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用低压金属有机物化学汽相沉积法(MOCVD)在Si(100)无偏角和Si(100)4°偏角衬底上外延生长GaAs层。异质外延采用两步生长法,并分别优化了两种衬底上的非晶低温缓冲层的生长条件。用X射线双晶衍射(XRD)和透射电子显微镜(TEM)对两种衬底上的GaAs外延层进行了结构表征,其中Si(100)4°偏角衬底上1.8μm厚GaAs的(004)面XRD衍射半高全宽338 arcsec,同比在无偏角衬底上的半高全宽为494arcsec,TEM图片显示4°偏角衬底上外延层中的位错密度大大降低。
The GaAs layer was epitaxially grown on a Si (100) unbiased and Si (100) 4 ° off-angle substrate by low pressure metalorganic chemical vapor deposition (MOCVD). The heteroepitaxy is grown by two-step growth method, and the growth conditions of the amorphous low temperature buffer layer on the two substrates are optimized respectively. The GaAs epitaxial layers on the two substrates were characterized by X-ray double crystal diffraction (XRD) and transmission electron microscopy (TEM). The thickness of (001 ) The full width at half maximum of the XRD diffraction is 338 arcsec, with a full width at half maximum of 494 arcsec on unbiased substrates compared to the same period of the previous year. The TEM images show that the dislocation density in the epilayers on the 4 ° offsets substrate is greatly reduced.