LEED structure analysis of Sb adsorbed Si(001) surface

Sb adsorbed Si(001) surfaces have been investigated by LEED and AES. After a few monolayer (ML) deposition at room temperature, the LEED patterns of 1 x 1, 2 x 1 and c(4 x 4) have been observed successively as elevating the a nnealing temperature. Two structures (1 x 1 and 2 x 1) were examined by LEE D I-V curve analysis. The genetic algorithm (GA) was operated to search a g lobal optimum structure. For the I x 1 structure, a good R-factor value of 0.22 was obtained for the model in which topmost 1 ML Sb atoms sit on the S i atoms of fourth substrate layer. For the 2 x 1 structure, two cases of 1 ML and a half ML Sb coverage was examined, and an Sb dimer model with 1 ML coverage gave a better R-factor value. (C) 2001 Elsevier Science B.V. All r ights reserved.