Study of As precipitates in LEC SI–GaAs wafer by Raman probe

As precipitates in the subsurface layer of LEC SI–GaAs substrates are characterized by Raman microprobe with a spatial resolution of 2 μm. We find that the LO line of GaAs at the As precipitate broadens asymmetrically because As precipitates and dislocations introduce disorder in the crystal. The compressive strain introduced by As precipitates results in the central frequency of LO line shifting to the blue.