Directional dependence of InAs island formation on patterned GaAs

Strained, coherent InAs islands were grown in the Stranski-Krastanov growth mode on patterned GaAs by chemical beam epitaxy. The present work represents initial steps in quantitatively understanding the placement and growth of islands in patterns. The trade-offs between regular pattern features and better island nucleation are demonstrated by a deposition on a pattern of concentric circles. InAs mass transport is also measured, where material is seen to move on the order of a micron to and from different local orientations. An important practical result is that the pattern definition for island alignment need not be finer than 0.25 mu m, within the reach of present-day optical lithography.