Grapho-epitaxy DSA process with dimension control of template pattern

1. A method for defining a template for directed self-assembly (DSA) materials, comprising:

patterning a resist layer using optical lithography to form a template pattern on a stack, the stack including an anti-reflection coating (ARC) and a mask layer formed over a hydrophilic layer;

forming the template pattern by reactive ion etching the ARC and the mask layer to form template lines which are trimmed to less than a minimum feature size achievable by lithography;

forming hydrophobic spacers on sidewalls of the template lines, the spacers including a fractional width of the minimum feature size;

grafting a neutral brush layer to exposed portions of the hydrophilic layer;

depositing a DSA material between the spacers of the template lines;

annealing the DSA material to form material domains in a form of alternating lines of a first material and a second material, wherein the first material in contact with the spacers includes a fractional size width less than a width of the lines;

adding a metal to the alternating material domains to form an etch resistant material with the second material; and

removing the first material and the spacers by reactive ion etching to form a DSA template pattern for etching underlying materials.

2. The method as recited in claim 1 , wherein the hydrophilic layer includes a silicon anti-reflection coating (SiARC).

3. The method as recited in claim 1 , wherein the template lines include a width of about 0.5 L, the spacers includes a width of about 0.25 L and the first material in contact with the spacers includes a width of about 0.25 L, where L is the minimum feature size.

4. The method as recited in claim 1 , wherein the DSA template pattern includes lines having a width of about 0.5 L, and spaces between the lines having a width of about 0.5 L.

5. The method as recited in claim 1 , wherein forming hydrophobic spacers includes depositing an organic material and reactive ion etching the organic material to form the spacers.

6. The method as recited in claim 1 , wherein depositing a DSA material includes depositing a block copolymer material.

7. The method as recited in claim 6 , wherein depositing the block copolymer material includes depositing one of a poly(styrene)-block-poly(methyl methacrylate) diblock copolymer (PS-b-PMMA)) and a poly(styrene)-block-poly(hydroxystyrene) diblock copolymer (PS-b-PHOST).

8. The method as recited in claim 1 , wherein adding a metal includes atomic layer depositing one of Ti or Al.

9. The method as recited in claim 1 , wherein the template lines include a same line width and spacing as the lines and spaces in the DSA template pattern.

10. A method for defining a template for directed self-assembly (DSA) materials, comprising:

forming a hydrophilic layer over a substrate;

forming an optical planarization layer (OPL) on the hydrophilic layer;

forming an anti-reflection coating (ARC) on the OPL;

patterning a resist layer using optical lithography to form a template pattern on the ARC;

forming the template pattern by reactive ion etching the ARC and the mask layer to form template lines which are trimmed to about 0.5 L where L is a minimum feature size achievable by lithography;

forming hydrophobic spacers on sidewalls of the template lines, the spacers including a width of about 0.25 L;

grafting a neutral brush layer to exposed portions of the hydrophilic layer;

depositing a DSA material between the spacers of the template lines;

annealing the DSA material to form material domains in a form of alternating lines of a first material and a second material, the lines having a width of about 0.5 L, wherein the first material in contact with the spacers includes a width of about 0.25 L;

adding a metal to the alternating material domains to form an etch resistant material with the second material; and

removing the first material and the spacers by reactive ion etching to form a DSA template pattern for etching underlying materials.

11. The method as recited in claim 10 , wherein the hydrophilic layer includes a silicon anti-reflection coating (SiARC).

12. The method as recited in claim 10 , wherein the DSA template pattern includes spaces between the lines having a width of about 0.5 L.

13. The method as recited in claim 10 , wherein forming hydrophobic spacers includes depositing an organic material and reactive ion etching the organic material to form the spacers.

14. The method as recited in claim 10 , wherein depositing a DSA material includes depositing a block copolymer material.

15. The method as recited in claim 14 , wherein depositing the block copolymer material includes depositing one of a poly(styrene)-block-poly(methyl methacrylate) diblock copolymer (PS-b-PMMA)) and a poly(styrene)-block-poly(hydroxystyrene) diblock copolymer (PS-b-PHOST).

16. The method as recited in claim 10 , wherein adding a metal includes atomic layer depositing one of Ti or Al.

17. The method as recited in claim 10 , wherein the template line includes a same line width and spacing as the lines and spaces in the DSA template pattern.

18. A method for defining a template for directed self-assembly (DSA) materials, comprising:

forming template lines by reactive ion etching an anti-reflection coating (ARC) and a mask layer and stopping on an underlying hydrophilic layer, which is formed over a semiconductor substrate;

trimming the template lines to less than a minimum feature size (L) achievable by lithography by the reactive ion etching;

forming hydrophobic spacers on sidewalls of the template lines, the spacers including a fractional width of the minimum feature size;

grafting a neutral brush layer to exposed portions of the hydrophilic layer;

depositing and annealing a DSA material including a block copolymer material, which is formed between the spacers of the template lines to create material domains in a form of alternating lines of a first material and a second material wherein the first material in contact with the spacers includes a fractional size width less than a width of the lines;

selectively depositing a metal on the second material to provide etch resistance;

removing the first material and the spacers by reactive ion etching to form a DSA template pattern for etching underlying materials; and

etching the substrate to form structures for use in fabricating electronic devices.

19. The method as recited in claim 18 , wherein the DSA template pattern includes lines and spaces between the lines each having a width of about 0.5 L and wherein the template lines include a same line width and spacing as the lines and spaces in the DSA template pattern.

20. The method as recited in claim 18 , wherein the block copolymer material includes one of a poly(styrene)-block-poly(methyl methacrylate) diblock copolymer (PS-b-PMMA)) and a poly(styrene)-block-poly(hydroxystyrene) diblock copolymer (PS-b-PHOST).