Patent ID: 9349652
Filing Date: 2016-05-24
CPC Classification: H01L

Claim Text:
1. A method comprising: forming a first gate stack over a first fin feature and second gate stack over a second fin feature; removing the first gate stack to form a first gate trench that exposes the first fin feature; removing the second gate stack to form a second gate trench that exposes the second fin feature; forming an oxidation layer in the first gate trench; after forming the oxidation layer, performing an annealing process to change a composition of a portion of the first fin feature, wherein performing the annealing process to change the composition of the portion of the first fin feature includes forming an oxide layer under the oxidation layer, wherein the oxidation layer is different from the oxide layer; and forming a first high-k/metal gate (HK/MG) within the first gate trench over the portion of the first fin feature and a second HK/MG within the second gate trench over the second fin feature, wherein the first HK/MG is formed with a first threshold voltage and the second HK/MG is formed with a second threshold voltage, which is different than the first threshold voltage.