Semiconductor device and manufacture method thereof
A semiconductor device includes a semiconductor substrate and at least one gate stack. The gate stack is present on the semiconductor substrate, and the gate stack includes at least one work function conductor and a filling conductor. The work function conductor has a recess therein. The filling conductor includes a plug portion and a cap portion. The plug portion is present in the recess of the work function conductor. The cap portion caps the work function conductor.
1. A semiconductor device, comprising:
a first gate stack comprising:
a first work function conductor; and
a first filling conductor comprising a plug portion and a cap portion; and
a first gate spacer disposed on a first side of the first gate stack, wherein:
the cap portion overlies an uppermost surface of the first work function conductor, and
a sidewall of the plug portion is spaced apart from a sidewall of the first gate spacer by the first work function conductor.
2. The semiconductor device of claim 1 , wherein a sidewall of the cap portion and a sidewall of the first work function conductor are in direct contact with the sidewall of the first gate spacer.
3. The semiconductor device of claim 1 , wherein the plug portion is between a first portion of the first work function conductor and a second portion of the first work function conductor.
4. The semiconductor device of claim 1 , comprising:
a second work function conductor overlying the first work function conductor.
5. The semiconductor device of claim 1 , comprising a dielectric cap overlying the cap portion.
6. The semiconductor device of claim 1 , comprising a semiconductor fin disposed below the first gate stack.
7. The semiconductor device of claim 4 , wherein the sidewall of the plug portion is spaced apart from the sidewall of the first gate spacer by the second work function conductor.
8. The semiconductor device of claim 4 , wherein the first work function conductor is one of an n-type work function conductor or a p-type work function conductor and the second work function conductor is the other of the n-type work function conductor or the p-type work function conductor.
9. The semiconductor device of claim 5 , wherein the dielectric cap is in direct contact with the sidewall of the first gate spacer.
10. The semiconductor device of claim 5 , wherein cap portion is between the first work function conductor and the dielectric cap.
11. A semiconductor device, comprising:
a first gate spacer and a second gate spacer; and
a gate stack disposed between the first gate spacer and the second gate spacer, the gate stack comprising:
a gate dielectric;
a first work function conductor over the gate dielectric;
a filling conductor over the first work function conductor; and
a dielectric cap, wherein a cap portion of the filling conductor is between an uppermost surface of the first work function conductor and the dielectric cap.
12. The semiconductor device of claim 11 , wherein the filling conductor comprises a plug portion and the cap portion, wherein the plug portion is spaced apart from first gate spacer by the first work function conductor.
13. The semiconductor device of claim 11 , wherein the gate dielectric is in direct contact with the first gate spacer and the second gate spacer.
14. The semiconductor device of claim 11 , comprising:
a second work function conductor between the first work function conductor and the filling conductor.
15. The semiconductor device of claim 12 , wherein the cap portion is in direct contact with the first gate spacer.
16. A method of manufacturing a semiconductor device, the method comprising:
forming a first work function conductor between a first gate spacer and a second gate spacer, wherein the first work function conductor defines a first recess;
recessing the first work function conductor to define a second recess having a second width greater than a first width of the first recess;
forming a filling conductor in the first recess and the second recess; and
recessing the filling conductor to define a third recess.
17. The method of claim 16 , comprising forming a dielectric layer in the third recess.
18. The method of claim 16 , the recessing the filling conductor comprising recessing the filling conductor while maintaining a portion of the filling conductor above an uppermost surface of the first work function conductor.
19. The method of claim 16 , comprising forming a second work function conductor over the first work function conductor prior to the recessing the first work function conductor.
20. The method of claim 16 , wherein the third recess has the second width.