Characterization of impurity levels in III-Nitrid semiconductors

III 族氮化物半导体中杂质水平的表征

• 批准号: 13650017
• 负责人: OKUMURA Tsugunori
• 金额: $ 2.3万
• 依托单位: Tokyo Metropolitan University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650017/
• 关键词: GaN; isothermal capacitance transient spectroscopy; photocapacitance spectroscopy; III-nitride semiconductors; schottky diode; impurity levels; ショットキーダイトード; GaN; DLTS; PHCAP; ICTS; PPC; YB

III-nitride semiconductors have attracted much attention as promising materials for applications to short wavelength light-emitting devices, high temperature and high power and high frequency devices because of their superior properties, such as wide direct bandgap, high breakdown voltage, high electron saturation velocity, high thermal conductivity and high thermal stability. Despite the remarkable progress in crystal growth technique for III-nitride semiconductors, the doping and the deep-level defects in III-nitride semiconductors are still not fully understood. It is important to understand the origin and role of native defects and impurities in III-nitride semiconductors, because these point defects directly influence on device performance. The objective of this work is to characterize the correlation between optical and electrical properties of the deep-level defects in III-nitride semiconductors and to discuss their origins.In this work, we have built the high-temperature capacitance transient spectroscopy system in order to characterize the deeper levels near the mid gap in GaN. We have also characterized the deep levels in the MOCVD-grown GaN layers by the developed measurement system. The increase in the photocapacitance was observed in both GaN samples in the range of 2.0 to 2.5 eV. This is due to the photoionization of carriers from the deep levels associated with the yellow luminescence (YL). In addition, the transient capacitance measurements after the photoionization were also performed in the range of 1.8 to 3.4 eV. The notable transient of capacitance was observed at the photon energies of about 2.1 eV and 3.4, which are correspond to the deep levels associated with YL and bandgap energy of GaN at room temperature, respectively. By using the isothermal capacitance transient spectroscopy (ICTS) analysis, it is noted that the deep trap levels is the minority carrier trap, because of the negative ICTS signals.

III族氮化物半导体因其宽直接带隙、高击穿电压、高电子饱和速度、高热导率和高热稳定性等优异性能，作为短波长发光器件、高温高功率和高频器件的有前景的材料而备受关注。尽管III族氮化物半导体的晶体生长技术取得了显着进展，但III族氮化物半导体中的掺杂和深能级缺陷仍不完全清楚。了解 III 族氮化物半导体中本征缺陷和杂质的起源和作用非常重要，因为这些点缺陷直接影响器件性能。这项工作的目的是表征III族氮化物半导体中深能级缺陷的光学和电学性质之间的相关性，并讨论其起源。在这项工作中，我们建立了高温电容瞬态光谱系统，以表征GaN中带隙附近的更深能级。我们还通过开发的测量系统对 MOCVD 生长的 GaN 层的深层能级进行了表征。在两个 GaN 样品中观察到光电容在 2.0 至 2.5 eV 范围内增加。这是由于与黄色发光（YL）相关的深能级载流子的光电离。此外，光电离后的瞬态电容测量也在1.8至3.4 eV的范围内进行。在约 2.1 eV 和 3.4 的光子能量处观察到显着的电容瞬态，这分别对应于室温下与 YL 和 GaN 带隙能量相关的深能级。通过使用等温电容瞬态谱（ICTS）分析，注意到由于ICTS信号为负，深陷阱能级是少数载流子陷阱。

项目成果

中村成志, 豊田泰弘, 劉沛, 須原理彦, 奥村次徳: "過渡容量分光法によるGaN中の深い準位評価"平成15年度春季第50回応用物理学関係連合会講演会講演予稿集. 398 (2003)

Masashi Nakamura、Yasuhiro Toyoda、Pei Liu、Hiko Subara、Tsunori Okumura：“使用瞬态电容谱评估 GaN 的深能级”2003 年第 50 届春季应用物理联合会会议记录 398 (2003)。

中村成志, 豊田泰弘, 劉沛, 須原理彦, 奥村次徳: "過渡容量分光法によるGaN中の深い準位評価"平成15年度春季第50回応用物理学関係連合会講演会講演予稿集. (印刷中). (2003)

Masashi Nakamura、Yasuhiro Toyoda、Pei Liu、Hiko Subara、Tsunori Okumura：“使用瞬态电容谱评估 GaN 的深能级”2003 年第 50 届春季应用物理联合会会议记录（2003 年）。

S.Nakamura, P.Liu, M.Suhara, T.Okumura: "Transient capacitance characterization of deep levels in undoped and Si-doped GaN"2003 MRS spring meeting proceedings. (印刷中). (2003)

S.Nakamura、P.Liu、M.Suhara、T.Okumura：“未掺杂和硅掺杂 GaN 中深能级的瞬态电容特性”2003 年 MRS 春季会议论文集（2003 年）。