Sputtering of the ternary alloy system AgAuCu with 2 keV Ar ions

Abstract

In the sputtering of composite materials it is found, in general, that the surface composition is changed due to preferential sputtering. The surface composition of the ternary alloy system AgAuCu has been studied under 2 keV argon ion bombardment using Auger electron spectroscopy. This alloy system forms solid solutions except for alloys rich in Ag and Cu. 28 alloys, 21 of which were singlephase, with different compositions were analyzed. The observe changes in the surface composition due to ion bombardment reference data for the bulk composition were obtained by scribing and fracturing the samples in the UHV-system. Surface enrichment of Au and Cu was found under ion bombardment. The surface concentration ratio Au/Cu, however, was not changed as compared with the bulk concentration ratio. The sputtering yield ratios S(Ag)/ S(Cu) and s(Ag)/ S(Au) were found to be about 2.5 independent of the alloy composition. These results agree well with measurements on the binary systems AgAu with Au enrichment and AuCu without changes in surface composition due to sputtering. For alloys rich in Ag and Cu, which do not form solid solutions, a pronounced enrichment of Ag for fractured surfaces was observed, and after scribing the surface was found equal in composition to the bulk.