Reaction Mechanism of GaAs Vapor‐Phase Epitaxy

Abstract

Reaction mechanisms of GaAs epitaxial growth using GaAs-AsCI~-H2 and GaAs-AsC13-N2 systems have been investigated by means of infrared spectroscopy, and probable reaction models are discussed. Over the whole temperature range of 400 ~ -840~ dominant gallium chlorides observed by a sampling method are Ga2C1G and an unidentified gallium compound with chlorine that has an absorption band at 1600 cm ' in the hydrogen carrier system, but only Ga2CIG in the nitrogen carrier system. Analyses by a mechanical balance have suggested that GaC13 samlSled frorfi ~reactor should dimerize into the greater part of Ga2C16 in a gas cell. A photoenhancement of AsC13 reduction by H2 has been examined by irradiating with an excimer laser. A photoexcitation of GaC13 has been ascertained, and epitaxial growth with a single flat temperature profile has been realized at low temperatures below 600~ by irradiation with a 249 nm laser.