Semiconductor device having work function metal stack
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsYen-Yu CHEN, Yu-Chi LU, Chih-Pin TSAO, Shih-Hsun CHANG
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Abstract
A method includes removing a dummy gate to form a gate trench. A gate dielectric layer is deposited over a bottom and sidewalls of the gate trench. A first work function metal layer is deposited over the gate dielectric layer. A dummy layer is deposited over the first work function metal layer. An impurity is introduced into the dummy layer and the first work function metal layer after the dummy layer is deposited. The dummy layer is removed after the impurity is introduced into the dummy layer and the first work function metal layer. The gate trench is filled with a conductive material after the dummy layer is removed.
Claims20
A device, comprising:
- a pair of gate spacers on a substrate;
- and
- a gate structure between the pair of gate spacers, the gate structure comprising a first work function metal layer, a tungsten-containing material over the first work function metal layer, a second work function metal layer over the tungsten-containing material, and a fill metal over the second work function metal layer.
A device, comprising:
- a gate stack on a substrate, the gate stack comprising a gate dielectric layer, a first p-type work function layer over the gate dielectric layer, a second p-type work function layer over the first p-type work function layer, and a tungsten-containing structure between the first p-type work function layer and the second p-type work function layer;
- and
- gate spacers on either side of the gate stack.
A device comprising:
- a p-type field effect transistor (PFET) comprising a PFET gate, the PFET gate comprising a first plurality of p-type work function metal layers, a first n-type work function metal layer, and a first tungsten-containing material interposing a first one and a second one of the first plurality of p-type work function metal layers;
- and
- an n-type field effect transistor (NFET) comprising an NFET gate, the NFET gate comprising a second plurality of p-type work function metal layers, a second n-type work function metal layer, and a second tungsten-containing material interposing a first one and a second one of the second plurality of p-type work function metal layers, wherein a number of the first plurality of p-type work function metal layers of the PFET gate is different from a number of the second plurality of p-type work function metal layers of the NFET gate.
Dependencies are inferred from the claim text.