Patent ID: 8906770

Claim:
A method of forming a semiconductor structure comprising: forming an isolation region; forming a gate insulation structure that touches and lies above a channel region of a first conductivity type; forming a gate structure that touches the gate insulation structure and the isolation region, and lies above the channel region; forming a first implant blocking structure to touch the gate structure, the first implant blocking structure having a first opening that exposes a first portion of the gate structure; implanting dopant atoms of a second conductivity type through the first opening into the gate structure to form a first gate region that lies above the channel region; replacing the first implant blocking structure with a second implant blocking structure that touches the gate structure, the second implant blocking structure having a second opening that exposes the first portion of the gate structure, a second portion of the gate structure, and a third portion of the gate structure; and implanting dopant atoms of the second conductivity type through the second opening into the gate structure to increase a dopant concentration of the first gate region, and form a second gate region and a third gate region that each touches the first gate region.