Salicide Process for Silicide Wiring by Cvd
Original Publication Date: 1984-Jan-01
Included in the Prior Art Database: 2005-Feb-02
This article describes a method for making self-aligned silicide structures ("salicides") using LPCVD (low pressure chemical vapor deposition) to deposit tungsten (W) and using WF6 as a carrier gas to chemically react with the Si surface and to preclean the surface to promote surface reaction and minimize the deposition of W over the sidewall oxide spacers and other oxide covered areas. Existing methods for fabricating salicide structures encounter problems which are due to the non-uniform surface reactivity with "nominally clean" Si surfaces. They require high temperatures (in excess of 800ŒC) for a complete reaction with the Si, which also results in bridging between closely spaced lines, due to lateral diffusion of the Si during the thermally induced reaction with the overlying metal.