The nitridation of GaAs and GaN deposition on GaAs examined by in situ time-of-flight low energy ion scattering and RHEED

The growth of GaN on traditional zincblende III-V semiconductors such as GaAs is important technologically. Due to the high lattice mismatch between GaAs and III-V nitrides, the use of a buffer layer is always required. This can be achieved through either a low temperature buffer, a strained superlattice, or nitridation of GaAs surfaces by electron cyclotron resonance (ECR) bombardment. While this last process was shown to improve the electrical and optical properties of the nitride thin films, no detailed investigation of the nitridation process has been reported. In this work, in situ time-of-flight low energy ion scattering (TOF-LEIS) and reflection high energy electron diffraction (RHEED) are used to monitor surface structure, major elements, and impurities during the nitridation of GaAs as a function of time, temperature, and ECR power.