Wrap-around contact for finFET

摘要

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.

主权项

1. A semiconductor structure, comprising:
a semiconductor substrate; a semiconductor fin disposed on the semiconductor substrate; an epitaxial region disposed on the semiconductor fin; a blanket oxide layer disposed on the semiconductor fin and the epitaxial region; a cavity in the blanket oxide layer, wherein at least one sidewall of the cavity comprises a contact etch stop layer, a width of the cavity is about a width of the epitaxial region plus twice a thickness of the contact etch stop layer, and a floor of the cavity comprises a top surface of the epitaxial region; and a fill metal disposed in the cavity, wherein the fill metal is in direct physical contact with the top surface of the epitaxial region.