Effects of the electron beam on InP(100)

Abstract

Auger Electron Spectroscopy (AES) is performed to monitor the InP(100) surface evolution while it is irradiated by an electron beam of 5 KeV energy and 10 −3 A.cm −2 current density. A charge phenomenon appears during the irradiation of sputter-cleaned InP(100) by Ar + at low energy (500 eV). The deposition of phosphorus or antimony at room temperature on cleaned InP(100) is a good way of preventing this charging problem. This is also achieved by the growth of stoichiometric indium phosphide on InP(100) substrate, from an injection of phosphine and indium trimethyl whose the ratio V/III is of 50, in a MOCVD (Metal Organic Chemical Vapor Deposition) reactor. The electron beam even acts to stimulate oxidation of the stoichiometric InP(100) surface involving on the top layers, into a well defined oxide such as InPO 4 or a contamination layer composed of carbon and oxygen. The partial pressure in the spectrometer is about 10 −9 Torr. The incident electrons produce breaking of (In-P) chemical bonds so that the resulting indium takes part in the oxidation process. The phosphorus is thought to be desorbed from the surface.