拉曼-光荧光光谱热壁外延生长GaAs/Si薄膜晶体质量研究

本文研究了用热壁外延（HWE）技术在Si衬底上，不同工艺条件生长的GaAs薄膜的拉曼（Raman)和光荧光（PL）光谱。研究表明，在室温下，GaAs晶膜的拉曼光谱的265cm^-1模声子（TO）峰和290cm^-1纵声子（LO）峰的峰值和面积之比随晶膜质量的变化而逐渐变大，FWHM变窄且峰值频移变小，而PL光谱出现在900nm光谱的FWHM较窄，这表明所测得的薄膜为单晶晶膜，在另外一些工艺条件下生长的GaAs薄膜拉曼光谱峰形好，但测不出PL光谱，所生的膜不是单晶，同时对同一晶膜也可判断出其均匀程度，因此我们可以通过拉曼光谱和荧光光谱相结合评定外延膜晶体质量。

Study of Raman-PL Spectra for GaAs Layer on Si Substrate in Hot Wall Epitaxy

The quality of GaAs layer on the Si substrat under different growth conditions with HWE technology was studied by Raman and PL spectra.The results show that the ratio of peak value to area for the TO peak at 265 cm -1 increased gradually with the improvement of the GaAs crystallinity quality for the GaAs layer at 300K.The FWHM of Raman spectra of TO peak at 265 cm -1 is narrow,and the Raman shift is 2 cm -1 .In the PL spectra,the FWHM at 900nm is narrow.Then the results show GaAs layer is highly structural quality.But if we can not measure the PL peak at 900nm,or the FWHM of Raman spectra of TO peak at 265 cm -1 is not narrow,the GaAs layer is not crystallinity.Therefore,we can estimate the layer quality by Raman and PL spectra.