Structures including multiple carbon layers and methods of forming and using same

1. A method of forming a structure, the method comprising the steps of:

providing a substrate within a reaction chamber, the substrate comprising one or more recesses formed on a surface of the substrate;

forming a first carbon layer overlying the surface; and

forming a second carbon layer overlying the first carbon layer,

wherein the first carbon layer is formed by forming initially flowable material,

wherein the first carbon layer fills the one or more recesses to a height above the surface of the substrate, and

wherein a density of the first carbon layer is higher than a density of the second carbon layer.

2. The method of claim 1 , wherein at least one recess of the one or more recesses is formed between two features.

3. The method of claim 2 , wherein a height of the first carbon layer relative to the surface is greater than a height of the features relative to the surface.

4. The method of claim 1 , wherein the density of the first carbon layer is greater than the density of the second carbon layer by about 10% to about 50%.

5. The method of claim 1 , further comprising a step of chemical mechanical polishing the second carbon layer.

6. The method of claim 1 , further comprising a step of chemical mechanical polishing at least a portion of the first carbon layer.

7. The method of claim 1 , wherein a chemical mechanical polishing rate of the first carbon layer is lower than a chemical mechanical polishing rate of the second carbon layer.

8. The method of claim 1 , wherein the step of forming the first carbon layer comprises a plasma process.

9. The method of claim 1 , wherein the step of forming the second carbon layer comprises a plasma process.

10. The method of claim 1 , further comprising a plasma treatment step to treat the first carbon layer.

11. The method of claim 1 , further comprising a plasma treatment step to treat the second carbon layer.

12. The method of claim 1 , wherein a temperature within the reaction chamber during the step of forming the first carbon layer is less than 100° C.

13. The method of claim 1 , wherein a temperature within the reaction chamber during the step of forming the second carbon layer is less than 100° C.

14. The method of claim 1 , wherein the step of forming the second carbon layer comprises providing a carbon precursor to the reaction chamber, wherein a chemical formula of the carbon precursor is represented by C x H y N z , wherein x is a natural number of 2 or more, y is a natural number and z is 0 or a natural number.

15. The method of claim 1 , wherein the step of forming the first carbon layer comprises providing a carbon precursor to the reaction chamber, wherein a chemical formula of the carbon precursor is represented by C x H y N z , wherein x is a natural number of 2 or more, y is a natural number and z is 0 or a natural number.

16. The method of claim 15 , wherein the carbon precursor comprises a cyclic structure.

17. The method of claim 16 , wherein the cyclic structure comprises a double bond.

18. The method of claim 1 , further comprising a step of etching the second carbon layer.

19. The method of claim 18 , wherein a step of etching the first carbon layer and the step of etching the second carbon layer comprise ionic etching.

20. The method of claim 1 , further comprising a step of etching the first carbon layer.

21. The method of claim 20 , wherein the steps of etching the first carbon layer and a step of etching the second carbon layer comprise non-selectively etching the second carbon layer and the first carbon layer.

22. The method of claim 1 , wherein a hardness of the first carbon layer is higher than a hardness of the second carbon layer.

23. The method of claim 1 , further comprising a step of forming a third layer overlying the second carbon layer.