Chracterization of strain and composition in InGaN films by photoreflection and Raman scattering

通过光反射和拉曼散射表征 InGaN 薄膜中的应变和成分

基本信息

批准号：
09650014
负责人：
HARIMA Hiroshi
金额：
$ 1.98万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650014/
关键词：
GaN InGaN AlGaN Raman scattering photo-reflection mixed crystal strain phonon

项目摘要

1. Strain and electric transport parameters in GaN :We have evaluated in-plane strains in GaN films from a measurement of the E2-phonon mode frequency by Raman scattering.We have also evaluated carrier concentration and mobility in n-type GaN films together with the spatial distribution by Raman scattering.Carrier concentration in p-type materials can be obtained from the intensity of inter-valence band transition of holes observed in Raman spectra.2. Spatial distribution of hexagona1- to cubic-components in GaN films :We have evaluated the ration and their spatial distribution by focusing on a characteristic feature in GaN Raman spectra.3. Composition in AIGaN and InGaN films :We have observed Raman spectra of cubic-AIGaN films for the first time for the whole range of Al composition (0-100%).We have observed various dependences of phonon frequencies on the Al content, and showed a good agreement with a theoretical model.We have also observed for the first time Raman spectra of hexagonal-InGaN films without thick GaN buffer layers in the growth process.We have observed a linear relation of the E2-phonon mode frequency on the In content of 0-7%.These results will be usable for composition characterizations.We have evaluated the bandgap energy by absorption and photoreflection measurements.The In contents were evaluated from the results and compared with Raman data on phonon frequencies.4. UV-excitation system for Raman microprobing and photo-reflection measurements :We have developed a UV-excitation system for Raman microprobing and photo-reflection measurements.We have tested the system performance by measuring Raman spectra of Si and GaN in the resonant Raman condition.

1. GaN 中的应变和电传输参数：我们通过拉曼散射测量 E2 声子模式频率来评估 GaN 薄膜中的面内应变。我们还评估了 n 型 GaN 薄膜中的载流子浓度和迁移率拉曼散射的空间分布。p型材料中的载流子浓度可以通过拉曼光谱中观察到的空穴价带间跃迁的强度来获得。2． GaN薄膜中六方到立方组分的空间分布：我们通过关注GaN拉曼光谱中的一个特征来评估其比例及其空间分布。3． AlGaN 和 InGaN 薄膜中的成分：我们首次观察到整个 Al 成分范围（0-100%）的立方 AlGaN 薄膜的拉曼光谱。我们观察到声子频率对 Al 含量的各种依赖性，并显示与理论模型吻合良好。我们还首次观察到生长过程中没有厚GaN缓冲层的六方InGaN薄膜的拉曼光谱。我们观察到E2声子模式频率与In含量为0-7%。这些结果可用于成分表征。我们通过吸收和光反射测量评估了带隙能量。根据结果评估了In含量，并与声子频率的拉曼数据进行了比较。 4．用于拉曼微探测和光反射测量的紫外激发系统：我们开发了一种用于拉曼微探测和光反射测量的紫外激发系统。我们通过在共振拉曼条件下测量硅和氮化镓的拉曼光谱来测试系统性能。