Vacancy-enhanced submonolayer nucleation of Si on Si(111)

Scanning tunneling microscopy (STM) and high-resolution low-energy electron diffraction techniques are used to determine the characteristics of the two-dimensional Si island distribution on detect-free and imperfect Si(1 1 1) surfaces in real space and reciprocal space. The surface power spectra of STM and modeling of diffraction profiles give consistent island separation. Unlike the submonolayer nucleation of silicon islands on a defect-free Si(1 1 1) surface, it is shown that the island size distribution of Si. nucleated on a Si(1 1 1) surface having a high density of vacancy defects,does not exhibit a preferred characteristic island size, The process is interpreted as defect-induced nucleation with the consistent with recent computer simulations, and are compared with other recent experimental work. (C) 2001 Elsevier Science B.V. All rights reserved.