Polymer for resist under layer film composition, resist under layer film composition, and patterning process

Patent metadata

Field	Value
Publication number	US-9805943-B2
Application number	US-201615060934-A
Country	US
Kind code	B2
Filing date	Mar 4, 2016
Priority date	Mar 27, 2015
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

The invention provides a polymer for a resist under layer film composition, containing a repeating unit shown by the formula (1) and a repeating unit shown by the formula (3),

wherein R 01 independently represents a hydrogen atom or a methyl group; R 02 represents a group selected from the formulae (1-1) to (1-3); R 03 represents a saturated or unsaturated tertiary alkyl group having 4 to 20 carbon atoms and optionally containing an oxygen functional group; and A 2 represents a single bond or a divalent linking group having 2 to 10 carbon atoms and containing an ester group,

wherein the dotted line represents a bonding arm. There can be provided a polymer for a resist under layer film composition that is capable of forming a resist under layer film having good alkali aqueous hydrogen peroxide resistance, excellent filling and planarizing properties, and excellent dry etching property

First claim

What is claimed is:

1. A polymer for a resist under layer film composition, comprising a repeating unit shown by the formula (1) and a repeating unit shown by the formula (3),

wherein R 01 independently represents a hydrogen atom or a methyl group; R 02 represents a group selected from the formulae (1-1) to (1-3); R 03 represents a saturated or unsaturated tertiary alkyl group having 4 to 20 carbon atoms and optionally containing a group selected from a cyclic ether group, an ether group, a hydroxy group, or an aromatic heterocyclic oxygen containing ring; and A 2 represents a single bond or a divalent linking group having 2 to 10 carbon atoms and containing an ester group,

wherein the dotted line represents a bonding arm,
wherein the repeating unit shown by the formula (3) is a repeating unit shown by the formula (3-1)

wherein R 01 and R 03 have the same meanings as above; n represents an integer of 1 to 5, and
the polymer for a resist under layer film composition further comprises a repeating unit shown by the formula (2),

wherein R 01 has the same meaning as above; A 1 represents a single bond, an ester group, or a divalent linking group having 2 to 10 carbon atoms and containing an ester group; Ar 1 represents a substituted or unsubstituted aryl group having 6 to 20 carbon atoms.

2. The polymer for a resist under layer film composition according to claim 1 , wherein a content of the repeating unit shown by the formula (1) is within a range of 20 mol % to 90 mol % with respect to the whole repeating units contained in the polymer, and a content of the repeating unit shown by the formula (3) is within a range of 5 mol % to 50 mol % with respect to the whole repeating units contained in the polymer.

3. The polymer for a resist under layer film composition according to claim 1 , wherein a content of the repeating unit shown by the formula (2) is within a range of 5 mol % to 50 mol % with respect to the whole repeating units contained in the polymer.

4. The polymer for a resist under layer film composition according to claim 1 , wherein a weight average molecular weight of the polymer is within a range of 1,000 to 20,000.

5. The polymer for a resist under layer film composition according to claim 1 , wherein a glass transition temperature of the polymer is 50° C. or lower.

6. The polymer for a resist under layer film composition according to claim 1 , wherein a dispersibility of the polymer is 2.0 or less, the dispersibility being shown by a weight average molecular weight/a number average molecular weight of the polymer.

7. A resist under layer film composition for use in a multilayer resist method, comprising
(A) a base resin of the polymer for a resist under layer film composition according to claim 1 , and
(B) an organic solvent.

8. The resist under layer film composition according to claim 7 , further comprising one or more of (C) an acid generator, (D) a surfactant, (E) a crosslinking agent, (F) a plasticizer, and (G) a colorant.

9. The resist under layer film composition according to claim 7 , wherein the resist under layer film composition is capable of forming a resist under layer film that is not peeled when the resist under layer film is formed on a silicon substrate and the silicon substrate is immersed in a 1.0 mass % aqueous hydrogen peroxide containing 0.5 mass % ammonia at 23° C. for 10 minutes.

10. The resist under layer film composition according to claim 7 , wherein the resist under layer film composition is capable of forming a resist under layer film that is not peeled when the resist under layer film is formed on a silicon substrate and the silicon substrate is immersed in a 1.0 mass % aqueous hydrogen peroxide containing 0.5 mass % ammonia at 65° C. for 5 minutes.

11. A patterning process for forming a pattern in a substrate to be processed, the process comprising the steps of:
(I-1) forming a resist under layer film on the substrate to be processed by using the resist under layer film composition according to claim 7 ;
(I-2) forming a resist upper layer film on the resist under layer film by using a photoresist composition;
(I-3) subjecting the resist upper layer film to pattern exposure and development with a developer to form a pattern in the resist upper layer film; and
(I-4) transferring the pattern to the resist under layer film by dry etching using the resist upper layer film having the formed pattern as a mask.

12. The patterning process according to claim 11 , further comprising, after the step (I-4), transferring the pattern to the substrate to be processed by wet etchingwith an alkali aqueous hydrogen peroxide using the resist under layer film having the transferred pattern as a mask.

13. The patterning process according to claim 11 , further comprising, after the step (I-4), implanting an ion by using the resist under layer film having the transferred pattern as a mask to form the pattern in the substrate to be processed.

14. The patterning process according to claim 13 , further comprising, after implanting the ion to form the pattern in the substrate to be processed, removing the resist middle layer film having the transferred pattern by wet etching with an alkali aqueous hydrogen peroxide.

15. The patterning process according to claim 11 , wherein a dry etching rate of the resist under layer film is higher than that of the resist upper layer film.

16. The patterning process according to claim 11 , wherein the resist under layer film is formed by applying the resist under layer film composition on the substrate to be processed and performing a heat treatment at 100° C. to 300° C. for 10 to 600 seconds.

17. The patterning process according to claim 11 , wherein the substrate to be processed is a substrate having a structure or a step with a height of 30 nm or more.

18. A patterning process for forming a pattern in a substrate to be processed, the process comprising the steps of:
(II-1) forming a resist under layer film on the substrate to be processed by using the resist under layer film composition according to claim 7 ;
(II-2) forming a resist middle layer film on the resist under layer film;
(II-3) forming a resist upper layer film on the resist middle layer film by using a photoresist composition;
(II-4) subjecting the resist upper layer film to pattern exposure and development with a developer to form a pattern in the resist upper layer film;
(II-5) transferring the pattern to the resist middle layer film by dry etching using the resist upper layer film having the formed pattern as a mask; and
(II-6) transferring the pattern to the resist under layer film by dry etching using the resist middle layer film having the transferred pattern as a mask.

19. The patterning process according to claim 18 , further comprising, after the step (II-6), removing the resist middle layer film having the transferred pattern by wet etching with an alkali aqueous hydrogen peroxide.

20. The patterning process according to claim 18 , further comprising, after the step (II-6), transferring the pattern to the substrate to be processed by wet etchin

Assignees

• Shinetsu Chemical Co

Inventors

• Kikuchi Rie
• Watanabe Takeru
• Tachibana Seiichiro
• Ogihara Tsutomu

Classifications

• H10P76/2043

  using an anti-reflective coating · CPC title

• H10P76/2041

  Photolithographic processes · CPC title

• H10P76/405

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

• H10P50/695

  characterised by the process involved to create the mask, e.g. lift-off masks or sidewalls or to modify the mask · CPC title

• H10P50/692

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