Characterization and optimization of atomic hydrogen cleaning of InP surface for selective molecular beam epitaxial growth of InGaAs quantum structure arrays

An oxide removal process for InP surface using atomic hydrogen cleaning was characterized and optimized for use in the selective molecular beam epitaxial (MBE) growth of InGaAs quantum structures. In-situ X-ray photoelectron spectroscopy (XPS). reflection high energy electron diffraction (RHEED). scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques were used. Detailed XPS measurements clarified the effects of atomic hydrogen on the planar InP surfaces. The cleaning efficiently removed oxygen. However, the P/In atomic ratio on the surface depended sensitively on the cleaning procedure. Under the optimum low-temperature atomic hydrogen cleaning, the surface stoichiometry could be maintained and realized an atomically flat InGaAs/InP interface. This has led to the formation of uniform InGaAs ridge quantum wires (QWRs) with good optical properties.