Selective area growth by metal organic vapor phase epitaxy and atomic layer epitaxy using Ga2O3 as a novel mask layer

A novel technique is proposed for advanced microstructure formation using Ga2O3 as a new mask material. Ga2O3 layers were prepared by RF sputtering with Ga2O3 powder target and patterned using photolithography. Scanning electron microscope (SEM) and Photoluminescence (PL) measurement findings indicate that reasonably high-quality single crystalline GaAs layers could be successfully grown selectively on the unmasked region by metal organic vapor phase epitaxy (MOVPE) and atomic layer epitaxy (ALE), The GaAs/AlGaAs quantum structure was also fabricated by selective area MOVPE, however, at this stage, polycrystalline AlGaAs layers formed on the mask region after the mask removal and the regrowth of AlGaAs overlayers. The key factor in this microstructure fabrication process is the sensitive dependence of Ga oxide layers against the reactor pressure under H-2 exposure.