Covalent bonding of metal atoms at the Schottky-barrier interface of GaAs, Ge, and Si

Electron energy loss and photoemission spectroscopies have been used to identify new interface electronic states due to the chemisorption of In on GaAs, Ge, and Si(111) surfaces. The chemical bonding at the metal–semiconductor interface appears to be intermediate between that of the bulk semiconductor and the free-electron behavior of the bulk metal.