Investigations on the origin of strain variation in the zinc-blende phase along the depth of GaP/Si(1 1 1) using spatially resolved polarized and wavelength dependent Raman spectroscopy

Abstract

The surface and micro structure variations in the technologically important GaP/Si hetero-structures are investigated by the spatially resolved polarized Raman spectroscopy. The hetero-structures probed from two different directions 〈1 1 1〉 and <11¯0> reveal the presence of strain distributed zinc-blende (ZB) GaP phases and the dominance of wurtzite (WZ) phase near the GaP-Si interface. The azimuthal dependence of the optical phonon intensity of nucleating layer endorses the dominance of WZ phase at the interface. The study illustrates that spatially resolved polarized Raman probe, across the hetero-junction is extremely useful for distinguishing the WZ and ZB stacks. It can positively be utilized for the integration of crystal phase quantum structures of III-V semiconductors on the Si and Ge substrates, without any physical damage to the structures.