Patent ID: 7943468

Claim:
A method of forming a semiconductor device, comprising: forming a gate stack on a well-free region of a substrate; implanting dopant impurity atoms of a first conductivity type into the substrate to form tip regions in the substrate on either side of the gate stack, wherein the gate stack blocks the implanting of dopant impurity atoms of the first conductivity type in the substrate directly below the gate stack during the formation of the tip regions; and implanting dopant impurity atoms of a second conductivity type, opposite the first conductivity type, into the substrate to form a pair of halo regions adjacent the tip regions and to form a threshold voltage implant region in the substrate directly below the gate stack, the threshold voltage implant region and both the halo regions forming a single continuous region beneath the entire gate stack, wherein implanting the dopant impurity atoms of the second conductivity type includes implanting through the gate stack into the substrate.