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US-12619149-B2 - DNQ-free chemically amplified resist composition

US12619149B2US 12619149 B2US12619149 B2US 12619149B2US-12619149-B2

Abstract

The disclosed subject matter relates to resist compositions that include: (A) an acetal functionalized acrylic polymer component comprising repeat units selected from ones having structure (1), (2), (3), (4), (5), (6), and (7); (B) a tert-alkyl functionalized acrylic polymer component comprising repeat units selected from ones having structure (1a), (2a), (3a), (4a), (5a), (6a), and (7a); (C) a phenolic resin component comprising a Novolak-based resin; (D) a photo acid generator (PAG) component and (E) a solvent component where the resist compositions does not include a diazonaphthoquinone (DNQ) component.

Inventors

  • Weihong Liu
  • Chunwei Chen

Assignees

  • MERCK PATENT GMBH

Dates

Publication Date
20260505
Application Date
20210423

Claims (20)

  1. 1 . A composition comprising (A) an acetal functionalized acrylic polymer component comprising repeat units selected from the group consisting of ones having structure (1), (2), (3), (4), (5), (6), and (7): wherein PG is an acid cleavable acetal protecting group, wherein said repeat units constitute 100 mole % of the repeat units in said acetal functionalized acrylic polymer, wherein the repeat unit of structure (1) ranges from about 10 mole % to about 35 mole % of the acrylic polymer, the repeat unit of structure (2) ranges from about 0 mole % to about 20 mole % of the acrylic polymer, the repeat unit of structure (3) ranges from about 15 mole % to about 55 mole % of the acrylic polymer, the repeat unit of structure (4) ranges from about 0 mole % to about 30 mole % of the acrylic polymer, the repeat unit of structure (5) ranges from about 15 mole % to about 55 mole % of the acrylic polymer, the repeat unit of structure (6) ranges from about 0 mole % to about 40 mole % of the acrylic polymer, the repeat unit of structure (7) ranges from about 0 mole % to about 25 mole % of the acrylic polymer, R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , and R 7 are individually selected from either H, F, a C-1 to C-4 perfluoroalkyl, or a C-1 to C-4 alkyl, R 8 and R 9 are individually selected from H, a C-1 to C-4 alkyl, a C-1 to C-4 alkyloxy alkyl, and a halogen, R 10 is selected from the group consisting of a C-1 to C-8 primary alkyl, a C-3 to C-8 secondary alkyl, a C-3 to C-8 cyclic secondary alkyl, and a C-7 to C-14 alicyclic secondary alkyl, R 11 a C-2 to C-8 (hydroxy)alkylene moiety, R 12 is a tertiary alkyl acid cleavable group, and further wherein, R 13 is a C-3 to C-12, (alkyloxy)alkylene moiety; (B) a tert-alkyl functionalized acrylic polymer component comprising repeat units selected from the group consisting of ones having structure (1a), (2a), (3a), (4a), (5a), (6a), and (7a): wherein theses repeat units constitute 100 mole % of the repeat units in said tert-alkyl functionalized acrylic polymer, the repeat unit of structure (1a) ranges from about 0 mole % to about 15 mole % of the acrylic polymer, wherein the repeat unit of structure (2a) ranges from about 0 mole % to about 20 mole % of the acrylic polymer, the repeat unit of structure (3a) ranges from about 0 mole % to about 30 mole % of the acrylic polymer, the repeat unit of structure (4a) ranges from about 0 mole % to about 30 mole % of the acrylic polymer, the repeat unit of structure (5a) ranges from about 15 mole % to about 40 mole % of the acrylic polymer, the repeat unit of structure (6a) ranges from about 30 mole % to about 45 mole % of the acrylic polymer, the repeat unit of structure (7a) ranges from about 0 mole % to about 20 mole % of the acrylic polymer, R 1a , R 2a , R 3a , R 4a , R 5a , R 6a , and R 7a are individually selected from either H, F, a C-1 to C-4 perfluoroalkyl, or a C-1 to C-4 alkyl, R 8a and R 9a are individually selected from H, a C-1 to C-4 alkyl, a C-1 to C-4 alkyloxy alkyl, and a halogen, R 10a is selected from the group consisting of a C-1 to C-8 primary alkyl, a C-3 to C-8 secondary alkyl, a C-3 to C-8 cyclic secondary alkyl, and a C-7 to C-14 secondary alicyclic alkyl, R 11a is a C-2 to C-8 (hydroxy)alkylene moiety, R 12a is a tertiary alkyl acid cleavable group, and R 13a is a C-3 to C-12, (alkyloxy)alkylene moiety; (C) a phenolic resin component comprising a Novolak-based resin; (D) a photo acid generator (PAG) component; and (E) a solvent component, wherein (A) the acetal functionalized polymer component and (B) the tert-alkyl functionalized acrylic polymer component are present in a wt. ratio of (A)/(B) which ranges from about 10 to about 2.3, and further wherein, the resist compositions do not include a diazonaphthoquinone (DNQ) component.
  2. 2 . The composition of claim 1 , wherein (A) the acetal functionalized acrylic polymer component comprises from about 15 mole % to about 35 mole % of the repeat unit of structure (1), from about 15 mole % to about 45 mole % of the repeat unit of structure (3), from about 15 mole % to about 35 mole % of the repeat unit of structure (5), from about 10 mole % to about 25 mole % of the repeat unit of structure (7), wherein said repeat units constitute 100 mole % of the repeat units in said acetal functionalized acrylic polymer.
  3. 3 . The composition of claim 1 , wherein (A) the acetal functionalized polymer component comprises from about 15 mole % to about 20 mole % of the repeat unit of structure (1), from about 5 mole % to about 25 mole % of the repeat unit of structure (2), from about 15 mole % to about 35 mole % of the repeat unit of structure (5), from about 10 mole % to about 40 mole % of the repeat unit of structure (6), wherein said repeat units constitute 100 mole % of the repeat units in said acetal functionalized acrylic polymer.
  4. 4 . The composition of claim 1 , wherein (A) the acetal functionalized acrylic polymer component comprises from about 20 mole % to about 35 mole % of the repeat unit of structure (1), from about 15 mole % to about 50 mole % of the repeat unit of structure (3), from about 15 mole % to about 30 mole % of the repeat unit of structure (5), from about 10 mole % to about 35 mole % of the repeat unit of structure (7), wherein said repeat units constitute 100 mole % of the repeat units in said acetal functionalized acrylic polymer.
  5. 5 . The composition of claim 1 , wherein (B) the tert-alkyl functionalized acrylic polymer component comprises from about 2 mole % to about 15 mole % of the repeat unit of structure (1a), from about 10 mole % to about 25 mole % of the repeat unit of structure (3a), from about 15 mole % to about 30 mole % of the repeat unit of structure (5a), from about 30 mole % to about 45 mole % of the repeat unit of structure (6a), from about 2 mole % to about 15 mole % of the repeat unit of structure (7a), wherein said repeat units constitute 100 mole % of the repeat units in said tert-alkyl functionalized acrylic polymer.
  6. 6 . The composition of claim 1 , wherein (B) the tert-alkyl functionalized acrylic polymer component comprises from about 2 mole % to about 15 mole % of the repeat unit of structure (1a), from about 10 mole % to about 25 mole % of the repeat unit of structure (3a), from about 10 mole % to about 25 mole % of the repeat unit of structure (4a), from about 25 mole % to about 35 mole % of the repeat unit of structure (5a), from about 30 mole % to about 45 mole % of the repeat unit of structure (6a), wherein said repeat units constitute 100 mole % of the repeat units in said tert-alkyl functionalized acrylic polymer.
  7. 7 . The composition of claim 1 , wherein (B) the tert-alkyl functionalized acrylic polymer component from about 5 mole % to about 10 mole % of the repeat unit of structure (1a), from about 10 mole % to about 25 mole % of the repeat unit of structure (3a), from about 25 mole % to about 35 mole % of the repeat unit of structure (5a), from about 35 mole % to about 45 mole % of the repeat unit of structure (6a), wherein said repeat units constitute 100 mole % of the repeat units in said tert-alkyl functionalized acrylic polymer.
  8. 8 . The composition of claim 1 , wherein (B) the tert-alkyl functionalized acrylic polymer component comprises from about 10 mole % to about 25 mole % of the repeat unit of structure (3a), from about 25 mole % to about 35 mole % of the repeat unit of structure (5a), from about 30 mole % to about 45 mole % of the repeat unit of structure (6a), from about 8 mole % to about 15 mole % of the repeat unit of structure (7a), wherein said repeat units constitute 100 mole % of the repeat units in said tert-alkyl functionalized acrylic polymer.
  9. 9 . The composition of claim 1 , wherein (A) the acetal functionalized polymer component and (B) the tert-alkyl functionalized acrylic polymer component are present in a wt. ratio of (A)/(B) which ranges from about 8 to about 2.3.
  10. 10 . The composition of claim 1 , wherein (A) the acetal functionalized polymer component and (B) the tert-alkyl functionalized acrylic polymer component are present in a wt. ratio of (A)/(B) which ranges from about 9 to about 2.3.
  11. 11 . The composition of claim 1 , wherein (A) the acetal functionalized polymer component and (B) the tert-alkyl functionalized acrylic polymer component are present in which ranges from about 9 to about 3.
  12. 12 . The composition of claim 1 , wherein (A) the acetal functionalized polymer component and (B) the tert-alkyl functionalized acrylic polymer component are present in a wt. ratio of (A)/(B) which ranges from about 8 to about 3.5.
  13. 13 . The composition of claim 1 , wherein (A) the acetal functionalized polymer component and (B) the tert-alkyl functionalized acrylic polymer component are present in a wt. ratio of (A)/(B) which ranges from about 7 to about 4.
  14. 14 . The composition of claim 1 , wherein (C) the Novolak-based resin component comprises repeat unit (I): where Ra1, Ra2 and Ra3 are each independently (i) a hydrogen, (ii) an unsubstituted C-1 to C-4 alkyl, (iii) a substituted C-1 to C-4 alkyl, (iv) an unsubstituted-X-Phenol group where X is —O—, —C(CH 3 ) 2 —, —CH 2 —, —(C═O)— or —SO 2 — or (v) an substituted-X-Phenol group where X is —O—, —C(CH 3 ) 2 —, —CH 2 —, —(C═O)— or —SO 2 —.
  15. 15 . The composition of claim 1 , wherein the photo acid generator (PAG) component is an aromatic imide N-oxysulfonate derivatives of an organic sulfonic acid, an aromatic sulfonium salt of an organic sulfonic acid, a trihalotriazine derivative or a mixture thereof.
  16. 16 . The composition of claim 1 , further comprising one or more optional ingredients selected from among an acid quencher, an auxiliary resin, a thiol, a plasticizer, a surface leveling agent and a stabilizer.
  17. 17 . The composition of claim 16 , wherein the thiol is a heterocyclic thiol.
  18. 18 . A process of coating a substrate comprising applying the composition of claim 1 on the substrate.
  19. 19 . A process for imaging a resist comprising the steps; i) coating the composition of claim 1 on a substrate to form a resist film; ii) selectively exposing the resist film to UV light using a mask to form a selectively exposed resist film; iii) developing the selectively exposed film to form a positively imaged resist film over the substrate.
  20. 20 . A process for imaging a resist comprising the steps; ia) coating the composition of claim 1 on a substrate to form a resist film; iia) selectively exposing the resist film to UV light using a mask to form a selectively exposed resist film; iiia) baking the selectively exposed resist film to form a baked selectively exposed resist film; iva) developing the selectively exposed and baked resist film to form a positively imaged resist film over the substrate.

Description

This application is a national stage application, filed under 35 U.S.C. § 371, of International Patent Application No. PCT/EP2021/060678 (filed on 23 Apr. 2021) which claims the benefit of U.S. Provisional Patent Application No. 63/015,813 (filed on 27 Apr. 2020) each of which applications is incorporated herein by reference in their entirety. FIELD The disclosed subject matter pertains to a positive radiation-sensitive aqueous base soluble photoresist composition used for making integrated circuit (IC), light emitting diode (LED) devices and display devices. BACKGROUND Photoresist compositions are used in microlithographic processes for making miniaturized electronic components such as in the fabrication of computer chips, integrated circuits, light emitting diode (LED) devices and displays. Generally, in these processes, a film of a photoresist composition is first applied to a substrate material, such as silicon wafers used for making integrated circuits. The coated substrate is then baked to evaporate solvent in the photoresist composition and to fix the coating onto the substrate. The baked, coated surface of the substrate is next subjected to an image-wise exposure to imaging radiation. This radiation exposure causes a chemical transformation in the exposed areas of the coated surface. Visible light, ultraviolet (UV) light, electron beam and X-ray radiant energy are imaging radiation types commonly used today in microlithographic processes. After this image-wise exposure, the coated substrate is treated with a developer solution to dissolve and remove either the radiation-exposed or the unexposed areas of the coated surface of the substrate. There are two types of photoresist compositions, negative-working and positive-working. When positive-working photoresist compositions are exposed image-wise to radiation, the areas of the resist composition exposed to the radiation become more soluble to a developer solution (e.g., release of base solubilizing group or photo-decomposition of dissolution inhibitor), while the unexposed areas of the photoresist coating remain relatively insoluble to such a solution. Thus, treatment of an exposed positive-working resist with a developer causes removal of the exposed areas of the photoresist coating and the creation of a positive image in the coating, thereby uncovering a desired portion of the underlying substrate surface on which the photoresist composition was deposited. The use of a positive-working, sensitive photoresist composition which is developable by aqueous base is known. Most of these compositions are either chemically amplified photoresists based on either phenolic or (meth)acrylate resin or non-chemically amplified photoresists based on Novolak/diazonaphthoquinone (DNQ). In a Novolak/DNQ photoresist a positive image is formed through the photodecomposition of the diazonaphthoquinone compound (PAC) which in resist areas exposed leads to a faster dissolution of the Novolak resin in aqueous base, these types of photoresists are employed at longer UV wavelengths such as i-line (365 nm), and were for many years workhorse photoresists in the manufacturing of integrated circuits (IC). In chemically amplified positive photoresists, a base soluble resin, usually a phenolic resin or (meth)acrylate resin, is released in areas of the resist exposed to radiation, rendering it aqueous base developable, by an acid catalyzed cleavage of protecting groups on these resins, originally masking the base solubilizing moieties. In these chemically amplified photoresists, the catalytic acid is formed by photodecomposition of a photo-acid generator (PAG) component. These types of resists are typically employed at shorter wavelengths in quest for higher resolution in the manufacture of IC's. For thick film applications, conventional Novolak/DNQ resist platforms produce sloped profiles, particularly at thicker films due to their high film absorption. Positive chemically amplified (CA) platforms, on the other hand can provide adequate performance over 5 to 10 μm film thickness, however the polymers conventionally used for these resists, are much more expensive than conventional Novolak resins. Also, certain designs for positive chemically amplified resists which require a post exposure bake may have a deleterious effect on IC device throughput because of poor post exposure delay latitude between exposure and post-exposure bake prior to development in aqueous base. Cost and device throughput are also an issue for applications pertaining to the manufacture of displays, however, here the thickness requirements for resists in this application are lower (1 to 3 μm). The potential effect on device throughput issue occurs in certain chemically amplified resists in which the protecting groups, masking the base solubilizing moiety, have a high activation energy acid for their cleavage, in order unmask the base solubilizing moiety. Although these high activation energy groups are removable