Arsenic-dominated chemistry in the acid cleaning of InGaAsand InAlAs surfaces

The surface cleaning of InGaAs and InAlAs is studied using synchrotron radiation photoelectron spectroscopy. Thermal annealing at 400 ° C cannot completely remove the native oxides from those surfaces. Elemental arsenic buildup is observed on both surfaces after acid treatment using HCl, HF, or H 2 S O 4 solution, which is similar to acid-cleaned GaAs surface. Cleaned InGaAs surface is oxide-free but small amount of aluminum oxide remains on cleaned InAlAs surface. The common chemical reactions between III-As semiconductors and acid solutions are identified and are found to be dominated by arsenic chemistry.