The deposition of transition metal layers on sulphur-terminated InP(100) surfaces studies by core level photoemission spectroscopy

Abstract

The deposition of thin layers of manganese and iron on sulphur-terminated InP(100) surfaces has been investigated by soft X-ray core level photoemission. The sulphur treatment was carried out in situ using an ultrahigh vacuum compatible electrochemical source. Thin metal layers of manganese and iron were deposited onto the sulphur-induced (2×1) surface reconstruction of both n- and p-type InP(100) at room temperature. The Fermi level position for both doping types following sulphur deposition and anneal was found to lie in the range 1.05–1.15 eV above the top of the valence band. There is evidence of a strong chemical interaction between the metals and the sulphur-terminated surface which removes the (2×1) surface reconstruction and moves the Fermi level back towards a mid-gap position for both doping types. Chemically shifted components of the In 4d and P 2P core levels diffuse out through the growing metal overlayers and the sulphur segregates to the top.