Microstructure of epitaxial Ag/Si(111) and Ag/Si(100) interfaces

Abstract

The Ag/Si(111) and Ag/Si(100) interfaces have been investigated by high-resolution transmission electron microscopy. Flat-on-micrographs show that Ag is epitaxial on both Si(111) and Si(100), when deposited at room temperature and then annealed to 400°C. Cross-sectional lattice images show that two types of interface are possible for the Ag/Si(111) interface, one being related to the other by a 180° rotation of Ag around the Si[111] axis. By custom, these two orientations are called A and B, with A corresponding to Si(111)//Ag(111) with Si[110]//Ag[110], and B corresponding to Si(111)//Ag(111) with Si[114]//Ag[110]. As with the A1/Si(111) case, the interface is seen to be partially coherent, with one misfit dislocation every four Ag lattice planes. There is no apparent amorphous or disordered layer at the interface. Lattice images of the Ag/Si(100) interface are also presented, where two epitaxial orientations are observed: Ag(111)//Si(100) with Ag [011]//Si[011], and Ag(100)//Si(100) with Ag[011]//Si[011].