Semiconductor device with dummy gate and metal gate and method of fabricating the same
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsAlexander Kalnitsky, Wei-Cheng Wu, Harry-Hak-Lay Chuang
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Abstract
A semiconductor device includes a substrate, a first well, a second well, a metal gate, a poly gate, a source region, and a drain region. The first well and the second well are within the substrate. The metal gate is partially over the first well. The poly gate is over the second well. The poly gate is separated from the metal gate, and a width ratio of the poly gate to the metal gate is in a range from about 0.1 to about 0.2. The source region and the drain region are respectively within the first well and the second well.
Claims20
A method of fabricating a semiconductor device, comprising:
- forming a first well and a second well in a substrate, wherein the first well and the second well are doped with different types of dopants;
- forming a dummy gate partially over the first well and partially over the second well, wherein the dummy gate comprises a dummy gate stack;
- forming a poly gate over the second well, wherein the poly gate comprises a poly gate stack, and a gap is between the dummy gate and the poly gate;
- forming a source region and a drain region respectively in the first well and the second well, wherein the source region and the drain region are doped with a same type of dopants;
- and
- replacing the dummy gate stack with a metal gate stack, comprising:
- disposing a hard mask covering the poly gate;
- removing the dummy gate stack to form a trench;
- filling the trench with materials of the metal gate stack while the hard mask remains covering the poly gate;
- performing a first planarization process to the materials of the metal gate stack, such that the hard mask is exposed;
- removing the hard mask after performing the first planarization process;
- and
- performing a second planarization process after removing the hard mask, such that a top surface of the metal gate stack is coplanar with a top surface of the poly gate.
A method of fabricating a semiconductor device, comprising:
- forming a first isolation structure and a second isolation structure in a substrate, wherein a portion of the substrate extends from the first isolation structure to the second isolation structure;
- forming a first dummy gate structure and a second dummy gate structure over the portion of the substrate;
- forming a source region and a drain region in the portion of the substrate, wherein the source region is between the first isolation structure and the first dummy gate structure, and the drain region is between the second dummy gate structure and the second isolation structure;
- forming a resist protection layer over the first and second dummy gate structures, wherein the resist protection layer extends from the first dummy gate structure to the second dummy gate structure;
- after forming the resist protection layer, forming a hard mask over the second dummy gate structure, wherein the hard mask covers the second dummy gate structure but exposes the first dummy gate structure, and the hard mask is in contact with the resist protection layer;
- and
- replacing the first dummy gate structure with a metal gate structure.
A method of fabricating a semiconductor device, comprising:
- forming a first dummy gate structure, a second dummy gate structure, a third dummy gate structure, and a fourth dummy gate structure over a substrate, wherein the second and third dummy gate structures are between the first and fourth dummy gate structures;
- forming a first source region, a second source region, and a drain region in the substrate such that the first and second dummy gate structures are between the first source region and the drain region and the third and fourth dummy gate structures are between the second source region and the drain region;
- forming a resist protection layer between the first and second dummy gate structures;
- forming a hard mask to cover the drain region, the second dummy gate structure, and the third dummy gate structure but not the first and fourth dummy gate structures;
- and
- after forming the hard mask, replacing the first and fourth dummy gate structures with metal gate structures.
Dependencies are inferred from the claim text.