Patent ID: 7390709

Claim:
A method for making a semiconductor device comprising: forming a first dielectric layer on a substrate; forming a trench within the first dielectric layer; forming a second dielectric layer on the substrate, the second dielectric layer having a first part that is formed at the bottom of the trench and a second part; forming a first metal layer having a first workfunction on the first part of the second dielectric layer and on the second part of the second dielectric layer; and converting the first metal layer, where formed on the first part of the second dielectric layer, into a second metal layer with a second workfunction by: masking the first metal layer with a sacrificial light absorbing material; forming a photoresist layer on the sacrificial light absorbing material; patterning the photoresist layer such that a first portion of the sacrificial light absorbing material may subsequently be removed; removing the first portion of the sacrificial light absorbing material, which first portion overlies the first part of the second dielectric layer, while leaving a second portion of the sacrificial light absorbing material overlying the second part of the second dielectric layer; and adding a workfunction shifting component to the first metal layer, where formed on the first part of the second dielectric layer, wherein: the sacrificial light absorbing material includes a light absorbing dye that absorbs light at a wavelength used in the patterning of the photoresist layer.