Extreme ultraviolet photoresist and method

• US 10,527,941 B2
• Filed: 05/30/2017
• Issued: 01/07/2020
• Est. Priority Date: 05/30/2017
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Liu, Chen-Yu, Chang, Ya-Ching, Wu, Cheng-Han, Chang, Ching-Yu, Lin, Chin-Hsiang
• Primary Examiner(s): Hamilton, Cynthia
• Application Number:
  US15/608,631
• Publication Number:
  US 20180348639A1
• Time in Patent Office: 952 Days
• CPC Class Codes: G03F 7/0392 the macromolecular compound being present in a chemically amplified positive photoresist composition
• CPC Class Codes: G03F 7/0395 the macromolecular compound having a backbone with alicyclic moieties
• CPC Class Codes: G03F 7/0397 the macromolecular compound having an alicyclic moiety in a side chain
• CPC Class Codes: G03F 7/203 comprising an imagewise exposure to electromagnetic radiation or corpuscular radiation
• CPC Class Codes: G03F 7/30 Imagewise removal using liquid means
• CPC Class Codes: G03F 7/325 Non-aqueous compositions
• CPC Class Codes: G03F 7/38 Treatment before imagewise removal, e.g. prebaking G03F7/265 takes precedence

Abstract

The present disclosure provides a method for lithography patterning in accordance with some embodiments. The method includes forming a resist layer over a substrate and performing an exposing process to the resist layer. The resist layer includes a polymer backbone, an acid labile group (ALG) bonded to the polymer backbone, a sensitizer bonded to the polymer backbone, a photo-acid generator (PAG), and a thermo-base generator (TBG). The method further includes baking the resist layer at a first temperature and subsequently at a second temperature. The second temperature is higher than the first temperature. The method further includes developing the resist layer in a developer, thereby forming a patterned resist layer.

Claims

1. A method, comprising:

forming a resist layer over a substrate, wherein the resist layer includes a polymer backbone, an acid labile group (ALG) bonded to the polymer backbone, a sensitizer bonded to the polymer backbone, a photo-acid generator (PAG), and a thermo-base generator (TBG);

performing an exposing process to the resist layer;

baking the resist layer at a first temperature and subsequently at a second temperature, wherein the second temperature is higher than the first temperature; and

developing the resist layer in a developer, thereby forming a patterned resist layer.

2. The method of claim 1, wherein:

the first temperature is lower than a triggering temperature for the TBG to release a base; and

the second temperature is higher than the triggering temperature.

3. The method of claim 2, wherein the baking of the resist layer is after the performing of the exposing process and prior to the developing of the resist layer.

4. The method of claim 2, wherein:

the first temperature is within a range of 90 degree Celsius to 130 degree Celsius; and

the second temperature is within a range of 140 degree Celsius to 250 degree Celsius.

5. The method of claim 1, wherein the TB G includes a chemical structure selected from the group consisting of an amide, a sulfonamide, an imide, an imine, an O-acyl oxime, and a benzoyloxycarbonyl derivative.

6. The method of claim 1, wherein the performing of the exposing process includes applying an extreme ultraviolet (EUV) radiation to the resist layer.

7. The method of claim 1, wherein the sensitizer is able to generate an electron in response to the exposing process.

8. The method of claim 7, wherein:

the sensitizer includes a phenol group; and

the polymer backbone includes one of an acrylate-based polymer, a poly(norbornene)-co-malaic anhydride (COMA) polymer, and a polyhydroxystyrene (PHS) polymer.

9. The method of claim 1, wherein the developer contains an organic solvent, the organic solvent including an ester group or a ketone group.

10. The method of claim 9, wherein the developer includes a compound selected from the group consisting of 2-heptanone, n-butyl acetate, isoamyl acetate, cyclohexanone, 2-heptanone, 5-methyl-2-hexanone, methyl-2-hydroxyisobutyrate, ethyl lactate, monomethyl ether acetate, n-pentyl acetate, n-butyl propionate, n-hexyl acetate, n-butyl butyrate, isobutyl butyrate, 2,5-dimethyl-4-hexanone, 2,6-dimethyl-4-heptanone, propyl isobutyrate, and isobutyl propionate.

11. A method for lithography patterning, comprising:

forming a photoresist layer over a substrate, wherein the photoresist layer includes a polymer backbone, an acid labile group (ALG) bonded to the polymer backbone, and a thermo-base generator (TBG);

exposing a portion of the photoresist layer to a radiation, resulting in a cleaved ALG;

performing a baking process after the exposing of the portion of the photoresist layer, wherein the TBG releases a base during the performing of the baking process and the cleaved ALG has a chemical reaction with the base, and wherein a polarity of the photoresist layer is adjusted after the chemical reaction with the base; and

removing an unexposed portion of the photoresist layer in a developer, resulting in a patterned photoresist layer.

12. The method of claim 11, wherein the performing of the baking process includes:

baking the photoresist layer at a first temperature, wherein the first temperature does not trigger the TBG to release the base; and

baking the photoresist layer at a second temperature that is higher than the first temperature, wherein the second temperature triggers the TBG to release the base.

13. The method of claim 11, wherein the cleaved ALG includes a carboxyl group.

14. The method of claim 13, wherein the carboxyl group is a COOH bonded to the polymer backbone, and wherein a solubility of the photoresist layer in the developer is reduced after the chemical reaction with the base.

15. The method of claim 11, wherein the radiation is an extreme ultraviolet (EUV) radiation.

16. The method of claim 15, wherein the photoresist layer further includes a sensitizer bonded to the polymer backbone, and wherein the sensitizer is able to generate an electron in response to the EUV radiation.

17. The method of claim 11, wherein the photoresist layer further includes a lactone bonded to the polymer backbone.

18. A method for lithography patterning, comprising:

forming a photoresist layer over a substrate, wherein the photoresist layer includes a polymer backbone, an acid labile group (ALG) bonded to the polymer backbone, a sensitizer bonded to the polymer backbone, a photo-acid generator (PAG), and a thermo-base generator (TBG);

performing an exposing process to the photoresist layer;

baking the photoresist layer at a first temperature lower than a triggering temperature which is for the TBG to release a base;

baking the photoresist layer at a second temperature higher than the triggering temperature; and

after the baking of the photoresist layer at the second temperature, developing the photoresist layer in a negative tone developer, thereby forming a patterned photoresist layer.

19. The method of claim 18, wherein:

the first temperature is within a range of 90 degree Celsius to 130 degree Celsius; and

the second temperature is within a range of 140 degree Celsius to 250 degree Celsius.

20. The method of claim 18, wherein the TBG includes a chemical structure selected from the group consisting of an amide, a sulfonamide, an imide, an imine, an O-acyl oxime, and a benzoyloxycarbonyl derivative.