Faceting of LPE GaAs grown on a misoriented Si(100) substrate

Abstract

By employing a special patterned mask, GaAs(100) facets have been formed and epitaxial lateral overgrowth (ELO) of GaAs was successfully achieved on a misoriented Si(100) substrate. After many trial and error experiments, two patterns of line seed arrangements were found to give a relatively good ELO. One is composed of short line seeds and the other of long line seeds in a star-like arrangement. When the first pattern was used and the orientation of the short line seeds was chosen as the direction of the substrate misorientation, a facet was easily formed and it was found that the facet goes from one end to the other of the line seed, since the step flow from the upper stream side is prevented by the presence of an oxide film which terminates on the end of the window. With the second pattern, facets were formed only on one side of the star, which has been explained by the non-uniformity of the supersaturation and the substrate misorientation. The best ELO ratio obtained so far by this technique is around 5.