[Study of Raman-PL spectra for GaAs layer on Si substrate in hot wall epitaxy]

The quality of GaAs layer on the Si substrate 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 300 K. 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 900 nm is narrow. Then the results show GaAs layer is highly structural quality. But if we can not measure the PL peak at 900 nm, 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.