US Patent 11949011 Vertical transistor with gate encapsulation layers

A semiconductor structure including a bottom source drain region arranged on a substrate, a semiconductor channel region extending vertically upwards from a top surface of the bottom source drain region, a metal gate disposed around the semiconductor channel region, a top source drain region above the semiconductor channel region, an amorphous silicon layer directly on top of the metal gate, and an oxidation layer directly on top of the amorphous silicon layer, where the amorphous silicon layer and the oxidation layer together completely separate the metal gate from a surrounding interlevel dielectric layer.