Photoresist composition and photoresist film using the same

Abstract

The present invention relates to a photoresist composition capable of realizing excellent pattern performance during formation of fine patterns, and of preparing a photoresist film that is excellent in chemical stability of a plating solution, and a photoresist film using the same.

Claims

1. A photoresist composition comprising a photoacid generator, and a (meth)acrylic resin containing a (meth)acrylic repeating unit and a functional group represented by Chemical Formula 1 bonded to a terminal of a branched chain in the repeating unit: ##STR00019## wherein, in the Chemical Formula 1, R.sub.1 and R.sub.2 are each independently hydrogen, a carboxyl group, a polyoxyalkylene-based functional group, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, or R.sub.1 and R.sub.2 form a cycloalkyl group having 3 to 20 carbon atoms, wherein the branched chain includes a functional group represented by Chemical Formula 2: ##STR00020## wherein, in the Chemical Formula 2, R.sub.3 is an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 30 carbon atoms, L is a direct bond, —O—, —CO—, —S—, —SO.sub.2—, —C(CH.sub.3).sub.2—, —C(CF.sub.3).sub.2—, —CONH—, —COO—, —(CH.sub.2).sub.y—, —O(CH.sub.2).sub.yO—, —{(CH.sub.2).sub.yO}.sub.p—, —NH—, —NH(CH.sub.2).sub.y—NH—, —NH(CH.sub.2).sub.yO—, —OCH.sub.2—C(CH.sub.3).sub.2—CH.sub.2O—, —COO—(CH.sub.2).sub.y—OCO—, or —OCO—(CH.sub.2).sub.y—COO—, and y and p are each independently an integer of 1 to 10 wherein the functional group of Chemical Formula 1 is bonded to R.sub.3 of the Chemical Formula 2, and wherein the (meth)acrylic repeating unit is represented by Chemical Formula 4: ##STR00021## wherein, in Chemical Formula 4, R.sub.4 to R.sub.7 are each independently hydrogen or a methyl group, R.sub.8 is an alkyl group having 4 to 10 carbon atoms which can be deprotected by an acid, R.sub.9 is the functional group represented by the Chemical Formula 2, R.sub.10 is a cycloalkyl group having 3 to 20 carbon atoms, and a molar ratio of a:b:c:d is 3 to 6:0.5 to 2:2 to 5:1 to 5.

2. The photoresist composition according to claim 1, wherein, in the Chemical Formula 2, R.sub.3 is a phenyl group, L is a direct bond or —{(CH.sub.2).sub.yO}.sub.p—, and y and p are each independently an integer of 1 to 5.

3. The photoresist composition according to claim 1, wherein the polyoxyalkylene-based functional group is a functional group represented by Chemical Formula 3: ##STR00022## wherein, in the Chemical Formula 3, R′ is an alkylene group having 1 to 5 carbon atoms, X is hydrogen, deuterium, a halogen, a cyano group, a nitro group, a hydroxyl group, a carbonyl group, an ester group, an imide group, an amide group, an amino group, a carboxyl group, a sulfonic acid group, a sulfonamide group, a phosphine oxide group, an alkoxy group, an aryloxy group, an alkylthioxy group, an arylthioxy group, an alkylsulfoxy group, an arylsulfoxy group, a silyl group, a boron group, an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, an aralkyl group, an aralkenyl group, an alkylaryl group, an arylphosphine group, or a heterocyclic group containing at least one of N, O, and S atoms, L′ is a direct bond, —O—, —CO—, —S—, —SO.sub.2—, —C(CH.sub.3).sub.2—, —C(CF.sub.3).sub.2—, —CONH—, —COO—, —(CH.sub.2).sub.z—, —O(CH.sub.2).sub.zO—, —O(CH.sub.2).sub.z—, —NH—, —NH(CH.sub.2).sub.z—NH—, —NH(CH.sub.2).sub.zO—, —OCH.sub.2—C(CH.sub.3).sub.2—CH.sub.2O—, —COO—(CH.sub.2).sub.z—OCO—, or —OCO—(CH.sub.2).sub.z—COO—, and z is an integer of 1 to 10.

4. The photoresist composition according to claim 1, wherein R.sub.1 and R.sub.2 together form a cycloalkyl group having 7 to 10 carbon atoms.

5. The photoresist composition according to claim 1, wherein the (meth)acrylic resin is a polymer represented by Chemical Formula 5: ##STR00023## wherein, in the Chemical Formula 5, R.sub.1 and R.sub.2 are each independently hydrogen, a carboxy group, a polyoxyalkylene-based functional group, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, or R.sub.1 and R.sub.2 together form a cycloalkyl group having 3 to 20 carbon atoms, R.sub.4 to R.sub.7 are each independently hydrogen or a methyl group, R.sub.8 is an alkyl group having 4 to 10 carbon atoms which can be deprotected by an acid, R.sub.10 is a cycloalkyl group having 3 to 20 carbon atoms, a molar ratio of a:b:c:d is 3 to 6:0.5 to 2:2 to 5:1 to 5, L is a direct bond, —O—, —CO—, —S—, —SO.sub.2—, —C(CH.sub.3).sub.2—, —C(CF.sub.3).sub.2—, —CONH—, —COO—, —(CH.sub.2).sub.y—, —O(CH.sub.2).sub.yO—, —{(CH.sub.2).sub.yO}.sub.p—, —NH—, —NH(CH.sub.2).sub.y—NH—, —NH(CH.sub.2).sub.yO—, —OCH.sub.2—C(CH.sub.3).sub.2—CH.sub.2O—, —OCO—(CH.sub.2).sub.y—OCO—, or —OCO—(CH.sub.2).sub.y—COO—, and y and p are each independently an integer of 1 to 10.

6. The photoresist composition according to claim 5, wherein the R.sub.10 is a polycyclic cycloalkyl group represented by the following Chemical Formula 6: ##STR00024## wherein, in the Chemical Formula 6, R.sub.11 and R.sub.12 are each independently hydrogen, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, or R.sub.11 and R.sub.12 together form a cycloalkyl group having 3 to 20 carbon atoms.

7. The photoresist composition according to claim 1, wherein the R.sub.10 is a polycyclic cycloalkyl group represented by the following Chemical Formula 6: ##STR00025## wherein, in the Chemical Formula 6, R.sub.11 and R.sub.12 are each independently hydrogen, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, or R.sub.11 and R.sub.12 together form a cycloalkyl group having 3 to 20 carbon atoms.

8. The photoresist composition according to claim 1, further comprising a hydroxystyrene resin in an amount of 1 to 90 parts by weight based on 100 parts by weight of the (meth)acryl resin.

9. The photoresist composition according to claim 8, wherein the hydroxystyrene resin contains a protecting group containing an acetal group or a tert-butyloxycarbonyl group (t-boc).

10. The photoresist composition according to claim 1, wherein the photoresist composition further includes at least one additive selected from the group of an acid diffusion control agent, a plasticizer, a surfactant, a photoinitiator, and a dissolution inhibitor.

11. The photoresist composition according to claim 1, wherein the photoresist composition contains less than 0.0001% by weight of a corrosion inhibitor that includes a triazine thiol compound or a triazole compound.

12. A photoresist film wherein a ratio of a footing length to a photoresist film thickness is 0.05 or less, wherein the photoresist film includes a cured product of a photoresist composition of claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a SEM image of measurement of the footing length and scum of the photoresist pattern obtained in Example 1.

(2) FIG. 2 shows a SEM image of measurement of the footing length and scum of the photoresist pattern obtained in Comparative Example 1.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(3) The invention will be described in more detail by way of the following examples. However, the following examples are given for illustrative purposes only, and the scope of the present invention is not intended to be limited by the following examples.

Synthesis Example: Synthesis of Acrylic Resin

Synthesis Example 1

(4) The weight ratio of tert-butyl methacrylate, methacrylic acid, (4-bromo)phenylmethacrylate, and 5-methacryloyloxy-2,3-trimethylenenorbornane was set to be 40/10/30/20, and a total amount (500 g) of acrylate monomers and 500 g of PGMEA were stirred. After the temperature was increased to 80° C., 5 g of AIBN (Azobisisobutyronitrile) was added thereto, and stirred for 12 hours while the temperature was maintained to synthesize an acrylic polymer represented by the following Chemical Formula A-1.

(5) A compound A′-1 was obtained by nucleophilic aromatic substitution reaction of the compound A-1 and the compound NaN.sub.3 as shown in Reaction Scheme 1-1 below.

(6) ##STR00008##

(7) A compound C-1 was obtained by a click reaction of the compound A′-1 and the compound B-1 as shown in Reaction Scheme 1-2 below. Specifically, the compound A′-1 and the compound B-1 were respectively dissolved in chloroform in an amount of 1.0 equiv. A catalyst solution (CuBr/PMDETA=1/1 mol/mol)(PMDETA:N,N,N′,N″,N-pentamethyl diethylene triamine) previously prepared was added in an amount of 0.05 equiv. based on CuBr at room temperature, and the mixture was stirred for 12 hours. The reaction solution was washed with water and HCl (1 N), and then the organic layer was concentrated and purified by column chromatography to obtain 21 g of a compound C-1 (yield: 60%).

(8) ##STR00009##

Synthesis Example 2

(9) A compound C-2 (yield: 60%) was obtained in the same manner as in Synthesis Example 1, except that the compound B-2 was used instead of the compound B-1 as shown in the following Reaction Scheme 1-3.

(10) ##STR00010##

Synthesis Example 3

(11) A compound C-3 (yield: 60%) was obtained in the same manner as in Synthesis Example 1, except that the compound B-3 was used instead of the compound B-1 as shown in the following Reaction Scheme 1-4.

(12) ##STR00011##

Synthesis Example 4

(13) A compound C-4 (yield: 60%) was obtained in the same manner as in Synthesis Example 1, except that a compound A-2 prepared by using (4-bromophenoxymethyl) methacrylate instead of (4-bromo)phenyl methacrylate was used as shown in the following Reaction Schemes 1-5 and 1-6.

(14) ##STR00012##

(15) ##STR00013##

Synthesis Example 5

(16) A compound C-5 (yield: 60%) was obtained in the same manner as in Synthesis Example 1, except that a compound A-3 prepared by using ((4-bromophenoxy)methoxy)methyl methacrylate instead of the (4-bromo)phenyl methacrylate was used as shown in the following Reaction Schemes 1-7 and 1-8.

(17) ##STR00014##

(18) ##STR00015##

Synthesis Example 6

(19) A compound C-6 (yield: 60%) was obtained in the same manner as in Synthesis Example 1, except that a compound A-4 prepared by using ((4-bromophenoxy)ethoxy)ethyl methacrylate instead of the (4-bromo)phenyl methacrylate was used as shown in the following Reaction Schemes 1-9 and 1-10.

(20) ##STR00016##

(21) ##STR00017##

Comparative Synthesis Example 1

(22) The weight ratio of tert-butyl methacrylate, methacrylic acid, (2-methoxyethoxy)ethylmethacrylate, and 5-methacryloyloxy-2,3-trimethylenenorbornane was set to be 40/10/30/20, and total amount (500 g) of acrylate monomers and 500 g of PGMEA were stirred. After the temperature was increased to 80° C., 5 g of AIBN was added thereto, stirred for 12 hours, and the temperature were maintained to synthesize an acrylic polymer represented by the following Chemical Formula A-5.

(23) ##STR00018##

Examples and Comparative Examples: Preparation of Photoresist Composition

(24) The components shown in Table 1 below were mixed to prepare photoresist compositions of examples and comparative examples, respectively.

(25) Specifically, the components used in Table 1 are as follows. Other resin: 1) Acetal protected polyhydroxystyrene (PHS-Acetal) resin (Mw 15,300 g/mol, substitution rate: 40%) 2) t-boc protected polyhydroxystyrene (PHS-t-boc) resin (Mw: 14,800 g/mol, substitution rate: 40%) Organic solvent: Propylene glycol methyl ether acetate (PGMEA) Photoacid generator: NAI-105 (manufactured by Midori Kagaku Co., Ltd.) Corrosion inhibitor: benzotriazole (BTA)

(26) TABLE-US-00001 TABLE 1 Acrylic resin Category Addtion Photoacid Corrosion Organic (unit: g) Type amount Other resin generator inhibitor solvent Example 1 Synthesis 120 15 (PHS-Acetal) 1 — 40 Example 1 Example 2 Synthesis 120 15 (PHS-Acetal) 1 — 40 Example 2 Example 3 Synthesis 120 15 (PHS-Acetal) 1 — 40 Example 3 Example 4 Synthesis 120 15 (PHS-Acetal) 1 — 40 Example 4 Example 5 Synthesis 120 15 (PHS-Acetal) 1 — 40 Example 5 Example 6 Synthesis 120 15 (PHS-Acetal) 1 — 40 Example 6 Example 7 Synthesis 120 15 (PHS-t-boc) 1 — 40 Example 2 Comparative Comparative 120 15 (PHS-Acetal) 1 0.3 40 Example 1 Synthesis Example 1

Experimental Example

(27) The physical properties of the photoresist composition were evaluated by the following methods using the respective photoresist compositions according to the examples and comparative examples, and the results are shown in Table 2 below.

(28) (1) Whether Scum Remained

(29) The photoresist composition prepared in the examples and comparative examples were spin-coated onto a copper (Cu) substrate having a metal surface so that the film thickness was 10 μm, dried on a hot plate at 110° C. for 2 minutes, exposed to light at 250 mJ/cm.sup.2 using an i-line irradiation device (equipped with a photomask in which a hole pattern with a size of about 10, 20, 30, 40, and 50 μm is formed), additionally dried with a hot plate at 90° C. for 2 minutes, and developed in an about 2.38 wt % tetramethylammonium hydroxide (TMAH) aqueous solution for 1 minute to prepare a resist pattern.

(30) The surface of the resist pattern was analyzed by FE-SEM (Hitachi, S-4800) equipment to determine whether or not scum was detected. Whether scum remained was evaluated based on the following criteria.

(31) Good: Scum not detected

(32) Defective: Scum detected

(33) In addition, scum measurement results (FE-SEM (Hitachi, S-4800)) of Example 1 are shown in FIG. 1 and scum measurement results (FE-SEM (Hitachi, S-4800)) of Comparative Example 1 are shown in FIG. 2.

(34) (2) Footing at Lower End of the Pattern

(35) The photoresist composition prepared in the examples and comparative examples were spin-coated onto a copper (Cu) substrate having a metal surface so that the film thickness is 30 μm, dried on a hot plate at 110° C. for 2 minutes, exposed to light at 250 mJ/cm.sup.2 using an i-line irradiation device (equipped with a photomask in which a hole pattern with a size of about 10, 20, 30, 40, and 50 μm is formed), additionally baked with a hot plate at 90° C. for 2 minutes, and developed in an about 2.38 wt % tetramethylammonium hydroxide (TMAH) aqueous solution for 3 minutes to prepare a resist pattern.

(36) The footing length was measured using the value of the difference between the hole diameter at the top of the resist pattern and the hole diameter at the bottom thereof. Using this, the footing length relative to the pattern thickness (footing length/pattern thickness) was obtained and the footing characteristics were evaluated.

(37) In addition, the results of measurement of the footing length (FE-SEM (Hitachi, S-4800)) of Example 1 are shown in FIG. 1, and the results of measurement of the footing length (FE-SEM (Hitachi, S-4800)) of Comparative Example 1 are shown in FIG. 2.

(38) (3) Resistance to Plating Solution

(39) After the resist pattern prepared in Experimental Example 1 was immersed in a SnAg plating solution for 2 hours, the surface of the resist pattern was analyzed by FE-SEM (Hitachi, S-4800) equipment. The resistance to the plating solution was evaluated based on the presence or absence of deformation of the resist pattern.

(40) Good: Absence of deformation of resist pattern

(41) Defective: Presence of deformation of resist pattern

(42) TABLE-US-00002 TABLE 2 Whether Scum Footing length/ Plating solution remained pattern thickness resistance Example 1 Good 0.008 Good Example 2 Good 0.016 Good Example 3 Good 0.012 Good Example 4 Good 0.008 Good Example 5 Good 0.014 Good Example 6 Good 0.013 Good Example 7 Good 0.015 Good Comparative Defective 0.059 Defective Example 1

(43) Referring to Table 2, it was confirmed that in the case of the photoresist composition according to the examples, pattern deformation did not occur even for the plating solution since no corrosion inhibitor was contained as an additive in the composition even while scum or footing at the lower end of the pattern was hardly generated after pattern formation.

(44) On the other hand, it was confirmed that in the case of the photoresist composition of Comparative Example 1, as the corrosion inhibitor was added to the composition separately from the resin, it was difficult to form a resist pattern suitable for bump formation due to an increase in the footing length as well as the occurrence of scum after pattern formation, and the pattern deformation occurred by the plating solution during the plating process.