Silicon hardmask layer for directed self-assembly

Patent metadata

Field	Value
Publication number	US-9249013-B2
Application number	US-201313862720-A
Country	US
Kind code	B2
Filing date	Apr 15, 2013
Priority date	Apr 16, 2012
Publication date	Feb 2, 2016
Grant date	Feb 2, 2016

Abstract

Compositions for directed self-assembly patterning techniques are provided which avoid the need for separate anti-reflective coatings and brush neutral layers in the process. Methods for directed self-assembly are also provided in which a self-assembling material, such as a directed self-assembly block copolymer, can be applied directly to the silicon hardmask neutral layer and then self-assembled to form the desired pattern. Directed self-assembly patterned structures are also disclosed herein.

First claim

We claim:

1. A method of forming a microelectronic structure using directed self-assembly, said method comprising:
providing a wafer stack, said stack comprising:
a substrate having a surface; and
one or more optional intermediate layers on said substrate surface;
spin coating a composition to form a hardmask layer adjacent said intermediate layers if present, or on said substrate surface if no intermediate layers are present, further comprising a pre-pattern comprising a plurality of raised features on top of said hardmask layer, said raised features being spaced apart and each being defined by respective sidewalls and a top surface; and

applying a self-assembling composition directly on top of said hardmask layer in spaces between said raised features,
said self-assembling composition self-assembling into a self-assembled layer directly adjacent said hardmask layer, wherein said self-assembled layer comprises a first self-assembled region and a second self-assembled region different from said first self-assembled region.

2. The method of claim 1 , further comprising removing one of said first self-assembled region or second self-assembled region to yield a pattern in said self-assembled layer.

3. The method of claim 2 , further comprising transferring said pattern into said hardmask layer, said intermediate layer, if present, and into said substrate, wherein said pattern comprises a plurality of features selected from the group consisting of trenches, spaces, via holes, and contact holes having an average feature size of less than about 30 nm.

4. The method of claim 1 , wherein said plurality of raised features are formed by:
applying a photosensitive composition to form an imaging layer on said hardmask layer; and
patterning said imaging layer to yield said pre-pattern, before applying said self-assembling composition to said hardmask layer.

5. The method of claim 4 , wherein said patterning comprises:
exposing said imaging layer to radiation to yield exposed and unexposed portions of said imaging layer; and
contacting said imaging layer with an organic non-alkaline solvent so as to remove said unexposed portions.

6. The method of claim 1 , wherein said hardmask layer comprises a surface having surface-modified regions and non-modified regions, said first and second self-assembled regions being adjacent said non-modified regions.

7. The method of claim 6 , wherein, before applying said self-assembling composition to said hardmask layer, said surface-modified regions and non-modified are formed by:
applying a photosensitive composition to form an imaging layer on said hardmask layer; and
patterning said imaging layer to yield said pre-pattern, wherein said patterning comprises selectively removing portions of said imaging layer to uncover portions of said hardmask layer;
contacting said uncovered portions of hardmask layer with an alkaline developer to yield said surface-modified regions; and
removing remaining portions of said imaging layer from said hardmask layer to yield said non-modified regions.

8. The method of claim 1 , wherein said hardmask layer is a crosslinked layer comprising siloxane crosslinkages.

9. The method of claim 1 , wherein said hardmask layer is formed from a composition comprising a silicon-containing polymer dissolved or dispersed in a solvent system.

10. The method of claim 9 , wherein said silicon-containing polymer is prepared by polymerization of silicon precursor materials selected from the group consisting of silanes, siloxanes, silsesquioxanes, and combinations thereof.

11. The method of claim 9 , wherein said silicon-containing polymer further comprises light attenuating moieties selected from the group consisting of phenyl, naphthalene, anthracene, carbazole, and combinations thereof.

12. The method of claim 9 , wherein said silicon-containing polymer comprises moieties compatible with said self-assembling composition.

13. The method of claim 1 , wherein said self-assembling composition comprises a block copolymer dispersed or dissolved in a solvent system.

14. The method of claim 13 , wherein said block copolymer comprises at least two distinct blocks each selected from the group consisting of polystyrene, poly(methyl methacrylate), poly(lactic acid), poly(ethylene oxide), polydimethylsiloxane, and polyvinylpyrrolidone.

15. The method of claim 13 , further comprising heating said self-assembling composition to at least about the glass transition temperature of said block copolymer, wherein said self-assembling composition self-assembles during said heating.

16. The method of claim 1 , wherein said self-assembling composition comprises a blend of immiscible polymers.

17. The method of claim 1 , wherein said first self-assembled region has a first etch rate in wet or dry etchants, and said second self-assembled region has a second etch rate in wet or dry etchants, and wherein said first etch rate is different from said second etch rate.

18. The method of claim 1 , wherein said hardmask layer is formed from a composition comprising a polymer dissolved or dispersed in a solvent system.

19. The method of claim 1 , wherein said hardmask layer is formed from a composition comprising a silicon-containing polymer dispersed or dissolved in a solvent system, said polymer comprising recurring units of

where each R 1 is individually selected from the group consisting of alkyls, chromophores, compatible moieties, and combinations thereof.

20. The method of claim 1 , wherein said hardmask layer comprises from about 20% to about 45% by weight silicon, based upon the total weight of the layer taken as 100% by weight.

21. A method of forming a microelectronic structure using directed self-assembly, said method comprising:
providing a wafer stack, said stack comprising:
a substrate having a surface; and
one or more optional intermediate layers on said substrate surface; and

spin coating a composition to form a hardmask layer adjacent said intermediate layers if present, or on said substrate surface if no intermediate layers are present;
forming surface-modified regions and non-modified regions by:
applying a photosensitive composition to form an imaging layer on said hardmask layer;
patterning said imaging layer to yield said pre-pattern, wherein said patterning comprises selectively removing portions of said imaging layer to uncover portions of said hardmask layer;
contacting said uncovered portions of hardmask layer with an alkaline developer to yield said surface-modified regions; and
removing remaining portions of said imaging layer from said hardmask layer to yield said non-modified regions; and

applying a self-assembling composition directly on top of said hardmask layer, said self-assembling composition self-assembling into a self-assembled layer directly adjacent said hardmask layer, wherein said self-assembled layer comprises a first self-assembled region and a second self-assembled region different from said first self-assembled region, said first and second self-assembled regions being adjacent said non-modified regions.

22. A method of forming a microelectronic structure using directed self-assembly, said method comprising:
providing a wafer stack, said stack comprising:
a substrate having a surface;
one or more optional intermediate layers on said substrate surface; and
spin coating a composition to

Assignees

• Brewer Science Inc

Inventors

• Wang Yubao
• Hockey Mary Ann
• Guerrero Douglas J
• Krishnamurthy Vandana
• Cox Robert C

Classifications

• H10P76/4085

  characterised by the processes involved to create the masks · CPC title

• H10P76/405

  characterised by their composition, e.g. multilayer masks · CPC title

• H10P50/73

  using masks for insulating materials · CPC title

• H10P14/6922

  the material containing Si, O and at least one of H, N, C, F or other non-metal elements, e.g. SiOC, SiOC:H or SiONC · CPC title

• H10P14/6686

  the compound being a molecule comprising at least one silicon-oxygen bond and the compound having hydrogen or an organic group attached to the silicon or oxygen, e.g. a siloxane · CPC title