Control of structure, size and density of Ge dot on Si (100) through multistep procedure

We propose a multistep procedure for Ge dot growth on Si (1 0 0) substrates . This procedure includes (i) submonolayer C deposition on a Ge wetting lay er or a Ge surface, (ii) Ge deposition at low temperature and (iii) postann ealing after Ge and C deposition for controlling size, structure and densit y of the Ge dots. The main effect of C on Ge wetting layer was to enhance a structure transition of the Ge dot. Meanwhile, C on the Ge surface was fou nd to suppress a structure modification of the Ge dots against post-anneali ng. The structure of Ge layers deposited at low temperature was readily mod ified upon post-annealing. By combining these procedures and optimizing exp erimental conditions, 10 nm-sized Ge dots with a high number density in the order of 10(11) cm(-2) were successfully grown on the Si (1 0 0) substrate . (C) 2001 Elsevier Science B.V. All rights reserved.