FinFET device

1. A device comprising:

a first fin structure disposed over a substrate and having a first height over a surface of the substrate;

a dummy semiconductor structure adjacent the first fin structure and disposed over the substrate, wherein the dummy semiconductor structure has a sidewall extending from the surface of the substrate to a second height that is less than the first height; and

an isolation structure extending from the first fin structure to the dummy semiconductor structure and at least partially covering a top surface of the dummy semiconductor structure, wherein the isolation structure extends continuously from the surface of the substrate to at least the top surface of the dummy semiconductor structure, the top surface of the dummy semiconductor structure facing away from the substrate.

2. The device of claim 1 , wherein the isolation structure includes a multi-layer structure having at least one liner layer.

3. The device of claim 1 , further comprising:

a second fin structure disposed over the substrate, wherein the dummy semiconductor structure interposes the first fin structure and the second fin structure.

4. The device of claim 3 , wherein the isolation structure extends from the first fin structure to the second fin structure.

5. The device of claim 1 , wherein the isolation structure directly interfaces the sidewall extending from the surface of the substrate to the second height and a top surface of the dummy semiconductor structure.

6. The device of claim 1 , further comprising:

a second fin structure disposed over the substrate adjacent the first fin structure; and

a merged source/drain feature disposed over the first and second fin structures.

7. The device of claim 1 , further comprising:

a second fin structure disposed over the substrate adjacent the first fin structure; and

a single gate structure disposed over the first and second fin structures.

8. A fin-type field effect transistor (FINFET) device comprising:

a first fin structure disposed over a substrate and having a first height over a surface of the substrate;

a second fin structure disposed over the substrate and having the first height over the surface of the substrate;

at least one residual dummy structure interposing the first and second fin structures, wherein the residual dummy structure is a protrusion of semiconductor material having a second height over the surface of the substrate, the second height less than the first height; and

an isolation structure extending from a sidewall of the first fin structure to a sidewall of the second fin structure and disposed in a space over the at least one residual dummy structure, wherein the isolation structure includes one or more dielectric materials.

9. The FINFET device of claim 8 , further comprising:

an active fin structure adjacent the first fin structure;

a first gate structure extending over the first and third fin structures; and

a second gate structure over the second fin structure, the second gate structure different than the first gate structure.

10. The FINFET device of claim 8 , wherein the isolation structure is a multi-layer isolation structure including more than one dielectric material.

11. The FINFET device of claim 10 , wherein the isolation structure is a shallow trench isolation (STI) feature.

12. The FINFET device of claim 8 , wherein the isolation structure entirely covers a top surface of the residual dummy structure.

13. The FINFET device of claim 8 , wherein the isolation structure directly interfaces with each of an entirety of a first sidewall of the protrusion; an entirety of a second sidewall of the protrusion, the second sidewall opposing the first sidewall; and an entirety of a top surface of the protrusion.

14. A fin-type field effect transistor (FINFET) device comprising:

first and second active fin structures each having a top surface disposed at a first height over a surface of the substrate;

a gate structure extending over the first and second active fin structures;

a source and drain feature extending over the first and second active fin structures;

a dummy fin structure over the surface of the substrate, wherein the dummy fin structure includes a protrusion of semiconductor material extending from the surface of the substrate, the protrusion having a top surface disposed at a second height over the surface of the substrate, and wherein the second height is less than the first height; and

an isolation structure disposed over the dummy fin structure, wherein the isolation structure covers the top surface of the protrusion and extends to a sidewall of the first active fin structure.

15. The device of claim 14 , wherein the isolation structure includes a liner layer and an insulating layer.

16. The device of claim 14 , further comprising:

another fin of the first height disposed over the substrate, wherein the dummy fin structure interposes the another fin and the first active fin structure.

17. The device of claim 16 , wherein the isolation structure extends continuously from a sidewall of the another fin to a sidewall of the first active fin structure.

18. The device of claim 17 , further comprising:

another dummy fin structure interposing the another fin and the first active fin structure, wherein the isolation structure continuously extends from the sidewall of the another fin to the sidewall of the first active fin and covers a top surface of the another dummy fin structure and covers the top surface of the protrusion.

19. The device of claim 14 , wherein the isolation structure interfaces a portion of the top surface of the substrate interposing the first active fin structure and the protrusion.

20. The device of claim 14 , wherein the first and second active fins, the dummy fin structure, and the substrate comprise a same semiconductor material.