Chemical dry etching of GaAs and InP by Cl2 using a new ultrahigh-vacuum dry-etching molecular-beam-epitaxy system

Abstract

Damage and contamination-free chemical dry etching of (100)GaAs and (100)InP by Cl2 was demonstrated using a new ultrahigh-vacuum dry-etching molecular-beam-epitaxy (MBE) system. This system consists of a combined etching chamber, an MBE chamber, and a sample preparation chamber, all at ultrahigh vacuum. A mirrorlike surface was obtained after etching at substrate temperatures ranging from 300 to 400 °C for GaAs, and from 200 to 400 °C for InP. In situ reflection high-energy electron diffraction observations were accomplished for GaAs, with a mirrorlike surface after etching, and (2×4) surface reconstruction was observed. Results show that a smooth surface was formed at an atomic level.