JP3868475B2 - Pattern formation method - Google Patents

Description

  The present invention relates to a pattern forming method including a step of reducing a size of an opening by flowing a resist pattern having the opening.

  In the manufacturing process of a semiconductor integrated circuit device, with the progress of high integration of semiconductor integrated circuits and miniaturization of semiconductor elements, resist patterns formed by lithography technology are further miniaturized.

  In particular, in the process of forming a resist pattern having an opening for forming a hole or groove in a film to be processed, the contrast in the conventional lithography technique decreases with the fineness of the size of the hole or groove. It has become difficult to form openings for forming holes or grooves.

  Therefore, a resist pattern having an opening made of a hole or a groove is caused to flow by heat to reduce the size of the opening, thereby forming an opening having a fine size exceeding the limit of lithography technology in the resist pattern. Technology has been proposed.

  Hereinafter, a conventional pattern forming method will be described with reference to FIGS.

  First, a chemically amplified resist material having the following composition is prepared.

Poly ((2-methyl-2-adamantyl methacrylate)-(γ-butyrolactone methacrylate) (however, 2-methyl-2-adamantyl methacrylate: γ-butyrolactone methacrylate = 50 mol%: 50 mol%) (base polymer) ………… ……… 1g
Triphenylsulfonium nonafluorobutane sulfonic acid (acid generator) …………………………………………………………………………………… 0.03 g
Propylene glycol monomethyl ether acetate (solvent) ………… 4g
Next, as shown in FIG. 3A, the above-mentioned chemically amplified resist material is applied on the substrate 1 to form a resist film 2 having a thickness of 0.5 μm, and then FIG. As shown in FIG. 4, pattern exposure is performed by irradiating the resist film 2 with an ArF excimer laser 3 emitted from an ArF excimer laser scanner (NA: 0.60) through a photomask 4 having a desired mask pattern. .

  Next, as shown in FIG. 3C, post-exposure heating (PEB) 5 is performed on the resist film 2 at a temperature of 105 ° C. for 90 seconds. In this way, acid is generated from the acid generator in the exposed portion 2a of the resist film 2 and therefore changes to be soluble in an alkaline developer. On the other hand, in the unexposed portion 2b of the resist film 2, the acid generator generates acid. Does not occur, it remains insoluble in the alkaline developer.

Next, 2.38 wt% of tetramethylammonium hydroxide developer the resist film 2 by developing for 60 seconds with (alkaline developer), as shown in FIG. 3 (d), size: W ₁ A resist pattern 7 having an opening 6 having a thickness of 0.20 μm is formed.

Next, the resist pattern 7 is heated 8 at a temperature of 150 ° C. to flow the resist pattern 7 as shown in FIG. In this way, the size of the opening 6 is reduced from W ₁ (= 0.20 μm) to W ₂ (= 0.15 μm).

  In this way, it is possible to form a resist pattern having fine openings that exceed the limits of lithography technology.

  However, as shown in FIG. 3E, there arises a problem that the sectional shape of the opening 6 whose size is reduced by the flow is greatly deteriorated.

  In addition, there is a problem that the variation in the size of the opening 6 whose size is reduced by the flow is 20% or more, and the variation in size becomes large.

  As described above, when etching is performed on a film to be processed using a resist pattern having openings whose cross-sectional shape is deteriorated or the size is varied, the shape of the obtained contact hole or wiring groove is deteriorated or the size is reduced. There is a problem that the yield of the semiconductor device is lowered because of variations.

  In view of the above, an object of the present invention is to reduce the size of the opening without deteriorating the shape of the opening formed in the resist pattern.

  In order to achieve the above object, a first pattern forming method according to the present invention includes a first polymer having a hydroxystyrene derivative containing an acetal group as a protecting group that is eliminated by the action of an acid, and a norbornene derivative. A step of forming a resist film made of a chemically amplified resist material having a polymer of No. 2 and an acid generator that generates an acid when irradiated with light, and selectively exposing the resist film to exposure light. The pattern exposure process, the pattern exposed resist film is developed to form a resist pattern having an opening made of holes or grooves, and the resist pattern is heated to reduce the size of the opening. Process.

  According to the first pattern formation method, the polymer having a norbornene derivative improves the heat flow contrast of the polymer having a hydroxystyrene derivative containing an acetal group, that is, suppresses the heat flow in the vicinity of the opening of the resist pattern. Therefore, the shape of the opening of the resist pattern does not deteriorate. Therefore, the size of the opening can be reduced without deteriorating the shape of the opening formed in the resist pattern.

  The second pattern formation method according to the present invention includes a first polymer having a hydroxystyrene derivative containing an acetal group as a protecting group that is released by the action of an acid, and a second polymer having a norbornene derivative-maleic anhydride. , A step of forming a resist film made of a chemically amplified resist material having an acid generator that generates an acid when irradiated with light, and pattern exposure by selectively irradiating the resist film with exposure light A step of developing a resist film that has been subjected to pattern exposure to form a resist pattern having an opening made of a hole or a groove, and a step of reducing the size of the opening by heating the resist pattern. ing.

  According to the second pattern forming method, the polymer having norbornene derivative-maleic anhydride improves the heat flow contrast of the polymer having a hydroxystyrene derivative containing an acetal group, that is, heat near the opening of the resist pattern. In order to suppress the flow, the shape of the opening of the resist pattern does not deteriorate. Therefore, the size of the opening can be reduced without deteriorating the shape of the opening formed in the resist pattern.

  A third pattern formation method according to the present invention includes a first polymer having a hydroxystyrene derivative containing an acetal group as a protecting group that is eliminated by the action of an acid, a second polymer having a norbornene derivative, and a norbornene derivative- Forming a resist film made of a chemically amplified resist material having a third polymer having maleic anhydride and an acid generator that generates acid when irradiated with light; and exposing the resist film to exposure light A step of performing pattern exposure by selectively irradiating, a step of developing a resist film subjected to pattern exposure to form a resist pattern having openings made of holes or grooves, and heating the resist pattern And a step of reducing the size of the part.

  According to the third pattern forming method, the polymer having a norbornene derivative and the polymer having a norbornene derivative-maleic anhydride improve the heat flow contrast of the polymer having a hydroxystyrene derivative containing an acetal group, that is, a resist pattern. Therefore, the shape of the opening of the resist pattern does not deteriorate. Therefore, the size of the opening can be reduced without deteriorating the shape of the opening formed in the resist pattern.

  As the acetal group in the first to third pattern forming methods, an ethoxyethyl group or a tetrahydropyranyl group can be used.

  According to the first pattern formation method, when the resist pattern is heated, the norbornene derivative suppresses the heat flow in the vicinity of the opening of the resist pattern, thereby causing deterioration of the shape of the opening formed in the resist pattern. And the size of the opening can be reduced.

  According to the second pattern formation method, when the resist pattern is heated, the norbornene derivative-maleic anhydride suppresses the heat flow in the vicinity of the opening of the resist pattern, so that the shape of the opening formed in the resist pattern is reduced. The size of the opening can be reduced without causing deterioration.

  According to the third pattern forming method, when the resist pattern is heated, the norbornene derivative and norbornene derivative-maleic anhydride suppress the heat flow in the vicinity of the opening of the resist pattern. The size of the opening can be reduced without causing deterioration of the shape.

(First embodiment)
Hereinafter, the pattern formation method according to the first embodiment will be described with reference to FIGS. The first embodiment uses a chemically amplified resist material having a base polymer containing a protecting group that is released by the action of an acid, an acrylic compound, and an acid generator that generates an acid when irradiated with light.

  Specifically, a chemically amplified resist material having the following components is prepared.

Poly ((2-methyl-2-adamantyl methacrylate)-(γ-butyrolactone methacrylate)) (however, 2-methyl-2-adamantyl methacrylate: γ-butyrolactone methacrylate = 50 mol%: 50 mol%) (base polymer) ……… 1g
Acrylic acid (acrylic compound) ……………………………………… 0.2g
Triphenylsulfonium nonafluorobutane sulfonic acid (acid generator) …………………………………………………………………………………… 0.03 g
Propylene glycol monomethyl ether acetate (solvent) ………… 4g
Next, as shown in FIG. 1A, the chemical amplification resist material is applied on the substrate 10 to form a resist film 11 having a thickness of 0.5 μm. As shown in FIG. 5, pattern exposure is performed by irradiating the resist film 11 with an ArF excimer laser 12 emitted from an ArF excimer laser scanner (NA: 0.60) through a photomask 13 having a desired mask pattern. .

  Next, as shown in FIG. 1C, post-exposure heating (PEB) 14 is performed on the resist film 11 at a temperature of 105 ° C. for 90 seconds. In this way, acid is generated from the acid generator in the exposed portion 11a of the resist film 11, so that it becomes soluble in an alkaline developer. On the other hand, in the unexposed portion 11b of the resist film 11, the acid generator generates acid. Does not occur, it remains insoluble in the alkaline developer.

Next, 2.38 wt% of tetramethylammonium hydroxide developer the resist film 11 by developing for 60 seconds with (alkaline developer), as shown in FIG. 1 (d), size: W ₁ A resist pattern 16 having an opening 15 having a thickness of 0.20 μm is formed.

  Next, the resist pattern 16 is irradiated with an ArF excimer laser 18 while being heated 17 at a temperature of 150 ° C., and the resist pattern 16 is caused to flow as shown in FIG.

In this way, the size of the opening 15 is reduced from W ₁ (= 0.20 μm) to W ₂ (= 0.15 μm), but the cross-sectional shape of the opening 15 is hardly deteriorated. Further, the variation of the size of the opening 15 in the wafer surface was 10% or less, which was favorable.

  According to the first embodiment, since the ArF excimer laser is irradiated while heating the resist pattern 16 made of the chemically amplified resist material having the above composition, the base polymer constituting the resist pattern 16 is made of an acrylic compound. In addition, since the base polymers are crosslinked between the base polymers, the shape of the opening 15 of the resist pattern 16 does not deteriorate. Therefore, the size of the opening 15 can be reduced without deteriorating the shape of the opening 15 formed in the resist pattern 16.

(Second Embodiment)
Hereinafter, a pattern forming method according to the second embodiment will be described with reference to FIGS. The second embodiment includes a base polymer containing a protecting group that is released by the action of an acid, a thermally crosslinkable compound that crosslinks the base polymer with heat, and an acid generator that generates an acid when irradiated with light. A chemically amplified resist material having the following formula is used.

  Specifically, the following chemically amplified resist material is prepared.

Poly ((2-methyl-2-adamantyl methacrylate)-(γ-butyrolactone methacrylate)) (however, 2-methyl-2-adamantyl methacrylate: γ-butyrolactone methacrylate = 50 mol%: 50 mol%) (base polymer) ……… 1g
Melamine compounds (for example, 2,4,6-tris (methoxymethyl) amino-1,3,5-s-triazine) (thermally crosslinkable compounds) ………………………………………… ...... 0.2g
Triphenylsulfonium nonafluorobutane sulfonic acid (acid generator) ………………………………………………………………………………… 0.025 g
Triphenylsulfonium trifluoromethanesulfonic acid (acid generator) ……………………………………………………………………………… 0.01g
Propylene glycol monomethyl ether acetate (solvent) ………… 4g
Next, as shown in FIG. 2A, after applying the chemically amplified resist material on the substrate 20 to form a resist film 21 having a thickness of 0.5 .mu.m, FIG. As shown in FIG. 4, pattern exposure is performed by irradiating the resist film 21 with an ArF excimer laser 22 emitted from an ArF excimer laser scanner (NA: 0.60) through a photomask 23 having a desired mask pattern. .

  Next, as shown in FIG. 2C, post-exposure heating (PEB) 24 is performed on the resist film 21 at a temperature of 105 ° C. for 90 seconds. In this way, acid is generated from the acid generator in the exposed portion 21a of the resist film 21, so that it becomes soluble in an alkaline developer. On the other hand, in the unexposed portion 21b of the resist film 21, acid is generated from the acid generator. Does not occur, it remains insoluble in the alkaline developer.

Next, 2.38 wt% of tetramethylammonium hydroxide developer the resist film 21 by developing for 60 seconds with (alkaline developer), as shown in FIG. 2 (d), size: W ₁ A resist pattern 26 having an opening 25 having a thickness of 0.20 μm is formed.

  Next, the resist pattern 26 is heated 27 at a temperature of 150 ° C. to flow the resist pattern 26 as shown in FIG.

In this way, the size of the opening 25 is reduced from W ₁ (= 0.20 μm) to W ₂ (= 0.15 μm), but the cross-sectional shape of the opening 25 is hardly deteriorated. Further, the variation of the size of the opening 15 in the wafer surface was 10% or less, which was favorable.

  According to the second embodiment, since the resist pattern 26 made of the chemically amplified resist material having the above composition is heated, a thermally crosslinkable compound is interposed between the base polymers to crosslink the base polymers. Therefore, the shape of the opening of the resist pattern 26 does not deteriorate. Therefore, the size of the opening 25 can be reduced without causing the shape of the opening 25 formed in the resist pattern 26 to deteriorate.

(First Modification of Second Embodiment)
Hereinafter, a first modification of the second embodiment will be described. However, since the first modification is different from the second embodiment only in the chemically amplified resist material, the chemical amplified type will be described below. Only the resist material will be described.

  In the first modification, a first polymer having a hydroxystyrene derivative containing an acetal group as a protecting group that is eliminated by the action of an acid, a second polymer having a norbornene derivative, and an acid are generated when irradiated with light. A chemically amplified resist material having an acid generator is used. Specifically, the following chemically amplified resist material is used.

Poly ((ethoxyethyloxystyrene)-(hydroxystyrene)) (however, ethoxyethyloxystyrene: hydroxystyrene = 40 mol%: 60 mol%) (first polymer) ………………………………… ………………………………………… 1g
Poly (5-t-butylnorbornene-5-carboxylic acid) (second polymer) ... 0.2g
1,4-diphenyldiazodisulfone (acid generator) .................. 0.025g
Propylene glycol monomethyl ether acetate (solvent) ………… 4g
According to the first modification, the polymer having a norbornene derivative improves the heat flow contrast of the polymer having a hydroxystyrene derivative containing an acetal group, that is, to suppress the heat flow in the vicinity of the opening of the resist pattern. The shape of the opening of the resist pattern does not deteriorate. Therefore, the size of the opening can be reduced without deteriorating the shape of the opening formed in the resist pattern.

  The mixing ratio of the second polymer to the first polymer is not particularly limited, but when the mixing ratio is 10 wt% or more, the shape deterioration of the opening portion of the resist pattern can be reliably prevented.

(Second modification of the second embodiment)
Hereinafter, a second modification of the second embodiment will be described. However, since the second modification is different from the second embodiment only in the chemically amplified resist material, in the following, the chemically amplified type will be described. Only the resist material will be described.

In the second modification, a first polymer having a hydroxystyrene derivative containing an acetal group as a protecting group that is eliminated by the action of an acid, and norbornene derivative-maleic anhydride (a polymer of norbornene derivative and maleic anhydride) A chemically amplified resist material having a second polymer having an acid generator that generates an acid when irradiated with light is used. Specifically, the following chemically amplified resist material is used.
(1) First specific example Poly ((ethoxyethyloxystyrene)-(hydroxystyrene)) (however, ethoxyethyloxystyrene: hydroxystyrene = 40 mol%: 60 mol%) (first polymer) ……………………………………………………………… 1g
Poly ((5-t-butylnorbornene-5-carboxylic acid)-(maleic anhydride)) (however, 5-t-butylnorbornene-5-carboxylic acid: maleic anhydride = 50 mol%: 50 mol%) (second Polymer) …………………………………………………… 0.2g
1,4-Diphenyldiazodisulfone (acid generator) ……………… 0.03g
Propylene glycol monomethyl ether acetate (solvent) ………… 4g
(2) Second specific example Poly ((tetrahydropyranyloxystyrene)-(hydroxystyrene)) (however, tetrahydropyranyloxystyrene: hydroxystyrene = 40 mol%: 60 mol%) (first polymer) …………………………………………………… 1g
Poly ((5-t-butylnorbornene-5-carboxylic acid)-(maleic anhydride)) (however, 5-t-butylnorbornene-5-carboxylic acid: maleic anhydride = 50 mol%: 50 mol%) (second Polymer) ………………………………………………………… 0.2g
Triphenylsulfonium tosylate (acid generator) …… 0.03g
Propylene glycol monomethyl ether acetate (solvent) ………… 4g
According to the second modification, the polymer having norbornene derivative-maleic anhydride improves the heat flow contrast of the polymer having a hydroxystyrene derivative containing an acetal group, that is, the heat flow near the opening of the resist pattern is increased. Therefore, the shape of the opening of the resist pattern does not deteriorate. Therefore, the size of the opening can be reduced without deteriorating the shape of the opening formed in the resist pattern.

  The mixing ratio of the second polymer to the first polymer is not particularly limited. However, when the mixing ratio is 10 wt% or more, the shape deterioration of the opening of the resist pattern can be reliably prevented.

(Third Modification of Second Embodiment)
Hereinafter, a third modified example of the second embodiment will be described. However, since the third modified example is different from the second embodiment only in the chemically amplified resist material, in the following, the chemically amplified type will be described. Only the resist material will be described.

  The third modification includes a first polymer having a hydroxystyrene derivative containing an acetal group as a protecting group that is eliminated by the action of an acid, a second polymer having a norbornene derivative, and norbornene derivative-maleic anhydride (norbornene derivative). And a chemically amplified resist material having a third polymer having a polymer of maleic anhydride and an acid generator that generates an acid when irradiated with light. Specifically, the following chemically amplified resist material is prepared.

Poly ((ethoxyethyloxystyrene)-(hydroxystyrene)) (however, ethoxyethyloxystyrene: hydroxystyrene = 40 mol%: 60 mol%) (first polymer) ………………………………… ………………………………………… 1g
Poly (5-t-butylnorbornene-5-carboxylic acid) (second polymer) ……………………………………………………………………………… ……… 0.1g
Poly ((5-t-butylnorbornene-5-carboxylic acid)-(maleic anhydride)) (wherein 5-t-butylnorbornene-5-carboxylic acid: maleic anhydride = 50 mol%: 50 mol%) (third Polymer) ………………………………………………………… 0.1g
1,4-diphenyldiazodisulfone (acid generator) .................. 0.025g
Propylene glycol monomethyl ether acetate (solvent) ………… 4g
According to a third variant, the polymer with norbornene derivative and the polymer with norbornene derivative-maleic anhydride improve the flow contrast by heat of the polymer with hydroxystyrene derivative containing acetal group, i.e. the opening of the resist pattern. In order to suppress the heat flow in the vicinity of the portion, the shape of the opening of the resist pattern does not deteriorate. Therefore, the size of the opening can be reduced without deteriorating the shape of the opening formed in the resist pattern.

The mixing ratio of the second polymer and the third polymer to the first polymer is not particularly limited. However, when the mixing ratio is 10 wt% or more, it is possible to reliably prevent the shape deterioration of the opening of the resist pattern. it can.
(1) Examples of the polymer having a protecting group that is eliminated by the action of an acid used in the first or second embodiment will be given below.
(a) Examples of methacrylic polymers containing protecting groups ○ Poly ((2-methyl-2-adamantane methacrylate)-(mevalonic lactone methacrylate)) (however, 2-methyl-2-adamantane methacrylate) : Mevalonic lactone methacrylate ester = 50 mol%: 50 mol%)
○ Poly ((2-ethyl-2-adamantane methacrylate)-(γ-butyrolactone methacrylate)) (However, 2-ethyl-2-adamantane methacrylate: γ-butyrolactone methacrylate = 50 mol%: 50 mol %)
(b) Examples of acrylic polymers containing protecting groups ○ Poly ((2-methyl-2-adamantane acrylate)-(mevalonic lactone acrylate)) (however, 2-methyl-2-adamantane acrylate : Mevalonic lactone acrylic ester = 50 mol%: 50 mol%)
○ Poly ((2-ethyl-2-adamantane acrylate)-(γ-butyrolactone acrylate)) (However, 2-ethyl-2-adamantane acrylate: γ-butyrolactone acrylate = 50 mol%: 50 mol %)
(c) Examples of (methacrylic + acrylic) polymer containing a protecting group ○ Poly ((2-methyl-2-adamantane acrylate)-(mevalonic lactone methacrylate)) (however, 2-methyl-2- Adamantane acrylate ester: Mevalonic lactone methacrylate ester = 50 mol%: 50 mol%)
○ Poly ((2-ethyl-2-adamantane acrylate)-(γ-butyrolactone methacrylate)) (However, 2-ethyl-2-adamantaneacrylate: γ-butyrolactone methacrylate = 50 mol%: 50 mol %)
(d) Examples of phenolic polymers containing protecting groups ○ Poly ((ethoxyethyloxystyrene)-(hydroxystyrene)) (however, ethoxyethyloxystyrene: hydroxystyrene = 35 mol%: 65 mol%)
○ Poly ((methoxymethyloxystyrene)-(hydroxystyrene)) (however, methoxymethyloxystyrene: hydroxystyrene = 40 mol%: 60 mol%)
○ Poly ((tetrahydropyranyloxystyrene)-(hydroxystyrene)) (however, tetrahydropyranyloxystyrene: hydroxystyrene = 35mol%: 65mol%)
○ Poly ((phenoxyethyloxystyrene)-(hydroxystyrene)) (however, phenoxyethyloxystyrene: hydroxystyrene = 32 mol%: 68 mol%)
○ Poly ((t-butyloxystyrene)-(hydroxystyrene)) (however, t-butyloxystyrene: hydroxystyrene = 30 mol%: 70 mol%)
○ Poly ((t-butyloxycarbonyloxystyrene)-(hydroxystyrene)) (however, t-butyloxycarbonyloxystyrene: hydroxystyrene = 30 mol%: 70 mol%)
○ Poly ((t-butyloxycarbonylmethyloxystyrene)-(hydroxystyrene)) (t-butyloxycarbonylmethyloxystyrene: hydroxystyrene = 28 mol%: 72 mol%)
(e) Examples of norbornene polymers containing protecting groups ○ Poly ((5-t-butylnorbornene-5-carboxylate)-(norbornene-5-carboxylate)) (however, 5-t-butylnorbornene-5-carboxyl (Rate: Norbornene-5-carboxylate = 40 mol%: 60 mol%)
○ Poly ((5-t-butylnorbornene-5-methylenehexafluoroisopropyl alcohol)-(norbornene-5-methylenehexafluoroisopropyl alcohol)) (however, 5-t-butylnorbornene-5-methylenehexafluoroisopropyl alcohol: Norbornene-5-methylenehexafluoroisopropyl alcohol = 35mol%: 65mol%)
(f) Examples of polymers of norbornene-maleic anhydride derivatives containing protecting groups ○ Poly ((5-t-butylnorbornene-5-carboxylate)-(maleic anhydride)) (however, 5-t-butylnorbornene- 5-carboxylate: maleic anhydride = 50 mol%: 50 mol%)
○ Poly ((5-t-butylnorbornene-5-carboxylate)-(norbornene-5-carboxylate)-(maleic anhydride)) (however, 5-t-butylnorbornene-5-carboxylate: norbornene-5 -Carboxylate: maleic anhydride = 40 mol%: 10 mol%: 50 mol%)
○ Poly ((5-t-butylnorbornene-5-methylenehexafluoroisopropyl alcohol)-(maleic anhydride)) (However, 5-t-butylnorbornene-5-methylenehexafluoroisopropyl alcohol: maleic anhydride = 50 mol% : 50mol%)
○ Poly ((5-t-butylnorbornene-5-methylenehexafluoroisopropyl alcohol)-(norbornene-5-methylenehexafluoroisopropyl alcohol)-(maleic anhydride)) (However, 5-t-butylnorbornene-5- (Methylenehexafluoroisopropyl alcohol: norbornene-5-methylenehexafluoroisopropyl alcohol: maleic anhydride = 35 mol%: 15 mol%: 50 mol%)
(g) Examples of polymers of norbornene-maleic anhydride derivatives containing protecting groups and methacrylic acid derivatives ○ Poly ((5-t-butylnorbornene-5-carboxylate)-(maleic anhydride)-(2-methyl- 2-adamantane methacrylate)-(γ-butyrolactone methacrylate)) (provided that 5-t-butylnorbornene-5-carboxylate: maleic anhydride: 2-methyl-2-adamantane methacrylate: γ-butyrolactone methacrylate = 25 mol%: 25 mol %: 30mol%: 20mol%)
○ Poly ((5-t-butylnorbornene-5-carboxylate)-(maleic anhydride)-(γ-butyrolactone methacrylate)) (however, 5-t-butylnorbornene-5-carboxylate: maleic anhydride: γ -Butyrolactone methacrylate = 40mol%: 40mol%: 20mol%)
(h) Examples of polymers of a norbornene-maleic anhydride derivative containing a protecting group and an acrylic acid derivative ○ Poly ((5-t-butylnorbornene-5-carboxylate)-(maleic anhydride)-(2-ethyl- 2-adamantane acrylate)-(mevalonic lactone acrylate)) (provided that 5-t-butylnorbornene-5-carboxylate: maleic anhydride: 2-ethyl-2-adamantane acrylate: mevalonic lactone acrylate = 25 mol% : 25mol%: 35mol%: 15mol%)
O Poly ((5-t-butylnorbornene-5-carboxylate)-(maleic anhydride)-(mevalonic lactone acrylate)) (however, 5-t-butylnorbornene-5-carboxylate: maleic anhydride: Mevalonic lactone acrylate = 40mol%: 40mol%: 20mol%)
(2) Examples of the acrylic compound used in the first embodiment will be given below.
○ Acrylic acid ○ Methyl acrylate ○ Ethyl acrylate ○ Phenyl acrylate ○ Vinyl acrylate
(3) Hereinafter, examples of thermally crosslinkable compounds used in the second embodiment will be given.
○ 2,4,6-Tris (ethoxymethyl) amino-1,3,5-s-triazine (melamine compound)
(4) Hereinafter, examples of hydroxystyrene derivatives containing an acetal group, which are included in the first polymer used in the first, second, or third modification of the second embodiment will be given.
○ Ethoxyethyloxystyrene ○ Methoxymethyloxystyrene ○ Tetrahydropyranyloxystyrene ○ Phenoxyethyloxystyrene
(5) Hereinafter, examples of the first polymer (polymer of hydroxystyrene derivative containing an acetal protecting group) used in the first, second, or third modification of the second embodiment will be given.
○ Poly ((ethoxyethyloxystyrene)-(hydroxystyrene)) (however, ethoxyethyloxystyrene: hydroxystyrene = 35mol%: 65mol%)
○ Poly ((methoxymethyloxystyrene)-(hydroxystyrene)) (however, methoxymethyloxystyrene: hydroxystyrene = 40 mol%: 60 mol%)
○ Poly ((tetrahydropyranyloxystyrene)-(hydroxystyrene)) (however, tetrahydropyranyloxystyrene: hydroxystyrene = 35mol%: 65mol%)
○ Poly ((phenoxyethyloxystyrene)-(hydroxystyrene)) (32 mol%: 68 mol%)
(6) Hereinafter, examples of norbornene derivatives contained in the second polymer used in the first or third modification of the second embodiment will be given.
○ 5-t-butylnorbornene-5-carboxylate ○ 5-t-butyloxycarbonylnorbornene-5-carboxylate ○ 5-t-butylnorbornene-5-methylenehexafluoroisopropyl alcohol ○ norbornene-5-carboxylate ○ norbornene -5-Methylenehexafluoroisopropyl alcohol ○ Norbornene
(7) Examples of the second polymer (polymer of norbornene derivative) used in the first or third modification of the second embodiment will be given below.
○ Poly ((5-t-butylnorbornene-5-carboxylate)-(norbornene-5-carboxylate)) (however, 5-t-butylnorbornene-5-carboxylate: norbornene-5-carboxylate = 40mol% : 60mol%)
○ Poly ((5-t-butylnorbornene-5-methylenehexafluoroisopropyl alcohol)-(norbornene-5-methylenehexafluoroisopropyl alcohol)) (however, 5-t-butylnorbornene-5-methylenehexafluoroisopropyl alcohol: Norbornene-5-methylenehexafluoroisopropyl alcohol = 35mol%: 65mol%)
○ Poly (5-t-butylnorbornene-5-carboxylate)
○ Poly (5-t-butyloxycarbonylnorbornene-5-carboxylate)
○ Poly (5-t-butylnorbornene-5-methylenehexafluoroisopropyl alcohol)
○ Poly (norbornene-5-carboxylate)
○ Poly (norbornene-5-methylenehexafluoroisopropyl alcohol)
○ Poly (norbornene)
(8) Examples of norbornene-maleic anhydride derivatives contained in the second polymer of the second modification of the second embodiment or the third polymer of the third modification will be given below.
○ 5-t-butylnorbornene-5-carboxylate-maleic anhydride ○ 5-t-butyloxycarbonylnorbornene-5-carboxylate-maleic anhydride ○ 5-t-butylnorbornene-5-methylenehexafluoroisopropyl alcohol Maleic anhydride ○ Norbornene-5-carboxylate-maleic anhydride ○ Norbornene-5-methylenehexafluoroisopropyl alcohol-maleic anhydride ○ Norbornene-maleic anhydride
(9) Examples of the second polymer of the second modification of the second embodiment or the third polymer of the third modification (polymer of norbornene-maleic anhydride derivative) will be given below.
○ Poly ((5-t-butylnorbornene-5-carboxylate)-(maleic anhydride) (however, 5-t-butylnorbornene-5-carboxylate: maleic anhydride = 50 mol%: 50 mol%)
○ Poly ((5-t-butylnorbornene-5-carboxylate)-(norbornene-5-carboxylate)-(maleic anhydride)) (however, 5-t-butylnorbornene-5-carboxylate: norbornene-5 -Carboxylate: maleic anhydride = 40 mol%: 10 mol%: 50 mol%)
○ Poly ((5-t-butylnorbornene-5-methylenehexafluoroisopropyl alcohol)-(maleic anhydride)) (However, 5-t-butylnorbornene-5-methylenehexafluoroisopropyl alcohol: maleic anhydride = 50 mol% : 50mol%)
○ Poly ((5-t-butylnorbornene-5-methylenehexafluoroisopropyl alcohol)-(norbornene-5-methylenehexafluoroisopropyl alcohol)-(maleic anhydride)) (However, 5-t-butylnorbornene-5- (Methylenehexafluoroisopropyl alcohol: norbornene-5-methylenehexafluoroisopropyl alcohol: maleic anhydride = 35 mol%: 15 mol%: 50 mol%)
○ Poly ((5-t-butylnorbornene-5-carboxylate)-(maleic anhydride)) (however, 5-t-butylnorbornene-5-carboxylate: maleic anhydride = 50 mol%: 50 mol%)
○ Poly ((5-t-butyloxycarbonylnorbornene-5-carboxylate)-(maleic anhydride)) (however, 5-t-butyloxycarbonylnorbornene-5-carboxylate: maleic anhydride = 50 mol%: 50 mol %)
○ Poly ((5-t-butylnorbornene-5-methylenehexafluoroisopropyl alcohol)-(maleic anhydride)) (However, 5-t-butylnorbornene-5-methylenehexafluoroisopropyl alcohol: maleic anhydride = 50 mol% : 50mol%)
○ Poly ((norbornene-5-carboxylate)-(maleic anhydride)) (however, norbornene-5-carboxylate: maleic anhydride = 50 mol%: 50 mol%)
○ Poly ((norbornene-5-methylenehexafluoroisopropyl alcohol)-(maleic anhydride)) (however, norbornene-5-methylenehexafluoroisopropyl alcohol: maleic anhydride = 50 mol%: 50 mol%)
○ Poly ((norbornene)-(maleic anhydride)) (however, norbornene: maleic anhydride = 50mol%: 50mol%)
(10) Examples of the acid generator used in the first embodiment, the second embodiment, or the first, second, or third modification of the second embodiment will be given below.
○ 1,4-Diphenyldiazodisulfone ○ Triphenylsulfonium tosylate ○ Camphor iminotosylate ○ Naphthyliminotosylate ○ Camphor iminotrifluoromethanesulfonic acid ○ Naphthyliminotrifluoromethanesulfonic acid ○ Triphenylsulfonium trifluoromethanesulfonic acid ○ Triphenylsulfonium nonafluorobutanesulfonic acid ○ Diphenyliodonium trifluoromethanesulfonic acid ○ Diphenyliodonium nonafluorobutanesulfonic acid ○ Di (4-t-butylphenyl) iodonium trifluoromethanesulfonic acid ○ Di (4-t-butylphenyl) iodonium Nonafluorobutane sulfonic acid

  As described above, the present invention is useful for a pattern forming method because the size of the opening can be reduced without causing deterioration of the shape of the opening formed in the resist pattern.

(A)-(e) is sectional drawing which shows each process of the pattern formation method which concerns on 1st Embodiment. (A)-(e) is sectional drawing which shows each process of the pattern formation method which concerns on 2nd Embodiment. (A)-(e) is sectional drawing which shows each process of the conventional pattern formation method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Substrate 11 Resist film 11a Exposed part 11b Unexposed part 12 ArF excimer laser 13 Photomask 14 Heating 15 Opening 16 Resist pattern 17 Heating 18 ArF excimer laser 20 Substrate 21 Resist film 21a Exposed part 21b Unexposed part 22 ArF excimer laser 23 Photomask 24 Heating 25 Opening 26 Resist pattern 27 Heating

Claims (4)

A first polymer having a hydroxystyrene derivative containing an acetal group as a protecting group released by the action of an acid, a second polymer having a norbornene derivative, and an acid generator that generates an acid when irradiated with light. Forming a resist film made of a chemically amplified resist material,
Performing pattern exposure by selectively irradiating the resist film with exposure light; and
Developing the resist film subjected to pattern exposure to form a resist pattern having an opening made of a hole or a groove; and
And a step of reducing the size of the opening by heating the resist pattern. A first polymer having a hydroxystyrene derivative containing an acetal group as a protecting group released by the action of an acid, a second polymer having a norbornene derivative-maleic anhydride, and an acid that generates an acid when irradiated with light Forming a resist film made of a chemically amplified resist material having a generator;
Performing pattern exposure by selectively irradiating the resist film with exposure light; and
Developing the resist film subjected to pattern exposure to form a resist pattern having an opening made of a hole or a groove; and
And a step of reducing the size of the opening by heating the resist pattern. A first polymer having a hydroxystyrene derivative containing an acetal group as a protecting group released by the action of an acid; a second polymer having a norbornene derivative; a third polymer having a norbornene derivative-maleic anhydride; Forming a resist film made of a chemically amplified resist material having an acid generator that generates an acid when irradiated with
Performing pattern exposure by selectively irradiating the resist film with exposure light; and
Developing the resist film subjected to pattern exposure to form a resist pattern having an opening made of a hole or a groove; and
And a step of reducing the size of the opening by heating the resist pattern.   The pattern formation method according to claim 1, wherein the acetal group is an ethoxyethyl group or a tetrahydropyranyl group.

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