Characterization and Surface Cleaning Technique for MOCVD Growth-Interrupted GaAs Films

Abstract

This paper presents a study of the electrical properties and impuritiy profiles for MOCVD GaAs films fabricated by a sequence consisting of growth interruption, exposure of the surface to air, and resumption of growth. The growth-interrupted interface is depleted of electrons, and carbon, oxygen, and silicon impurities accumulate. The cause of the carrier depletion is found to be carbon acceptors which compensate donors. Wet chemical etching of the air-exposed surface (about 300 Å) is very effective in removing the surface contaminants, and this then eliminates the carrier depletion.