US Patent 9159794 Method to form wrap-around contact for finFET

Embodiments of the present invention provide an improved contact formation process for a finFET. Epitaxial semiconductor regions are formed on the fins. A contact etch stop layer (CESL) is deposited on the epitaxial regions. A nitride-oxide conversion process converts a portion of the nitride CESL into oxide. The oxide-converted portions are removed using a selective etch process, and a fill metal is deposited which is in direct physical contact with the epitaxial regions. Damage, such as gouging, of the epitaxial regions is minimized during this process, resulting in an improved contact for finFETs.