FINFET WITH WIDE UNMERGED SOURCE DRAIN EPI

摘要

A method including forming fin spacers on opposite sidewalls of a semiconductor fin made from a semiconductor substrate, forming a dielectric layer in direct contact with the fin spacers such that a top surface of the fin and a top surface of the fin spacers remain exposed, recessing a portion of the fin between the fin spacers, removing the fin spacers to create an opening, and epitaxially growing an unmerged source drain region in the opening, where lateral growth of the unmerged source drain region is constrained on opposite sides by the dielectric layer.

主权项

1. A method comprising:
forming a fin on a semiconductor substrate; forming a shallow trench isolation layer directly on top of the substrate adjacent to the fin; forming a dummy gate directly on top of the shallow trench isolation layer, the dummy gate oriented perpendicular to and directly covering a first portion of the fin; forming dummy gate spacers on opposite sidewalls of the dummy gate, and forming fin spacers on opposite sidewalls of a second portion of the fin; forming a dielectric layer directly on top of the shallow trench isolation layer and in contact with the fin spacers, a top surface of the dielectric layer is at or below a top surface of the fin; recessing the second portion of the fin between the fin spacers down to or below a top surface of the shallow trench isolation layer to form a first opening; removing the fin spacers selective to the dielectric layer to expand the first opening and to form a second opening between adjacent portions of the dielectric layer; and forming an unmerged source drain region in the second opening by epitaxially growing a semiconductor material from an exposed surface of a remaining portion of the fin at or near a bottom of the second opening, wherein lateral growth of the semiconductor material is constrained by the dielectric layer.