Effects of the Growth Conditions on Deep Level Concentration in MOCVD GaAs

Abstract
Growth parameter dependence of the concentration of a dominant deep level (E c-0.84 eV) in undoped and S-doped MOCVD grown GaAs has been studied by DLTS. Considerable attention has been paid to the analysis of DLTS signal in order to obtain the true concentration from the experimental data. It has been found that the concentration of 0.84 eV level is proportional to ([AsH3]/[TMG])1/4. It increases with growth temperature, and decreases with increase in the concentration of doped S. The mole ratio dependence of the 0.84 eV level concentration suggests that the dominant deep level in GaAs is closely related to a Ga vacancy.