Improvement of GaN epi-layer quality and reduction of dislocation density by selective growth method using buried metal

利用掩埋金属选择性生长方法提高 GaN 外延层质量并降低位错密度

• 批准号: 12650308
• 负责人: FUKE Shunro
• 金额: $ 2.3万
• 依托单位: Shizuoka Uhiversity
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650308/
• 关键词: Compound Semiconductor; Nitride; Selective Growth; Organometallic Vapor Phase Epitax; Dislocation Density; High Quality; 高品位化

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.

为了用简单的生长工艺获得高结晶质量的GaN外延层，尝试通过在GaN层中埋置Ga点来降低MOCVD生长在蓝宝石上的GaN层中的缺陷密度。在Ga、Al、In和Mg等低熔点金属中，Ga是最合适的金属。在850 ℃下，仅供给TMG源气体，在0.6 μ mGaN层（底层）上自动形成Ga点。随着TMG气体的增加，底层上的Ga点尺寸变大，密度减小。在1040 ℃下，在GaN衬底上生长出不同状态的Ga点（尺寸和密度）的GaN薄膜。当再生长速率变高时，发现Ga点容易被掩埋，并且再生长GaN层的表面形貌和结晶度都得到改善。GaN再生长层的缺陷密度（其由InGaN覆盖层表面上的凹坑密度估计）从我们的标准外延层的5 × 10^9/cm ^2降低到具有两个掩埋Ga点层的样品的2 × 10^7/cm ^2。研究发现，再生长层的晶体学倾斜很小，且不依赖于横向生长方向。

项目成果

来正洋一, 他: "Ga埋め込みGaN成長による欠陥密度の低減"電子情報通信学会技術研究報告. CPM2001-13. 71-76 (2001)

Yoichi Kurimasa 等人：“通过 Ga 嵌入式 GaN 生长降低缺陷密度”CPM2001-13 (2001)。

M.Sumiya: "Reduction of Defect Density in GaN Epilayer having buried Ga Metal by MOCVD"Journal of Crystal Growth. 237-239 P2. 1060-1064 (2002)

M.Sumiya：“通过 MOCVD 降低具有埋入 Ga 金属的 GaN 外延层中的缺陷密度”晶体生长杂志。

M.Sumiya: "Reduction of Defect Density in GaN Epilayer having buried Ga Metal by MOCVD"Abstract of 13^<th> International Conf. on Crystal Growth. 520 (2001)

M.Sumiya：“通过 MOCVD 减少具有掩埋 Ga 金属的 GaN 外延层中的缺陷密度”第 13 届国际会议摘要。

M.Sumiya et al.: "Reduction of Defect Density in GaN Epilayer having buried Ga Metal by MOCV-P"J. Crystal Growth. 237/239(Pt,2). 1060-1064 (2002)

M.Sumiya 等人：“通过 MOCV-P 降低具有掩埋 Ga 金属的 GaN 外延层中的缺陷密度”J。

来正 洋一: "Ga埋め込みGaN成長による欠陥密度の低減"電子情報通信学会 信学技報. CPM2001-13. 71-76 (2001)

Yoichi Kurimasa：“通过嵌入 Ga 的 GaN 生长来降低缺陷密度”电子、信息和通信工程师协会 IEICE 技术报告 CPM2001-13 (2001)。