Initial stage of MOCVD growth of GaAs on Si

Abstract

The initial stage of the heteroepitaxy of GaAs on Si(100) has been studied by scanning electron microscopy to make clear the mechanism for obtaining a single domain layer. In the initial stage of the growth, three-dimensional GaAs islands with a stick-like shape were grown. It was found that the direction of the islands should be aligned to obtain a single domain layer. To align the direction of the islands at an early stage of the growth, there were three key factors: (1) Employment of misoriented substrates. (2) Growth with low temperatures and/or high growth rates to grow the small islands with a high enough density that the islands coalesce at an early stage of the growth. (3) Thermal annealing of the islands. In the annealing stage, the direction of the islands were completely aligned. It was also demonstrated that even at the high growth temperature of 600 ° C, a single domain layer was obtained with the high growth rate of 3000 Å/min.