SURFACTANT-MEDIATED EPITAXY OF GE ON PARTIALLY GA-TERMINATED SI(111) SURFACES

Surfactant-mediated heteroepitaxy of Ge on Si(111) with Ga as surfacta nt has been studied using a recently developed apparatus of scanning r eflection electron microscopy combined with scanning tunneling microsc opy. It has been found that Ge film formation of 4.3 ML thickness on a Ga-terminated root 3x root 3 surface results in two-dimensional islan d growth in contrast with pseudomorphic growth on 7x7 surface. Irregul ar growth of Ge clusters along the lower sides of atomic step edges al so takes place on the root 3x root 3 surface at an elevated substrate temperature. Ge film was also grown on partially Ga-terminated Si(lll) with both Ga-adsorbed root 3x root 3 and Ga-desorbed 7x7 reconstructi on areas on the surface. It has been found that self-organized Ge clus tering occurs along the Ga-desorbed 7x7 area with stripe shape. (C) 19 96 American Institute of Physics.