Patent ID: 9496143
Filing Date: 2016-11-15
CPC Classification: H01L

Claim Text:
1. A method of fabricating a midgap semiconductor device, the method comprising: providing a p-type semiconductor device; creating an annealed first work function layer over only the p-type semiconductor device, wherein the first work function layer comprises a transition metal nitride; creating an unannealed second work function layer over the annealed first work function layer, wherein the second work function layer comprises a transition metal nitride; creating a barrier layer over the second work-function layer; creating n-type metal over the barrier layer, wherein the p-type semiconductor device, the annealed first work function layer, the second work function layer, the barrier layer and the n-type metal together form a midgap semiconductor device, the midgap semiconductor device having a work-function between that of an n-type device and a p-type device; wherein the p-type semiconductor device comprises a p-type field-effect transistor (PFET); and wherein the first work function layer and the second work function layer comprise TiN, and wherein the barrier layer has a thickness of about 10 Angstroms, the n-type metal has a thickness of about 30 Angstroms to about 70 Angstroms, the second layer of TiN has a thickness of about 20 Angstroms to about 50 Angstroms, and the layer of annealed TiN has a thickness of about 30 Angstroms to about 60 Angstroms.