Dishing prevention structure embedded in a gate electrode

1. A semiconductor device, comprising:

a semiconductor substrate;

a gate dielectric disposed over the semiconductor substrate;

a first source/drain region and a second source/drain region disposed in the semiconductor substrate and on opposite sides of the gate dielectric;

a gate electrode disposed over the gate dielectric; and

a plurality of dishing prevention structures embedded in the gate electrode, wherein:

each of the plurality of dishing prevention structures is disposed within a perimeter of the gate electrode;

each of the plurality of dishing prevention structures have a bottommost surface that is disposed vertically between an upper surface of the gate electrode and an upper surface of the gate dielectric; and

each of the plurality of dishing prevention structures are laterally spaced from each other one of the plurality of dishing prevention structures.

2. The semiconductor device of claim 1 , wherein the plurality of dishing prevention structures have rounded bottom surfaces.

3. The semiconductor device of claim 1 , wherein:

the plurality of dishing prevention structures comprise a dielectric material; and

the gate electrode comprises a metal.

4. The semiconductor device of claim 1 , wherein an area of a first dishing prevention structure of the plurality of dishing prevention structures is substantially the same as an area of a second dishing prevention structure of the plurality of dishing prevention structures.

5. The semiconductor device of claim 1 , wherein an area of a first dishing prevention structure of the plurality of dishing prevention structures is different than an area of a second dishing prevention structure of the plurality of dishing prevention structures.

6. The semiconductor device of claim 1 , further comprising:

a conductive contact electrically coupled to the gate electrode, wherein the conductive contact is spaced from each of the plurality of dishing prevention structures.

7. The semiconductor device of claim 6 , wherein:

the gate electrode comprises a sidewall; and

the conductive contact is disposed closer to the sidewall than each of the plurality of dishing prevention structures.

8. The semiconductor device of claim 1 , wherein each of the plurality of dishing prevention structures have an upper surface that is at or below an uppermost point of the gate electrode.

9. The semiconductor device of claim 1 , wherein each of the plurality of dishing prevention structures directly contact the gate electrode.

10. The semiconductor device of claim 9 , wherein:

the bottommost surface of each of the plurality of dishing prevention structures directly contacts the gate electrode; and

each of the plurality of dishing prevention structures have sidewalls that directly contact the gate electrode.

11. The semiconductor device of claim 1 , wherein:

the perimeter of the gate electrode is defined by a plurality of outer sidewalls of the gate electrode; and

each of the plurality of dishing prevention structures are laterally spaced from each of the plurality of outer sidewalls of the gate electrode.

12. The semiconductor device of claim 1 , wherein the plurality of dishing prevention structures comprise:

a first row of dishing prevention structures;

a second row of dishing prevention structures, wherein the second row of dishing prevention structures is laterally spaced from the first row of dishing prevention structures in a first direction;

a first column of dishing prevention structures; and

a second column of dishing prevention structures, wherein the second column of dishing prevention structures is laterally spaced from the first column of dishing prevention structures in a second direction that is perpendicular to the first direction.

13. An integrated chip (IC), comprising:

a semiconductor substrate;

a first gate dielectric disposed over the semiconductor substrate;

a first gate electrode disposed over the first gate dielectric, wherein the first gate electrode has a first length;

a second gate dielectric disposed over the semiconductor substrate and spaced from the first gate dielectric;

a second gate electrode disposed over the semiconductor substrate and spaced from the first gate electrode, wherein the second gate electrode has a second length greater than the first length; and

a plurality of dishing prevention structures embedded in the second gate electrode, wherein:

each of the plurality of dishing prevention structures have a bottommost surface that is disposed between an upper surface of the second gate electrode and a bottom surface of the second gate electrode;

each of the plurality of dishing prevention structures have an upper surface that is disposed at or below an uppermost point of the second gate electrode;

each of the plurality of the dishing prevention structures are laterally surrounded by a corresponding portion of the second gate electrode; and

each of the plurality of dishing prevention structures are laterally spaced from each other one of the plurality of dishing prevention structures.

14. The IC of claim 13 , wherein the second gate electrode comprises:

a first conductive structure having a first conductive material; and

a second conductive structure having a second conductive material different than the first conductive material, wherein the second conductive structure lines a bottom surface of the first conductive structure and sidewalls of the first conductive structure, and wherein each of the plurality of dishing prevention structures is spaced from the second conductive structure by a corresponding portion of the first conductive structure.

15. The IC of claim 13 , wherein:

each of the plurality of dishing prevention structures have a first chemical-mechanical polishing (CMP) removal rate for a CMP process;

the second gate electrode has a second CMP removal rate for the CMP process; and

the second CMP removal rate is greater than the first CMP removal rate.

16. The IC of claim 13 , wherein:

the first gate electrode comprises a first conductive structure comprising a metal; and

the metal extends continuously between opposite sidewalls of the first conductive structure in an uppermost portion of the first conductive structure.

17. The IC of claim 13 , wherein the bottommost surface of each of the plurality of dishing prevention structures are vertically spaced from an upper surface of the second gate dielectric.

18. A semiconductor device, comprising:

a semiconductor substrate;

a gate dielectric disposed over the semiconductor substrate;

a pair of source/drain regions disposed in the semiconductor substrate, wherein the source/drain regions are disposed on opposite sides of the gate dielectric;

a gate electrode disposed over the gate dielectric, wherein the gate electrode comprises a metal, and wherein the gate electrode comprises a plurality of outer sidewalls; and

a plurality of dishing prevention structures embedded in the gate electrode, wherein:

each of the plurality of dishing prevention structures have a bottommost surface that is disposed between an upper surface of the gate electrode and an upper surface of the gate dielectric;

each of the plurality of dishing prevention structures are laterally spaced from each other one of the plurality of dishing prevention structures;

each of the plurality of dishing prevention structures are spaced from each of the plurality of outer sidewalls in both a first lateral direction and a second lateral direction; and

the first lateral direction is perpendicular to the second lateral direction.

19. The semiconductor device of claim 18 , further comprising:

a sidewall spacer disposed along the plurality of outer sidewalls, wherein:

the sidewall spacer laterally surrounds the gate electrode in a closed loop path;

the sidewall spacer has a plurality of inner sidewalls that define an inner perimeter of the sidewall spacer;

each of the plurality of dishing prevention structures are spaced from each of the plurality of inner sidewalls; and

each of the plurality of dishing prevention structures are disposed within the inner perimeter of the sidewall spacer.

20. The semiconductor device of claim 19 , wherein:

the plurality of outer sidewalls comprises a first outer sidewall and a second outer sidewall;

the first outer sidewall is laterally spaced from the second outer sidewall in the first lateral direction;

the gate electrode has a lower portion that extends laterally in the first lateral direction;

the lower portion of the gate electrode extends continuously from the first outer sidewall to the second outer sidewall; and

the plurality of dishing prevention structures directly overlie the lower portion of the gate electrode.