Patent ID: 7750374

Claim:
A process for forming an electronic device comprising: forming a semiconductor layer immediately adjacent to a semiconductor substrate; forming a first gate dielectric layer over and abutting the semiconductor layer; forming a first metal film over the first gate dielectric layer, wherein the first metal film abuts the first gate dielectric layer, includes a first metal element, and has a first work function; forming a second gate dielectric layer over and abutting the semiconductor layer, wherein the first and second gate dielectric layers have substantially the same composition and substantially the same thickness; forming a second metal film over the second gate dielectric layer, wherein the second metal film abuts the second gate dielectric layer, includes a second metal element, and has a second work function different from the first work function; forming a first metal gate electrode over the semiconductor layer, wherein: the first metal gate electrode includes a portion of the first metal film; the first metal gate electrode has substantially the first work function; and a first channel region associated with the first metal gate electrode has a first minority carrier type; and a first transistor includes the first metal gate electrode and the first channel region, and the first transistor has a first threshold voltage; and forming a second metal gate electrode over the semiconductor layer, wherein: the second metal gate electrode includes a portion of the second metal film; the second metal gate electrode has substantially the second work function; a second channel region associated with the second metal gate electrode has the first minority carrier type; and a second transistor includes the second metal gate electrode and the second channel region, and the second transistor has a second threshold voltage, wherein a potential difference between 0 volts and the second threshold voltage is greater than a potential difference between 0 volts and the first threshold voltage.