JP2008158157A - Photoresist composition and pattern forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photoresist composition which avoids cracking of a resist pattern in plating, without having to add any plasticizer, and can obtain a wrinkle-free uniform film thickness when a resist film is formed of the photoresist composition. <P>SOLUTION: The photoresist composition comprises an alkali-soluble novolac resin (A), in which the hydrogen atoms of phenolic hydroxyl groups have been partly substituted by a substituent, having a structure represented by general Formula (2) and a photosensitizing agent (B). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a photoresist composition and a pattern forming method for forming a resist pattern using the same.

  In recent years, along with the downsizing and thinning of electronic devices, higher integration of integrated circuits such as LSIs and the development of integrated circuits for specific applications are rapidly progressing, and accordingly, LSIs are mounted on electronic devices. Therefore, a multi-pin thin film mounting is required, and bare chip mounting using a TAB method or a flip chip method has attracted attention. In such a multi-pin mounting method, it is necessary that bump electrodes, which are connection terminals, having a height of 20 μm or more be arranged on the substrate with high accuracy. In the future, further miniaturization of LSIs will be required. Correspondingly, higher precision of bumps has become more necessary. Further, in order to assist the formation of the connection terminals, a rewiring process is performed to form a wiring between the chip and the connection terminals.

  The connection terminals and wirings described above are formed by applying a photoresist on a substrate, patterning it, and then performing a plating process along the formed pattern. When a photoresist is used for such an application, it is necessary that a thick film can be formed on the substrate with a film thickness of about 5 μm or more, for example, 5 to 20 μm. There is a demand for plating solution properties, good wettability with respect to the plating solution, and good releasability in the release treatment after the plating treatment. In addition, with further higher integration of LSI, it is expected that the connecting terminals and wirings to be formed will be further miniaturized and the pitch of the arrangement will be narrowed, and a space pattern with good verticality can be formed. There is a need for a photoresist having resolution.

  Currently, positive photoresist compositions containing an alkali-soluble novolak resin and a quinonediazide group-containing compound as a photosensitizer are mainly used as the photoresist. However, when a resist pattern is formed using such a positive photoresist composition and a plating process such as gold plating is performed to form a connection terminal or a wiring pattern (plating pattern), a crack is generated in the resist pattern. There was a problem such as.

  Here, the occurrence of cracks has the problem of causing abnormal shape of the plating pattern to be formed, and in order to suppress the occurrence of cracks, a plasticizer such as an acrylic resin is added to the positive photoresist composition. Has been proposed. However, when a positive photoresist composition containing a plasticizer is used, the resolution is lowered and the dimension of the formed plating pattern is larger than the dimension of the resist pattern immediately after development. There was a problem such as.

In order to solve such a problem, Patent Document 1 discloses a positive photoresist composition containing a novolak resin obtained by converting a part of a phenolic hydroxyl group into a hydroxyalkyl ether and a photosensitizer. ing. According to the invention described in Patent Document 1, it is possible to form a resist pattern that has good resolution and suppresses the occurrence of cracks during plating, and can improve the pattern thickness of the plating pattern.
JP 2005-037723 A

  However, when the resist film is formed using the positive photoresist composition described in Patent Document 1, there is a problem that a uniform film thickness cannot be obtained as a whole, and wrinkles are partially generated. . Since the generation of wrinkles adversely affects the patterning of the resist, it needs to be improved.

  The present invention has been made in view of the above problems, and is a photoresist composition in which cracks and the like do not occur in a resist pattern during plating without adding a plasticizer, and a uniform resist film without wrinkles An object of the present invention is to provide a photoresist composition capable of forming

  In the photoresist composition, when a part of the phenolic hydroxyl group of the novolak resin is bonded to a predetermined compound, a uniform film thickness without wrinkles is obtained, and the resolution is good. The present inventors have found that a photoresist composition capable of forming a resist pattern in which generation of cracks during plating is suppressed can be provided, and the present invention has been completed.

  Specifically, the present invention provides the following.

［式（ａ−１）中、Ｒ^１は下記一般式（ａ−２）

（式（ａ−２）中、Ｒａ、Ｒｂはそれぞれ独立に水素原子又は炭素数１〜５のアルキル基を表し、ｘは３〜７の整数を表し、ｙは１〜５０の整数を表す。）
で表される構造を含む置換基を表し、Ｒ^２は水素原子、水酸基、又は炭素数１〜４のアルキル基を表し、ｍは１〜３の整数を表す。］
で表される構成単位（ａ１）、及び下記一般式（ａ−３）

［式（ａ−３）中、Ｒ^３は水素原子、水酸基、又は炭素数１〜４のアルキル基を表し、ｎは１〜３の整数を表す。］
で表される構成単位（ａ２）を有するアルカリ可溶性ノボラック樹脂（Ａ）、及び感光剤（Ｂ）を含有することを特徴とするフォトレジスト組成物である。 A first aspect of the present invention is the following general formula (a-1)

[In the formula (a-1), R ¹ represents the following general formula (a-2)

(In formula (a-2), Ra and Rb each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, x represents an integer of 3 to 7, and y represents an integer of 1 to 50. )
R ² represents a hydrogen atom, a hydroxyl group, or an alkyl group having 1 to 4 carbon atoms, and m represents an integer of 1 to 3. ]
And a structural unit (a1) represented by the following general formula (a-3)

[In Formula (a-3), R ³ represents a hydrogen atom, a hydroxyl group, or an alkyl group having 1 to 4 carbon atoms, and n represents an integer of 1 to 3. ]
A photoresist composition comprising an alkali-soluble novolak resin (A) having a structural unit (a2) represented by formula (A2) and a photosensitizer (B).

［式（ａ−１）中、Ｒ^１は下記一般式（ａ−２）

（式（ａ−２）中、Ｒａ、Ｒｂはそれぞれ独立に水素原子又は炭素数１〜５のアルキル基を表し、ｘは３〜７の整数を表し、ｙは１〜５０の整数を表す。）
で表される構造を含む置換基を表し、Ｒ^２は水素原子、水酸基、又は炭素数１〜４のアルキル基を表し、ｍは１〜３の整数を表す。］
で表される構成単位（ａ１）、及び下記一般式（ａ−３）

［式（ａ−３）中、Ｒ^３は水素原子、水酸基、又は炭素数１〜４のアルキル基を表し、ｎは１〜３の整数を表す。］
で表される構成単位（ａ２）を有する樹脂であって、該樹脂に含まれる水酸基の水素原子の一部が１，２−ナフトキノンジアジドスルホニル基で置換されているアルカリ可溶性ノボラック樹脂（Ａ’）を含有することを特徴とするフォトレジスト組成物である。 The second aspect of the present invention is the following general formula (a-1)

[In the formula (a-1), R ¹ represents the following general formula (a-2)

(In formula (a-2), Ra and Rb each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, x represents an integer of 3 to 7, and y represents an integer of 1 to 50. )
R ² represents a hydrogen atom, a hydroxyl group, or an alkyl group having 1 to 4 carbon atoms, and m represents an integer of 1 to 3. ]
And a structural unit (a1) represented by the following general formula (a-3)

[In Formula (a-3), R ³ represents a hydrogen atom, a hydroxyl group, or an alkyl group having 1 to 4 carbon atoms, and n represents an integer of 1 to 3. ]
An alkali-soluble novolak resin (A ′) having a structural unit (a2) represented by the formula: wherein a part of hydrogen atoms of a hydroxyl group contained in the resin is substituted with a 1,2-naphthoquinonediazidosulfonyl group It is a photoresist composition characterized by containing.

  Furthermore, in the third aspect of the present invention, the photoresist composition of the first aspect or the second aspect is applied on a substrate, pre-baked, selectively exposed, and then alkali-developed to form a resist pattern. It is a pattern formation method characterized by forming.

  According to the present invention, a uniform film thickness without wrinkles can be obtained, a resist pattern excellent in resolution can be formed, the shape of the plated pattern after plating is good, and no crack is generated in the plating. A composition and a pattern forming method using the composition can be provided.

  Hereinafter, embodiments of the present invention will be described in detail. In the following embodiments, the case where the photoresist composition of the present invention is used as a positive photoresist composition will be described.

<First embodiment>
First, the first embodiment of the present invention will be described in detail.

[Positive photoresist composition]
The positive photoresist composition according to the present embodiment comprises an alkali-soluble novolak resin (A) having a specific structural unit (hereinafter sometimes referred to as “component (A)”) and a photosensitive agent (B). It is characterized by including.

  In the present specification, “structural unit” means a monomer unit constituting a polymer.

［式（ａ−１）中、Ｒ^１は後述する一般式（ａ−２）で表される構造を含む置換基を表し、Ｒ^２は水素原子、水酸基、又は炭素数１〜４のアルキル基を表し、ｍは１〜３の整数を表す。］

［式（ａ−３）中、Ｒ^３は水素原子、水酸基、又は炭素数１〜４のアルキル基を表し、ｎは１〜３の整数を表す。］ (Alkali-soluble novolak resin (A) having a specific structural unit)
The component (A) has the structural unit (a1) represented by the general formula (a-1) and the structural unit (a2) represented by the general formula (a-3), and phenols and aldehydes. In the novolak resin obtained by reacting with the above, a substituent having a structure represented by the general formula (a-2) described later is bonded to a part of the phenolic hydroxyl group.

[In Formula (a-1), R ¹ represents a substituent containing a structure represented by General Formula (a-2) described later, and R ² represents a hydrogen atom, a hydroxyl group, or an alkyl group having 1 to 4 carbon atoms. M represents an integer of 1 to 3. ]

[In Formula (a-3), R ³ represents a hydrogen atom, a hydroxyl group, or an alkyl group having 1 to 4 carbon atoms, and n represents an integer of 1 to 3. ]

In General Formulas (a-1) and (a-3), R ² and R ³ are each independently a hydrogen atom, a hydroxyl group, or an alkyl group having 1 to 4 carbon atoms, Examples of the alkyl group include a methyl group, an n-propyl group, an isopropyl group, an n-butyl group, and a t-butyl group. Among these, R ² and R ³ are preferably methyl groups.

  M and n each independently represents an integer of 1 to 3, but preferably m = 1 and n = 1.

When R ² and R ³ are methyl groups and m = 1 and n = 1, the bonding positions of R ² and R ³ are not particularly limited, but with respect to the oxygen atom bonded to the aromatic ring The meta position or the para position is preferable. Further, in the component (A), the ratio (meta position / para position) between the bonding position of R ² and R ^{3 in} the meta position and that in the para position (meta position / para position) is 3/7 to 8/2. It is preferable.

When R ² and R ³ satisfy the conditions as described above, good sensitivity can be imparted to the positive photoresist, and the solubility in the developer and the reduction in film thickness can be easily adjusted.

  The ratio of the bonding positions can be measured using, for example, an NMR apparatus. Or (A) component which has such ratio can be manufactured by adjusting the preparation ratio of the phenolic monomer used in the case of manufacture of alkali-soluble novolak resin.

［式（ａ−２）中、Ｒａ、Ｒｂはそれぞれ独立に水素原子又は炭素数１〜５のアルキル基を表し、ｘは３〜７の整数を表し、ｙは１〜５０の整数を表す。］ R ¹ is a substituent having a structure represented by the general formula (a-2).

[In formula (a-2), Ra and Rb each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, x represents an integer of 3 to 7, and y represents an integer of 1 to 50. ]

Since R ¹ is a substituent having a structure represented by the general formula (a-2), the formed resist film has a uniform thickness without wrinkles. Moreover, crack resistance is also improved.

  In the general formula (a-2), Ra and Rb are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. , N-butyl group, isobutyl group, n-pentyl group, isopentyl group and the like. Among these, a hydrogen atom and a methyl group are preferable.

  Moreover, although x is an integer of 3-7, it is preferable that it is an integer of 3-5 especially. y is an integer of 1 to 50, and an integer of 1 to 10 is particularly preferable. When y is in the range of 1 to 10, the developer solubility at the time of forming the resist pattern and the pattern shape obtained are improved, and the crack resistance is also improved. In the positive photoresist composition of the present embodiment, y shown in the general formula (a-2) exists in a form having a plurality of substituents having different values within the range of 1 to 50. .

  By forming a substituent having the structure represented by the general formula (a-2) as a substituent satisfying the above conditions, when forming a resist pattern using a positive photoresist composition, A uniform film thickness can be obtained, the developer solubility and shape pattern can be improved, and the crack resistance during plating can be improved.

［式（ａ−４）中、Ｒｃは炭素数３〜１２の「アルキレン基」若しくは「シクロアルキレン基」又は炭素数４〜１２の「主鎖にシクロアルキレン基を有するアルキレン基」を表し、Ｒａ、Ｒｂ、ｘ、及びｙは前記と同様の意味を表す。］ R ¹ is preferably a substituent represented by the general formula (a-4).

[In the formula (a-4), Rc represents an "alkylene group" or "cycloalkylene group" having 3 to 12 carbon atoms or "an alkylene group having a cycloalkylene group in the main chain" having 4 to 12 carbon atoms; , Rb, x, and y have the same meaning as described above. ]

  In the general formula (a-4), Rc is an “alkylene group” or “cycloalkylene group” having 3 to 12 carbon atoms or an “alkylene group having a cycloalkylene group in the main chain” having 4 to 12 carbon atoms. Examples of the “alkylene group” include n-propylene group, isopropylene group, n-butylene group, isobutylene group, n-pentylene group, isopentylene group, n-hexylene group, isohexylene group, n-heptylene group, isoheptylene group, n- An octylene group, an isooctylene group, an n-nonylene group, an isononylene group, an n-decylene group, an isodecylene group, an n-undecylene group, an isoundecylene group, an n-dodecylene group, an isododecylene group, and a part of these hydrogen atoms. Mention may be made of groups substituted by any functional group. Of these, n-propylene groups are preferred. In the “cycloalkylene group” and the “alkylene group having a cycloalkylene group in the main chain”, the cycloalkylene group is preferably a cycloalkylene group having 5 to 10 carbon atoms (5- to 10-membered ring). In the case of an alkylene group having a cycloalkylene group, the alkylene group is preferably an alkylene group having 6 to 12 carbon atoms as a whole. Here, the cycloalkylene group is more preferably a cyclohexylene group. Rc is preferably a group having a hydroxyl group at the α-position of a carbon atom bonded to an oxygen atom derived from a phenolic hydroxyl group.

［式（ａ−５）中、Ｒｄは炭素数１〜６のアルキレン基を表し、Ｒａ、Ｒｂ、ｘ、及びｙは前記と同様の意味を表す。］ R ¹ is more preferably a substituent represented by the general formula (a-5).

[In formula (a-5), Rd represents an alkylene group having 1 to 6 carbon atoms, and Ra, Rb, x, and y represent the same meaning as described above. ]

  In General Formula (a-5), Rd is an alkylene group having 1 to 6 carbon atoms. Examples of the alkylene group having 1 to 6 carbon atoms include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, n -Butylene group, isobutylene group, n-pentylene group, and isopentylene group can be mentioned. Among these, a methylene group and an ethylene group are preferable.

  In the general formula (a-5), as for the relative bonding site between the relative hydroxyl group and Rd on cyclohexane, the one in which Rd is located at the 3-position with respect to the hydroxyl group is exemplified. Alternatively, Rd may be located at the 4-position with respect to the hydroxyl group.

  The novolak resin into which the substituent represented by the general formula (a-4) or the general formula (a-5) is introduced can be easily synthesized by a reaction between the novolac resin and an epoxy compound described later.

  In the component (A), the ratio (molar ratio) between the structural unit (a1) and the structural unit (a2) is preferably 1:99 to 80:20. Since the ratio of the structural unit (a1) is not less than the above lower limit value, the effect of improving the crack resistance of the photoresist is sufficiently obtained, and since it is not more than the above upper limit value, the solubility in an alkali developer does not decrease, Sufficient sensitivity can be maintained and pattern thickening due to plating can be suppressed. In order to adjust the above characteristics with a good balance, the ratio of the structural unit (a1) to the structural unit (a2) is more preferably 5:95 to 40:60.

  The ratio of the structural units can be measured using, for example, an NMR apparatus. Alternatively, in the production of the component (A), by adjusting the reaction ratio (preparation ratio) of the novolak resin and the substituent introduction agent containing the structure represented by the general formula (a-2), The component (A) having such a ratio can be produced. This is because the phenolic hydroxyl group of the novolak resin and the substituent introduction agent containing the structure represented by the general formula (a-2) react substantially in a stoichiometric manner.

  In the component (A), the bonding state of the two types of structural units, the structural unit (a1) and the structural unit (a2), is not particularly limited. That is, the component (A) includes a random polymer in which two types of structural units are bonded without regularity, a block polymer in which one of the structural units is continuously bonded, and a part of the random polymer is a block polymer. Any of the structures bonded in a shape may be used. In any case, it is only necessary that two types of structural units have the above structure and form a polymer.

  The mass average molecular weight of the component (A) is a mass average molecular weight in terms of polystyrene as measured by gel permeation chromatography (GPC), and is preferably 500 to 30000. When the mass average molecular weight is within the above range, the developability, resolution, and plating solution resistance of the photoresist can be improved. That is, since the mass average molecular weight is not less than the above lower limit value, the film does not decrease and the resist shape cannot be formed. On the other hand, since it is below the upper limit, sensitivity and resolution do not decrease. The mass average molecular weight is more preferably 1000 to 25000.

The mass average molecular weight is a calibration curve prepared using a polystyrene standard substance by GPC measurement using the following GPC apparatus under the conditions of a flow rate of 0.1 ml / min and a column temperature of 40 ° C. using tetrahydrofuran as an elution solvent. Calculated based on
・ Main body: “HLC-8020” manufactured by TOSOH
-Detector: “UV-8011” manufactured by TOSOH, set at a wavelength of 280 nm
Column for analysis: “SHODEX KF-802, KF-803, KF-805” manufactured by Showa Denko KK

(Method for producing alkali-soluble novolak resin (A) having a specific structural unit)
In producing the component (A), first, a novolak resin is synthesized by reacting phenols and aldehydes, and then a substituent introducing agent containing a structure represented by the general formula (a-2) is used. It can manufacture by introduce | transducing the said substituent.

  Although it does not specifically limit as said novolak resin, It is preferable that it is what is obtained by carrying out the condensation reaction in the ratio of 0.5-1.0 mol of aldehydes with respect to 1 mol of phenols under an acidic catalyst. .

  Here, as phenols used, for example, phenol; cresols such as o-cresol, m-cresol, and p-cresol; 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, Xylenols such as 2,6-xylenol, 3,4-xylenol, and 3,5-xylenol; ethylphenols such as o-ethylphenol, m-ethylphenol, and p-ethylphenol; isopropylphenol, butylphenol, and alkylphenols such as pt-butylphenol; polyhydric phenols such as resorcin, catechol, hydroquinone, pyrogallol, and phloroglucin; and alkyl polyphenols such as alkylresorcin, alkylcatechol, and alkylhydroquinone Any of the carbon atoms the alkyl group may be mentioned a is), etc. 1-4. These phenols may be used alone or in combination of two or more.

  Among the phenols, m-cresol and p-cresol are particularly preferable. By using these phenols and adjusting the blending ratio of both, various characteristics such as sensitivity and heat resistance as a photoresist can be adjusted.

  When m-cresol and p-cresol are used as phenols, the blending ratio (molar ratio) is not particularly limited, but is preferably m-cresol / p-cresol = 3/7 to 8/2. Since the ratio of m-cresol is not less than the above lower limit value, the sensitivity does not decrease, and since it is not more than the above upper limit value, the heat resistance is maintained at a certain level or more.

  As the aldehydes, it is preferable in terms of characteristics to use formaldehyde and paraformaldehyde.

  Examples of the acid catalyst include, but are not limited to, inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, and phosphorous acid; organic acids such as oxalic acid, diethyl sulfuric acid, paratoluenesulfonic acid, and organic sulfonic acid; zinc acetate And metal salts such as These acid catalysts may be used alone or in combination of two or more.

［式（ａ−６）中、Ｒｅ、Ｒｆ、及びＲｇはそれぞれ独立に水素原子又はアルキル基を表し、Ｒｈはアルキレン基を表し、Ｒｅ、Ｒｆ、Ｒｇ、及びＲｈの炭素数の総和は１〜１０である。また、Ｒａ、Ｒｂ、ｘ、及びｙは前記と同様の意味を表す。］

［式（ａ−７）中、Ｒｉは水素原子又はアルキル基を表し、Ｒｊはアルキレン基を表し、Ｒｋは直接結合又はアルキレン基を表し、Ｒｉ、Ｒｊ、及びＲｋの炭素数の総和は１〜１０である。また、Ｒａ、Ｒｂ、ｘ、及びｙは前記と同様の意味を表す。］ A method for introducing a substituent containing a structure represented by the general formula (a-2) is not particularly limited. For example, in the general formula (a-6) or the general formula (a-7), A method of reacting the represented epoxy compound with a novolac resin can be given.

[In the formula (a-6), Re, Rf, and Rg each independently represents a hydrogen atom or an alkyl group, Rh represents an alkylene group, and the total number of carbon atoms of Re, Rf, Rg, and Rh is 1 to 10. Ra, Rb, x, and y have the same meaning as described above. ]

[In the formula (a-7), Ri represents a hydrogen atom or an alkyl group, Rj represents an alkylene group, Rk represents a direct bond or an alkylene group, and the total number of carbon atoms of Ri, Rj and Rk is 1 to 10. Ra, Rb, x, and y have the same meaning as described above. ]

［式（ａ−８）中、Ｒａ、Ｒｂ、Ｒｄ、ｘ、及びｙは前記と同様の意味を表す。］ As an epoxy compound represented by general formula (a-7), the compound represented by general formula (a-8) is preferable, for example.

[In the formula (a-8), Ra, Rb, Rd, x, and y represent the same meaning as described above. ]

  The conditions for ring-opening addition of the phenolic hydroxyl group of the novolak resin to the epoxy compound include reaction conditions for reacting for 3 hours to 7 hours in the presence of an acid catalyst at a temperature of 70 ° C. to 90 ° C. be able to. Here, examples of the acid catalyst include hydroquinone.

［式（ａ−９）中、Ｒｅ、Ｒｆ、Ｒｇ、及びＲｈは前記と同様の意味を表す。］

［式（ａ−１０）中、Ｒｉ、Ｒｊ、及びＲｋは前記と同様の意味を表す。］

［式（ａ−１１）中、Ｒｄは前記と同様の意味を表す。］

［式（ａ−１２）中、Ｒａ、Ｒｂ、及びｘは前記と同様の意味を表す。］ Here, as a synthesis method of the epoxy compound represented by General Formula (a-6), General Formula (a-7), and General Formula (a-8), General Formula (a-9), General Formula ( Examples thereof include a method in which an epoxy compound represented by a-10) and a general formula (a-11) is reacted with a lactone represented by the general formula (a-12) in the presence of a catalyst.

[In the formula (a-9), Re, Rf, Rg and Rh represent the same meaning as described above. ]

[In formula (a-10), Ri, Rj, and Rk represent the same meaning as described above. ]

[In the formula (a-11), Rd represents the same meaning as described above. ]

[In the formula (a-12), Ra, Rb, and x represent the same meaning as described above. ]

  Commercially available epoxy compounds represented by general formula (a-9), general formula (a-10), and general formula (a-11) may be used, but unsaturated compounds corresponding to these compounds may be used. It can be obtained by epoxidizing alcohol with an epoxidizing agent or the like. Examples of the epoxidizing agent include organic percarboxylic acids such as performic acid, peracetic acid, perpropionic acid, and perbenzoic acid.

  Examples of the lactone represented by the general formula (a-12) include ε-caprolactone, trimethylcaprolactone, β-methyl-δ-valerolactone, and butyrolactone.

  Catalysts that can be used in the above reaction include titanium compounds such as tetrabutoxy titanium, tetrapropoxy titanium, and tetraethoxy titanium; organotin compounds such as tin octylate, dibutyltin oxide, and dibutyltin laurate; stannous chloride, Examples thereof include stannous bromide and tin halides such as stannous iodide; and heteropolyacids such as phosphotungstic acid and silicotungstic acid.

  The reaction can be performed at a temperature of 30 ° C. or higher and 230 ° C. or lower. When a titanium-based or tin-based catalyst is used, the reaction is preferably performed at a temperature of 100 ° C. or higher and 180 ° C. or lower. On the other hand, when phosphotungstic acid or the like is used, the reaction can proceed at a relatively low temperature of 30 ° C. or higher and 100 ° C. or lower.

・・・（ｂ−１）
［式（ｂ−１）中、Ｒ^１１〜Ｒ^２０はそれぞれ独立に水素原子、ハロゲン原子、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、又は炭素数３〜６のシクロアルキル基を表し；Ｒ^２２〜Ｒ^２５はそれぞれ独立に水素原子又は炭素数１〜６のアルキル基を表し；Ｒ^２１が水素原子又は炭素数１〜６のアルキル基の場合は、Ｑ^１は水素原子、炭素数１〜６のアルキル基又は下記化学式（ｂ−２）で表される残基であり、Ｑ^１がＲ^２１の末端と結合する場合は、Ｑ^１はＲ^２１及び、Ｑ^１とＲ^２１との間の炭素原子と共に、炭素鎖３〜６のシクロアルキル基を表し；ａ、ｂは１〜３の整数を表し；ｄ、ｅは０〜３の整数を表し；ｈ、ｉはｈ＋ｉ＝０〜３となる整数を表す。］

［式（ｂ−２）中、Ｒ^２６及びＲ^２７はそれぞれ独立に水素原子、ハロゲン原子、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、又は炭素数３〜６のシクロアルキル基を表し；ｃは１〜３の整数を示す。］ (Photosensitive agent (B))
Examples of the photosensitizer (B) include naphthoquinone diazide esterified products. The naphthoquinone diazide esterified product is not particularly limited as long as it is generally used as a photosensitizer in a positive photoresist composition, and one or more photosensitizers can be arbitrarily selected and used. . Specifically, for example, an esterified product of a phenol compound represented by the following general formula (b-1) and a naphthoquinone diazide sulfonic acid compound can be used.

... (b-1)
[In Formula (b-1), R ^{11 to} R ²⁰ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cyclohexane having 3 to 6 carbon atoms. R ^{22 to} R ²⁵ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; when R ²¹ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, Q ¹ is hydrogen. atoms, a residue represented by alkyl or chemical formula 1 to 6 carbon atoms (b-2), ^{if Q 1} is bonded with the terminal of ^{R 21} is, ^{Q 1} is ^{R 21} and, ^{Q 1} and Together with the carbon atom between R ²¹ , represents a cycloalkyl group having 3 to 6 carbon chains; a and b represent an integer of 1 to 3; d and e represent an integer of 0 to 3; h and i represent h + i represents an integer of 0-3. ]

[In Formula (b-2), R ²⁶ and R ²⁷ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cyclohexane having 3 to 6 carbon atoms. Represents an alkyl group; c represents an integer of 1 to 3; ]

Incidentally, ^{Q 1, R 21} and, together with the carbon atoms between ^{Q 1, R 21,} when forming a cycloalkyl group having a carbon chain 3-6, ^{Q 1, R 21} is attached, the number of carbon atoms 2 to 5 alkylene groups are formed.

Among these, a phenol compound represented by the following formula (b-3) is preferable.

In addition to the phenolic compound of formula (b-3), the phenolic compound corresponding to general formula (b-1) is:
Tris (4-hydroxyphenyl) methane, bis (4-hydroxy-3-methylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,3,5-trimethylphenyl) -2-hydroxyphenylmethane, Bis (4-hydroxy-3,5-dimethylphenyl) -4-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3-hydroxyphenylmethane, bis (4-hydroxy-3,5- Dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -4-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3-hydroxyphenylmethane, Bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyl Nylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, bis (4- Hydroxy-2,5-dimethylphenyl) -2,4-dihydroxyphenylmethane, bis (4-hydroxyphenyl) -3-methoxy-4-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) ) -4-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -2-hydroxyphenyl Methane and bis (5-cyclohexyl-4- Proxy-2-methylphenyl) -3,4-trisphenol compounds such dihydroxyphenyl methane;
Linear types such as 2,4-bis (3,5-dimethyl-4-hydroxybenzyl) -5-hydroxyphenol and 2,6-bis (2,5-dimethyl-4-hydroxybenzyl) -4-methylphenol Trinuclear phenolic compounds;
1,1-bis [3- (2-hydroxy-5-methylbenzyl) -4-hydroxy-5-cyclohexylphenyl] isopropane, bis [2,5-dimethyl-3- (4-hydroxy-5-methylbenzyl) ) -4-hydroxyphenyl] methane, bis [2,5-dimethyl-3- (4-hydroxybenzyl) -4-hydroxyphenyl] methane, bis [3- (3,5-dimethyl-4-hydroxybenzyl)- 4-hydroxy-5-methylphenyl] methane, bis [3- (3,5-dimethyl-4-hydroxybenzyl) -4-hydroxy-5-ethylphenyl] methane, bis [3- (3,5-diethyl- 4-hydroxybenzyl) -4-hydroxy-5-methylphenyl] methane, bis [3- (3,5-diethyl-4-hydroxybenzyl) -4- Loxy-5-ethylphenyl] methane, bis [2-hydroxy-3- (3,5-dimethyl-4-hydroxybenzyl) -5-methylphenyl] methane, bis [2-hydroxy-3- (2-hydroxy-) 5-methylbenzyl) -5-methylphenyl] methane, bis [4-hydroxy-3- (2-hydroxy-5-methylbenzyl) -5-methylphenyl] methane, and bis [2,5-dimethyl-3- Linear tetranuclear phenolic compounds such as (2-hydroxy-5-methylbenzyl) -4-hydroxyphenyl] methane;
2,4-bis [2-hydroxy-3- (4-hydroxybenzyl) -5-methylbenzyl] -6-cyclohexylphenol, 2,4-bis [4-hydroxy-3- (4-hydroxybenzyl) -5-methylbenzyl] -6-cyclohexylphenol, 2,6-bis [2,5-dimethyl-3- (2-hydroxy-5-methylbenzyl) -4-hydroxybenzyl] -4-methylphenol, etc. Linear polyphenolic compounds such as linear pentanuclear phenolic compounds;

Bis (2,3-trihydroxyphenyl) methane, bis (2,4-dihydroxyphenyl) methane, 2,3,4-trihydroxyphenyl-4′-hydroxyphenylmethane, 2- (2,3,4- Trihydroxyphenyl) -2- (2 ′, 3 ′, 4′-trihydroxyphenyl) propane, 2- (2,4-dihydroxyphenyl) -2- (2 ′, 4′-dihydroxyphenyl) propane, 2- (4-hydroxyphenyl) -2- (4′-hydroxyphenyl) propane, 2- (3-fluoro-4-hydroxyphenyl) -2- (3′-fluoro-4′-hydroxyphenyl) propane, 2- ( 2,4-dihydroxyphenyl) -2- (4′-hydroxyphenyl) propane, 2- (2,3,4-trihydroxyphenyl) -2- (4′-hydroxypheny) ) Propane, and 2- (2,3,4-hydroxyphenyl) -2- (4'-hydroxy-3 ', 5'-dimethylphenyl) bisphenol compounds such as propane;
1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene and 1- [1- (3-methyl-4-hydroxyphenyl) isopropyl] Polynuclear branched compounds such as -4- [1,1-bis (3-methyl-4-hydroxyphenyl) ethyl] benzene;
In addition, condensed phenol compounds such as 1,1-bis (4-hydroxyphenyl) cyclohexane are exemplified.

  These may be used alone or in combination of two or more.

  Esterification of all or part of the phenolic hydroxyl group of the phenol compound represented by the general formula (b-1) with a naphthoquinone diazide sulfonic acid compound can be performed by a conventional method. For example, naphthoquinone diazide sulfonyl chloride is generally used. It can be obtained by condensation with a phenol compound represented by the formula (b-1).

  Specifically, for example, a phenol compound represented by the general formula (b-1) and naphthoquinone-1,2-diazide-4 (or 5) -sulfonyl chloride are mixed with dioxane, n-methylpyrrolidone, dimethylacetamide, And a predetermined amount dissolved in an organic solvent such as tetrahydrofuran, to which one or more basic catalysts such as triethylamine, triethanolamine, pyridine, alkali carbonate, and alkali hydrogen carbonate are added and reacted, and the resulting product is It can be prepared by washing with water and drying.

  As the photosensitizer, in addition to these exemplified preferred naphthoquinone diazide esterified products, other naphthoquinone diazide esterified products can also be used. For example, an esterified product of a phenol compound such as polyhydroxybenzophenone or alkyl gallate and a naphthoquinone diazide sulfonic acid compound can be used. The amount of these other naphthoquinone diazide esterification products is preferably 80% by mass or less, more preferably 50% by mass or less in the photosensitive agent from the viewpoint of improving the effect of the present invention.

  5-40 mass% is preferable with respect to (A) component, and, as for the compounding quantity of the photosensitive agent in a positive type photoresist composition, 10-20 mass% is more preferable. By making the compounding quantity of a photosensitive agent more than the said lower limit, the film loss of an unexposed part can be suppressed. Moreover, by making it below the upper limit, the transmittance of the ghi line can be kept high, and a highly sensitive resist composition can be obtained.

(Plasticizer (C))
In the positive photoresist composition of the present embodiment, an alkali-soluble acrylic resin may be blended as a plasticizer in order to further improve the plating resistance such as generation of cracks. As an alkali-soluble acrylic resin, what is generally mix | blended with the positive photoresist composition can be used as a plasticizer.

  More specifically, the alkali-soluble acrylic resin is derived from an alkali-soluble acrylic resin containing 30 to 90% by mass of a structural unit derived from a polymerizable compound having an ether bond, and a polymerizable compound having a carboxyl group. An alkali-soluble acrylic resin containing 50 to 2% by mass of the structural unit.

  Examples of the polymerizable compound having an ether bond include 2-methoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxy polyethylene glycol (meta ) Radical polymerizable compounds such as (meth) acrylic acid derivatives having an ether bond and an ester bond, such as acrylate, methoxypolypropylene glycol (meth) acrylate, and tetrahydrofurfuryl (meth) acrylate. Among these, 2-methoxyethyl acrylate and methoxytriethylene glycol acrylate can be preferably used. These compounds may be used alone or in combination of two or more.

  Examples of the polymerizable compound having a carboxyl group include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid; and 2-methacryloyloxyethyl succinic acid, 2 -Radical polymerizable compounds such as methacrylic acid derivatives having a carboxyl group and an ester bond such as methacryloyloxyethylmaleic acid, 2-methacryloyloxyethylphthalic acid, and 2-methacryloyloxyethylhexahydrophthalic acid. Among these, acrylic acid and methacrylic acid can be preferably used. These compounds may be used alone or in combination of two or more.

  The content of the polymerizable compound having an ether bond in the alkali-soluble acrylic resin is preferably 30 to 90% by mass, and more preferably 40 to 80% by mass. By being within 90 mass%, good compatibility with the solution of the component (A) can be obtained. In addition, since a Benard cell (a pentagonal-pentagonal network pattern having nonuniformity generated on the surface of the coating film due to gravity or a surface tension gradient) during pre-baking can be prevented, a uniform resist film can be obtained. By setting it as 30 mass% or more, the crack generation at the time of plating can be suppressed.

  Moreover, 2-50 mass% is preferable and, as for content of the polymeric compound which has a carboxyl group in alkali-soluble acrylic resin, 5-40 mass% is more preferable. By setting it to 2% by mass or more, good alkali solubility of the acrylic resin can be obtained, and sufficient developability can be obtained. Moreover, since high releasability is obtained, the resist residual film on a board | substrate can be prevented. By setting the content to 50% by mass or less, it is possible to suppress film loss in the unexposed area and to improve the plating resistance.

  The mass average molecular weight of the alkali-soluble acrylic resin is preferably 10,000 to 800,000, and more preferably 30,000 to 500,000. By setting it to 10,000 or more, a sufficiently strong resist film can be obtained, so that the swelling of the profile during plating can be prevented and the crack resistance can be improved. By being 800,000 or less, high peelability can be provided.

  Further, the alkali-soluble acrylic resin may contain other radical polymerizable compound as a monomer for the purpose of appropriately controlling physical and chemical properties. Here, the “other radical polymerizable compound” means a radical polymerizable compound other than the above-described polymerizable compound.

  Examples of such radically polymerizable compounds include (meth) acrylic acid alkyl esters such as methyl (meth) acrylate, ethyl (meth) acrylate, and butyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate and 2- (Meth) acrylic acid hydroxyalkyl esters such as hydroxypropyl (meth) acrylate; (meth) acrylic acid aryl esters such as phenyl (meth) acrylate and benzyl (meth) acrylate; dicarboxylic acids such as diethyl maleate and dibutyl fumarate Acid diesters; vinyl group-containing aromatic compounds such as styrene and α-methylstyrene; vinyl group-containing aliphatic compounds such as vinyl acetate; conjugated diolefins such as butadiene and isoprene; Lil group-containing polymerizable compound; can be used as well as amide-bond-containing polymerizable compounds such as acrylamide and methacrylamide; chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride. These compounds may be used alone or in combination of two or more. Among these, n-butyl acrylate, benzyl methacrylate, methyl methacrylate, and the like are particularly preferable. The other radically polymerizable compound in the alkali-soluble acrylic resin is preferably less than 50% by mass, and more preferably less than 40% by mass.

  Examples of the polymerization solvent used in the synthesis of the alkali-soluble acrylic resin include alcohols such as ethanol and diethylene glycol; alkyl ethers of polyhydric alcohols such as ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, and diethylene glycol ethyl methyl ether; ethylene Alkyl ether acetates of polyhydric alcohols such as glycol ethyl ether acetate and propylene glycol methyl ether acetate; aromatic hydrocarbons such as toluene and xylene; ketones such as acetone and methyl isobutyl ketone; and ethyl acetate and butyl acetate These esters can be used. Among these, polyhydric alcohol alkyl ethers and polyhydric alcohol alkyl ether acetates are particularly preferable.

  As a polymerization catalyst used when synthesizing an alkali-soluble acrylic resin, an ordinary radical polymerization initiator can be used. For example, azo compounds such as 2,2′-azobisisobutyronitrile; benzoyl peroxide and di-t -Organic peroxides such as butyl peroxide can be used.

  In the positive photoresist composition of the present embodiment, the blending amount of the alkali-soluble acrylic resin is preferably 13 parts by mass or less and more preferably 7 parts by mass or less with respect to 100 parts by mass of the component (A). Conventionally, the alkali-soluble acrylic resin as a plasticizer is usually blended in an amount of about 15 to 25 parts by mass with respect to 100 parts by mass of the base resin. In this embodiment, the component (A) described above as the base resin is used. By using it, a sufficient plasticizing effect can be obtained with a blending amount of 13 parts by mass or less. Further, when the blending amount is 7 parts by mass or less, the strength of the formed resist film becomes sufficient, and swelling and the like are less likely to occur. For this reason, a clear profile is obtained and the resolution is improved.

(Adhesion improver (D))
The positive photoresist composition according to this embodiment may contain an adhesion improver as necessary. Examples of the adhesion improver include adhesion improvers described in JP-A-62-262043 and JP-A-11-223937, such as 6-methyl-8-hydroxyquinoline, 6-ethyl-8-hydroxyquinoline, 5-methyl-8-hydroxyquinoline, 8-hydroxyquinoline, 8-acetyloxyquinoline, 4-hydroxypteridine, 2,4-dihydroxypteridine, 4-hydroxypteridine-2-sulfonic acid 2-ethyl-4-hydroxypteridine, 2-methyl-4-hydroxypteridine, 1,10-phenanthroline, 5,6-dimethyl-1,10-phenanthroline, 3,8-dimethyl-1,10-phenanthroline, 3, , 8-dihydroxy-1,10-phenanthroline, 5-carboxy- , 10-phenanthroline, 5,6-dihydroxy-1,10-phenanthroline, 1,10-phenanthroline-5-sulfonic acid, 4,4′-dimethyl-2,2′-bipyridyl, 2,2′-bipyridyl, 2, 2,2′-bipyridyl-5-carboxylic acid, 5,5′-dichloro-2,2′-bipyridyl, 3,3′-dihydroxy-2,2′-bipyridyl, and 3,3′-dimercapto-2,2 '-Bipyridyl etc. are mentioned.

  Further, particularly on the ring, at least one selected from the group consisting of bonds represented by the following general formulas (d-1) and (d-2), and a bond represented by the following general formula (d-3): By blending an aromatic heterocyclic compound having the above, the adhesion of the positive photoresist composition to the substrate can be remarkably enhanced.

［式（ｄ−２）中、Ｒ^３４は、水素原子又は炭素数１〜３のアルキル基を表す。］

[In the formula (d-2), R ³⁴ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. ]

［式（ｄ−３）中、Ｒ^３５は、水酸基又は水酸基が置換した炭素数１〜５の直鎖又は分枝状のアルキル基を表す。］

[In the formula (d-3), R ³⁵ represents a hydroxyl group or a linear or branched alkyl group having 1 to 5 carbon atoms substituted by a hydroxyl group. ]

  As the heterocyclic compound, for example, “Organic Compound Structural Index” (issued on December 20, 1977, Maruzen Co., Ltd.) pp. Indole compounds, indoline compounds, and indigo compounds described in 362-401 having a 5-membered ring skeleton of 1 atom of nitrogen; pyridine compounds, quinoline compounds, hydroquinoline compounds, isoquinoline compounds , Acridine compounds, benzoquinoline compounds, naphthoquinoline compounds, phenanthroline compounds and the like having a 6-membered ring skeleton of nitrogen; pyrazole compounds, imidazole compounds, imidazoline compounds, benzimidazole compounds, and the like Having a 5-membered ring skeleton of nitrogen 2 atoms; having a 6-membered ring skeleton of nitrogen 2 such as diazine compounds, hydropyridine compounds, benzodiazine compounds, and dibenzodiazine compounds; triazole compounds and Benzotriazole compounds Those having a 5-membered ring skeleton of nitrogen 3 atoms; those having a 6-membered ring skeleton of nitrogen 3 such as triazine compounds; those having a 5-membered skeleton of nitrogen 4 such as tetrazole and pentetrazole; Those having a 6-membered ring skeleton of 4 atoms of nitrogen such as 2,4,5-tetrazine; and other purine compounds, pteridine compounds, alloxazine compounds, and 2H-pyrrole. Among these, the compound represented by the following general formula (d-4) is preferable in that it can suppress the generation of scum and can provide a positive photoresist composition having excellent adhesion to a substrate, and 2- ( 2-Hydroxyethyl) pyridine is more preferred.

［式（ｄ−４）中、ｋは１〜３の整数を表し、Ｒ^３５は前記と同様の意味を表す。］

[In formula (d-4), k represents an integer of 1 to 3, and R ³⁵ represents the same meaning as described above. ]

  The addition amount of the adhesion improver is preferably 0.1 to 1.0% by mass, preferably 0.2 to 0.7%, based on the total amount of the component (A) and the alkali-soluble acrylic resin blended as required. More preferred is mass%. By being 0.1 mass% or more, the effect of improving the adhesion of the positive photoresist composition to the substrate can be sufficiently obtained. By setting it to 1.0% by mass or less, high resolution can be maintained. Further, it is possible to prevent the upper part of the space pattern from spreading and the occurrence of scum on the substrate.

［式（ｅ−１）中、Ｒ^４１〜Ｒ^４８はそれぞれ独立に水素原子、ハロゲン原子、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシル基、又はシクロアルキル基を表し；Ｒ^４９〜Ｒ^５１はそれぞれ独立に水素原子又は炭素数１〜６のアルキル基を表し；Ｑは水素原子、炭素数１〜６のアルキル基、Ｒ^４９と結合し、炭素原子鎖３〜６のシクロ環又は下記の化学式（ｅ−２）で表される残基を表し；ｗ、ｓは１〜３の整数を表し；ｕは０〜３の整数を表し；ｖは０〜３の整数を表す。］

［式（ｅ−２）中、Ｒ^５２及びＲ^５３はそれぞれ独立に水素原子、ハロゲン原子、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシル基、又はシクロアルキル基を表し；ｔは１〜３の整数を示す。］ (Sensitizer (E))
Moreover, in this embodiment, a sensitizer can be mix | blended as needed. There is no restriction | limiting in particular as a sensitizer which can be used by this embodiment, It can select arbitrarily from what can be normally used as a sensitizer in a positive type photoresist composition. For example, a phenol compound represented by the following general formula (e-1) can be used.

[In Formula (e-1), R ^{41 to} R ⁴⁸ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxyl group having 1 to 6 carbon atoms, or a cycloalkyl group; ^{49 to} R ⁵¹ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; Q is bonded to a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or R ⁴⁹ to form a cyclohexane having 3 to 6 carbon atoms. Represents a ring or a residue represented by the following chemical formula (e-2); w, s represents an integer of 1 to 3; u represents an integer of 0 to 3; v represents an integer of 0 to 3 . ]

[In Formula (e-2), R ⁵² and R ⁵³ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxyl group having 1 to 6 carbon atoms, or a cycloalkyl group; Represents an integer of 1 to 3. ]

  Examples of the phenol compound represented by the general formula (e-1) include bis (4-hydroxy-2,3,5-trimethylphenyl) -2-hydroxyphenylmethane, 1,4-bis [1- (3 , 5-dimethyl-4-hydroxyphenyl) isopropyl] benzene, 2,4-bis (3,5-dimethyl-4-hydroxyphenylmethyl) -6-methylphenol, bis (4-hydroxy-3,5-dimethylphenyl) ) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl Benzene, 1- [1- (3-methyl-4-hydroxyphenyl) isopropyl] -4- [1,1-bis (3-methyl-4-hydroxyphenyl) ethyl] benzene, 2,6-bis [1 -(2,4-dihydroxyphenyl) isopropyl] -4-methylphenol, 4,6-bis [1- (4-hydroxyphenyl) isopropyl] resorcin, 4,6-bis (3,5-dimethoxy-4-hydroxy) Phenylmethyl) pyrogallol, 4,6-bis (3,5-dimethyl-4-hydroxyphenylmethyl) pyrogallol, 2,6-bis (3-methyl-4,6-dihydroxyphenylmethyl) -4-methylphenol, 2 , 6-bis (2,3,4-trihydroxyphenylmethyl) -4-methylphenol, and 1,1-bis (4-hydroxyphenol) Le) cyclohexane, and the like. In addition, 6-hydroxy-4a- (2,4-dihydroxyphenyl) -9-1'-spirocyclohexyl-1,2,3,4,4a, 9a-hexahydroxanthene, and 6-hydroxy-5-methyl -4a- (2,4-dihydroxy-3-methylphenyl) -9-1'-spirocyclohexyl-1,2,3,4,4a, 9a-hexahydroxanthene and the like can also be used. These sensitizers may be used alone or in combination of two or more. Among these, 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene and bis (4-hydroxy-2,3,5-trimethylphenyl) The combination with -2-hydroxyphenylmethane is preferable in that the sensitivity can be increased and the verticality of the space pattern is excellent.

  As the sensitizer, a phenol compound represented by the following general formula (e-3) can also be used.

［式（ｅ−３）中、Ｒ^６１〜Ｒ^６３はそれぞれ独立に、低級アルキル基（直鎖でも分岐でもよく、好ましくは炭素数１〜５、より好ましくは炭素数１〜３）、シクロアルキル基（好ましくは炭素数５〜７）、又は低級アルコキシ基（直鎖でも分岐でもよく、好ましくは炭素数１〜５、より好ましくは炭素数１〜３）を表す。ｑ、ｒは１〜３、好ましくは１〜２の整数を表す。ｌ、ｏ、ｐは０又は１〜３の整数を表す。］

[In Formula (e-3), R ^{61 to} R ⁶³ are each independently a lower alkyl group (which may be linear or branched, preferably 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms), cycloalkyl Represents a group (preferably having 5 to 7 carbon atoms) or a lower alkoxy group (which may be linear or branched, preferably having 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms). q and r each represent an integer of 1 to 3, preferably 1 or 2. l, o, and p represent 0 or an integer of 1 to 3. ]

  More specifically, examples of the phenol compound represented by the general formula (e-3) include compounds represented by the following formulas (e-4) to (e-8).

［式（ｅ−９）中、Ｒ^７１〜Ｒ^７９はそれぞれ独立に水素原子、アルキル基、ハロゲン原子又はヒドロキシ基を表す。これらのうち少なくとも１つはヒドロキシ基であり、好ましくは、Ｒ^７１〜Ｒ^７４のうちの少なくとも１つと、Ｒ^７５〜Ｒ^７９のうちの少なくとも１つがヒドロキシ基である。Ｒ^７１〜Ｒ^７９のアルキル基としては、直鎖でも分岐でもよく、好ましくは炭素数１〜５、より好ましくは炭素数１〜３である。Ｒ^８０〜Ｒ^８５はそれぞれ独立に水素原子、アルキル基、アルケニル基、シクロアルキル基又はアリール基を表す。Ｒ^８０〜Ｒ^８５のアルキル基としては、直鎖でも分岐でもよく、炭素数１〜１０のアルキル基が好ましい。アルケニル基としては、炭素数１〜４のアルケニル基が好ましい。］ As the sensitizer, a phenol compound represented by the following general formula (e-9) can also be used.

Wherein ^(e-9), each represent R 71 ^{to R 79} independently represent a hydrogen atom, an alkyl group, a halogen atom or a hydroxy group. At least one of these is a hydroxy group, and preferably at least one of R ^{71 to} R ⁷⁴ and at least one of R ^{75 to} R ⁷⁹ is a hydroxy group. The alkyl group for R ^{71 to} R ⁷⁹ may be linear or branched, and preferably has 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms. R ^{80 to} R ⁸⁵ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, or an aryl group. The alkyl group of R ^{80 to} R ⁸⁵ may be linear or branched and is preferably an alkyl group having 1 to 10 carbon atoms. As the alkenyl group, an alkenyl group having 1 to 4 carbon atoms is preferable. ]

  More specifically, examples of the phenol compound represented by the general formula (e-9) include a compound represented by the following general formula (e-10).

［式（ｅ−１０）中、Ｒ^８６、Ｒ^８７はそれぞれ独立に、アルキル基を表す。アルキル基としては、直鎖でも分岐でもよく、好ましくは炭素数１〜５、より好ましくは炭素数１〜３である。ｆ、ｇは１〜３、好ましくは１〜２の整数を表す。ｊ、ｚは０又は１〜３の整数を表す。］

[In formula (e-10), R ^<86 >, R ^<87 > represents an alkyl group each independently. The alkyl group may be linear or branched, and preferably has 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms. f and g represent an integer of 1 to 3, preferably 1 or 2. j and z represent 0 or an integer of 1 to 3. ]

  More specifically, examples of the phenol compound represented by the general formula (e-9) include compounds represented by the following formulas (e-11) and (e-12).

  The blending amount of the sensitizer is preferably 1 to 30% by mass, more preferably 3 to 20% by mass with respect to the component (A).

(High boiling point organic solvent (F))
In the present embodiment, the bulk effect of the resist film, that is, the deviation of the film density can be reduced by blending a high boiling point organic solvent having a boiling point of about 200 to 350 ° C. as necessary. Thereby, even when a thick resist film is formed on a substrate having a step on the surface using a positive photoresist composition, a space pattern having excellent perpendicularity can be formed. In addition, when a high-boiling organic solvent is used, a favorable space pattern can be formed regardless of the conditions (heating time, heating means, etc.) of the pre-bake treatment and PEB (post-exposure heating) treatment.

  Examples of the high boiling point organic solvent include benzyl acetate, isoamyl salicylate, methyl salicylate, benzyl salicylate, diethyl phthalate, dibutyl phthalate, dimethyl phthalate, γ-butyrolactone, ethyl benzoate, butyl benzoate, propyl benzoate, and benzoate. Benzyl acid, ethylene glycol monophenyl ether, ethylene glycol monohexyl ether, 1,3-octylene glycol, diethylene glycol, diethylene glycol diacetate, diethylene glycol dibutyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether Butyl ether acetate, dipropylene glycol, dipropy Glycol monobutyl ether, triethylene glycol, triethylene glycol di-2-ethylbutyrate, triethylene glycol dimethyl ether, triethylene glycol monoethyl ether, triethylene glycol monomethyl ether, tripropylene glycol, tripropylene glycol monomethyl ether, 2- Examples include ethylhexanoic acid, caprylic acid, caproic acid, catechol, octylphenol, and N-methylpyrrolidone. These may be used alone or in combination of two or more. Among these, those having a boiling point of 250 to 350 ° C. are preferable, and benzyl salicylate is particularly preferable.

  The blending amount of the high-boiling organic solvent is preferably 3 to 15% by mass, and 6 to 12% by mass with respect to the total amount of the above component (A) and the sensitizer blended as necessary. More preferably it is. When the blending amount is 3% by mass or more, the above-described effects can be sufficiently exhibited. Moreover, since the spreading | diffusion of the space pattern upper part can be prevented because a compounding quantity is 15 mass% or less, perpendicularity can be hold | maintained.

(Acid generator (G))
Moreover, in this embodiment, an acid generator can be mix | blended as needed. Although it does not specifically limit as an acid generator which can be used in this embodiment, The thing which decomposes | disassembles by heat processing or irradiation of a radiation and can generate | occur | produce an acid can be used. In consideration of application to an actual manufacturing process, a compound that generates an acid by irradiation with the same i-line (365 nm) as the positive photoresist composition of the present embodiment is preferable. Examples of such acid generators include triazine acid generators, oxime sulfonate acid generators, onium salt acid generators and the like described in JP-A-5-107755. . Among these, 3- (methylsulfonyl) oxy-1,2,3-benzotriazine-4 (3H) one is excellent in acid generation effect both in heat treatment and ultraviolet irradiation, and efficiently crosslinks acid-crosslinkable materials. This is preferable because it can be applied to the positive photoresist composition according to this embodiment. The compounding amount of the acid generator is preferably about 0.01 to 5.0% by mass, preferably 0.1 to 1.0% by mass, based on the composition (total solid content), although it depends on the type. More preferably.

(Other ingredients)
In the positive photoresist composition according to the present embodiment, p-toluenesulfonic acid chloride (PTSC), 4,4′-bis (diethylamino) benzophenone, for the purpose of improving resolution, exposure margin, and remaining film ratio, 1,4-bis [1- (2-methyl-4-hydroxy-5-cyclohexylphenyl) isopropyl] benzene and 1,3-bis [1- (2-methyl-4-hydroxy-5-cyclohexylphenyl) isopropyl Benzene or the like may be added. The addition amount is about 0.01 to 10% by mass with respect to the composition.

  In addition, the positive photoresist composition of the present embodiment further includes a compatible additive, for example, an ultraviolet absorber for preventing halation, such as 4-dimethylamino-2 ′, 4′-, if necessary. Dihydroxybenzophenone, 5-amino-3-methyl-1-phenyl-4- (4-hydroxyphenylazo) pyrazole, 4-dimethylamino-4′-hydroxyazobenzene, 4-diethylamino-4′-ethoxyazobenzene, 4,4 '-Diethylaminoazobenzene, curcumin and the like, and surfactants for preventing striation, such as Fluorad FC-430, FC431 (trade name, manufactured by Sumitomo 3M Ltd.), F-top EF122A, EF122B, EF122C, EF126 (product) Name, manufactured by Tochem Products Co., Ltd.), and Mega Fuck R 08 (manufactured by Dainippon Ink and Chemicals, Inc.) or the like may be contained added in the range not interfering with the purposes of the present invention.

  The positive photoresist composition according to this embodiment is preferably used in the form of a solution by dissolving in a suitable solvent. Examples of such solvents include solvents used in conventional positive photoresist compositions, such as ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, and 2-heptanone; ethylene glycol, Polyhydric alcohols such as propylene glycol, diethylene glycol, ethylene glycol monoacetate, propylene glycol monoacetate, diethylene glycol monoacetate or monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether and derivatives thereof; Cyclic ethers such as: ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methoxypropyl Methyl phosphate, and esters such as ethyl ethoxypropionate can be exemplified. These may be used alone or in combination of two or more. Especially, ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, and 2-heptanone; ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate Etc. are preferred.

  The amount of these solvents used may be set so that the solid content concentration in the solution is from 30% by mass to 65% by mass, for example, for the purpose of obtaining a film thickness of 10 μm or more by using a spin coating method. preferable. When the solid content concentration is 30% by mass or more, for example, a thick film having a thickness of 3 μm or more can be formed. Moreover, since the fluidity | liquidity of a composition can be hold | maintained by setting it as 65 mass% or less, handling becomes easy and a uniform resist film can also be obtained by a spin coat method.

  The positive photoresist composition according to the present embodiment can be prepared by, for example, mixing and stirring the above components by a usual method, and using a disperser such as a dissolver, a homogenizer, or a three roll mill as necessary. , May be mixed. Moreover, after mixing, you may further filter using a mesh, a membrane filter, etc.

  The positive photoresist composition according to this embodiment forms a thick photoresist layer having a thickness of 3 to 40 μm, more preferably 3 to 30 μm, and still more preferably 5 to 20 μm on the support. Suitable for

[Resist pattern formation method]
Next, a preferred example of the resist pattern forming method according to this embodiment will be shown.

  First, a positive photoresist composition according to this embodiment is dissolved in an appropriate solvent as described above on a substrate of Au, Si, Cu or the like, applied with a spinner or the like, and dried to form a photosensitive layer. . Next, a high pressure mercury lamp, an ultra high pressure mercury lamp, or a low pressure mercury lamp is used as a light source, and exposure is performed through a desired mask pattern. Next, PEB (post-exposure heating) treatment is performed as necessary, and the exposed portion is dissolved and removed by immersing it in an alkaline aqueous solution such as an aqueous solution of 1 to 10% by mass of tetramethylammonium hydroxide (TMAH). By doing so, a resist pattern faithful to the mask pattern can be obtained.

  In the case where a high aspect ratio resist pattern having a width of 0.8 μm or less is formed under a thick film condition of 3 μm or more, particularly about 6 to 8 μm, a known method using an acid crosslinkable material is used as necessary. A pattern forming method can also be used. The pattern forming method includes a step of forming a film of an acid-crosslinkable material that causes a crosslinking reaction by the action of an acid over the entire surface of the substrate on which the resist pattern is drawn; Step of cross-linking the acid-crosslinkable material in the portion in contact with the resist pattern; removing the acid-crosslinkable material in the non-crosslinked region with a developer to form a space width of the resist pattern before forming a film of the acid-crosslinkable material Forming a resist pattern having a narrower width, and forming a film of an acid-crosslinkable material that causes a crosslinking reaction by the action of an acid on the entire surface of the substrate on which the resist pattern is drawn; A step of generating an acid on the surface or inside of the resist pattern by performing whole surface exposure or selective exposure by irradiation; heat treatment A step of cross-linking the acid cross-linkable material in a portion in contact with the resist pattern by the action of an acid diffused from the resist pattern surface; coating of the acid cross-linkable material by removing the acid cross-linkable material in a region not cross-linked by the developer There is known a method of forming a resist pattern including a step of forming a resist pattern having a width narrower than the space width of the resist pattern before forming the resist pattern. The acid crosslinkable material and the developer are not particularly limited, and examples thereof include those described in JP-A-11-204399.

  The resist pattern obtained using the positive photoresist composition according to the present embodiment has high resolution, and can suppress pattern thickening and cracking during plating. Further, in the conventional positive photoresist composition, when forming a resist pattern, after development, there is a problem of releasability in which the resist is not completely removed and a residue remains on the substrate. A positive photoresist composition using the components also has good peelability.

  Moreover, in this embodiment, although the positive type photoresist composition using (A) component was demonstrated, it is not limited to this. That is, the photoresist composition containing the component (A) can act as a negative photoresist composition by appropriately examining the type of the photosensitizer and developer, or by adding other additives. It is. Such negative photoresist compositions are also within the scope of the present invention.

<Second Embodiment>
Next, a second embodiment of the present invention will be described in detail. In the present embodiment, description of the same matters as in the first embodiment may be omitted.

[Positive photoresist composition]
The positive photoresist composition according to the present embodiment has an alkali-soluble novolak resin (A ′) (hereinafter referred to as “a”) having a specific structural unit and having a 1,2-naphthoquinonediazidosulfonyl group bonded to a part of the phenolic hydroxyl group. (It may be called "(A ') component"). In addition, the positive photoresist composition of the present embodiment is further provided with a photosensitizer (B), a plasticizer (C) such as an alkali-soluble acrylic resin, if necessary, and an adhesion for increasing the adhesion to the substrate. A property improver (D), a sensitizer (E), a high boiling point organic solvent (F), an acid generator (G), and various additive components conventionally used in the technical field may be blended.

(Alkali-soluble novolak resin (A ′) having a specific structural unit and having a 1,2-naphthoquinonediazidosulfonyl group bonded to a part of the phenolic hydroxyl group)
The component (A ′) is obtained by bonding a 1,2-naphthoquinonediazidosulfonyl group to a part of the hydrogen atoms of the phenolic hydroxyl group contained in the component (A) described in the first embodiment. . When the component (A ′) is used, the sensitivity of the photoresist composition can be further improved because the naphthoquinonediazidesulfonyl group having a small amount of the component (A ′) itself has photosensitivity.

  The substitution with a 1,2-naphthoquinonediazide sulfonyl group can be synthesized by an esterification reaction between the component (A) produced in the first embodiment and a 1,2-naphthoquinonediazidesulfonic acid compound. Examples of 1,2-naphthoquinone diazide sulfonic acid compounds that can be used here include halogens of quinone diazide compounds such as 1,2-naphthoquinone diazide-4-sulfonic acid chloride and 1,2-naphthoquinone diazide-5-sulfonic acid chloride. A compound.

  The proportion of 1,2-naphthoquinonediazidosulfonyl group bonded to the phenolic hydroxyl group, that is, the reaction rate of the esterification reaction is preferably 2 to 10 mol%, more preferably 3 to 7 mol%, still more preferably 3 to 3 mol%. 5 mol%. By setting the reaction rate to 2 mol% or more, the effect of suppressing film loss in the unexposed portion is increased. In addition, it is possible to prevent the space pattern from spreading over. By setting the reaction rate to 10 mol% or less, a high transmittance for the ghi line can be obtained. In addition, the space pattern upper portion is prevented from spreading and the perpendicularity of the cross-sectional shape is kept good.

(Photosensitive agent (B))
In the positive photoresist composition according to this embodiment, it is preferable to add a photosensitizer as necessary. That is, the photosensitive agent is not an essential component and may not be added, but a small amount may be added. As an addition amount at the time of adding a photosensitizer, 1-10 mass% is preferable with respect to (A ') component, and 2-5 mass% is still more preferable.

  EXAMPLES Hereinafter, although the photoresist composition of this invention is demonstrated in detail by an Example, this invention is not limited to the Example demonstrated below at all.

<Synthesis Example 1; Alkali-soluble resin obtained by lactone modification of a part of phenolic hydroxyl group>
2 mol of ε-caprolactone was added to 1 mol of compound (1) obtained by epoxidizing 3-cyclohexene-1-methanol with perbenzoic acid in a three-necked flask equipped with a nitrogen introduction tube, a thermometer, and a stirring device. 0.06 parts by mass of butoxytitanium was added to 1 part by mass of compound (1). A compound (2) was obtained by reacting the mixture at 130 ° C. for 6 hours while blowing nitrogen gas. The structures of compound (1) and compound (2) are shown below.

  Here, the compound (2) is a mixture of compounds represented by the formula (2), where n is an integer of 1 to 10.

  Next, 465 parts by mass of 37% formalin aqueous solution and oxalic acid 2 with respect to 1000 parts by mass of phenols in which m-cresol and p-cresol were mixed at a molar ratio (m-cresol: p-cresol) 60:40. A part by mass was added, and the reaction was performed under reflux for 4 hours. Next, dehydration was performed under normal pressure to an internal temperature of 170 ° C., and dehydration / demonomerization was further performed under reduced pressure to 200 ° C. to obtain a novolak resin having a mass average molecular weight of 5900. By adding 25 parts by mass of compound (2) and 0.06 parts by mass of hydroquinone to 100 parts by mass of this novolak resin, the reaction was carried out at 80 ° C. for 5 hours while blowing air into the reaction solution, thereby allowing one of the phenolic hydroxyl groups. An alkali-soluble novolak resin (resin A) whose part was lactone-modified was obtained.

<Synthesis Example 2; alkali-soluble resin>
For 1000 parts by mass of phenols obtained by mixing m-cresol and p-cresol in a molar ratio (m-cresol: p-cresol) of 60:40, 465 parts by mass of 37% formalin aqueous solution and 2 parts by mass of oxalic acid were added. The mixture was added and reacted for 4 hours under reflux. Subsequently, dehydration was performed under normal pressure to an internal temperature of 170 ° C., and dehydration / demonomerization was further performed under reduced pressure to 200 ° C. to obtain a novolak resin (resin B) having a mass average molecular weight of 5900.

<Synthesis Example 3; Alkali-soluble resin in which part of phenolic hydroxyl group is converted to hydroxyalkyl ether>
Phenols prepared by mixing m-cresol and p-cresol in a molar ratio (m-cresol: p-cresol) 60:40 in a 3 L four-necked flask equipped with a stirrer, a thermometer, and a heat exchanger With respect to 1000 parts by mass, 465 parts by mass of 37% formalin aqueous solution and 2 parts by mass of oxalic acid were charged, and the reaction was performed for 4 hours under reflux. Thereafter, dehydration was performed under normal pressure up to an internal temperature of 170 ° C., and dehydration / demonomerization was performed up to 200 ° C. under a reduced pressure of 70 torr to obtain 850 parts by mass of a novolak type phenol resin having a mass average molecular weight of 5900.

Next, using the same reaction apparatus as described above, 26 parts by mass of propylene carbonate and 1 part by mass of potassium carbonate were added to 100 parts by mass of the resin, and the mixture was heated to 190 ° C. and reacted for 3 hours. Thereafter, the reaction solution was neutralized with acetic acid, washed with water by adding acetone and water, and neutralized salts were removed. By the above operation, 120 parts by mass of Resin C having a mass average molecular weight of 6500 represented by the following general formula (3) was obtained. This resin C was x: y = 30: 70 in the general formula (3). The ratio of x and y was calculated from the reaction ratio between the novolak type phenol resin and the hydroxyalkyl etherifying agent.

<Synthesis Example 4; Plasticizer>
After replacing the flask equipped with a stirrer, a reflux device, a thermometer, and a dropping tank with nitrogen, 200 g of propylene glycol methyl ether was added as a solvent, and the temperature of the solvent was raised to 80 ° C. while stirring. . 2,2′-Asobisisobutyronitrile (polymerization catalyst) 0.5 g, 2-methoxyethyl acrylate 130 g, benzyl methacrylate 50.0 g, and acrylic acid 20.0 g are added to the dropping tank and stirred until the polymerization catalyst is dissolved. After that, this solution was dropped uniformly into the flask for 3 hours, and then polymerization was carried out at 80 ° C. for 5 hours. This was cooled to room temperature to obtain an alkali-soluble acrylic resin (plasticizer).

<Example 1>
As shown in Table 1, 2 mol of resin A and 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene in 1 mol of phenolic hydroxyl group A photosensitizer in which 1,2-naphthoquinonediazide-4-sulfonyl group was introduced in a ratio (shown as “photosensitizer” in Table 1), was dissolved in propylene glycol monoethyl ether acetate (shown as “solvent” in Table 1). And filtered using a membrane filter to prepare a positive photoresist composition.

<Example 2>
A positive photoresist composition was prepared in the same manner as in Example 1 except that 5 parts by mass of a plasticizer was further added to each component shown in Example 1 above.

<Comparative Example 1>
A positive photoresist composition was prepared in the same manner as in Example 1 except that Resin B was used instead of Resin A.

<Comparative example 2>
A positive photoresist composition was prepared in the same manner as in Comparative Example 1 except that 10 parts by mass of a plasticizer was further added to each component shown in Comparative Example 1.

<Comparative Example 3>
A positive photoresist composition was prepared in the same manner as in Comparative Example 1 except that 15 parts by mass of a plasticizer was further added to each component shown in Comparative Example 1.

<Comparative Example 4>
A positive photoresist composition was prepared in the same manner as in Example 1 except that Resin C was used instead of Resin A.

<Inspection method>
Each of the above photoresist compositions was applied onto a 6-inch gold wafer using a spinner and then pre-baked on a hot plate at 120 ° C. for 4 minutes to obtain a coating film having a thickness of 10 μm. Next, exposure was performed with an ultrahigh pressure mercury lamp (USH-250D manufactured by Ushio Co., Ltd.) using a mask having a square cut pattern. Thereafter, the resist pattern was developed with a developer (trade name: PMER series, NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.).

  The evaluation method for each evaluation item will be described below. In all items, the part on the wafer to be observed when performing the evaluation was a wafer peripheral part where wrinkles are likely to occur.

(Pattern shape)
When exposure is performed using a mask having a line-shaped blank pattern of 5 μm so that the bottom dimension of the resist is finished to 5 μm, the ratio of the top dimension (Tum) to the bottom dimension (T / 5) of the resist is 1 ≦ T ◯ when /5<1.1, △ when 1.1 ≦ T / 5 <1.2, or 1.2 ≦ T / 5 or due to rounding of the upper part of the resist pattern When it was impossible, it was set as x.

(Resolution)
When exposure and development are performed in the same manner as in the above (pattern shape) evaluation, it is possible to resolve a line-shaped blanking pattern that can resolve 2 μm or less, and a pattern that exceeds 2 μm and 4 μm or less. The thing which only resolved what exceeded (triangle | delta) and 4 micrometers was set to x.

(Remaining film properties during development)
The ratio b / a between the film thickness a immediately after coating and pre-baking each photoresist composition and the film thickness b after development is 0.95 ≦ b / a, 0.90 ≦ b / a <0. .95 is Δ, and b / a <0.90 is ×.

(Crack generation due to thermal shock)
Immediately after applying and pre-baking each of the above photoresist compositions, the case where cracks occurred on the surface of the coating film when quenched to 23 ° C. was evaluated as x, and the case where cracks were not formed was evaluated as ◯.

(Crack generation during gold plating)
After developing the resist pattern as described above, a plating process was performed at 65 ° C. for 40 minutes by an electrolytic plating method using a non-cyanide gold sulfite plating solution. After the plating treatment, the case where no crack was generated around the resist pattern was indicated by ◯, the case where a crack occurred only around the periphery was indicated by Δ, and the case where the generated crack was straddled between adjacent patterns was indicated by ×.

(Wrinkle)
About each said photoresist composition, as described in said (pattern shape), after developing a resist pattern, the resist pattern was observed with the optical microscope. At this time, the case where no wrinkle was generated was marked with ◯, and the case where wrinkles were partially generated was marked with x.

  The resolution, the remaining film property during development, and the crack during gold plating in Comparative Example 4 could not be evaluated because the pattern was broken by wrinkles.

  As shown in Table 2, in the positive photoresist composition using resin A (Example 1), the occurrence of cracks is suppressed compared to the positive photoresist composition using resin B (Comparative Example 1). I understand that It can be seen that cracking is more strongly suppressed when a plasticizer is further added to the resin A (Example 2). On the other hand, the suppression of the occurrence of cracks can also be achieved by adding a plasticizer to the resin B (Comparative Examples 2 and 3). In this case, however, a larger amount of addition is required than when the resin A is used. Therefore, it can be seen that there is an adverse effect on the pattern shape, resolution, and residual film formation during development.

  Further, in Example 1, no wrinkles were generated in the resist film on the peripheral edge of the wafer. However, in Comparative Example 4, a pattern could not be formed because wrinkles were generated. In Example 1, since it is possible to form a pattern on the entire wafer including the peripheral edge of the wafer, it is possible to improve chip production efficiency per wafer.

Claims (7)

The following general formula (a-1)

[In the formula (a-1), R ¹ represents the following general formula (a-2)

(In formula (a-2), Ra and Rb each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, x represents an integer of 3 to 7, and y represents an integer of 1 to 50. .)
R ² represents a hydrogen atom, a hydroxyl group, or an alkyl group having 1 to 4 carbon atoms, and m represents an integer of 1 to 3. ]
And a structural unit (a1) represented by the following general formula (a-3)

[In Formula (a-3), R ³ represents a hydrogen atom, a hydroxyl group, or an alkyl group having 1 to 4 carbon atoms, and n represents an integer of 1 to 3. ]
A photoresist composition comprising an alkali-soluble novolak resin (A) having a structural unit (a2) represented by formula (A2) and a photosensitizer (B). The following general formula (a-1)

[In the formula (a-1), R ¹ represents the following general formula (a-2)

(In formula (a-2), Ra and Rb each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, x represents an integer of 3 to 7, and y represents an integer of 1 to 50. .)
R ² represents a hydrogen atom, a hydroxyl group, or an alkyl group having 1 to 4 carbon atoms, and m represents an integer of 1 to 3. ]
And a structural unit (a1) represented by the following general formula (a-3)

[In Formula (a-3), R ³ represents a hydrogen atom, a hydroxyl group, or an alkyl group having 1 to 4 carbon atoms, and n represents an integer of 1 to 3. ]
An alkali-soluble novolak resin (A ′) having a structural unit (a2) represented by the formula: wherein a part of hydrogen atoms of a hydroxyl group contained in the resin is substituted with a 1,2-naphthoquinonediazidosulfonyl group A photoresist composition comprising:   The photoresist composition according to claim 2, further comprising a photosensitizer (B). The R ¹ is the following general formula (a-4)

[In the formula (a-4), Rc represents an “alkylene group” or “cycloalkylene group” having 3 to 12 carbon atoms or an “alkylene group having a cycloalkylene group in the main chain” having 4 to 12 carbon atoms. ]
The photoresist composition according to any one of claims 1 to 3, which is a substituent represented by the following formula.   The photoresist composition according to any one of claims 1 to 4, wherein Rc has a hydroxyl group at the α-position of carbon bonded to the oxygen atom of the hydroxyl group of the structural unit (a1). The R ¹ is the following general formula (a-5)

[In formula (a-5), Rd represents an alkylene group having 1 to 6 carbon atoms. ]
The photoresist composition according to claim 4 or 5, which is a substituent represented by the formula:   A pattern forming method comprising applying the photoresist composition according to claim 1 onto a substrate, pre-baking, selectively exposing, and then performing alkali development to form a resist pattern.