JPH0255359A - Positive type photoresist composition - Google Patents

Abstract

PURPOSE:To enhance the sensitivity of the compsn. and the adhesive property to a base and to lower a residual film rate by using an alkaline soluble resin consisting of specific two kinds of novolak resins. CONSTITUTION:A mixture composed of the metacresol novolak resin (A1) and orthocresol novolak resin (A2) is used for the component A of the compsn. consisting of the alkaline soluble resin (A) and 1,2-quinonediazide compd. (B). The mixing ratio of the components A1 and A2 is preferably 60:40-40:60 by weight. The weight average mol. wt. of the component A1 is preferably 8,000-18,000 and the weight average mol. wt. of the component A2 is 2,000-4,000. The mixing ratio of the components A and B is preferably 80:20-65:35 by weight. This compsn. is preferably used as a resist for ultrafine processing or for lithographic printing plates.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable as a resist for ultrafine processing used in the production of elements such as ICs and LSIs, and as a photosensitive material used in the production of lithographic printing plates. The present invention relates to possible positive photoresist compositions.

[Conventional technology]

Conventionally, attempts have been made to improve the alkaline earth metal fat used in positive photoresist compositions in order to improve the sensitivity, residual film rate, resolution, etc. of positive photoresist compositions.

For example, as the alkali-soluble resin, US Pat.
Novolac resins obtained by condensing a mixture of o-cresol, m-cresol and p-cresol with formaldehyde are proposed in Japanese Patent Application Laid-open No. 529682 and Japanese Patent Application Laid-Open No. 17112/1982. JP-A-60-1
No. 58440 proposes a resin obtained by condensing a mixture of m-cresol, p-cresol and 2,5-xylenol with formaldehyde. JP-A-60-159846 proposes a novolac resin obtained by condensing a mixture of m-cresol and p-cresol with formaldehyde. JP-A-60-176034 proposes a novolac resin obtained by condensing a mixture of m-cresol and 3,5-xylenol with formaldehyde.

However, positive photoresist compositions containing these Noblak resins are not fully satisfactory in terms of sensitivity and residual film rate, and in particular, an aqueous solution of an inorganic alkali such as sodium hydroxide or potassium hydroxide is used as an alkaline developer. When using this method, both sensitivity and residual film rate were insufficient.

In order to improve the sensitivity of a positive photoresist composition consisting of a 1.2-quinone diazide compound and a novolak resin, the molecular weight of the novolak resin is reduced, and 1,2-
Methods such as lowering the amount of the quinonediazide compound added are known.

However, when such a method is used, the alkali solubility of the positive photoresist composition is good, and the sensitivity is improved, but the residual film rate is reduced and the resulting resist pattern falls off from the support. It becomes easier.

Conversely, if the molecular weight of the novolac resin is increased in order to improve the residual film rate of a positive photoresist composition, the alkali solubility will deteriorate and the sensitivity will decrease.

[Problem to be solved by the invention]

The problem to be solved by the present invention is to provide a positive photoresist composition that has excellent sensitivity, residual film rate, and adhesion to a support.

[Means to solve the problem]

In order to solve the above problems, the present invention provides a positive photoresist composition comprising an alkali-soluble resin and a 1,2-quinonediazide compound, in which the alkali-soluble resin is a resin mixture comprising a meta-cresol tumerac resin and an ortho-cresol novolak resin. Certain positive photoresist compositions are provided.

The metacresol novolak resin and orthocresol novolak resin used in the present invention contain 1 to 10% formaldehyde per mole of metacresol or orthocresol.
It is obtained by mixing each at a ratio of 1.2 mol and condensing each in a conventional manner in the presence of an acid catalyst such as shiulic acid.

Weight average molecular weight (polystyrene equivalent value, the same shall apply hereinafter) of the metacresol novolak resin used in the present invention.
(hereinafter abbreviated as hen) is s, ooo ~ 18,000
A range of 0 is preferred.

For the orthocresol novolac resin used in the present invention, the range is preferably from 2,000 to 4,000.

If the ratio of meta-cresol novolac resin is greater than 18,000, or if the ratio of ortho-cresol novolac resin is greater than 4,000, the solubility in alkaline developer decreases, and the sensitivity of the positive photoresist composition decreases. This is not desirable because it tends to

The section on meta-cresol novolac resin is s, oo.

If the Mw of the orthocresol novolak resin is too small, or if the Mw of the orthocresol novolac resin is less than 2,000, it becomes easily soluble in an alkaline developer and the residual film rate of the positive photoresist composition tends to decrease, which is not preferable. Furthermore, in order to prevent the tendency of the residual film ratio to decrease, it is necessary to lower the alkaline concentration of the alkaline developer, which is not preferable because the life of the alkaline developer is shortened.

The mixing ratio of meta-cresol tumerac resin and ortho-cresol novolac resin is not particularly limited, but in order to fully exhibit the effects of the present invention, the mixing ratio is 40% by weight.
:60 to 60:40 is preferable.

If the proportion of the metacresol novolak resin in the alkali-soluble resin is more than 60 weights, it is not preferred because the sensitivity of the positive photoresist composition tends to decrease. When the proportion of the lac resin in meta-cresol is less than 40w/f1%, the apparent sensitivity of the positive photoresist composition improves, but the residual film rate decreases and the resist no. This is not preferable because the turns tend to easily fall off from the support.

The 1,2-quinonediazide compound used in the present invention is not particularly limited, but includes, for example, 1,2-benzoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-4-sulfonic acid ester, ,2-
Examples include naphthoquinone diazide-5-sulfonic acid ester. Specifically, p-cresol-1,
2-benzoquinonediazide-4-sulfonic acid ester,
Resorcinol-1,2-naphthoquinonediazide-4-sulfonic acid ester, pyrogaroll-1,2-naphthoquinone di7di)'-5-sulfonic acid ester, fluorocricinol-1,2-naphthoquinonediazide-5-sulfone Acid ester of (poly)hydroxybenzene 1,2-
Quinonediazide sulfonic acid esters; 2,4-dihydroxyphenyl globil keto/-1,2-henfuquinonediazide-4-sulfonic acid ester, 2,4-dihydroxyphenyl-n-hexyl ketone-1,2-naphthoquinonediazide -4-sulfonic acid ester, 2,4-dihydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3.4-)dihydroxyphenyl-n-hexylketone-1,2-naphthoquinonediazide -4-sulfonic acid ester, 2,3
．． 4-) Dihydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3
．． 4-trihydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,4.6
-Dorihydroxypenzophenone-1.2-su7toquinone diazido 4-sulfo/acid ester, 2.4.6-
1,2-quinonediazide sulfonic acid esters of (poly)hydroxyphenylalkyl ketone or (poly)hydroxyphenylaryl ketone such as doryhydroxypenzophenone-1,2-nathoquinonediazide-5-sulfonic acid ester; bis(p- hydroxyphenyl)
Methane-1,2-naphthoquinonediazide-4-sulfonic acid ester, bis(2,4-dihydroxyphenyl)methane-1,2-su7toquinonediazide-5-sulfonic acid ester, bis(2,3,4-trihydroxyphenyl) hydroxyphenyl)methane-1,2-naphthoquinonediazide-5-sulfo/acid ester, 2,2-bis(p-hydroxyphenyl)propane-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,2-bis (2,4-dihydroxyphenyl)f-1.2l-7)quinonediazide-5-sulfonic acid ester, 2,2-bis(2,3,4
-) dihydroxyphenyl) propane-1,2-naphthoquinonediazide-5-sulfonic acid ester, etc.
1,2-quinonediazide sulfonic acid esters of (poly)hydroxyphenyl corekanes; 3,5-dihydroxybenzoic acid lacrileum 1,2-naphthoquinonediazide
4-sulfonic acid ester, 2,3,4-) phenyl hydroxybenzoate-1,2-naphthoquinone diazide
5-sulfonic acid ester, 3,4.5-)trihydroxybenzoate, acid ucrylic 1,2-su7toquinonediazide 5-sulfonic acid triester, 3.4.5-propyl-1 trihydroxybenzoate, 2-su7toquinone diazido 5-sulfonic acid ester, 3,4.5-)
1,2-quinonediazide sulfonic acid esters of (poly)hydroxybenzoic acid alkyl esters or (/su)hydroxybenzoic acid aryl esters such as IJ hydroxybenzoic acid phenyl-1,2-su7toquinonediazide 5-sulfonic acid esters ;bis(2,5-dihydroxybenzoyl)methane-1,2-naphthoquinone-4-sulfonic acid ester, bi,*(2,3,4-)IJhydroxype/zoyl)methane-1,2-naphthoquinonediazide- 5-sulfonic acid ester, bis(2,4,6-
) IJ hydroxybenzoyl)methane-1,2-naphthoquinonediazide-5-sulfonic acid ester, p-bis(2,5-dihydroxypensoyl]benzene-1,2
-naphthoquinonediacid-4-sulfonic acid ester, p
-Bis(2,3,4-)! j hydroxybenzoyl)
Bis[(- 1,2-quinonecyacytosulfonic acid esters of hydroxybenzoyl corekane or bis[(poly)hydroxybenzoyl]benzene; ethylene glycol-roots (3,5
) -1,2-naphthoquinonediazide-4-sulfonic acid ester, polyethylene glycoluge (3,5-dihydroxybenzonytone-1,2-naphthoquinonediazide-5-sulfonic acid ester, polyethylene glycoluge ( 3,4,5-)
IJ hydroxybenzoate) -1,2-naphthoquinone noanodo-5-sulfonic acid ester, etc. (poly)ethylene glycoluge [(poly)hydroxybenzoate] 1,2-quinonediacid sulfonic acid ester, etc. be able to. In addition to these exemplified 1,2-quinonediazide compounds, there are also
-5ensitive Systems #339~
352 p. (1965), John Wiley
& 5ons (New York), W, S,
Written by Do, Forest'' Photoreslst
'50.

(1975) e Me Graw-Hllll, In
1 described in c, , (New York)
, 2-quinone cyacyto compounds can also be mentioned.

The mixing ratio of the alkali-soluble resin and the 1,2-quinonediazide compound is preferably in the range of 80:20 to 65:35 by weight.

If the proportion of the 1.2-quinonediazide compound is less than 20% by weight, the resist pattern becomes easily dissolved in an alkaline developer, and the residual film rate of the positive photoresist composition tends to decrease, which is not preferable.

When the proportion of the 1.2-quinonediazide compound is more than 35% by weight, the 1,2-quinonediazide compound is not easily precipitated from the positive photoresist composition, and the sensitivity and resolution of the positive photoresist composition are reduced. This is not desirable because it tends to

A dye and a surfactant can also be added to the positive photoresist composition of the present invention.

Examples of dyes that can be added to the positive photoresist composition of the present invention include methyl violet 2
B (C, 1, No. 42535), Crystal Violet (C, 1, No. 42555), Maracite Green (C, 1, No. 42000), Victoria Blue B (C, I.

No. 44045), Neutral Red (C, 1
, No., 50040). The amount of these dyes added is preferably in the range of 1 to 10% by weight. The addition of dye has the effect of increasing resolution by preventing backscattering from the support from occurring.

Examples of the surfactant that can be added to the positive photoresist composition of the present invention include derioxyethylene nonylphenyl ether, polyoxyethylene octyl ether, polyoxyethylene dinonylphenyl ether, and the like. can. The amount of these surfactants added is preferably in the range of 0.1 to 5 weight. Addition of a surfactant has the effect of increasing the residual film rate by improving wetting between the support and the positive photoresist composition.

The positive photoresist composition of the present invention is dissolved in a suitable solvent and applied onto a support. The solid content concentration of the positive photoresist composition of the present invention when applied onto a support is preferably in the range of 20 to 45% by weight. Solid concentration is 2
If it is less than 0% by weight, film forming properties tend to deteriorate, which is not preferable. If the solid content concentration is higher than 45% by weight, the viscosity tends to increase, which is not preferable.

Examples of the solvent used for dissolving the positive photoresist composition of the present invention include methyl cellosolve, ethyl seron lub, methyl selon lub acetate, ethyl cello solve acetate, cyclohexanone, dimethyl sulfoxide, dimethyl formamide, dioxane, and tetrahydro 7-ran. These may be used alone or in combination.

Examples of the support to which the positive photoresist composition of the present invention is applied include silicon wafer aluminum plate,
A glass plate, a copper plate, a copper-clad laminate for printed wiring, etc. are used as appropriate depending on the purpose.

Coating the positive photoresist composition of the present invention onto a support using a suitable coating means such as a spinner roll coater,
A photosensitive layer is formed by drying. The photosensitive layer is
Actinic rays such as ultraviolet rays, electron beams, and X-rays are irradiated through a transparent original image such as a patterned mask or Tsucutan film, and then developed with an alkaline developer.

Examples of alkaline developers include sodium hydroxide,
Potassium hydroxide, sodium silicate, potassium silicate, sodium triphosphate, potassium triphosphate, sodium carbonate,
An inorganic alkali such as potassium carbonate; an aqueous solution of an organic alkali such as ethanolamine, and optionally polyoxyethylene nonylphenyl. Lyoxyethylene octylphenyl ether,? A surfactant such as dioxyethylene diuryl ether, o, o o s ~ 0
．． 5 liters of alcohol such as gropanol, butanol, ethylene glycol, and benzyl alcohol.
A developer containing 0.05 to 0.5% by weight can be used.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Synthesis Example 1 (Synthesis of 1,2-quinonediazide compound) 2
．． 3.4-) I) Hydroxybenzophenone 23.
53.1' of P-1,2-naphthoquinone-2-diazido-5-sulfonyl chloride was dissolved in 470 ml of dioxane, and 20.2 iP of triethylamine was added dropwise to this solution with stirring, followed by reaction for 2 hours. After the reaction was completed, the reaction mixture was dispersed in pure water 41, and the resulting precipitate was separated and dried to obtain a mixture of 1,2-quinonediazide compounds. This mixture was subjected to liquid chromatography (
As a result of analysis by HLC), 7% by weight of monoester
It was a mixture of 26% by weight of diester and 64% by weight of triester. Synthesis Example 2 (Synthesis of metacresol no?lac tree) 50
m-cresol 108 in a 0xJ four-hole flask? ,
37% formalin 80/- and Scheric acid 0.1? was charged and gradually heated in an oil bath, and reacted for 5 hours while maintaining the system internal temperature at 100°C.

Then, while distilling, the temperature inside the flask was increased from 100℃ to 2
Water, unreacted formalin and m-cresol in the system were removed by raising the temperature to 00"Ct and further distilling under reduced pressure of 50 wxHg. The contents of the flask were taken out of the system, A solid metacresol novolac resin was obtained by cooling to room temperature.The softening point of this metacresol novolak resin was 160°C.As a result of measurement by gas chromatography (GPC), it was found that the weight of this metacresol novolac resin was 160°C. The average molecular weight of the bath was 10,000 in terms of polystyrene.

Synthesis Example 3 (Synthesis of orthocresol novolac resin) In a 500rnl four-loaf flask, 10 O-cresol was added.
8iP, 37 thiformin 89iP and citric acid 2? was charged and gradually heated in an oil bath, and reacted for 5 hours while maintaining the system internal temperature at 100°C.

Then, while distilling, the temperature inside the flask was increased from 100℃ to 2
The water, unreacted formalin, and 0-
Cresol was removed. The contents of the flask were taken out of the system and cooled to room temperature to obtain a solid orthocresol novolac resin.

The softening point of this orthocresol novolak resin is 138
It was ℃. As a result of measurement by GPC, the weight average molecular weight Mw of this orthocresol novolac resin was 3.200 in terms of polystyrene.

Example 1 Mixture of 1,2-quinonediazide compounds obtained in Synthesis Example 1 2JF-1 Meta-cresol obtained in Synthesis Example 2 was used as lac resin 3.41P, and orthocresol obtained in Synthesis Example 3 was used as lac resin 3.41P. A positive photoresist solution was prepared by dissolving the positive photoresist in cellosolve acetate (19,7P) and filtering this solution through a 0.2 μm microfilter.

This solution was applied to a glass substrate with an ITO film (manufactured by Matsuzaki Vacuum Co., Ltd.) using a spinner so that the dry film thickness was 1.35 μm, and prebaked at 90°C for 30 minutes in a clean open oven to form a photoresist film. was formed.

Next, the step tablet was brought into close contact with the photoresist film, and the sensor of the illuminance meter r UV-MOI J (manufactured by Oak Manufacturing Co., Ltd.) measured the amount of light (light amount on the surface of the photoresist film 17
Corresponds to rnW/d. ), contact exposure was performed using an ultra-high pressure mercury rung, and then the photoresist film was exposed at 24~
The resist was removed and turned by immersion for 1 minute in an alkaline developer consisting of 1% KOH aqueous solution at 25°C. Resist/Mother turn has a sensitivity of 25 mJ and Otsu 1.
2, the remaining film rate was 100.

Therefore, the positive photoresist composition used in Example 1 had a high residual film rate.

Example 2 Instead of the step tablet used in Example 1, 5
After exposing and developing in the same manner as in Example 1 except that P, N (C4101) was used, the plate was exposed and developed using concentrated nitric acid/concentrated hydrochloric acid/water-0,1/without post-baking.
50℃ with etching solution of 1.0/1.0 (volume ratio), 2
Etching was performed for a minute.

As an indicator of adhesion, 12.5 μm line and sweep I? At the turn, the difference in line width before and after etching was measured. In this example, the amount of side etching was 0.6 μm.

Comparative Example 1 In place of the positive photoresist solution used in Example 1, PR-8J (a novolac resin consisting of a mixture of m-cresol:p-cresol-6:4 and formaldehyde was used as the alkali-soluble resin). The sensitivity and residual film rate were measured in the same manner as in Example 1, except that a positive photoresist composition manufactured by Tokyo Ohka Kogyo Co., Ltd. was used.The sensitivity was 60 mJ, /;-, and the residual film rate was lOOchi. However, the exposure amount was 2.4 times that of Example 1.

Comparative Example 2 The amount of sand etching was measured in the same manner as in Example 2, except that rPR-8J used in Comparative Example 1 was used instead of the positive photoresist solution used in Example 2. As a result, 1. It was 4 μm. The amount of sand etching was 2.3 times that of Example 2.

Comparative Example 3 In place of the positive photoresist solution used in Example 1, rAZ-816J (as an alkali-soluble resin, m
The same procedure as in Example 1 was carried out except that a positive-working photoresist composition manufactured by A, G, Co., Ltd.) was used. When the sensitivity and residual film rate were measured, the sensitivity was 35 rnJ/cm” and the residual film rate was 98.
It was Chi. Although the exposure dose was 1.4 times that of Example 1, a film reduction of 2 inches was observed.

Comparative Example 4 The sand etching amount was measured in the same manner as in Example 2 except that rAZ-816J used in Comparative Example 1 was used instead of the digital photoresist solution used in Example 2. As a result, the sand etching amount was measured at 2.0 μm. there were. 3.3 compared to Example 2
The amount of sand etching was doubled.

〔Effect of the invention〕

The positive photoresist composition of the present invention has excellent sensitivity, residual film rate, and adhesion to a support, so it is useful as a photosensitive material used in the production of resists for ultrafine processing and lithographic printing plates. .

Claims (1)

[Claims] 1. A positive photoresist composition comprising an alkali-soluble resin and a 1,2-quinonediazide compound, characterized in that the alkali-soluble resin is a resin mixture comprising a meta-cresol novolac resin and an ortho-cresol novolac resin. A positive photoresist composition. 2. The mixing ratio of metacresol novolak resin and orthocresol novolac resin is 60:40 to 40 by weight.
2. The positive photoresist composition according to claim 1, wherein the photoresist composition has a molecular weight of 60. 3. The positive photoresist composition according to claim 1 or 2, wherein the metacresol novolac resin has a weight average molecular weight in the range of 8,000 to 18,000. 4. The positive photoresist composition according to claim 1, 2 or 3, wherein the orthocresol novolac resin has a weight average molecular weight in the range of 2,000 to 4,000. 5. The positive photoresist composition according to claim 1 or 2, wherein the mixing ratio of the alkali-soluble resin and the 1,2-quinonediazide compound is in the range of 80:20 to 65:35 by weight. 6. A resist for ultrafine processing comprising the positive photoresist composition according to claim 1. 7. A photosensitive composition for lithographic printing comprising the positive photoresist composition according to claim 1. 8. A photosensitive lithographic printing plate comprising the positive photoresist composition according to claim 1.