Gate patterning of nano-channel devices

Abstract

Methodologies and gate etching processes are presented to enable the fabrication of gate conductors of semiconductor devices, such as NFETs and/or PFETs, which are equipped with nano-channels. In one embodiment, a sacrificial spacer of equivalent thickness to the diameter of the gate nano-channel is employed and is deposited after patterning the gate conductor down to the gate dielectric. The residue gate material that is beneath the nano-channel is removed utilizing a medium to high density, bias-free, fluorine-containing or fluorine-and chlorine-containing isotropic etch process without compromising the integrity of the gate. In another embodiment, an encapsulation/passivation layer is utilized. In yet further embodiment, no sacrificial spacer or encapsulation/passivation layer is used and gate etching is performed in an oxygen and nitrogen-free ambient.