Patent ID: 7678631

Claim:
A method of forming a semiconductor structure comprising: forming a substrate comprising an amorphous region and a crystalline region; depositing non-selectively in a process chamber a two-component epitaxial layer above said amorphous region and above said crystalline region of said substrate, wherein said two-component epitaxial layer is comprised of carbon-doped silicon, and wherein the depositing of said two-component epitaxial layer comprises first flowing the deposition gases SiH 4 , CH 3 SiH 3 and H 2 in a ratio of 300:55:500 sccm for about 1 minute and then doing a hydrogen gas purge at 1 slm for about 1 minute; and then, without removing said substrate from said chamber, etching in said process chamber said two-component epitaxial layer, wherein the etching of said two-component epitaxial layer comprises first flowing the etch gases Cl 2 and H 2 in the ratio 16 sccm:1 slm for about 45 seconds and then doing a hydrogen gas purge at 2 slm for about 2 minutes, wherein etching said two-component epitaxial layer removes the portion of said two-component epitaxial layer above said amorphous region of said substrate, and wherein etching said two-component epitaxial layer does not remove the portion of said two-component epitaxial layer above said crystalline region of said substrate.