Abstract
A genuine GaAs surface was covered with a relatively thick layer (~ nm) of native oxide pinning the surface Fermi level within the band gap of semiconductor. The method presented in this work is related to the sulphur passivation by treating n-GaAs in sulphide solutions (e.g. pure ammonium sulphide and sulphur monochloride) that combines both chemical and electronic passivation by reducing the surface state density. The presence of the covalent bonds As-S and Ga-S was putted into evidence by XPS analysis. It is presented the independence of XPS measurements on n-GaAs substrate orientation for
(100) and (110) planes. At the surface of n-GaAs it is developed an adherent layer of sulphur compound as a result of chemical interaction of sulphur ions with n-GaAs surface.
Keywords
XPS analysis, Sulphide chemical passivation, n-GaAs substrates.
Citation
R. V. GHITA, C. C. NEGRILA, F. UNGUREANU, C. LOGOFATU, XPS study of chemically sulphur-passivated n-GaAs, Optoelectronics and Advanced Materials - Rapid Communications, 4, 11, November 2010, pp.1736-1739 (2010).
Submitted at: Oct. 28, 2010
Accepted at: Nov. 10, 2010