Raman studies on GaAs epitaxial films on Si
Raman studies on GaAs epitaxial films on Si
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Si 上 GaAs 外延薄膜的拉曼研究
DOI：
10.1016/0169-4332(91)90336-i
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发表时间：
1991
影响因子：
6.7
通讯作者：
S. Hinotani
中科院分区：
文献类型：
--
作者：
Y. Matsuda;K. Fujita;S. Hinotani
用拉曼光谱研究了热膨胀和晶格失配对薄膜应力的影响。由GaAsLO声子频率和半宽度估算了不同厚度的GaAs膜中的应力大小。用空间相关(SC)模型对测量的GaAsLO声子频率进行了修正，结果表明，当薄膜很薄时，由于晶格失配的调节，薄膜中存在压应力。研究还发现，压应力随膜厚的增加而减小。用高分辨透射电子显微镜研究了GaAs/Si界面的失配位错。失配位错密度随着薄膜厚度的增加而增加。由晶格失配调节引起的压应力主要通过异质界面失配位错密度随薄膜厚度的增加而释放。
Raman spectroscopy has been applied to the study of the effects of thermal expansion and lattice mismatch between GaAs and Si on the stress in GaAs films. The amount of stress in GaAs films of various thicknesses has been estimated from the GaAs LO phonon frequency and the half-width. By correcting the measured GaAs LO phonon frequency by using the spatial correlation (SC) model, it is shown that compressive stress exists in GaAs films due to accommodation of the lattice mismatch when the film is very thin. It has been also found that the compressive stress decreases with increased film thickness. The misfit dislocations at theGaAs/Si interface have been investigated by HR-TEM. The density of misfit dislocations increases with increased film thickness. The compressive stress in GaAs films due to accommodation of the lattice mismatch is released mainly by an increase of the density of misfit dislocations at the heterointerface as the film thickness increases.