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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 |
Electronic materials/Electric materials
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| Research Institution | Shizuoka Uhiversity |
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Principal Investigator |
FUKE Shunro Shizuoka University, Dep. of Engineering, Professor, 工学部, 教授 (00022236)
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| Co-Investigator(Kenkyū-buntansha) |
SUMIYA Masatomo Shizuoka University, Dep. of Engineering, Assistant, 工学部, 助手 (20293607)
TAKANO Yasushi Shizuoka University, Dep. of Engineering, Associate Professor, 工学部, 助教授 (00197120)
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| Project Period (FY) |
2000 – 2001
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| Keywords | Compound Semiconductor / Nitride / Selective Growth / Organometallic Vapor Phase Epitax / Dislocation Density / High Quality |
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| Research Abstract |
In order to obtain GaN epilayer with higher crystalline quality using a simple growth process, the reduction of defect density in GaN layer grown on sapphire by MOCVD is attempted by burying Ga dots in GaN layer. Ga is found to be most suitable metal among low-melting metal such as Ga, Al, In and Mg. The Ga dots are automatically formed on 0.6 μ m GaN layer (underlayer) at 850 ℃ by supplying only TMG source gas. With the increase of TMG gas, Ga dot size on the underlayer becomes larger and its density decreases. GaN films are regrown on the GaN underlayer with various states of Ga dots (size and density) at 1040 ℃. When the regrowth rate becomes higher, it is found that the Ga dots are easily buried and that both surface morphology and crystallinity of regrowth GaN layer are improved. The defect density of GaN re-growth layer, which is estimated by the pit density on the surface of InGaN overlayer, decreases from 5 X 10^9/cm^2 for our standard epilayer to 2 X 10^7/cm_2 for the sample having two buried Ga dots layers. It is found that the crystallographic tilt of regrowth layer is small and does not depend on the direction of lateral growth.
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