Electrochemical and Solid-State Letters vol:2 issue:4 pages:195-197
An interfacial intermixed Pt-Si layer formed during Pt sputtering at room temperature, and a subsequent selective etch step are found to be the keys for formation of continuous and uniform ultrathin PtSi layers. The etching, performed after the metal deposition, removes Pt at very fast rates. The etch rate is slowed when the Pt- Si interfacial layer is reached and an oxide is formed on top of the intermixed Pt-Si layer, which prevents further etching. During this process, a short- range diffusion mechanism is believed to transform the intermixed Pt-Si layer into a 3 nm thick continuous PtSi film. A subsequent annealing results in a more uniform grain size distribution, without changing the other characteristics of the film. Moreover, the silicide formed is insensitive to sputter conditions such as sputter power and time. (C) 1999 The Electrochemical Society. S1099- 0062( 98) 10- 119- 0. All rights reserved.