| 摘要 |
A method for preparing a semiconductor substrate and a polysilicon gate for subsequent silicide formation. In one embodiment, the present invention performs an oxide etch to remove oxide from source and drain diffusion regions of the semiconductor substrate and from the top surface of the polysilicon gate. Next, the present invention subjects the semiconductor substrate and the polysilicon gate to an ashing environment. In the present invention, the ashing environment is comprised of H2O vapor, and a gaseous fluorocarbon or a fluorinated hydrocarbon gas. In so doing, contaminants introduced into the source and drain diffusion regions of the semiconductor substrate and into the top surface of the polysilicon gate during the oxide etch are removed. Next, the present invention performs a semiconductor wafer surface clean step. The semiconductor wafer surface clean step provides a semiconductor wafer surface which is substantially similar to a virgin silicon surface. As a result, the source and drain diffusion regions of the semiconductor substrate and the top surface of the polysilicon gate are prepared for subsequent silicide formation therein.
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