Anti-reflective imaging layer for multiple patterning process

• US 7,914,974 B2
• Filed: 08/15/2007
• Issued: 03/29/2011
• Est. Priority Date: 08/18/2006
• Status: Active Grant

• Current Assignee: Brewer Science Inc.
• Original Assignee: Brewer Science Inc.
• Inventors: Mercado, Ramil-Marcelo L., Guerrero, Douglas J.
• Primary Examiner(s): Duda; Kathleen
• Assistant Examiner(s): Sullivan; Caleen O
• Application Number:
  US11/839,317
• Publication Number:
  US 20080044772A1
• Time in Patent Office: 1,322 Days
• Field of Search: 430/311, 430/394, 430/312, 430/313
• US Class Current: 430/312
• 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 7/0392 the macromolecular compound being present in a chemically amplified positive photoresist composition
• CPC Class Codes: G03F 7/168 Finishing the coated layer, e.g. drying, baking, soaking
• CPC Class Codes: H01L 21/0274 Photolithographic processes

Abstract

Novel methods of double patterning a photosensitive resin composition are provided. The methods involve applying the photosensitive composition to a substrate and thermally crosslinking the composition. The crosslinked layer can be used to provide reflection control. Upon exposure to light, the crosslinked polymer (or oligomer or monomer) in the compositions will decrosslink, rendering the light-exposed portions soluble in typical photoresist developing solutions (e.g., alkaline developers). Advantageously, the crosslinked portions of the composition remain insoluble in the solvent used to form the photosensitive composition. As a result, the coating, lithographic, and or developing steps can be repeated multiple times in varying order, depending upon the particular process, without destroying earlier-formed patterns.

Claims

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

(a) providing a substrate having a surface;

(b) applying a photosensitive composition to form an imaging layer adjacent said substrate surface, said composition comprising a component selected from the group consisting of polymers, oligomers, and monomers;

(c) crosslinking said component in said imaging layer to yield a crosslinked imaging layer, said crosslinked imaging layer having a k value of from about 0.2 to about 0.5;

(d) exposing said crosslinked imaging layer to light to yield light-exposed portions in said layer;

(e) contacting said layer with a developer so as to remove said light-exposed portions from said substrate, yielding a patterned imaging layer; and

without heating said patterned imaging layer, applying a second photosensitive composition to form a second imaging layer on said patterned imaging layer.

2. The method of claim 1, wherein no heating occurs during (a), (b), (d), (e), or (f) other than a post-exposure bake after (d).

3. The method of claim 1, said wherein patterned imaging layer and substrate are not etched prior to (f).

4. The method of claim 1, wherein said patterned imaging layer remains intact during (f).

5. The method of claim 1, wherein (c) comprises thermally crosslinking said components.

6. The method of claim 1, wherein said second photosensitive composition is the same as the photosensitive composition of (a).

7. The method of claim 1, wherein said second photosensitive composition comprises a component selected from the group consisting of polymers, oligomers, and monomers, said method further comprising:

(g) crosslinking said component in said second imaging layer;

(h) exposing said second imaging layer to light to yield light-exposed portions in said second imaging layer; and

(i) contacting said second imaging layer with a developer so as to remove said light-exposed portions from said substrate, yielding a second patterned imaging layer.

8. The method of claim 7, further comprising:

(j) optionally repeated (f)-(i) one or more times; and

(k) transferring the patterns of the patterned imaging layers to the substrate.

9. The method of claim 8, wherein said (k) comprises etching said patterned imaging layers and substrate.

10. The method of claim 1, wherein said photosensitive composition further comprises a photoacid generator, a crosslinker, and a solvent system, wherein said component, photoacid generator, and crosslinker are dissolved or dispersed in said solvent system.

11. The method of claim 10, wherein said crosslinker is a vinyl ether crosslinker.

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

(a) providing a substrate having a surface;

(b) applying a photosensitive composition to form an imaging layer adjacent said substrate surface, said composition comprising a component selected from the group consisting of polymers, oligomers, and monomers;

(c) crosslinking said component in said imaging layer to yield a crosslinked imaging layer, said crosslinked imaging layer having a k value of from about 0.2 to about 0.5;

(d) exposing portions of said crosslinked imaging layer to light to yield light-exposed portions in said layer;

(e) exposing additional portions of said crosslinked imaging layer to light to yield further light-exposed portions in said layer;

(f) optionally repeating (e); and

(g) contacting said layer with a developer so as to remove said light-exposed portions from said substrate, yielding a patterned imaging layer.

13. The method of claim 12, further comprising:

(h) after (d) and prior to (e), contacting said layer with a developer so as to remove said light-exposed portions of (d) from said substrate, yielding a patterned imaging layer.

14. The method of claim 12, wherein no heating occurs during (a), (b), (d), (e), (f), or (g) other than a post-exposure bake after (d) and/or (e).

15. The method of claim 12, wherein said patterned imaging layer and substrate are not etched prior to (g).

16. The method of claim 12, wherein (c) comprises thermally crosslinking said components.

17. The method of claim 12, further comprising transferring the pattern of the patterned imaging layer to the substrate after (g).

18. The method of claim 17, wherein said transferring comprises etching said patterned imaging layers and substrate.

19. The method of claim 12, wherein said photosensitive composition further comprises a photoacid generator, a crosslinker, and a solvent system, wherein said component, photoacid generator, and crosslinker are dissolved or dispersed in said solvent system.

20. The method of claim 19, wherein said crosslinker is a vinyl ether crosslinker.