International Business Machines Corporation
VFET device with controllable top spacer

Abstract:

Techniques for controlling top spacer thickness in VFETs are provided. In one aspect, a method of forming a VFET device includes: depositing a dielectric hardmask layer and a fin hardmask(s) on a wafer; patterning the dielectric hardmask layer and the wafer to form a fin(s) and a dielectric cap on the fin(s); forming a bottom source/drain at a base of the fin(s); forming bottom spacers on the bottom source/drain; forming a gate stack alongside the fin(s); burying the fin(s) in a dielectric fill material; selectively removing the fin hardmask(s); recessing the gate stack to form a cavity in the dielectric fill material; depositing a spacer material into the cavity; recessing the spacer material to form top spacers; removing the dielectric cap; and forming a top source/drain at a top of the fin(s). A VFET device is also provided.