Structure and formation of H-induced (111) platelets in Si

Abstract

We investigate the energetics of various structures for H-induced (1 1 1) platelets in Si through first-principles pseudopotential calculations. The formation energies are calculated as a function of lattice dilation along the [1 I I] direction. We find that a double-layer-H-2(*) structure is most stable in the absence of lattice dilation, while as dilation increases, an H-saturated Si(1 1 1) internal surface structure ([2Si-H](n)) is stabilized, accompanied with the generation of H-2 molecules. For the [2Si-H](n) structure with H-2 molecules in the void, calculated dilation length, internal pressure, and H-vibrational frequencies are in good agreements with experiments. (C) 2001 Elsevier Science B.V. All rights reserved.