Morphology of GaAs epitaxial layers grown by MOCVD

Abstract

Abstract The morphology of GaAs epitaxial layers grown by low-pressure MOCVD on GaAs substrates oriented (100)±0.5° at a temperature of about 630 to 650°C was investigated. It was demonstrated that there are surface defects which form line patterns or cell structures similar to the etch pit patterns of substrates. The correspondence of these surface defects and chemical etch pits was ascertained by a molten-KOH etching technique. These defects were not observed on the layers which were grown on the substrates oriented(100) + 2° → 〈110〉, or on the layers deposited at a higher temperature of 730°C. The formation processes of these defects are discussed briefly.