Separately optimized gate structures for n-channel and p-channel transistors in an integrated circuit Patent #: 6255698
ApplicationNo. 754637 filed on 01/04/2001
US Classes:257/369, Complementary insulated gate field effect transistors257/407, With gate electrode of controlled workfunction material (e.g., low workfunction gate material)257/412, Gate electrode of refractory material (e.g., polysilicon or a silicide of a refractory or platinum group metal)257/915WITH TITANIUM NITRIDE PORTION OR REGION
ExaminersPrimary: Prenty, Mark V.
Attorney, Agent or Firm
Foreign Patent References
International ClassH01L 029/76
Foreign Application Priority Data2000-01-21 JP
AbstractOne object of the present invention is to suppress a threshold voltage of at least an n-channel MISFET using a nitride of a high melting point metal at it's gate electrode. In order to achieve the object, a gate electrode 109 of a p-channel MISFET is constituted of a titanium nitride film 106 and a tungsten film 107 formed on the film 106 and a gate electrode 110a of an n-channel MISFET is constituted of a titanium nitride film 106a and a tungsten film 107 formed on the film 106a. The titanium nitride film 106a is formed by nitrogen ion implantation in the titanium nitride film 106 to decrease the work function.
Field of SearchComplementary insulated gate field effect transistors
Complementary transistors in wells of opposite conductivity types more heavily doped than the substrate region in which they are formed, e.g., twin wells
Insulated gate field effect transistors of different threshold voltages in same integrated circuit (e.g., enhancement and depletion mode)
With gate electrode of controlled workfunction material (e.g., low workfunction gate material)
Gate insulator includes material (including air or vacuum) other than SiO 2
Gate electrode of refractory material (e.g., polysilicon or a silicide of a refractory or platinum group metal)
WITH TITANIUM NITRIDE PORTION OR REGION