Heteroepitaxy of III-nitride thin films with ultra low defect density

超低缺陷密度III族氮化物薄膜的异质外延

• 批准号: 23656020
• 负责人: TANAKA Satoru
• 金额: $ 2.5万
• 依托单位: Kyushu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Challenging Exploratory Research
• 财政年份: 2011
• 资助国家: 日本
• 起止时间: 2011 至 2012
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-23656020/
• 关键词: エピタキシャル成長; ワイドギャップ半導体; 貫通転位; III族窒化物; 低転位化; ポリタイプ; SiC; 選択成長; 窒化物半導体

In-situRHEED and AFM at the initial growth stages indicate nucleation of 6H-GaN at the nanofacets followed by step-flow towards the vicinal direction [1-100] of the substrate. No nuclei on the terraces, generally resulting in 2H-polytype, are observed. Continuous growth under the same condition gives a ~50nm-thick GaN film to be analyzed by Raman and PL. Clear two zone-folded phonon modes are observed between E1(TO) and E2(high), which is indicative of the formation of 6H-polytype. The PL spectrum indicates different energy transitions from 2H-GaN: a peak at 3.33eV is shifted by -0.13eV, which also supports the formation of the 6H-polytype. This is due to the reduced bandgap in 6H-polytype, in agreement with theoretical predictions.

在初始生长阶段的原位HEED和AFM表明，6 H-GaN在纳米晶面处成核，然后向衬底的邻位方向[1-100]逐步流动。梯田上没有核，通常导致2 H-多型体，观察。在相同条件下连续生长得到厚度约为50 nm的GaN薄膜，并对其进行了拉曼和PL分析。在E1（TO）和E2（high）之间观察到明显的两个带折叠声子模，表明6 H多型体的形成。PL谱显示了与2 H-GaN不同的能量跃迁：3.33eV处的峰移动了-0.13eV，这也支持了6 H-多型体的形成。这是由于6 H-多型体中的带隙减小，与理论预测一致。

项目成果

New polytypes (4H, 6H) of III-nitrides grown by hetero-step-flow mode on vicinal SiC surfaces

邻位 SiC 表面异质步流模式生长的 III 族氮化物的新多型（4H、6H）

• 发表时间: 2012
• 作者: Y. Ishiyama;M. Takaki;M. Funato;Y. Kawakami;A. Hashimoto;S. Tanaka
• 通讯作者: S. Tanaka