Resist underlayer film-forming composition comprising carbonyl-containing polyhydroxy aromatic ring novolac resin

Abstract

There is provided resist underlayer film for lithography process with high dry etching resistance, wiggling resistance, and heat resistance. Resist underlayer film-forming composition for lithography including polymer having unit structure of Formula (1): wherein A is hydroxy group-substituted C.sub.6-40 arylene group derived from polyhydroxy aromatic compound; B is C.sub.6-40 arylene group or C.sub.4-30 heterocyclic group containing nitrogen atom, oxygen atom, sulfur atom, or combination thereof; X.sup.+ is H.sup.+, NH.sub.4.sup.+, primary ammonium ion, secondary ammonium ion, tertiary ammonium ion, or quaternary ammonium ion, T is hydrogen atom, C.sub.1-10 alkyl group or C.sub.6-40 aryl group that may be substituted with halogen group, hydroxy group, nitro group, amino group, carboxylate ester group, nitrile group, or combination thereof as substituent, or C.sub.4-30 heterocyclic group containing nitrogen atom, oxygen atom, sulfur atom, or combination thereof, B and T may form C.sub.4-40 ring together with carbon atom to which they are bonded. ##STR00001##

Claims

1. A resist underlayer film-forming composition for lithography comprising: a polymer having a unit structure of Formula (1): ##STR00020## wherein: A is a benzenediol group, a benzenetriol group, or a naphthalenediol group; B is a C.sub.6-40 arylene group and is an organic group based on a benzene ring, a naphthalene ring, or an anthracene ring, or an organic group based on a fluorene ring bonded to T, or a C.sub.4-30 heterocyclic group containing a nitrogen atom, an oxygen atom, a sulfur atom, or a combination thereof and is an organic group based on an optionally substituted furan ring, thiophene ring, pyrrole ring, carbazole ring, or dibenzofuran ring; X.sup.+ is H.sup.+, NH.sub.4.sup.+, a primary ammonium ion, a secondary ammonium ion, a tertiary ammonium ion, or a quaternary ammonium ion, T is a hydrogen atom, a C.sub.1-10 alkyl group or a C.sub.6-40 aryl group that may be substituted with a halogen group, a hydroxy group, a nitro group, an amino group, a carboxylate ester group, a nitrile group, or a combination thereof as a substituent, or a C.sub.4-30 heterocyclic group containing a nitrogen atom, an oxygen atom, a sulfur atom, or a combination thereof, B and T may form a C.sub.4-40 ring together with a carbon atom to which they are bonded, and n1 is an integer of 1 to the number of group(s) capable of being substituted with hydrogen atom(s) in the group defined by B or hydrogen atom(s) in the ring formed by bonding B and T, and a crosslinker, wherein the composition has a solid content of 0.1 to 70% by mass, wherein a cured resist underlayer film formed from the resist underlayer film-forming composition after baking at 240° C. for 1 minute is not soluble when immersed in a photoresist solvent composed of propylene glycol monomethyl ether or propylene glycol monomethyl ether acetate but is removable when immersed in an aqueous solution of tetramethylammonium hydroxide and without ashing, and wherein the polymer having a unit structure of Formula (1) is a polymer having a unit structure corresponding to the following Formula (1-1): ##STR00021##

2. The resist underlayer film-forming composition according to claim 1, wherein B is said arylene group.

3. The resist underlayer film-forming composition according to claim 2, wherein said arylene group is an organic group based on an anthracene ring.

4. The resist underlayer film-forming composition according to claim 2, wherein said arylene group is an organic group is based on an organic group based on a fluorene ring bonded to T.

5. The resist underlayer film-forming composition according to claim 1, wherein B is said heterocyclic group.

6. The resist underlayer film-forming composition according to claim 1, wherein the arylene group or the heterocyclic group defined by B has a halogen group, a hydroxy group, a nitro group, an amino group, a carboxylate ester group, a nitrile group, or a combination thereof as a substituent.

7. The resist underlayer film-forming composition according to claim 1, wherein the crosslinker has the substructure of Formula (2), or is a polymer or oligomer having a repeating unit of Formula (3), as follows: ##STR00022## wherein, in Formula (2), R.sup.10 and R.sup.11 are each a hydrogen atom, a C.sub.1-10 alkyl group, or a C.sub.6-20 aryl group, n10 is an integer of 1 to 4, n11 is an integer of 1 to (5-n10), and (n10+n11) is an integer of 2 to 5; in Formula (3), R.sup.12 is a hydrogen atom or a C.sub.1-10 alkyl group, R.sup.13 is a C.sub.1-10 alkyl group, n12 is an integer of 1 to 4, n13 is an integer of 0 to (4-n12), (n12+n13) is an integer of 1 to 4, and the number of repeating unit structures falls within a range of 2 to 100.

8. The resist underlayer film-forming composition according to claim 1, wherein the hydroxy group-substituted arylene group defined by A is a benzenediol group or a benzenetriol group.

9. The resist underlayer film-forming composition according to claim 1, wherein the polymer having a unit structure of Formula (1) is a copolymer having a unit structure corresponding to Formula (1-1) and a unit structure corresponding to the following Formula (1-8): ##STR00023##

10. The resist underlayer film-forming composition according to claim 1, wherein the polymer having a unit structure of Formula (1) is a copolymer having a unit structure corresponding to Formula (1-1) and a unit structure corresponding to the following Formula (1-5): ##STR00024##

11. A resist underlayer film obtained by applying the resist underlayer film-forming composition according to claim 1 to a semiconductor substrate, followed by baking.

12. A method for forming a resist pattern used in production of a semiconductor comprising a step of applying the resist underlayer film-forming composition according to claim 1 to a semiconductor substrate, followed by baking, to form an underlayer film.

13. A method for producing a semiconductor device comprising steps of forming an underlayer film on a semiconductor substrate from the resist underlayer film-forming composition according to claim 1, forming a resist film on the underlayer film, forming a resist pattern by exposure to light or electron beam and development, etching the underlayer film through the resist pattern, and processing the semiconductor substrate through the patterned underlayer film.

14. A method for producing a semiconductor device comprising steps of forming a resist underlayer film on a semiconductor substrate from the resist underlayer film-forming composition according to claim 1, forming a hard mask on the resist underlayer film, forming a resist film on the hard mask, forming a resist pattern by exposure to light or electron beam and development, etching the hard mask through the resist pattern, etching the resist underlayer film through the patterned hard mask, and processing the semiconductor substrate through the patterned resist underlayer film.

15. The method according to claim 14, wherein the hard mask is formed by an applied inorganic substance or vapor deposition of an inorganic substance.

16. A resist underlayer film-forming composition for lithography comprising: a polymer having a unit structure of Formula (1): ##STR00025## wherein: A is a benzenediol group, a benzenetriol group, a naphthalenediol group, or the following polyhydroxy-substituted structures: ##STR00026## B is a C.sub.6-40 arylene group or a C.sub.4-30 heterocyclic group containing a nitrogen atom, an oxygen atom, a sulfur atom, or a combination thereof; X.sup.+ is H.sup.+, NH.sub.4.sup.+, a primary ammonium ion, a secondary ammonium ion, a tertiary ammonium ion, or a quaternary ammonium ion, T is a hydrogen atom, a C.sub.1-10 alkyl group or a C.sub.6-40 aryl group that may be substituted with a halogen group, a hydroxy group, a nitro group, an amino group, a carboxylate ester group, a nitrile group, or a combination thereof as a substituent, or a C.sub.4-30 heterocyclic group containing a nitrogen atom, an oxygen atom, a sulfur atom, or a combination thereof, B and T may form a C.sub.4-40 ring together with a carbon atom to which they are bonded, and n1 is an integer of 1 to the number of group(s) capable of being substituted with hydrogen atom(s) in the group defined by B or hydrogen atom(s) in the ring formed by bonding B and T, and a crosslinker, wherein the composition has a solid content of 0.1 to 70% by mass, wherein a cured resist underlayer film formed from the resist underlayer film-forming composition after baking at 240° C. for 1 minute is not soluble when immersed in a photoresist solvent composed of propylene glycol monomethyl ether or propylene glycol monomethyl ether acetate but is removable when immersed in an aqueous solution of tetramethylammonium hydroxide, and wherein the polymer having a unit structure of Formula (1) is a polymer having a unit structure corresponding to the following Formula (1-1): ##STR00027##

Description

EXAMPLES

Synthesis Example 1

(1) 20.0 g of phloroglucinol (manufactured by Tokyo Chemical Industry Co., Ltd.), 20.3 g of terephthalaldehyde acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 120.8 g of propylene glycol monomethyl ether were placed in a 300-mL flask. After then, the mixture was stirred for about 5 hours under heating-reflux. After completion of the reaction, ion-exchange treatment was carried out to obtain a brownish-red phloroglucinol resin solution. The resulting polymer corresponded to Formula (1-1). The weight-average molecular weight Mw measured by GPC in terms of polystyrene was 2,450, and the polydispersity Mw/Mn was 1.6.

Synthesis Example 2

(2) 5.1 g of phloroglucinol (manufactured by Tokyo Chemical Industry Co., Ltd.), 6.5 g of 1,5-dihydroxynaphthalene (manufactured by Tokyo Chemical Industry Co., Ltd.), 9.2 g of terephthalaldehyde acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 62.3 g of propylene glycol monomethyl ether were placed in a 100-mL flask. After then, the mixture was stirred for about 3 hours under heating-reflux. After completion of the reaction, ion-exchange treatment was carried out to obtain a brownish-red resin solution. The resulting polymer corresponded to a copolymer containing unit structures of Formulae (1-1) and (1-8). The weight-average molecular weight Mw measured by GPC in terms of polystyrene was 4,430, and the polydispersity Mw/Mn was 6.4.

Synthesis Example 3

(3) 5.5 g of phloroglucinol (manufactured by Tokyo Chemical Industry Co., Ltd.), 4.8 g of resorcinol (manufactured by Tokyo Chemical Industry Co., Ltd.), 10.7 g of terephthalaldehyde acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 63.1 g of propylene glycol monomethyl ether were placed in a 100-mL flask. After then, the mixture was stirred for about 3 hours under heating-reflux. After completion of the reaction, ion-exchange treatment was carried out to obtain a brownish-red phloroglucinol resin solution. The resulting polymer corresponded to a copolymer containing unit structures of Formulae (1-1) and (1-5). The weight-average molecular weight Mw measured by GPC in terms of polystyrene was 3,000, and the polydispersity Mw/Mn was 1.9.

Comparative Synthesis Example 1

(4) 12.0 g of phloroglucinol (manufactured by Tokyo Chemical Industry Co., Ltd.), 10.1 g of benzaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.), 53.7 g of propylene glycol monomethyl ether, and 0.92 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) were placed in a 100-mL eggplant-shaped flask. After then, the mixture was stirred for about 4 hours under heating-reflux. After completion of the reaction, ion-exchange treatment was carried out to obtain a brownish-red phloroglucinol resin solution. The resulting polymer corresponded to Formula (3-1). The weight-average molecular weight Mw measured by GPC in terms of polystyrene was 1,870, and the polydispersity Mw/Mn was 1.6.

(5) ##STR00018##

Comparative Synthesis Example 2

(6) 45.0 g of phloroglucinol (manufactured by Tokyo Chemical Industry Co., Ltd.), 43.6 g of 4-hydroxybenzaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.), 170.9 g of propylene glycol monomethyl ether, and 3.46 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) were placed in a 300-mL eggplant-shaped flask. After then, the mixture was stirred for about 3 hours under heating-reflux. After completion of the reaction, ion-exchange treatment was carried out to obtain a brownish-red phloroglucinol resin solution. The resulting polymer corresponded to Formula (3-2). The weight-average molecular weight Mw measured by GPC in terms of polystyrene was 1,260, and the polydispersity Mw/Mn was 1.5.

(7) ##STR00019##

Example 1

(8) 2 g (solid content) of the resin obtained in Synthesis Example 1 and 0.3 g of tetramethoxymethyl glycoluril were dissolved in 16.1 g of propylene glycol monomethyl ether and 6.9 g of propylene glycol monomethyl ether acetate to prepare a solution of a resist underlayer film-forming composition used in a lithography process using a multilayer film.

Example 2

(9) 2 g (solid content) of the resin obtained in Synthesis Example 2 and 0.3 g of tetramethoxymethyl biphenol were dissolved in 16.1 g of propylene glycol monomethyl ether and 6.9 g of propylene glycol monomethyl ether acetate to prepare a solution of a resist underlayer film-forming composition used in a lithography process using a multilayer film.

Example 3

(10) 2 g (solid content) of the resin obtained in Synthesis Example 3 and 0.3 g of tetramethoxymethyl glycoluril were dissolved in 16.1 g of propylene glycol monomethyl ether and 6.9 g of propylene glycol monomethyl ether acetate to prepare a solution of a resist underlayer film-forming composition used in a lithography process using a multilayer film.

Comparative Example 1

(11) 1 g (solid content) of cresol novolac resin (commercial product, weight-average molecular weight: 4,000) was dissolved in 10.34 g of propylene glycol monomethyl ether and 2.59 g of cyclohexanone to prepare a solution of a resist underlayer film-forming composition used in a lithography process using a multilayer film.

Comparative Example 2

(12) 2 g (solid content) of the resin obtained in Comparative Synthesis Example 1 was dissolved in 0.3 g of tetramethoxymethyl glycoluril, 16.1 g of propylene glycol monomethyl ether, and 6.9 g of propylene glycol monomethyl ether acetate to prepare a solution of a resist underlayer film-forming composition used in a lithography process using a multilayer film.

Comparative Example 3

(13) 2 g (solid content) of the resin obtained in Comparative Synthesis Example 2 was dissolved in 0.3 g of tetramethoxymethyl glycoluril, 16.1 g of propylene glycol monomethyl ether, and 6.9 g of propylene glycol monomethyl ether acetate to prepare a solution of a resist underlayer film-forming composition used in a lithography process using a multilayer film.

(14) (Measurement of Optical Parameter)

(15) Each solution of resist underlayer film-forming composition prepared in Examples 1 to 3 and Comparative Examples 1 to 3 was applied to a silicon wafer using a spin coater. The silicon wafer was baked on a hot plate at 240° C. for 1 minute) to form a resist underlayer film (thickness: 0.05 vim). The refractive index (n value) and the light absorption coefficient (k value, also referred to as attenuation coefficient) of the resist underlayer film were measured at a wavelength of 193 nm using a spectroscopic ellipsometer. The results are shown in Table 1.

(16) TABLE-US-00001 TABLE 1 Table 1 Refractive index n and light absorption coefficient k n k Example 1 Film baked at 240° C. 1.41 0.60 Example 2 Film baked at 240° C. 1.42 0.56 Example 3 Film baked at 240° C. 1.39 0.65 Comparative Example 1 Film baked at 240° C. 1.53 0.42 Comparative Example 2 Film baked at 240° C. 1.57 0.85 Comparative Example 3 Film baked at 240° C. 1.47 0.69

(17) (Measurement of Dry Etching Rate)

(18) As an etcher and an etching gas used in the measurement of dry etching rate, the following etcher and gas were used.

(19) RIE-10NR (manufactured by SAMCO INC.): CF.sub.4

(20) Each solution of resist underlayer film-forming composition prepared in Examples 1 to 3 and Comparative Examples 2 to 3 was applied to a silicon wafer using a spin coater. The silicon wafer was baked on a hot plate at 240° C. for 1 minute and at 400° C. for 2 minute (at 240° C. for 1 minute in Comparative Example 1), to form a resist underlayer film (thickness: 0.20 μm). The dry etching rate was measured using CF.sub.4 gas as an etching gas.

(21) The solution in Comparative Example 1 was applied to a silicon wafer using a spin coater to form a film. The dry etching rate was measured using CF.sub.4 gas as an etching gas. The dry etching rates of the resist underlayer films in Examples 1 to 3 and Comparative Examples 2 and 3 were compared with the dry etching rate of the resist underlayer film in Comparative Example 1. The results are shown in Table 2. A rate ratio is a ratio of the dry etching rates of (the resist underlayer film obtained in each of Examples 1 to 3 and Comparative Examples 2 and 3)/(the resist underlayer film obtained Comparative Example 1).

(22) TABLE-US-00002 TABLE 2 Table 2 Dry etching rate ratio Rate ratio of (resist underlayer film in 1.25 Example 1) Rate ratio of (resist underlayer film in 1.18 Example 2) Rate ratio of (resist underlayer film in 1.23 Example 3) Rate ratio of (resist underlayer film in 0.98 Comparative Example 2) Rate ratio of (resist underlayer film in 1.15 Comparative Example 3)

(23) (Elution Test into Photoresist Solvent)

(24) Each solution of resist underlayer film-forming composition prepared in Examples 1 to 3 and Comparative Examples 1 to 3 was applied to a silicon wafer using a spin coater. The silicon wafer was baked on a hot plate at 240° C. for 1 minute to form a resist underlayer film (thickness: 0.20 μm). The resist underlayer film was subjected to an immersion test in a solvent used for a resist, such as propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate. The results are shown in Table 3. A remaining film ratio was obtained by immersing the resist underlayer film in each solvent for 60 seconds, measuring the thickness before and after the immersion, and calculating (film thickness after the immersion)/(film thickness before the immersion)×100.

(25) TABLE-US-00003 TABLE 3 Table 3 Remaining film ratio (%) after elution test PGME PGMEA Example 1 Film baked at 240° C. 100 100 Example 2 Film baked at 240° C. 100 100 Example 3 Film baked at 240° C. 100 100 Comparative Example 1 Film baked at 240° C. 100 100 Comparative Example 2 Film baked at 240° C. 0 0 Comparative Example 3 Film baked at 240° C. 93 98

(26) (Dissolution Test of Alkaline Liquid)

(27) Each solution of resist underlayer film-forming composition prepared in Examples 1 to 3 was applied to a silicon wafer using a spin coater. The silicon wafer was baked on a hot plate at 240° C. for 1 minute to form a resist underlayer film (thickness: 0.20 μm). The resist underlayer film was subjected to an immersion test in 2.38% by mass tetramethylammonium hydroxide aqueous solution. The results are shown in Table 4. The resist underlayer film was immersed in 2.38% by mass tetramethylammonium hydroxide aqueous solution for 60 seconds, and the overview of the immersed film was observed. A case where the film does not remain is considered as removable, and a case where the film remains is considered as nonremovable.

(28) TABLE-US-00004 TABLE 4 Table 4 Results of dissolution test of alkaline liquid) Example 1 Film baked at 240° C. Removable Example 2 Film baked at 240° C. Removable Example 3 Film baked at 240° C. Removable Comparative Example 1 Film baked at 240° C. Nonremovable Comparative Example 2 Film baked at 240° C. Removable Comparative Example 3 Film baked at 240° C. Removable

INDUSTRIAL APPLICABILITY

(29) The material for a resist underlayer film for a lithography process using a multilayer film of the present invention has high dry etching resistance, which is different from a conventional anti-reflective coating having high etching rate. The material has characteristics of a hard mask. Conventionally, ashing (removal using ashing) is used in removal of the resist underlayer film. However, since the resist underlayer film obtained by the present invention can be removed by an aqueous alkaline solution, a decrease in damage to a substrate during removal is expected.