Changing the size and shape of Ge island by chemical etching

Self-assembled Ge islands were grown on Si (1 0 0) substrate by Si2H6-Ge mo lecular beam epitaxy. Subjected to a chemical etching, it is found that the size and shape (i.e. ratio of height to base width) of Ge islands change w ith etching time. In addition, the photoluminescence from the etched Ge isl ands shifted to the higher energy side compared to that of the as-deposited Ge islands. Our results demonstrated that chemical etching can be a way to change the size and shape of the as-deposited islands as well as their lum inescence property. (C) 2001 Elsevier Science B.V. All rights reserved.