Patent ID: 8716077

Claim:
A method comprising: forming a recessed channel by forming a trench in a substrate; forming a first gate oxide to a first thickness lining the channel and second gate oxide to a second thickness over a portion of an upper surface of the substrate, wherein the first thickness differs from the second thickness; forming a first polysilicon gate having a first portion in the trench and a second portion overlying the first portion, above the upper surface of the substrate; forming a second polysilicon gate on the second gate oxide; forming first spacers on opposite sides of the second portion of the first polysilicon gate and second spacers on opposite sides of the second polysilicon gate; removing the first and second polysilicon gates, forming first and second cavities respectively; forming a high-k dielectric layer on the first and second gate oxides; and forming first and second metal gates in the first and second cavities, respectively.