Patent ID: 9685383
Date: 2017-06-20
CPC Classifications: H01L

Claim:
1. A method of forming a semiconductor device, comprising: forming a first work function layer on a substrate; forming a first patterned photoresist layer on the first work function layer; partially removing the first work function layer by using the first patterned photoresist layer as a mask to form a patterned first work function layer, wherein a plurality of CxHyFz polymers is formed while partially removing the first work function layer; and removing the first patterned photoresist layer by providing radical oxygen, wherein the entire removing of the first patterned photoresist layer is performed with the radical oxygen, the CxHyFz polymers are oxidized by the radical oxygen and surfaces of non-removed first work function layer are also oxidized by the radical oxygen to obtain precise threshold voltage (Vt) differences between transistor regions by minimizing inaccuracy between a center Vt and an edge Vt in each of the transistor regions to less than 5 my.