Raman scattering as a quantitative tool for residual acceptor assessment in semi-insulating GaAs

Abstract

Electronic Raman scattering has been employed to characterize as‐grown semi‐insulating GaAs. All samples investigated exhibit electronic Raman signals from residual acceptors (carbon and/or zinc). The intensity of these signals varies by more than one order of magnitude from sample to sample. Comparative local vibrational mode measurements to determine the carbon content suggest a quantitative correlation with the carbon acceptor concentration. The detection limit for this Raman characterization is well below 10¹⁵ acceptors/cm³ for samples cut from 500‐μm‐thick standard wafer material. Spatially resolved studies show that the scattering intensity fluctuates significantly across a 2‐in. GaAs wafer.