Control of residual impurities in very high purity GaAs grown by organometallic vapor phase epitaxy

Abstract
Very high purity GaAs layers with 77 K electron mobility values as high as 210 000 cm2/V s and a compensation ratio as low as ≊0.05 (NA+ND≊1014 cm−3) have been grown by organometallic vapor phase epitaxy. 4.2 K photoluminescence and magnetophotoluminescence spectra of these layers confirm their high purity. The degree of material purity and the compensation are found to be controllably dependent on the growth conditions, the optimum growth temperature being about 650 °C at a V:III ratio of 17.5.