International Business Machines Corporation
Channel strain formation in vertical transport FETS with dummy stressor materials

Abstract:

Techniques for forming VTFET devices with tensile- and compressively-strained channels using dummy stressor materials are provided. In one aspect, a method of forming a VTFET device includes: patterning fins in a wafer; forming bottom source and drains at a base of the fins; forming bottom spacers on the bottom source and drains; growing at least one dummy stressor material along sidewalls of the fins above the bottom spacers configured to induce strain in the fins; surrounding the fins with a rigid fill material; removing the at least one dummy stressor material to form gate trenches in the rigid fill material while maintaining the strain in the fins by the rigid fill material; forming replacement gate stacks in the gate trenches; forming top spacers on the replacement gate stacks; and forming top source and drains over the top spacers at tops of the fins. A VTFET device is also provided.