Pattern forming method

1. A pattern forming method, comprising:

forming a graphoepitaxy on a substrate, the graphoepitaxy having a plurality of depressions and a plurality of projections;

forming a first self-assembly material layer in the depressions of the graphoepitaxy, the first self-assembly material layer having at least a first segment and a second segment;

forming a first self-assembly pattern by phase separating the first self-assembly material layer, the first self-assembly pattern having a first region containing the first segment and a second region containing the second segment;

forming a second self-assembly material layer on the first self-assembly pattern and a surface of the projections, the second self-assembly material layer having a third segment and a fourth segment, wherein a solvent used in the formation of the first self-assembly material layer differs from a solvent used in the formation of the second self-assembly material layer; and

forming a second self-assembly pattern by phase separating the second self-assembly material layer, the second self-assembly pattern having a third region containing the third segment and a fourth region containing the fourth segment.

2. The pattern forming method of claim 1 , wherein a pitch of the first self-assembly pattern is n times a pitch of the second self-assembly pattern.

3. The pattern forming method of claim 1 , wherein

a solution used in the formation of first self-assembly material layer contains a thermal cross-linking agent.

4. The pattern forming method of claim 1 , wherein the projected portion has a neutral surface for the third segment and the fourth segment.

5. The pattern forming method of claim 4 , wherein a pitch of the first self-assembly pattern is n times a pitch of the second self-assembly pattern.

6. The pattern forming method of claim 4 , wherein a solution used in the formation of first self-assembly material layer contains a thermal cross-linking agent.

7. The pattern forming method of claim 1 , wherein the first segment and the third segment comprise the same polymer.

8. The pattern forming method of claim 7 , wherein the projected portion has a neutral surface for the third segment and the fourth segment.

9. The pattern forming method of claim 8 , wherein a solution used in the formation of first self-assembly material layer contains a thermal cross-linking agent.

10. The pattern forming method of claim 7 , wherein the second segment and the fourth segment comprise the same polymer.

11. The pattern forming method of claim 10 , wherein the projected portion has a neutral surface for the third segment and the fourth segment.

12. The pattern forming method of claim 10 , wherein a pitch of the first self-assembly pattern is n times a pitch of the second self-assembly pattern.

13. The pattern forming method of claim 10 , wherein a solution used in the formation of first self-assembly material layer contains a thermal cross-linking agent.

14. A pattern forming method, comprising:

forming a resist layer on a substrate, the resist layer having a plurality of projections adjacent to a plurality of depressions;

forming a first self-assembly material layer on each of the plurality of depressions of the resist layer, the first self-assembly material layer including at least a first segment and a second segment;

forming a first self-assembly pattern in the first self-assembly material layer, the first self-assembly pattern having a first region containing the first segment and a second region containing the second segment;

forming a second self-assembly material layer on the first self-assembly pattern and exposed portions of the resist layer, the second self-assembly material layer including a third segment and a fourth segment, wherein a solvent solution used in the formation of the first self-assembly material layer differs from a solvent solution used in the formation of the second self-assembly material layer; and

forming a second self-assembly pattern in the second self-assembly material layer, the second self-assembly pattern having a third region containing the third segment, and a fourth region containing the fourth segment,

wherein the first segment and the third segment each comprise a first polymer, and the second segment and the fourth segment each comprise a second polymer that is different from the first polymer.

15. The pattern forming method of claim 14 , wherein a pitch of the first self-assembly pattern is n times a pitch of the second self-assembly pattern.

16. A pattern forming method, comprising:

forming a graphoepitaxy on a substrate, the graphoepitaxy having a plurality of depressions and a plurality of projections;

forming a first self-assembly material layer in the depressions of the graphoepitaxy, the first self-assembly material layer having at least a first segment and a second segment;

forming a first self-assembly pattern by phase separating the first self-assembly material layer, the first self-assembly pattern having a first region containing the first segment and a second region containing the second segment;

forming a second self-assembly material layer on the first self-assembly pattern and a surface of the projections, the second self-assembly material layer having a third segment and a fourth segment, wherein a pitch of the first self-assembly pattern is n times a pitch of the second self-assembly pattern, n being an integer greater than or equal to 2; and

forming a second self-assembly pattern by phase separating the second self-assembly material layer, the second self-assembly pattern having a third region containing the third segment and a fourth region containing the fourth segment.