New reconstructions of platinum silicide surface

Scanning tunneling microscopy (STM) studies of platinum suicide growth have been carried out after 5 and 10 monolayer (ML) of Pt deposition on a Si(111)7 × 7 surface and subsequent annealing at various temperatures up to 1100°C. Above 500°C, the islands of platinum suicide are terminated with different, new reconstructions depending on the amount of deposited material. Models for observed reconstructions are proposed, and the growth orientations and composition of formed suicides are determined. Between the islands, structural domains with a √3 × √ pattern expanding at the expense of platinum suicide crystallites with increasing temperature separated by numerous boundaries are found. From the structural features of domain borders it has been deduced that reconstruction atoms occupy only one type of site.