KR20050085257A - Positive type photoresist composition for lcd production and method of forming resist pattern - Google Patents

Abstract

A positive type photoresist composition for LCD production, characterized by comprising (A) an alkali-soluble resin ingredient comprising an alkali-soluble novolak resin synthesized by the condensation of one or more phenols comprising 3,4-xylenol with an aldehyde, (B) an esterified naphthoquinonediazide, (C) a compound containing a phenolic hydroxy group and having a molecular weight of 1, 000 or lower, and (D) an organic solvent; and a process for producing a resist pattern. With the composition, satisfactory resolution can be attained even under low-NA conditions. The composition has excellent linearity even under low-NA conditions and is hence suitable for use in producing system LCDs.

Description

Formation method of positive type photoresist composition for resist manufacture and resist pattern {POSITIVE TYPE PHOTORESIST COMPOSITION FOR LCD PRODUCTION AND METHOD OF FORMING RESIST PATTERN}

The present invention relates to a method of forming a positive photoresist composition and a resist pattern for LCD production.

In addition, this application is based on Japanese Patent Application No. 2002-355365, The content shall be inserted here.

Until now, in manufacturing a liquid crystal display device (LCD) for forming a liquid crystal display portion on a glass substrate, it is relatively inexpensive, and in that it is possible to form a resist pattern excellent in sensitivity, resolution and shape. The positive type photoresist material which consists of a system of the novolak resin-quinonediazide group containing compound currently used for is used.

However, for example, in the manufacture of a semiconductor device, a disc-shaped silicon wafer having a maximum diameter of 8 inches (about 200 mm) to 12 inches (about 300 mm) is used, but in manufacturing LCDs, at least 360 mm × A rectangular glass substrate of about 460 mm is used.

As described above, in the field of LCD manufacturing, the substrate to which the resist material is applied is, of course, different in material and shape, but in terms of its size, it is significantly different from that used in the manufacture of semiconductor devices.

For this reason, the resist material for LCD manufacture is calculated | required that the resist pattern with favorable shape and dimensional stability etc. can be formed with respect to the whole board | substrate whole surface.

In addition, since a very large amount of resist material is consumed in the manufacture of LCDs, in addition to the above-described characteristics, inexpensive ones are also desired for resist materials for LCD manufacture.

There are many reports as a resist material for LCD manufacture so far (for example, following patent documents 1-6). The resist materials described in Patent Literatures 1 to 6 are inexpensive and can form resist patterns excellent in coating properties, sensitivity, resolution, shape and dimensional stability, for example, on small substrates of about 360 mm × 460 mm. . Therefore, it can use preferably for the purpose of manufacturing a comparatively small LCD.

[Patent Document 1]

Japanese Laid-Open Patent Publication No. 9-160231

[Patent Document 2]

Japanese Patent Laid-Open No. 9-211855

[Patent Document 3]

Japanese Unexamined Patent Publication No. 2000-112120

[Patent Document 4]

Japanese Unexamined Patent Publication No. 2000-131835

[Patent Document 5]

Japanese Laid-Open Patent Publication 2000-181055

[Patent Document 6]

JP 2001-75272 A

However, in recent years, the demand for large-sized LCDs is increasing compared with the past due to the enlargement of the display of a PC, the spread of the liquid crystal television, etc. In addition, lower cost is also required, and improvement in manufacturing efficiency of LCDs is required.

Therefore, in the LCD manufacturing field, it is desired to make the exposure area as wide as possible at least 100 mm 2 from the viewpoint of improving throughput (processing amount per unit time). In addition, in glass substrates with larger unevenness than silicon wafers, it is very difficult to maintain the planar uniformity of the resist film within a wide exposure range, and therefore, it is desired to have a large depth of focus (DOF). Therefore, in general, as for the manufacture of LCDs, it is desirable to use an exposure process with a NA condition in which NA (the numerical aperture of the lens) is, for example, 0.3 or less, in particular, 0.2 or less.

However, in the case of using an exposure process with a low NA condition, in a resist material for producing conventional LCDs, it is difficult to form a resist pattern having excellent shape at high resolution, for example, under a low NA condition of 0.3 or less.

In other words, in general, the resolution (resolution limit) is a Rayleigh equation expressed by the following equation:

R = k ₁ × λ / NA

[Wherein R is a resolution limit, k ₁ is a proportional constant determined by a resist or process, an image forming method, λ is a wavelength of light used in the exposure process, and NA is a numerical aperture of the lens]

Is displayed. Therefore, the resolution can be raised by using a light source having a short wavelength [lambda] or by using a high NA exposure process. For example, instead of the g line (436 nm) exposure used in the manufacture of conventional LCDs, the resolution can be increased by using photolithography techniques using shorter wavelength i line (365 nm) exposure.

However, in manufacture of LCD, as mentioned above, high NA which narrows an exposure area and becomes small in depth of focus is not preferable, and it was desired to use the exposure process in low NA conditions. Therefore, it was difficult to obtain high resolution.

In addition, even if a high-resolution resist pattern, that is, a fine resist pattern is obtained, the finer the pattern dimension, the more the depth of focus characteristic tends to deteriorate remarkably. Therefore, it is difficult to form a fine resist pattern with a good depth of focus characteristic. It was.

Also, as a next-generation LCD, so-called "system LCD" in which integrated circuit parts such as a driver, a digital-to-analog converter (DAC), an image processor, a video controller, and a RAM are simultaneously formed on a single glass substrate together with the display part. The technology development for high performance LCD called "Semiconductor FPD World 2001.9, pp.50-67) is being actively performed.

In this case, since the integrated circuit portion is also formed on the substrate in addition to the display portion, the substrate tends to be further enlarged. Therefore, exposure at lower NA conditions is preferable than in the case of normal LCD production.

Moreover, in the system LCD which concerns on this, although the pattern dimension of a display part is about 2-10 micrometers, the integrated circuit part is formed in the fine dimension about 0.5-2.0 micrometers, for example. Therefore, under the same exposure conditions, it is preferable to simultaneously form the display portion and the integrated circuit portion having different pattern dimensions, and they are exposed under the same linearity conditions (the same exposure conditions (the same amount of exposure but different mask dimensions on the reticle). In this case, a resist material having a higher resolution than that of a conventional LCD material resist material having excellent characteristics of accurately reproducing resist patterns corresponding to other mask dimensions on a reticle is desired.

However, as mentioned above, since the resist material for conventional LCD manufacture is difficult to form in high resolution under low NA conditions, it is difficult to use it for manufacture of a system LCD. For example, under low NA conditions of 0.3 or less, it is difficult to form a fine resist pattern that is excellent in shape, for example, 2.0 μm or less, and the resulting resist pattern tends to have a taper shape instead of a rectangle, and has a depth of focus width. Properties also deteriorated.

Specifically, the said patent document 6 (Unexamined-Japanese-Patent No. 2001-75272) describes the liquid crystal resist which contains alkali-soluble resin and the photosensitive component, and does not contain a sensitizer, for example.

However, this liquid crystal resist is not suitable for i line | wire exposure, and formation of the resist pattern of 2.0 micrometers or less required for manufacture of system LCD was difficult, and there existed a problem, such as lack of lineality.

Therefore, in the manufacturing process of a system LCD, the resist material which is good in lineality and which can form the fine resist pattern excellent in a shape even under low NA conditions of 0.3 or less, for example was desired.

FIG. 1 is a view illustrating a developer having a positive photoresist composition applied to a glass substrate, baked, dried, pattern exposed, and subjected to a pattern exposure for evaluation of the linearity under low NA conditions. It is explanatory drawing to put liquid over.

Best Mode for Carrying Out the Invention

[Positive Photoresist Composition for LCD]

<(A) component>

(A) component is alkali-soluble resin component containing alkali-soluble novolak resin which can be synthesize | combined by the condensation reaction of phenols and aldehydes containing 3, 4- xylenol.

In the above phenols, novolak resins suitable for the adjustment of the resist material for LCD production, which are excellent in resolution in low NA conditions, can be obtained by using 3,4-xylenol.

And the novolak resin which is excellent in lineality and suitable for the resist material for system LCD can be obtained.

Moreover, the effect that heat resistance is also favorable is acquired. In the positive photoresist composition, if the heat resistance is good, since the dimensional change rate of the resist pattern after the heat treatment step is small, it is suitable for LCD, and the rectangular shape of the resist pattern is good for integrated circuit formation. Suitable for

Moreover, the effect that there is little scum after a resist pattern formation is also acquired.

The lower limit is 5 mol% or more, preferably 7 mol% or more, and the upper limit is 40 mol% or less, preferably 30 mol% or less, more preferably 20 mol%. It becomes as follows. By setting it as more than a lower limit, a favorable effect is acquired. Moreover, although content of 3, 4- xylenol in phenols may be 100 mol%, since there exists a possibility that a sensitivity may fall when there is much compounding quantity of 3, 4- xylenol, it is preferable that it is below the said upper limit.

In the said phenols, what can be used other than 3, 4- xylenol can be arbitrarily selected 1 type, or 2 or more types from what is used as a material of the novolak resin for positive type photoresist compositions. have. For example, phenols, such as m-cresol, p-cresol, xylenol other than 3, 4- xylenol, and trimethyl phenol, are mentioned, and m-cresol is especially preferable at the point of a sensitivity improvement.

In the positive type photoresist composition for LCD, it is said that the sensitivity of about 50 mJ is preferable in terms of manufacturing efficiency improvement, throughput, etc., and when m-cresol is used together, it can be easily obtained.

In addition, when combining phenols other than 3, 4- xylenol and 3, 4- xylenol, content of 3, 4- xylenol is 5-30 mol%, Preferably it is 7-20 mol%. If desired, the effect added by phenols other than 3,4-xylenol can also be exhibited while maintaining the effect of 3,4-xylenol.

By using more than a lower limit, it is effective at the resolution and lineality under low NA conditions. Moreover, heat resistance is also improved and it is preferable also from the viewpoint of suppression of scum generation. It is preferable at the point of sensitivity by using below an upper limit.

For example, as mentioned above, when combining 3, 4- xylenol, m-cresol, and other phenols as needed as mentioned later, content of 3, 4- xylenol is made into the said ratio. Thereby, the thing with the characteristic which can suppress generation | occurrence | production of scum can also be provided with high resolution, high heat resistance, and high sensitivity under low NA conditions. It can also provide excellent lineality.

At this time, the ratio of m-cresol in the phenols is preferably 95 to 40 mol%, preferably 93 to 60 mol% in view of sensitivity. Since the sensitivity improves by setting it as 40 mol% or more, and the compounding quantity of 3, 4- xylenol can also be ensured by setting it as 95 mol% or less, it is preferable at the point of resolution, lineality, etc.

In addition, as described above, other phenols other than 3,4-xylenol and m-cresol may be used, if necessary, and other phenols may be used together with 3,4-xylenol and m-cresol. In this case, 0 to 30 mol% (that is, whether or not other phenols are used), preferably 5 to 20 mol%, among the phenols is preferable in view of resolution, linearity characteristics and sensitivity.

As aldehydes, as long as it is generally used for the synthesis | combination of the novolak resin for positive photoresist compositions, 1 type, or 2 or more types can be arbitrarily selected and used without a restriction | limiting. Examples include acetaldehyde, propionaldehyde, silylaldehyde, formaldehyde, formaldehyde precursor, 2-hydroxybenzaldehyde, 3-hydroxybenzaldehyde, 4-hydroxybenzaldehyde, and the like. Aldehyde and formaldehyde are preferable, and it is especially preferable to combine both.

When using propionaldehyde, when 5 mol% or more, preferably 15 mol% or more of aldehydes are used, it is preferable at the point that resolution is favorable and a rectangular resist pattern tends to be obtained.

In the case of using formaldehyde, at least 50 mol%, preferably at least 60 mol% of the aldehydes is preferable in view of sensitivity.

When using a combination of propionaldehyde and formaldehyde, the molar ratio of propionaldehyde to formaldehyde is preferably 10:90 to 30:70, preferably 25:75. By setting it in this range, the effect of a high sensitivity, a high resolution, and high heat resistance is acquired.

Here, if the especially preferable aspect of the said alkali-soluble novolak resin which is essential in this invention is put together, it becomes as follows.

That is, it is preferable to contain alkali-soluble novolak resin which can be synthesize | combined using the phenols containing 3, 4- xylenol and m-cresol.

In addition, alkalis which can be synthesized using phenols containing 5 to 30 mol% of 3,4-xylenol, 95 to 40 mol% of m-cresol, and 0 to 30 mol% of other phenols (other phenols are optional). It is preferable to contain a soluble novolak resin.

Moreover, it is preferable to contain alkali-soluble novolak resin which can be synthesize | combined as said aldehydes using the aldehyde containing one or both (preferably both) of propionaldehyde and formaldehyde.

Thus, most preferred are alkali-soluble novolac resins which can be synthesized using phenols containing 3,4-xylenol and m-cresol and aldehydes containing propionaldehyde and formaldehyde.

At this time, it is more preferable to satisfy the conditions of 5 to 30 mol% of 3,4-xylenol, 95 to 40 mol% of m-cresol, and 0 to 30 mol% of other phenols among phenols.

The alkali-soluble novolak resin can be synthesized by, for example, condensation reaction of phenols and aldehydes in the presence of an acid catalyst according to a conventional method.

The molar ratio of phenols and aldehydes is, for example, 1: 0.5 to 1: 0.95, preferably 1: 0.6 to 1: 0.9.

The mass average molecular weight (Mw) of the alkali-soluble novolac resin is 3000 to 30000, preferably 4000 to 20000 in terms of polystyrene by GPC (gel permeation chromatography) in terms of applicability and heat resistance.

Moreover, the said alkali-soluble novolak resin can be used 1 type or in combination of 2 or more types.

In addition, in this invention, you may mix | blend other alkali-soluble resin other than essential alkali-soluble novolak resin to (A) component.

The compounding quantity of another alkali-soluble resin becomes 50 mass% or less in the (A) component, Preferably it becomes 30 mass% or less (The lower limit is although it does not specifically limit, 0 mass% may be sufficient). If it is in a range, there is no possibility that it may inhibit the effect of the said essential alkali-soluble novolak resin, and it is preferable.

In addition to the essential alkali-soluble novolac resin, the compoundable alkali-soluble resin can be used without particular limitation as long as it is an alkali-soluble resin generally used in a positive photoresist composition. Hydroxystyrene resins such as homopolymers of hydroxystyrene, copolymers of hydroxystyrene and other styrene monomers, copolymers of hydroxystyrene and acrylic acid or methacrylic acid or derivatives thereof; Acrylic acid or methacrylic acid resin which is a copolymer of acrylic acid or methacrylic acid, and its derivative (s) is mentioned.

<(B) component>

(B) component is a naphthoquinone diazide ester compound.

Generally, (B) component can be used arbitrarily selecting 1 type, or 2 or more types, without a restriction | limiting as long as it is used as a photosensitive component in positive type photoresist composition.

Among them, the following general formula (I)

[Wherein, R ¹ to R ⁸ each independently represent 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 cycloalkyl group having 3 to 6 carbon atoms; R ¹⁰ and R ¹¹ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; When R ⁹ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, Q ¹ is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a residue represented by the following general formula (II):

Wherein R ¹² and R ¹³ each independently represent 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 cycloalkyl group having 3 to 6 carbon atoms; represents an integer of 1 to 3) and, if Q ¹ is coupled with the terminal of R ⁹ is, Q ¹ is and R ^9, Q ¹ and together with the carbon atom between R ^9, cycloalkyl of 3 to 6 carbon chain, Represents; a and b represent the integer of 1-3; d represents an integer of 0 to 3; n represents an integer of 0 to 3]

The ester compound of the phenol compound and the naphthoquinone diazide sulfonic acid compound which are represented by is suitable for photolithography using the i-line, and is desired to form a fine resist pattern of 2.0 μm or less under low NA conditions in a good shape. Do. That is, it is preferable in terms of high resolution and also in terms of lineality.

In addition, when forming a C3-C6 cycloalkyl group with the carbon atom between Q <^1> and R <^9> and Q <^1> and R <^9> , Q <^1> and R <^9> couple | bonds and it is C2-C5 alkyl. Forming a Ren group.

Phenolic compounds corresponding to the general formula include 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-hydroxyphenylmethane, bis (4-hydroxy Hydroxy-3,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, bis (4-hydroxy 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- Trisphenol-type compounds such as methylphenyl) -2-hydroxyphenylmethane and bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -3,4-dihydroxyphenylmethane;

2,4-bis (3,5-dimethyl-4-hydroxybenzyl) -5-hydroxyphenol, 2,6-bis (2,5-dimethyl-4-hydroxybenzyl) -4-methylphenol Linear trinuclear phenol 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- Hydroxy-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, bis [2,5-dimethyl Linear tetranuclear phenol compounds such as 3- (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-hydroxy Hydroxybenzyl) -5-methylbenzyl] -6-cyclohexylphenol, 2,6-bis [2,5-dimethyl-3- (2-hydroxy-5-methylbenzyl) -4-hydroxybenzyl] -4 Linear polyphenol compounds such as linear pentanuclear phenol compounds such as -methyl phenol;

Bis (2,3,4-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-tri Hydroxyphenyl) -2- (4'-hydroxyphenyl) propane, 2- (2,3,4-trihydroxyphenyl) -2- (4'-hydroxy-3 ', 5'-dimethylphenyl) Bisphenol-type compounds such as propane;

 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene, 1- [1- (3-methyl-4-hydroxyphenyl Multinuclear branched compounds such as) isopropyl] -4- [1,1-bis (3-methyl-4-hydroxyphenyl) ethyl] benzene;

Condensation type phenol compounds, such as 1, 1-bis (4-hydroxyphenyl) cyclohexane, etc. are mentioned.

These can be used 1 type or in combination or 2 or more types.

Among them, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -3,4-dihydroxyphenylmethane (hereinafter abbreviated as (B1 ')] and bis (2,4-dihydroxyphenyl) Methane [hereinafter abbreviated as (B2 ')], bis (4-hydroxy-2,3,5-trimethylphenyl) -2-hydroxyphenylmethane [hereinafter abbreviated as (B3')] Photoresist compositions containing one or more (preferably three of these) naphthoquinone diazide ester compounds of phenolic compounds are preferable in that they can form a resist pattern with high sensitivity, high resolution, and good shape. Do.

In addition, each naphthoquinone diazide esterified product of the said (B1 '), (B2'), (B3 ') is abbreviated as (B1), (B2), (B3).

When using (B1), (B2) or (B3), the compounding quantity in (B) component is more preferable in it being 10 mass% or more and 15 mass% or more, respectively.

In addition, in the case of using all of (B1), (B2), and (B3), each compounding quantity is 50-90 mass% of (B1), Preferably it is 60-80 mass%, (B2) from the viewpoint of an effect. The compounding quantity of 5-20 mass%, Preferably it is 10-15 mass%, The compounding quantity of (B3) becomes 5-20 mass%, Preferably it is 10-15 mass%.

The naphthoquinone diazide sulfonic-acid esterification method of all or one part of the phenolic hydroxyl group of the compound represented by the said General formula (I) can be used by a conventional method.

For example, it can obtain by condensing naphthoquinone diazide sulfonyl chloride with the compound represented by the said General formula (I).

Specifically, For example, the compound represented by said general formula (I), and naphthoquinone- 1, 2- diazide- 4 (or 5) -sulfonyl chloride are dioxane and n-methylpyrrolidone. , A predetermined amount is dissolved in an organic solvent such as dimethylacetamide, tetrahydrofuran, and at least one basic catalyst such as triethylamine, triethanolamine, pyridine, alkali carbonate and alkali hydrogen carbonate is added thereto to react. It can be prepared by washing with water and drying.

As (B) component, as mentioned above, in addition to these illustrated preferable naphthoquinone diazide ester compound, other naphthoquinone diazide ester compound can also be used. For example, esterification products of phenol compounds such as polyhydroxybenzophenone and alkyl gallate and naphthoquinone diazide sulfonic acid compounds may be used.

It is preferable that the usage-amount of these other naphthoquinone diazide ester compounds is 80 mass% or less, especially 50 mass% or less in (B) component from the point of the improvement of the effect of this invention.

The compounding quantity of (B) component in a photoresist composition becomes 20-70 mass% with respect to the total amount of (A) component and the following (C) component, Preferably it is 25-60 mass%.

By making the compounding quantity of (B) component more than the said lower limit, the image faithful to a pattern is obtained and transferability improves. Deterioration of a sensitivity can be prevented by using below the said upper limit, the homogeneity of the formed resist film improves, and the effect that resolution is improved is acquired.

<(C) component>

(C) component is a phenolic hydroxyl group containing compound. By using this component (C), a system having excellent sensitivity improving effect, high sensitivity, high resolution, and a material suitable for the manufacture of an LCD even in the i-ray exposure process under low NA conditions, more preferably, excellent in lineality A material suitable for the LCD is obtained.

The molecular weight of the component (C) is preferably 1000 or less, preferably 700 or less, substantially 200 or more, and preferably 300 or more, in view of the above effects.

(C) As a component, it is a phenolic hydroxyl group containing compound generally used for a photoresist composition, Preferably, if it satisfy | fills the conditions of the said molecular weight, there will be no restriction | limiting in particular, One or two or more types can be arbitrarily selected and used. have. And especially, the following general formula (III)

[Wherein, R ¹¹ to R ¹⁸ each independently represent 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 cycloalkyl group having 3 to 6 carbon atoms; R ²⁰ and R ²¹ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; When R <^19> is a hydrogen atom or a C1-C6 alkyl group, Q <^2> is a hydrogen atom, a C1-C6 alkyl group, or the residue represented by following General formula (IV)

Wherein R ²² and R ²³ each independently represent 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 cycloalkyl group having 3 to 6 carbon atoms; represents an integer of 1 to 3) and, in the case where Q ² is coupled with the terminal of R ^19, R ¹⁹ and Q ² is, together with the carbon atoms between Q ² and R ^19, a cycloalkyl group of 3 to 6 carbon chain, Represents; e and f represent the integer of 1-3; h represents an integer of 0 to 3; n represents an integer of 0 to 3]

The phenolic compound represented by this shows the said characteristic well, and it is preferable.

Specifically, for example, the phenol compound used in the naphthoquinone diazide esterified product of the phenol compound exemplified in the component (B) can be preferably used, and among them, 1- [1- (4- Preference is given to hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene.

The compounding quantity of (C) component is 10-70 mass% with respect to (A) component from a viewpoint of an effect, Preferably it becomes the range of 20-60 mass%.

<(D) component>

The component (D) may be one or two or more kinds selected without particular limitation as long as it is a general one used in the photoresist composition, and the one containing propylene glycol monoalkyl ether acetate and / or 2-heptanone is applied. It is preferable at the point which is excellent in property and excellent in the film thickness uniformity of the resist film on a large glass substrate.

In addition, although both propylene glycol monoalkyl ether acetate and 2-heptanone can be used, respectively, when using independently or in mixture with another organic solvent is preferable at the point of the film thickness uniformity at the time of application | coating using a spin coat method etc. There are many.

It is preferable to contain 50-100 mass% of propylene glycol monoalkyl ether acetates in (D) component.

Propylene glycol monoalkyl ether acetate has, for example, a linear or branched alkyl group having 1 to 3 carbon atoms, and among these, propylene glycol monomethyl ether acetate (hereinafter sometimes abbreviated as PGMEA) is a large glass substrate. It is especially preferable because the film thickness uniformity of the resist film on the phase is very excellent.

Although 2-heptanone is not specifically limited, It is a preferable solvent when it combines with the non-benzophenone type photosensitive component as (B) naphthoquinone diazide ester compound as mentioned above.

2-heptanone is excellent in heat resistance compared with PGMEA, has the characteristic of providing the resist composition with reduced scum generation, and is a very preferable solvent.

Moreover, you may use it, mixing another solvent with these preferable solvents.

For example, when alkyl lactate, such as methyl lactate and ethyl lactate (preferably ethyl lactate), is mix | blended, it is preferable because it can form the resist pattern excellent in the film thickness uniformity of a resist film, and excellent in shape.

When using propylene glycol monoalkyl ether acetate and alkyl lactate, it is preferable to mix | blend 0.1-10 times, preferably 1-5 times the amount of alkyl lactate with respect to propylene glycol monoalkyl ether acetate.

Moreover, organic solvents, such as (gamma) -butyrolactone and a propylene glycol monobutyl ether, can also be used.

When using gamma -butyrolactone, it is preferable to mix | blend in the range of 0.01-1 time, preferably 0.05-0.5 time by mass ratio with respect to propylene glycol monoalkyl ether acetate.

Moreover, the following are mentioned specifically as an organic solvent which can be mix | blended other, for example.

Namely, ketones, such as acetone, methyl ethyl ketone, cyclohexanone, and methyl isoamyl ketone; Ethylene glycol, 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 thereof Polyhydric alcohols and derivatives thereof; Cyclic ethers such as dioxane; And esters such as methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate and ethyl ethoxypropionate.

When using these solvents, it is preferable that it is 50 mass% or less in (D) component.

In the positive photoresist composition of the present invention, additives, plasticizers, preservative stabilizers, etc., for improving the performance of a compatible additive, for example, a resist film, etc., as necessary, within a range that does not impair the object of the present invention, A common additive, such as surfactant, a coloring agent for making a developed image more visible, a sensitizer for improving a sensitization effect, a dye for antihalation, and an adhesive improvement agent, can be contained.

Anti-halation dyes include ultraviolet absorbers (e.g., 2,2 ', 4,4'-tetrahydroxybenzophenone, 4-dimethylamino-2', 4'-dihydroxybenzophenone, 5-amino-3 -Methyl-1-phenyl-4- (4-hydroxyphenylazo) pyrazole, 4-dimethylamino-4'-hydroxyazobenzene, 4-diethylamino-4'-ethoxyazobenzene, 4-diethylamino Azobenzene, curcumin, etc.) can be used.

Surfactant can be added, for example, for prevention of striation, etc. For example, Florade FC-430, FC431 (brand name, the Sumitomo 3M Corporation make), F-top EF122A, EF122B, EF122C, EF126 (brand name, Fluorine-based surfactants such as Tochem Products Co., Ltd., and R-08 (trade name, manufactured by Dainippon Ink and Chemicals, Inc.).

The positive photoresist composition of the present invention is preferably prepared by dissolving the component (A), the component (B), the component (C) and other components in the (D) organic solvent, if necessary.

Moreover, the usage-amount of (D) component, Preferably melt | dissolves (A)-(C) component and other components used as needed, and can adjust suitably so that a uniform positive photoresist composition may be obtained. Preferably it is used so that solid content concentration [(A)-(C) component and other components used as needed] may be 10-50 mass%, More preferably, it is 20-35 mass%.

[Formation method of resist pattern]

Below, an example of the preferable formation method of the resist pattern in manufacture of LCD is shown.

First, the positive type photoresist composition of this invention mentioned above is apply | coated to a board | substrate with a spinner etc., and a coating film is formed. As the substrate, a glass substrate is preferable. Amorphous silica is usually used as the glass substrate, and low temperature polysilicon is preferable in the field of system LCD. As the glass substrate, since the composition of the present invention is excellent in resolution under low NA conditions, a large substrate of 500 mm × 600 mm or more, particularly 550 mm × 650 mm or more can be used.

Subsequently, the glass substrate on which this coating film was formed is heat-processed (prebaked), for example at 100-140 degreeC, and residual solvent is removed and a resist film is formed. As a prebaking method, it is preferable to perform a proximity baking which makes the clearance gap between a hotplate and a board | substrate.

In addition, the resist film is subjected to selective exposure using a mask on which a mask pattern is drawn.

It is preferable to use i line (365 nm) as a light source in order to form a fine pattern. In addition, it is preferable that the exposure process employ | adopted by this exposure is an exposure process of NA NA of 0.3 or less, Preferably it is 0.2 or less, More preferably, it is low NA conditions of 0.15 or less. In the method of forming a resist pattern, in the case of manufacturing a system LCD, in the step of performing the selective exposure, a mask pattern for forming a resist pattern of 2.0 µm or less and a resist pattern for forming a resist pattern of more than 2.0 µm as the mask. It is preferable to use the mask in which both of the mask patterns were drawn.

Next, heat treatment (post exposure bake: PEB) is performed on the resist film after selective exposure. Examples of the PEB method include a proximity bake having a gap between the hot plate and the substrate and a direct bake without a gap. And in order to prevent a board | substrate from bending and to acquire the diffusion effect by PEB, the method of performing a direct bake after carrying out a proximity baking is preferable. Moreover, heating temperature is 90-140 degreeC, especially 110-130 degreeC is preferable.

With respect to the resist film after the PEB, a developing solution using, for example, an aqueous alkaline solution such as 1 to 10 mass% tetramethylammonium hydroxide (TMAH) aqueous solution is dissolved, and the exposed portion is dissolved and removed to form a resist pattern. . When using a mask in which both the resist pattern forming mask pattern of 2.0 μm or less and the mask pattern for resist pattern forming of more than 2.0 μm are drawn, a resist pattern for an integrated circuit and a resist pattern for a liquid crystal display portion on a substrate are used. This is formed at the same time.

The resist pattern can be formed by washing the developer remaining on the surface of the resist pattern with a rinse solution such as pure water.

And since the positive photoresist composition for LCDs of this invention is excellent in lineality, the resist pattern which faithfully reproduced both a rough pattern and a fine pattern of a mask pattern is obtained. Therefore, if the step of simultaneously forming a resist pattern using the mask on which both sides are drawn is performed, a resist pattern for an integrated circuit having a pattern dimension of 2.0 μm or less and a resist for a liquid crystal display portion of more than 2.0 μm are formed on the substrate. Patterns can be formed at the same time.

As described above, the positive photoresist composition of the present invention is suitable for an exposure process under low NA conditions. It is also suitable for the i line exposure process. Therefore, in manufacture of LCD, at least the resist pattern of a display part can be obtained with high resolution.

Moreover, since the positive photoresist composition of this invention is also excellent in the linearity under low NA conditions, a rough pattern and a fine pattern can be formed on one board | substrate under the same exposure conditions. Therefore, even under low NA conditions, the display portion of the system LCD and the resist pattern of the finer integrated circuit portion can be obtained at the same time with high resolution, and are suitable for the manufacture of the system LCD.

In addition, in the component (A), by using an alkali-soluble novolac resin containing 3,4-xylenol, the heat resistance is improved, and the residual film property after alkali development is improved. In addition, since the resolution is good, it is suitable for the system LCD.

Moreover, high sensitivity can also be implement | achieved preferably by the combination of phenols in essential soluble novolak resin.

It also has the effect of less scum being generated.

In addition, in the positive type photoresist composition for LCD, although the width | variety of the depth of focus is necessary to the point of manufacture efficiency, the controllability of manufacturing conditions, etc., the positive type photoresist composition for LCDs of this invention is required. Silver can realize the width (for example, 15 micrometers or more) of the depth of focus which is practical for LCD use.

In addition, good lineality is not equivalent to high-resolution characteristics, but in a positive resist composition, even if the resolution is good, the lineality may be poor.

On the other hand, the positive type photoresist composition for LCD of the present invention has a high resolution under low NA conditions (even when a large area is exposed, uniform and good resolution is obtained), and also has good linearity. In addition, it can be used suitably also as a positive type photoresist composition for general LCDs, and it is especially preferable for system LCDs.

Moreover, according to the resist pattern formation method of this invention using the said positive type photoresist composition excellent in the resolution under low NA conditions, the throughput in LCD manufacture is improved.

In addition, according to the method for forming a resist pattern of the present invention, a high-resolution resist pattern can be formed even in a low NA condition exposure process suitable for LCD production. In particular, since it is possible to simultaneously form, for example, a resist pattern for an integrated circuit having a pattern dimension of 2.0 µm or less and a resist pattern for a liquid crystal display portion larger than 2.0 µm, for example, on the substrate. It can be used preferably.

That is, the present invention is integrated on one substrate, which is excellent in lineality under low NA conditions, and at the same time obtains a resist pattern of a display portion of a system LCD and an integrated circuit portion finer than that in a good pattern shape at the same time. It is an object of the present invention to provide a method of forming a resist material and a resist pattern suitable for manufacturing an LCD in which circuits and liquid crystal display portions are formed.

In order to solve the said subject, the positive type photoresist composition for LCDs of this invention is alkali-soluble novolak resin which can be synthesize | combined by condensation reaction of the phenols and aldehydes containing (A) 3, 4- xylenol. Alkali-soluble resin component containing

(B) naphthoquinone diazide ester compound,

(C) a phenolic hydroxyl group containing compound whose molecular weight is 1000 or less,

(D) an organic solvent,

It is characterized by containing.

This positive photoresist composition for LCD is preferable as a positive photoresist composition for LCD for i line | wire exposure processes.

Moreover, NA is preferable as a positive photoresist composition for LCD for exposure processes of 0.3 or less.

Moreover, it is preferable as a positive type photoresist composition for LCD for LCD manufacture in which an integrated circuit and a liquid crystal display part were formed on one board | substrate.

In addition, in the description of the present invention, the term "system LCD" refers to "LCD having an integrated circuit and a liquid crystal display portion formed on one substrate".

In addition, the method of forming the resist pattern of the present invention,

(1) applying the positive photoresist composition of the present invention on a substrate to form a coating film,

(2) heat-processing (prebaking) the board | substrate with which the said coating film was formed, and forming a resist film on a board | substrate,

(3) a step of selectively exposing the resist film using a mask on which both a resist pattern forming mask pattern of 2.0 µm or less and a mask pattern for forming resist pattern of 2.0 µm or more are drawn;

(4) performing a heat treatment (post exposure bake) on the resist film after the selective exposure;

(5) The development process using aqueous alkali solution is performed with respect to the resist film after the said heat processing, On the said board | substrate, the resist pattern for integrated circuits with a pattern dimension of 2.0 micrometers or less, and the liquid crystal display part more than 2.0 micrometers Simultaneously forming a resist pattern,

(6) and a rinsing step of washing the developer remaining on the resist pattern surface.

Next, although an Example is shown and this invention is demonstrated in detail, this invention is not limited to a following example.

[Evaluation Method of Positive Photoresist Composition]

About the positive type photoresist composition of the following Example or a comparative example, the evaluation method of the following physical properties (1)-(5) is shown below.

(1) Lineality Evaluation:

The positive type photoresist composition was applied onto a glass substrate (550 mm x 650 mm) on which a Ti film was formed using a resist coating apparatus for large substrates (device name: TR36000 manufactured by Tokyo Kogyo Co., Ltd.), and then the temperature of the hot plate. Is 100 degreeC, the 1st drying for 90 second is performed by the proximity baking spaced about 1 mm, Then, the temperature of a hotplate is made 90 degreeC, and the proximity baking spaced 0.5 mm The 2nd drying for 90 second was performed and the resist film of 1.5 micrometers of film thicknesses was formed.

Subsequently, an i-line exposure apparatus (device name: FX-702J, manufactured by Nikon Corporation) through a test chart mask (reticle) in which a mask pattern for reproducing a resist pattern of 3.0 µm line and space (L & S) and a 1.5 µm L & S was simultaneously drawn. = 0.14), and selective exposure was performed with the exposure amount (Eop exposure amount) which can faithfully reproduce 3.0 micrometers L & S.

Subsequently, the temperature of the hot plate is set to 120 ° C., and 0.5 mm intervals are used to perform 30 seconds of heat treatment by proximity bake, followed by 60 seconds of heating by direct bake not spaced at the same temperature. Treatment was carried out.

Subsequently, a 23.degree. C., 2.38 mass% TMAH aqueous solution was used at the board | substrate edge part X as shown in FIG. 1 using the developing apparatus which has a slit coater nozzle (apparatus name: TD-39000 demonstration machine, the Tokyo Kogyo KK make). After passing through Y and over Z, the liquid was held on the substrate for 10 seconds, held for 55 seconds, washed with water for 30 seconds, and spin-dried.

Then, the cross-sectional shape of the obtained resist pattern was observed by SEM (scanning electron microscope) photograph, and the reproducibility of the resist pattern of 1.5 micrometer L & S was evaluated.

(2) Sensitivity evaluation:

The Eop exposure amount was used as an index of sensitivity evaluation.

(3) Resolution Evaluation:

The limit resolution in the said Eop exposure amount was calculated | required.

(4) DOF characteristic evaluation:

In the above Eop exposure amount, the focal point was properly shifted up and down, and the width of the depth of focus (DOF) obtained within a range of the dimensional change rate of 1.5 µm L & S was ± 10% was obtained in the unit of µm.

(5) Scum evaluation:

In the said Eop exposure amount, the surface of the board | substrate in which 1.5 micrometer L & S was drawn was observed by SEM, and the presence or absence of scum was investigated.

(6) heat resistance evaluation:

In the said Eop exposure amount, the board | substrate in which 1.5 micrometer L & S was drawn was left still for 300 second on the hotplate set to 140 degreeC, and was left still for 30 minutes in the oven set to 200 degreeC next. As a result, (circle) and what were more than 105%-110% or less of (circle) and what were more than 100% of 105 micrometers of dimensional change rate of 1.5 micrometers L & S were represented by x.

(Example 1)

The following were prepared as (A)-(D) component.

(A) 100 parts by mass of alkali-soluble novolak resin

A1: 1 mol of a mixed phenol of [m-cresol / 3,4-xyllen = 9/1 (molar ratio) and 0.86 mol of a mixed aldehyde of propionaldehyde / formaldehyde = 1/3 (molar ratio) are conventionally used. Novolac resin synthesized by the method of Mw = 4750 and Mw / Mn (dispersity) = 2.44]

(B) 40 mass parts of naphthoquinone diazide ester compounds

Naphthoquinone diazide ester compound which mixed B1 / B2 / B3 by 6/1/1 (mass ratio)

1 mole of B1: B1 'and 2 mole of 1,2-naphthoquinone diazide-5-sulfonic acid chloride (hereinafter referred to as "5-NQD")

B2: 1 mole of B2 'and 4 mole of 5-NQD esterification product

B3: 1 mole of B3 'and 2 moles of 5-NQD esterification product

(C) 25 mass parts of phenolic hydroxyl group containing compounds

C1: 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene

(D) organic solvent

D1: PGMEA

Surfactant (product name "R-08"; product made by Dainippon Ink and Chemicals, Inc.) of 450 ppm relative to the total mass of the components (A) to (C) and these (A) to (C) , Dissolved in PGMEA which is (D) component, and it adjusted so that solid content [the sum of (A)-(C) component] concentration may be 25-28 mass%, and this was filtered using the membrane filter of 0.2 micrometer of pore diameters, , Positive photoresist composition was prepared.

(Examples 2 to 6) and (Comparative Examples 1 to 5)

A positive photoresist composition was prepared in the same manner as in Example 1 except that the components (A) to (D) were changed to those shown in Table 1 below.

(A) (B) (mass ratio) (C) (D) Example One A1 B1 / B2 / B3 (6/1/1) C1 D1 2 A2 Same as above Same as above Same as above 3 A3 Same as above Same as above Same as above 4 A4 Same as above Same as above Same as above 5 A1 Same as above Same as above D2 6 Same as above Same as above Same as above D3 Comparative example One A5 Same as above Same as above D1 2 A6 Same as above Same as above Same as above 3 A7 Same as above Same as above Same as above 4 A8 Same as above Same as above Same as above 5 A1 Same as above C2 Same as above

In addition, A1, B1-3, C1, and D1 in Table 1 are as above-mentioned.

In addition, about component (B), B1 / B2 / B3 (6/1/1) shows that B1 / B2 / B3 was mixed and used by the mass ratio of 6/1/1 as mentioned above.

In addition, A2-8, C2, D2-3 are as follows.

A2: Conventional method using 1 mol of mixed phenols of m-cresol / 3,4-xylen = 97/3 (molar ratio) and 0.86 mol of mixed aldehyde of propionaldehyde / formaldehyde = 1/3 (molar ratio). Compounded by Mw = 7000, Mw / Mn = 3.5, novolac resin

A3: Conventional method using 1 mol of mixed phenols of m-cresol / 3,4-xyleneol = 6/4 (molar ratio) and 0.86 mol of mixed aldehyde of propionaldehyde / formaldehyde = 1/3 (molar ratio). Compounded by Mw = 4000, Mw / Mn = 2.5, novolac resin

A4: 1 mol of mixed phenols of m-cresol / 3,4-xylenol / 2,5-xylenol = 60/15/25 (molar ratio) and formaldehyde / salicyaldehyde = 4/1 (molar ratio) Novolak resin of Mw = 7000 and Mw / Mn = 3.5 synthesize | combined by the conventional method using 0.85 mol of mixed aldehydes of

A5: Mixed aldehyde of 1 mol of mixed phenols of m-cresol / p-cresol / 2,3,5-trimethylphenol = 45/35/25 (molar ratio) and formaldehyde / salicyaldehyde = 2/1 (molar ratio) Novolak resin of Mw = 5000 and Mw / Mn = 3.5 synthesize | combined by the conventional method using 0.85 mol.

A6: 1 mol of mixed phenols of m-cresol / p-cresol / 2,3,5-trimethylphenol = 90/5/5 (molar ratio) and formaldehyde / crotonaldehyde = 2/1 (molar ratio) 0.85 Novolak resin of Mw = 4000 and Mw / Mn = 3.05 synthesize | combined by the conventional method using mole.

A7: Novolak resin of Mw = 7050 and Mw / Mn = 3.5 synthesize | combined by the conventional method using 1 mol of m-cresols and 0.85 mol of formaldehyde.

A8: Mw synthesize | combined by the conventional method using 1 mol of mixed phenols of m-cresol / p-cresol / 2,3,5-trimethylphenol = 45/35/25 (molar ratio), and 0.85 mol of formaldehyde. Novolac resin of = 2500, Mw / Mn = 1.9

C2: novolac low molecular weight Mw = 1300 synthesized using m-cresol and formaldehyde

D2: 2-heptanone

D3: ethyl lactate

Linearity evaluation (μm) Sensitivity evaluation (mJ) Resolution Evaluation (㎛) DOF evaluation (μm) Scum Reviews Heat resistance rating Example One 1.5 40 1.3 More than 15 radish ○ 2 1.6 50 1.4 More than 15 radish ◎ 3 1.6 50 1.5 More than 15 radish ○ 4 1.5 40 1.4 More than 15 radish ◎ 5 1.5 60 1.3 More than 15 radish ○ 6 1.6 50 1.4 More than 15 radish ○ Comparative example One 1.5 60 1.3 10 U × 2 2.0 100 1.5 0 radish - 3 3.0 50 2.0 0 radish - 4 2.0 50 1.6 0 radish - 5 3.0 60 1.6 0 radish -

Positive type photoresist compositions for LCDs require high resolution under low NA conditions.

In addition, more linearity is required for system LCDs.

Heat resistance and sensitivity are commonly required for LCDs and system LCDs.

As is clear from the results shown in Table 2, all of the compositions of Examples 1 to 8 satisfied the conditions.

Also, no scum was generated, and the depth of focus (DOF) was also wide, which was satisfactory in this respect.

On the other hand, since the composition of Comparative Example 1 was different from that of the present invention in the component (A), the evaluation of the linearity, sensitivity, and resolution was good, but the occurrence of scum was observed.

Since the composition of the comparative example 2 differs from the thing of this invention (A) component, since the sensitivity is very slow at 100 mJ and the field of LCD manufacture which highly sensitive about 50 mJ is requested | required, it was a material which was remarkably difficult to employ | adopt.

Since the composition of Comparative Example 3 differs from that of the present invention in the component (A), the linearity was poor.

Since the composition of Comparative Example 4 differs from that of the present invention in the component (A), the linearity is poor and the depth of focus width (DOF) is also narrow.

In the positive photoresist composition for LCD and the method of manufacturing a resist pattern of the present invention, good resolution is obtained even under low NA conditions. In addition, it is preferable for the production of system LCDs in that it is also excellent in lineality under low NA conditions.

Claims (12)

(A) Alkali-soluble resin component containing alkali-soluble novolak resin which can be synthesize | combined by the condensation reaction of phenols and aldehydes containing 3, 4- xylenol, (B) naphthoquinone diazide ester compound, (C) a phenolic hydroxyl group containing compound whose molecular weight is 1000 or less, (D) an organic solvent, Positive type photoresist composition for LCD production, containing. The LCD for producing an LCD according to claim 1, wherein the alkali-soluble novolak resin contains an alkali-soluble novolak resin which can be synthesized using phenols containing 3,4-xylenol and m-cresol. Positive photoresist composition. The phenols according to claim 2, wherein the alkali-soluble novolac resin contains 5 to 30 mol% of 3,4-xyllenol, 95 to 40 mol% of m-cresol, and 0 to 30 mol% of other phenols. Positive type photoresist composition for LCD production, characterized in that the alkali-soluble novolak resin that can be synthesized by. The positive type photoresist composition for LCD production according to claim 1, wherein the alkali-soluble novolac resin is an alkali-soluble novolac resin which can be synthesized using aldehydes containing propionaldehyde and formaldehyde. The positive type photoresist composition for LCD production according to claim 1, wherein the content of propylene glycol monoalkyl ether acetate in the component (D) is 50 to 100% by mass. The positive type photoresist composition for LCD production according to claim 1, wherein the content of 2-heptanone in the component (D) is 50 to 100% by mass. The positive type photoresist composition for manufacturing an LCD according to claim 1, which is for an i-ray exposure process. The positive type photoresist composition for LCD production according to claim 1, wherein NA is for an exposure process of 0.3 or less. The positive type photoresist composition according to claim 1, which is for manufacturing an LCD in which an integrated circuit and a liquid crystal display portion are formed on one substrate. (1) Process of apply | coating positive type photoresist composition of Claim 1 on a board | substrate, and forming a coating film, (2) heat-processing (prebaking) the board | substrate with which the said coating film was formed, and forming a resist film on a board | substrate, (3) a step of selectively exposing the resist film using a mask on which both a resist pattern forming mask pattern of 2.0 µm or less and a mask pattern for forming resist pattern of 2.0 µm or more are drawn; (4) performing a heat treatment (post exposure bake) on the resist film after the selective exposure; (5) The development process using aqueous alkali solution is performed with respect to the resist film after the said heat processing, On the said board | substrate, the resist pattern for integrated circuits with a pattern dimension of 2.0 micrometers or less, and the liquid crystal display part more than 2.0 micrometers Simultaneously forming a resist pattern, (6) Rinse step of washing the developer remaining on the resist pattern surface Forming a resist pattern, characterized in that it comprises a. The method of forming a resist pattern according to claim 10, wherein the step (3) of performing selective exposure is performed by an exposure process using i line as a light source. The method of forming a resist pattern according to claim 10, wherein the step (3) of performing selective exposure is performed by an exposure process under low NA conditions of NA of 0.3 or less.