Patent ID: 11942375
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 13:
14. A complementary metal-oxide-semiconductor (CMOS) transistor comprising:
a PMOS transistor having p-type epitaxial source/drains and a single n-type silicon germanium projection from a silicon substrate, wherein the single n-type silicon germanium projection is between the p-type epitaxial source/drains, a PMOS channel is formed by the single n-type silicon germanium projection, and the p-type epitaxial source/drains extend from recessed n-type silicon germanium projections from the silicon substrate;
an NMOS transistor having n-type epitaxial source/drains and a single p-type silicon projection that extends from the silicon substrate, wherein the single p-type silicon projection is between the n-type epitaxial source/drains and an NMOS channel is formed by the single p-type silicon projection and the n-type epitaxial source/drains extend from recessed p-type silicon projections from the silicon substrate;
wherein the PMOS transistor and the NMOS transistor have a common gate that covers a top of the single n-type silicon germanium projection and a top of the single p-type silicon projection, the top of the single p-type silicon projection has a first etched width, the top of the single n-type silicon germanium projection has a second etched width that is less than the first etched width, and the first etched width and the second etched width are along a longitudinal direction of the common gate; and
the first etched width of the single p-type silicon projection is about 6 nm to about 7 nm, the second etched width of the single n-type silicon germanium projection is about 4 nm to about 6 nm, an etched width difference between the first etched width of the single p-type silicon projection and the second etched width of the single n-type silicon germanium projection is 0.5 nm to 3 nm, and an etched width ratio of the first etched width of the single p-type silicon projection to the second etched width of the single n-type silicon germanium projection is 1.1 to 1.3.