A Study of Elemental Interdiffusion in GaN/Si Wafer Grown by Metalorganic Vapor Phase Epitaxy

Abstract

ABSTRACTSecondary ion mass spectrometry (SIMS) study shows that a short-time interdiffusion process occurs at the interface of buffer/Si in the GaN/Si wafers grown by metalorganic vapor phase epitaxy (MOVPE). Increasing the growth temperature of the buffer layer from 1150°C to 1210°C reduces the dropping rate of Al concentration in the silicon substrate from ∼20nm/decade to ∼30nm/decade near the interface. The impact of the interdiffusion on the band structure is investigated by photocurrent spectroscopy measurement. The experimental results indicate that different build-in electric fields are formed in the GaN/n-Si(111) and GaN/p-Si(111) devices as the consequence of the MOVPE growth.