On-track process for patterning hardmask by multiple dark field exposures

• US 8,133,659 B2
• Filed: 01/29/2009
• Issued: 03/13/2012
• Est. Priority Date: 01/29/2008
• Status: Active Grant

• Current Assignee: Brewer Science Inc.
• Original Assignee: Brewer Science Inc.
• Inventors: Sun, Sam X., Xu, Hao, Flaim, Tony D.
• Primary Examiner(s): Lee, Sin J.
• Application Number:
  US12/362,268
• Publication Number:
  US 20090191474A1
• Time in Patent Office: 1,139 Days
• Field of Search: None
• US Class Current: 430/311
• CPC Class Codes: G03F 7/0035 Multiple processes, e.g. applying a further resist layer on an already in a previously step, processed pattern or textured surface
• CPC Class Codes: G03F 7/0752 in non photosensitive layers or as additives, e.g. for dry lithography
• CPC Class Codes: G03F 7/0758 with silicon- containing groups in the side chains
• CPC Class Codes: G03F 7/095 having more than one photosensitive layer G03F7/075 takes precedence
• CPC Class Codes: G03F 7/322 Aqueous alkaline compositions
• CPC Class Codes: H01L 21/02118 carbon based polymeric organic or inorganic material, e.g. polyimides, poly cyclobutene or PVC polymers per se C08G, photoresist per se G03F
• CPC Class Codes: H01L 21/0271 comprising organic layers
• CPC Class Codes: H01L 21/0332 characterised by their composition, e.g. multilayer masks, materials
• CPC Class Codes: H01L 21/0337 characterised by the process involved to create the mask, e.g. lift-off masks, sidewalls, or to modify the mask, e.g. pre-treatment, post-treatment
• CPC Class Codes: H01L 21/0338 Process specially adapted to improve the resolution of the mask
• CPC Class Codes: H01L 21/312 Organic layers, e.g. photoresist H01L21/3105, H01L21/32 take precedence; photoresists per se G03C

Abstract

This invention provides methods of creating via or trench structures on a developer-soluble hardmask layer using a multiple exposure-development process. The hardmask layer is patterned while the imaging layer is developed. After the imaging layer is stripped using organic solvents, the same hardmask can be further patterned using subsequent exposure-development processes. Eventually, the pattern can be transferred to the substrate using an etching process.

Claims

1. A method of forming a microelectronic structure, said method comprising:

(a) providing a substrate having a surface;

(b) applying a hardmask composition adjacent the substrate surface, said hardmask composition comprising a polymer dispersed or dissolved in a solvent system, said polymer comprising recurring monomers of

2. The method of claim 1, further comprising the step of applying an intermediate layer to said substrate prior to applying said hardmask layer.

3. The method of claim 1, said wherein no dry etching occurs during (a)-(h).

4. The method of claim 1, wherein the pattern of said patterned hardmask layer remains intact during (g).

5. The method of claim 1, wherein said first imaging layer is a photoresist.

6. The method of claim 1, wherein said first imaging layer has a thickness of from about 20 nm to about 200 nm.

7. The method of claim 1, wherein said hardmask composition is thermally crosslinked during (c) yielding a cured hardmask layer.

8. The method of claim 1, said hardmask layer having an initial solubility in a base developer, wherein:

said exposing (e) further comprises exposing at least a portion of said hardmask layer to activating radiation to yield exposed portions of said hardmask layer, said exposed portions of said hardmask layer having a final solubility in base developer, said final solubility being greater than said initial solubility.

9. The method of claim 1, further comprising:

(i) exposing said second imaging layer to activating radiation to yield exposed portions in said second imaging layer;

(j) contacting said second imaging layer with a developer so as to remove said exposed portions, wherein said contacting also results in the removal of portions of said hardmask layer beneath said exposed portions in said second imaging layer, yielding a further patterned hardmask layer; and

(k) contacting said second imaging layer with an organic solvent so as to remove said second imaging layer.

10. The method of claim 9, wherein the pattern of the patterned hardmask layer formed in (j) remains intact during (k).

11. The method of claim 9, wherein no dry etching occurs during (a)-(k).

12. The method of claim 9, further comprising:

(l) transferring the pattern of the patterned hardmask layer formed in (j) to the substrate.

13. The method of claim 12, wherein (l) comprises etching said patterned hardmask layer and substrate.

14. The method of claim 12, wherein the pattern of said patterned hardmask layer comprises vias and trenches.