Effect of hydrogen on undoped and lightly Si-doped molecular beam epitaxial GaAs layers

Abstract

This letter describes a series of experiments in which pure hydrogen gas (at up to 1.2×10−6 Torr partial pressure) was introduced during molecular beam epitaxial (MBE) growth of low-doped and undoped GaAs at a substrate temperature of 580 °C. A major improvement in the electrical properties of the epitaxial layer has been observed. Electron mobilities at 77 K and deep level transient spectroscopy (DLTS) spectra are presented. A sharp increase in electron mobility and a dramatic reduction of M1 and M4 deep electron traps as shown by DLTS have been achieved with small amounts of H2 gas at 1.2×10−6 Torr partial pressure.