Influence of Composition Ratio of In and Ga Atoms of InGaSb Bi-layer on Growth of InGaSb Thin Films on Si(111) Substrate

Abstract

The heteroepitaxial growth of InGaSb films via indium- and/or gallium-induced surface reconstruction on a Si(111) substrate was carried out by using surface reconstruction controlled epitaxy method in an ultra-high vacuum chamber. The influence of the composition ratio of the InGaSb bi-layer on the growth of the InGaSb films was studied. To find the growth condition for the 30°-rotated InGaSb films without twin, the composition ratio of In and Ga atoms of the initial InGaSb bi-layer on Si(111) surface was varied from 10 : 0 to 2 : 8 under the condition in which the composition ratio of the InGaSb films is fixed. The 30°-rotated InGaSb film with respect to the Si substrate was able to grow on the InSb bi-layer, but it showed a twin nature of the film. On the InGaSb bi-layer with the higher In composition ratio, the InGaSb films tend to form twins. On the other hand, InGaSb grown on the InGaSb bi-layer with the higher Ga composition does not rotate with respect to Si surface and has few twins. The structure of the InGaSb films is affected by the composition ratio of the underlying InGaSb bi-layer and by the composition ratio of the film. We could narrow down the range of growth conditions requited to grow 30°-rotated InGaSb films without twins in this study.