Patent ID: 7952149

Claim:
A semiconductor device, comprising: a first gate of a first gate length and a second gate of a second gate length; a first compensating dopant under the first gate, the first compensating dopant having a first concentration; and a second compensating dopant under the second gate, the second compensating dopant having a second concentration, wherein: the first gate length is longer than the second gate length, the first concentration is about 5.4×10 18 /cm 3 , the first concentration is higher than the second concentration, the first gate length is 40 nm, the second gate length is 30 nm, the second concentration lies in a range of about 3.0×10 18 /cm 3 to about 3.6×10 18 /cm 3 , and at least one of the first compensating dopant and the second compensating dopant comprise phosphorous.