International Business Machines Corporation
Forming Gate Last Vertical FET With Self-Aligned Spacers and Junctions

Abstract:

Techniques for forming gate last VFET devices are provided. In one aspect, a method of forming a VFET device includes: forming a stack on a wafer including: i) a doped bottom source/drain, ii) sacrificial layers having layers of a first sacrificial material with a layer of a second sacrificial material therebetween, and iii) a doped top source/drain; patterning trenches in the stack to form individual gate regions; filling the trenches with a channel material to form vertical fin channels; selectively removing the layers of the first sacrificial material forming first cavities in the gate regions; forming gate spacers in the first cavities; selectively removing the layer of the second sacrificial material forming second cavities in the gate regions; and forming replacement metal gates in the second cavities. A VFET device is also provided.