Atomically Flat GaAs(001) Surfaces Obtained by High-Temperature Treatment with Atomic Hydrogen Irradiation

An atomically flat GaAs(001) surface can be obtained by a two-step atomic hydrogen (atomic-H) irradiation technique. This method includes low-temperature cleaning and high-temperature smoothening of the GaAs substrate surface. The reflection high energy electron diffraction (RHEED) and AFM study showed that a wide terrace with a 1 monolayer step height was observed when a GaAs(001) surface was cleaned at 400 °C and smoothened at 540 °C with atomic-H irradiation. The irradiation of atomic-H during the high temperature process maintained a certain surface stoichiometry, and resulted in an atomically flat substrate surface. This technique is useful for heterovalent epitaxy systems involving a single chamber growth system.