Control of abnormal edge growth in selective area MOVPE of InP

In selective-area MOVPE of InP, we often encounter an abnormally grown ridge near the mask edge accompanied by various facets. The effect of mask shape and growth conditions on the shape and cross-sectional area of the ridge was investigated. The cross-sectional area showed a parabolic increase with time. The direction of the stripe growth area had a significant effect on the edge growth. When the stripe was oriented to [1 0 0] or [0 1 0] direction, the cross-sectional area of the ridge showed a significant increase and was accompanied by a (1 1 0) facet, although the edge growth in other conditions was often accompanied by (1 1 1)B facets. A numerical simulation, incorporating the surface diffusion of a precursor, was introduced and the amount of the edge growth was reproduced. The effect of growth conditions on the cross-sectional area of the edge growth was interpreted in terms of the surface diffusion length of the precursor on both masks and growth areas.