Nondestructive characterization of Ga1−xAlxAs–GaAs interfaces using nuclear profiling

Abstract

We present a new method for the nondestructive determination of the depth distribution of Al in Ga1−xAlxAs–GaAs heterostructures by means of nuclear profiling. This approach utilizes the 27Al(p,γ)28Si nuclear reaction which has an extremely sharp resonance width for protons incident at 992 keV. The presence of the Al is detected by means of the emitted 10.7 MeV γ ray. Depth profiling is accomplished by varying the energy of the incident proton beam. We have investigated the Al distribution of samples prepared using three different modifications of the liquid phase epitaxy method. Our results, after correction for straggling, are in good agreement with general considerations of the growth conditions.