Patent ID: 8372703

Claim:
A method comprising: providing a transistor region having: a first source/drain region formed in a substrate and doped with a first dopant of a first conductivity type; a second source/drain region formed in the substrate and doped with the first dopant; a channel region located in the substrate between the first and second source/drain regions; a first sidewall formed over the substrate; a second sidewall formed over the substrate; a trench located between the first and second sidewalls over at least a portion of the channel region; a gate dielectric layer formed over the substrate and located within the trench, wherein the gate dielectric layer is formed of a high-k material; and an original gate electrode formed over the gate dielectric layer and doped with the first dopant; isolating and exposing the original gate electrode; removing the exposed original gate electrode with a wet etch solution, wherein the wet etch solution is more reactive with the first dopant than a second dopant of a second conductivity type, and wherein the wet etch solution is generally nonreactive with the gate dielectric layer, and wherein, following the step of removing, the trench includes a first surface, a second surface, and a third surface, and wherein the first and second surfaces are substantially parallel to one another and border the first and second sidewalls, and wherein the third surface is substantially perpendicular to the first and second surfaces and defines the length of the trench, and wherein the gate dielectric layer extends across the entire length of the trench; following the step of removing, forming a first liner layer in the trench and over the gate dielectric layer, wherein the first liner layer includes a first metal; forming a second liner layer in the trench and over the first liner layer, wherein the second liner layer includes a second metal; and forming a replacement gate electrode over the second liner layer so as to substantially fill the trench, wherein the gate electric electrode includes a third metal.