Patent ID: 6873048
Filing Date: 2005-03-29
Classification: H01L

Abstract:
1. In a dual-gate MOSFET with metal gates, a method for setting threshold voltage, the method comprising: forming a gate oxide layer overlying first and second channel regions; forming a first metal layer having a first thickness overlying the gate oxide layer; forming a second metal layer having a second thickness overlying the first metal layer first thickness; selectively removing the second metal layer overlying the first channel region; forming a third metal layer having a fourth thickness overlying the first and second channel regions; establishing a first MOSFET with a gate work function responsive to the thicknesses of the first and third metal layers overlying the first channel region; and, establishing a second MOSFET, complementary to the first MOSFET, with a gate work function responsive to the combination of the thicknesses of the first, second, and third metal layers overlying the second channel region.