热壁外延生长GaAs／Si薄膜质量研究

本文研究了用热壁外延（HWE）技术在Si衬底上不同工艺下生长的GaAs薄膜的拉曼（Raman)和荧光（PL）光谱。研究表明：在室温下，GaAs晶膜的Raman光谱的265cm^-1横声子（TO）峰和289cm^-1纵声子（LO）峰的峰值之比随晶膜质量的变化而逐渐变大、半高宽（FWHM）变窄且峰值频移动变小，而LC光谱出现在871nm光谱的FWHM较窄，表明所测得的薄膜为单晶晶膜，对同一晶膜也可判断出均匀程度。因此可以通过拉曼光谱和PLC光谱相结合评定外延膜晶体质量。

Analysis of Spectroscopy for GaAs Layer on Si Substrate in Wall Expectixy

The paper studies Raman and Photoluminescense (PL) spectroscopyof the GaAs layer on Si substrate with different grown condition by hot wall expectixy (HWE) method.The result of Raman experiement shows that the ratio of the intensities of TO peak 265 cm－1 and LO peak 289 cm－1 have gradually increased with the GaAs layer crystal quality at room temperature.In addiction to it was found that LO peak of GaAs／Si were shifted 3 cm－1 compare with the standard GaAs*Besides,the peak of PL is in 871 nm,and the FWHM of Raman spectra and the FWHM of PL spectra are both narrow.It seems that the more the shift,the poor the quality.Then,these result show that GaAs／Si is high structural quality.At the same time,same layer spectra crystallinity can also be measured its homogeneity.Therefore,the quality of the epitaxial layer of GaAs／Si measurement one can estimate through Raman-PL spectra