Valence band and core lines investigation on the Ge–Au system by photoelectron spectroscopy with synchrotron radiation

Abstract

Core level and valence band photoemission experiments coupled to theoretical calculations reveal the formation of a stoichiometric Ge–Au phase during gold deposition onto Ge(111) at room temperature. This result is significantly different with respect to that found for the Si–Au system.

Gold Deposition by Galvanic Displacement on Semiconductor Surfaces: Effect of Substrate on Adhesion

“…The reason for the enhanced oxidation can be traced to the galvanic coupling between Au and semiconductor substrate . Furthermore, in the case of germanium, the 0.2−0.3 eV shift of the elemental Ge peak at nonzero Au coverage is indicative of a chemical interaction and is in agreement with previous synchrotron studies of the Au/Ge interface formed in a vacuum …”

“…18 Furthermore, in the case of germanium, the 0.2-0.3 eV shift of the elemental Ge peak at nonzero Au coverage is indicative of a chemical interaction and is in agreement with previous synchrotron studies of the Au/Ge interface formed in a vacuum. 19 The analysis of the valence band (VB) spectra, described below, bears out more striking signature of such interaction and points to the formation of the stoichiometric compound Au 3 Ge. Valence band spectra in the range from -2 eV to 14 eV were collected for silicon and germanium with increasing gold coverage, as well as for thick sputtered gold film as a reference.…”

“…In the absence of previous studies of interfacial formation during the galvanic displacement process, one can gain some insight in the process by turning to theoretical and experimental work on the electronic structure of Au-semiconductor interfaces formed in a vacuum. 19,[21][22][23][24][25][26][27][28][29][30] The occurrence of solid-state reactions at the interface between gold films and silicon or germanium has been evaluated at different temperatures, revealing significant differences between the two semiconductors. Despite the fact that the binary alloy phase diagrams 31 for Au/Si and Au/Ge appear similar and both are characterized by eutectic phases, several authors reported the formation of gold silicide and germanide with different structure.…”

“…In the absence of previous studies of interfacial formation during the galvanic displacement process, one can gain some insight in the process by turning to theoretical and experimental work on the electronic structure of Au−semiconductor interfaces formed in a vacuum. ,− …”

Forensic science

“…SEXAFS has beep used to study the adsorption of Cl, I, and Te on Ge(lll) and Ge(lll)-2 X 8 (765, 766). Valence band and core line investigations of the Ge-Au phase on gold-deposited Ge(lll) have been carried out by use of synchrotron photoemission spectroscopy (719). The atomic structure of Ge(lll) and its reactions with aluminum have been studied with LEED (1015).…”