STEP SUBSTRATE COATING COMPOSITION

Abstract

A step substrate coating composition for efficiently forming a coating that is capable of filling and flattening a pattern. A step substrate coating composition comprising a compound (A) of a main agent, a crosslinking agent, and a solvent, the compound (A) including a partial structure expressed by formula (A-1) (where the broken line represents bonding with an aromatic ring, the aromatic ring forming a polymer skeleton or a monomer, and n represents an integer of 1-4).

Claims

1. A stepped substrate coating composition comprising a compound (A) serving as a main agent, a crosslinking agent, and a solvent, wherein the compound (A) has a partial structure of the following Formula (A-1): ##STR00028## wherein the broken line is a bond to an aromatic ring; the aromatic ring is an aromatic ring forming a polymer skeleton or a monomer, and n is an integer of 1 to 4).

2. The stepped substrate coating composition according to claim 1, wherein the aromatic ring is a benzene ring, a naphthalene ring, or an anthracene ring.

3. The stepped substrate coating composition according to claim 1, wherein the polymer containing the aromatic ring is a polymer having a hydroxyaryl novolac structure, and the hydroxyl group of the polymer is substituted with the partial structure of Formula (A-1).

4. The stepped substrate coating composition according to claim 1, wherein, in the monomer containing the aromatic ring, the hydroxyl group of the aromatic ring is substituted with the partial structure of Formula (A-1).

5. The stepped substrate coating composition according to claim 1, wherein the composition further comprises an acid generator.

6. The stepped substrate coating composition according to claim 1, wherein the composition further comprises a surfactant.

7. A coated substrate production method comprising a step (i) of applying the stepped substrate coating composition according to claim 1 to a stepped substrate; and a step (ii) of heating the composition applied in the step (i).

8. The coated substrate production method according to claim 7, wherein the composition is heated at a temperature of 100° C. to 500° C. in the step (ii).

9. The coated substrate production method according to or claim 7, wherein the stepped substrate has an open area (non-patterned area) and a patterned area of DENSE (dense) and ISO (coarse), and the pattern has an aspect ratio of 0.1 to 100.

10. The coated substrate production method according to claim 7, wherein the stepped substrate has an open area (non-patterned area) and a patterned area of DENSE (dense) and ISO (coarse), and the difference in coating level (Bias) between the open area and the patterned area is 1 nm to 50 nm.

11. A semiconductor device production method comprising a step of forming, on a stepped substrate, an underlayer film from the stepped substrate coating composition according to claim 1; a step of forming a resist film on the underlayer film; a step of irradiating the resist film with light or electron beams, or heating the resist film during or after irradiation with light or electron beams, and then developing the resist film, to thereby form a resist pattern; a step of etching the underlayer film with the formed resist pattern; and a step of processing the semiconductor substrate with the patterned underlayer film.

12. The semiconductor device production method comprising a step of forming, on a stepped substrate, an underlayer film from the stepped substrate coating composition according to claim 1; a step of forming a resist film on the underlayer film; a step of irradiating the resist film with light or electron beams, or heating the resist film during or after irradiation with light or electron beams, and then developing the resist film, to thereby form a resist pattern; a step of etching the underlayer film with the formed resist pattern; and a step of processing the semiconductor substrate with the patterned underlayer film, wherein the underlayer film forming step comprises a step (i) of applying the stepped substrate coating composition according to claim 1; and a step (ii) of heating the composition applied in the step (i).

13. The semiconductor device production method according to claim 12, wherein the composition is heated at a temperature of 100° C. to 500° C. in the step (ii).

14. The semiconductor device production method according to claim 11, wherein the stepped substrate has an open area (non-patterned area) and a patterned area of DENSE (dense) and ISO (coarse), and the pattern has an aspect ratio of 0.1 to 100.

15. The semiconductor device production method according to claim 11, wherein the stepped substrate has an open area (non-patterned area) and a patterned area of DENSE (dense) and ISO (coarse), and the underlayer film formed from the stepped substrate coating composition has a difference in coating level (Bias) between the open area and the patterned area of 1 nm to 50 nm.

16. A semiconductor device production method comprising a step of forming, on a stepped substrate, an underlayer film from the stepped substrate coating composition according to claim 1; a step of forming a hard mask on the underlayer film; a step of forming a resist film on the hard mask; a step of irradiating the resist film with light or electron beams, or heating the resist film during or after irradiation with light or electron beams, and then developing the resist film, to thereby form a resist pattern; a step of etching the hard mask with the formed resist pattern; a step of etching the underlayer film with the patterned hard mask; and a step of processing the semiconductor substrate with the patterned underlayer film.

17. The semiconductor device production method comprising a step of forming, on a stepped substrate, an underlayer film from the stepped substrate coating composition according to claim 1; a step of forming a hard mask on the underlayer film; a step of forming a resist film on the hard mask; a step of irradiating the resist film with light or electron beams, or heating the resist film during or after irradiation with light or electron beams, and then developing the resist film, to thereby form a resist pattern; a step of etching the hard mask with the formed resist pattern; a step of etching the underlayer film with the patterned hard mask; and a step of processing the semiconductor substrate with the patterned underlayer film, wherein the underlayer film forming step comprises a step (i) of applying the stepped substrate coating composition according to claim 1 to the stepped substrate; and a step (ii) of heating the composition applied in the step (i).

18. The semiconductor device production method according to claim 17, wherein the composition is heated at a temperature of 100° C. to 500° C. in the step (ii).

19. The semiconductor device production method according to claim 17, wherein the stepped substrate has an open area (non-patterned area) and a patterned area of DENSE (dense) and ISO (coarse), and the pattern has an aspect ratio of 0.1 to 100.

20. The semiconductor device production method according to claim 17, wherein the stepped substrate has an open area (non-patterned area) and a patterned area of DENSE (dense) and ISO (coarse), and the underlayer film formed from the stepped substrate coating composition has a difference in coating level (Bias) between the open area and the patterned area of 1 nm to 50 nm.

Description

EXAMPLES

Synthesis Example 1

[0092] Proportions of materials added: HP4700/9AC/PA=100/50/50

[0093] A 100-mL two-necked flask was charged with 4.127 g of 9-anthracenecarboxylic acid (available from Tokyo Chemical Industry Co., Ltd.) (hereinafter abbreviated as “9AC”), 6.00 g of HP-4700 (available from DIC Corporation), 0.345 g of ethyltriphenylphosphonium bromide (available from HOKKO CHEMICAL INDUSTRY CO., LTD.), and 28.736 g of propylene glycol monomethyl ether. Subsequently, the resultant mixture was heated to 140° C., and the mixture was stirred under reflux in a nitrogen atmosphere for about 24 hours. Thereafter, the mixture was cooled to room temperature, and 1.951 g of propiolic acid (available from Tokyo Chemical Industry Co., Ltd.) (hereinafter abbreviated as “PA”) was added to the mixture, followed by stirring under reflux in a nitrogen atmosphere at 60° C. for about 36 hours. After completion of the reaction, 12.315 g of an anion-exchange resin (product name: DOWEX [registered trademark] 550A, available from MUROMACHI TECHNOS CO., LTD.) and 12.315 g of a cation-exchange resin (product name: Amberlite [registered trademark] 15JWET, available from ORGANO CORPORATION) were added to the resultant solution, and the mixture was subjected to ion-exchange treatment at room temperature for four hours. The ion-exchange resins were then separated to thereby prepare a solution of compound of Formula (1-1). The compound was found to have a weight average molecular weight Mw of 1,570 as determined by GPC in terms of polystyrene.

##STR00024##

Synthesis Example 2

[0094] Proportions of materials added: HP4770/9AC/PA=100/50/50

[0095] A 100-mL two-necked flask was charged with 4.356 g of 9-anthracenecarboxylic acid (available from Tokyo Chemical Industry Co., Ltd.), 8.00 g of HP-4770 (available from DIC Corporation), 0.364 g of ethyltriphenylphosphonium bromide (available from HOKKO CHEMICAL INDUSTRY CO., LTD.), and 34.485 g of propylene glycol monomethyl ether acetate. Subsequently, the resultant mixture was heated to 140° C., and the mixture was stirred under reflux in a nitrogen atmosphere for about 24 hours. Thereafter, the mixture was cooled to room temperature, and 2.059 g of propiolic acid (available from Tokyo Chemical Industry Co., Ltd.) was added to the mixture, followed by stirring under reflux in a nitrogen atmosphere at 60° C. for about 36 hours. After completion of the reaction, 14.779 g of an anion-exchange resin (product name: DOWEX [registered trademark] 550A, available from MUROMACHI TECHNOS CO., LTD.) and 14.779 g of a cation-exchange resin (product name: Amberlite [registered trademark] 15JWET, available from ORGANO CORPORATION) were added to the resultant solution, and the mixture was subjected to ion-exchange treatment at room temperature for four hours. The ion-exchange resins were then separated to thereby prepare a solution of compound of Formula (1-2). The compound was found to have a weight average molecular weight Mw of 2,620 as determined by GPC in terms of polystyrene.

##STR00025##

Synthesis Example 3

[0096] Proportions of materials added: NC7300/9AC/PA=100/50/50

[0097] A 100-mL two-necked flask was charged with 4.154 g of 9-anthracenecarboxylic acid (available from Tokyo Chemical Industry Co., Ltd.), 8.00 g of NC7300 (available from Nippon Kayaku Co., Ltd.), 0.347 g of ethyltriphenylphosphonium bromide (available from HOKKO CHEMICAL INDUSTRY CO., LTD.), and 21.697 g of propylene glycol monomethyl ether acetate. Subsequently, the resultant mixture was heated to 140° C., and the mixture was stirred under reflux in a nitrogen atmosphere for about 24 hours. Thereafter, the mixture was cooled to room temperature, and 1.964 g of propiolic acid (available from Tokyo Chemical Industry Co., Ltd.) was added to the mixture, followed by stirring under reflux in a nitrogen atmosphere at 60° C. for about 36 hours. After completion of the reaction, 14.465 g of an anion-exchange resin (product name: DOWEX [registered trademark] 550A, available from MUROMACHI TECHNOS CO., LTD.) and 14.465 g of a cation-exchange resin (product name: Amberlite [registered trademark] 15JWET, available from ORGANO CORPORATION) were added to the resultant solution, and the mixture was subjected to ion-exchange treatment at room temperature for four hours. The ion-exchange resins were then separated to thereby prepare a solution of compound of Formula (1-3). The compound was found to have a weight average molecular weight Mw of 750 as determined by GPC in terms of polystyrene.

##STR00026##

Synthesis Example 4

[0098] In a two-necked flask, 40.0 g of trade name EHPE3150 (available from Daicel Corporation), 20.3 g of 9-anthracenecarboxylic acid, and 13.7 g of benzoic acid were dissolved in 302.0 g of propylene glycol monomethyl ether. Thereafter, 1.5 g of benzyltriethylammonium was added to the solution, and the mixture was refluxed for 24 hours, to thereby allow reaction to proceed. To the resultant solution were added 11 g of an anion-exchange resin (product name: DOWEX [registered trademark] 550A, available from MUROMACHI TECHNOS CO., LTD.) and 11 g of a cation-exchange resin (product name: Amberlite [registered trademark] 15JWET, available from ORGANO CORPORATION), and the mixture was subjected to ion-exchange treatment at room temperature for four hours. The ion-exchange resins were then separated to thereby prepare a solution of compound of Formula (1-4). The compound was found to have a weight average molecular weight Mw of 4,100 as determined by GPC in terms of polystyrene.

##STR00027##

Example 1

[0099] Firstly, 3.390 g of the resin solution prepared in Synthesis Example 1 (solid content: 24.42%) was mixed with 0.497 g of propylene glycol monomethyl ether containing 5% TAG2689 (thermal acid generator, available from King Industries Inc.), 0.166 g of TMOM-BP (crosslinking agent, available from Honshu Chemical Industry Co., Ltd.), 0.166 g of propylene glycol monomethyl ether acetate containing 1% surfactant (product name: MEGAFAC [trade name] R-40, fluorine-containing surfactant, available from DIC Corporation), 2.822 g of propylene glycol monomethyl ether, and 4.266 g of propylene glycol monomethyl ether acetate. Thereafter, the resultant mixture was filtered with a polytetrafluoroethylene-made microfilter (pore size: 0.1 μm), to thereby prepare a solution of a resist underlayer film-forming composition.

Example 2

[0100] Firstly, 4.085 g of the resin solution prepared in Synthesis Example 2 (solid content: 20.27%) was mixed with 0.497 g of propylene glycol monomethyl ether containing 5% TAG2689 (thermal acid generator, available from King Industries Inc.), 0.166 g of TMOM-BP (crosslinking agent, available from Honshu Chemical Industry Co., Ltd.), 0.166 g of propylene glycol monomethyl ether acetate containing 1% surfactant (product name: MEGAFAC [trade name] R-40, fluorine-containing surfactant, available from DIC Corporation), 0.260 g of propylene glycol monomethyl ether, and 7.522 g of propylene glycol monomethyl ether acetate. Thereafter, the resultant mixture was filtered with a polytetrafluoroethylene-made microfilter (pore size: 0.1 μm), to thereby prepare a solution of a resist underlayer film-forming composition.

Example 3

[0101] Firstly, 4.239 g of the resin solution prepared in Synthesis Example 3 (solid content: 19.53%) was mixed with 0.497 g of propylene glycol monomethyl ether containing 5% TAG2689 (thermal acid generator, available from King Industries Inc.), 0.1656 g of TMOM-BP (crosslinking agent, available from Honshu Chemical Industry Co., Ltd.), 0.166 g of propylene glycol monomethyl ether acetate containing 1% surfactant (product name: MEGAFAC [trade name] R-40, fluorine-containing surfactant, available from DIC Corporation), 2.822 g of propylene glycol monomethyl ether, and 4.111 g of propylene glycol monomethyl ether acetate. Thereafter, the resultant mixture was filtered with a polytetrafluoroethylene-made microfilter (pore size: 0.1 μm), to thereby prepare a solution of a resist underlayer film-forming composition.

Comparative Example 1

[0102] Firstly, 5.212 g of the resin solution prepared in Synthesis Example 3 (solid content: 19.53%) was mixed with 0.204 g of propylene glycol monomethyl ether acetate containing product name: MEGAFAC [trade name] R-40 (fluorine-containing surfactant), 3.290 g of propylene glycol monomethyl ether, and 3.294 g of propylene glycol monomethyl ether acetate. Thereafter, the resultant mixture was filtered with a polytetrafluoroethylene-made microfilter (pore size: 0.1 μm), to thereby prepare a solution of a resist underlayer film-forming composition.

Comparative Example 2

[0103] Firstly, 4.226 g of the resin solution prepared in Synthesis Example 4 (solid content: 23.24%) was mixed with 0.393 g of propylene glycol monomethyl ether containing 5% TAG2689 (thermal acid generator, available from King Industries Inc.), 0.196 g of TMOM-BP (crosslinking agent, available from Honshu Chemical Industry Co., Ltd.), 0.196 g of propylene glycol monomethyl ether acetate containing 1% surfactant (product name: MEGAFAC [trade name] R-40, fluorine-containing surfactant, available from DIC Corporation), 2.794 g of propylene glycol monomethyl ether, and 7.195 g of propylene glycol monomethyl ether acetate. Thereafter, the resultant mixture was filtered with a polytetrafluoroethylene-made microfilter (pore size: 0.1 μm), to thereby prepare a solution of a resist underlayer film-forming composition.

Solvent Resistance Test

[0104] Each of the resist underlayer film compositions prepared in Example 3 and Comparative Example 1 was applied onto a silicon wafer with a spin coater. The silicon wafer was heated on a hot plate at 240° C. for 60 seconds, to thereby form a resist underlayer film having a thickness of 200 nm. For evaluation of solvent resistance, the baked coating film was immersed in a solvent mixture of propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate (7:3) for one minute, spin-dried, and then baked at 100° C. for 60 seconds. The thickness of the resultant film was measured to thereby calculate film remaining rate (Table 1).

[0105] In Example 3, solvent resistance was achieved (film remaining rate: 100%) through curing by reaction with a crosslinking agent. In contrast, in Comparative Example 1, solvent resistance failed to be achieved due to insufficient curing only by heating.

TABLE-US-00001 TABLE 1 Film remaining rate Example 3 100% Comparative Example 1  6%

Evaluation of Planarity and Fillability on Stepped Substrate

[0106] For evaluation of planarity on a stepped substrate, the thicknesses of portions of a coating film were compared on an SiO.sub.2 substrate having a thickness of 200 nm and having a dense patterned area (DENSE) (trench width: 50 nm, pitch: 100 nm) and a non-patterned open area (OPEN). Each of the resist underlayer film compositions prepared in Examples 1 to 3 and Comparative Example 2 was applied onto the aforementioned substrate with a spin coater, and then heated on a hot plate at 240° C. for 60 seconds. The planarity of the stepped substrate was evaluated by observation with a scanning electron microscope (S-4800) available from Hitachi High-Technologies Corporation, and by measurement of the difference between the thickness of the substrate at the dense area (patterned area) and that at the open area (non-patterned area) (i.e., the difference in coating level between the dense area and the open area, which is called “Bias”). The term “planarity” as used herein refers to the case where a small difference is present between the thicknesses of portions of the coating film applied onto the patterned area (dense area) and the non-patterned area (open area); i.e., ISO-DENSE Bias is small (Table 2).

[0107] In Examples 1 to 3, the crosslinking initiation temperature of the crosslinkable group contained in the polymer can be increased, and thus sufficient reflow property is achieved, resulting in good planarity. In contrast, in Comparative Example 2, the crosslinking initiation temperature of the crosslinking agent is low, and thus sufficient reflow property fails to be achieved, resulting in poor planarity.

TABLE-US-00002 TABLE 2 DENSE OPEN DENSE/OPEN Thickness Thickness Difference in (nm) (nm) coating level (nm) Example 1 240° C./60 s 145 181 36 Example 2 240° C./60 s 163 185 22 Example 3 240° C./60 s 168 187 19 Comparative 240° C./60 s 157 210 53 Example 2

INDUSTRIAL APPLICABILITY

[0108] The stepped substrate coating composition of the present invention can fill a pattern sufficiently and thus can be used for forming a coating film having planarity on a substrate.