JPS62255937A - Positive type photoresist composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition having good coating characteristics such as flexibility by incorporating a specific N-(hydroxyphenyl)-maleimide copolymer, a novolak resin and a quinone azide compd. to the titled composition. CONSTITUTION:(1): The N-(hydroxyphenyl)-maleimide polymer polymerized from constitution units shown by formulas I, II and III wherein R1 is aryl, 1-16C alkyl or cycloalyl group, R2 is hydrogen atom or lower alkyl group, a ratio of (n), (l) and (m) atisfys the following formulas; 0.01<n/(l+m)<=10 and 0.1<l(l+m)<=1. (2): The novolak resin is used for one component of the titled composition. (3): The quinone azide compd. as the photosensitve agent is exemplified by for example, naphthoquinone diazide sulfonic acid ester and benzoquinone diazide sulfonic acid ester, etc. The titled composition isobtd. by incorporating the compds. (1), (2) and (3). Thus, the titled composition capable of forming a coatings having a good flexibility and a high fine pattern, and having good sticking property against a substrate and an excellent heat-resisting property is obtd.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a positive photoresist composition, specifically, an alkali-soluble N-(hydroxyphenyl)maleimidoisobutylene copolymer. The present invention relates to a positive photoresist composition that has improved film performance, adhesion to a substrate, and heat resistance by blending it into a positive photoresist made of a novolac resin. In addition to being used for the production of printed wiring boards, PS lithography, and photo-letter printing, the product can also be used for the formation of ordinary wiring patterns and the production of integrated circuits such as ICs and LSIs, and is used in the photo industry, printing industry, Widely used in fields such as electronic industry.

[Traditional technique]

Conventionally, compounds having a quinone diazide group have been widely used in positive-working photosensitive materials because they produce indenecarboxylic acid when exposed to ultraviolet rays and become alkali-soluble. It is widely used industrially as a type photoresist.

A positive photoresist composition containing a compound having such a quinonediazide group is, for example, naphthoquinone-(1
, 2) -diazide-sulfonic acid ester, etc.
- It is a mixture of an ester compound of quinonediazide sulfonic acid and an alkali-soluble resin, such as a novolak resin, and as the novolak resin, phenol-formaldehyde novolak resin and talesol-formaldehyde novolak resin are widely used in practical use.

[Problem that the invention seeks to solve]

The positive photoresist composition made from the above-mentioned novolac resin is based on the physical properties and molecules of the novolac resin! Due to the low t, the film lacks flexibility and is brittle (the image is easily scratched due to impact), and the adhesion to the substrate is still not fully satisfactory. do not have.

Accordingly, an object of the present invention is to provide a positive photoresist composition that has good flexibility and performance, and has excellent adhesion to a substrate.

[Means for solving problems]

As a result of various studies, the present inventors have achieved the above object by using a specific N-(hythrodiphenyl)maleimide-isobutylene copolymer mixed with a novolak resin and adding a quinonediazide compound thereto. It has been found that a positive photoresist composition that achieves the above-mentioned results can be obtained, and that the composition also has excellent heat resistance.

The present invention was made based on the above findings, and includes (wherein,
The ratio of n and (#+m) is 1 and the ratio of l and (1+m) is 1 +m j! +m. The present invention provides a positive photoresist hm acid compound containing an N-(hydroxyphenyl)maleimide-isobutylene copolymer having the structure J1-position shown in the following formula, a novolac resin, and a quinonediazide compound as a photosensitizer.

The positive photoresist composition of the present invention will be explained in detail below.

N-(
The hydroxyphenyl)maleimide-isobutylene copolymer has the following formula:
) and the ratio is preferably . ) It is an alkali-soluble copolymer having the structural unit shown below.

The above N (hydroxyphenyl)maleimide-isobutylene copolymer has a ratio of n to (f+m) (n/
If (f + m)) exceeds 10, the alkali solubility will decrease, and if the ratio of n to (f + m) is too small, the texture will become weak or weak, which is not suitable. Also, the ratio between i and (11m) [1/(β0m)
) is less than 0.1, there will be a difference in alkali solubility between irradiated and non-irradiated areas in the photoresist.
, 6i+ thermal properties are also not sufficient.

Further, in the N-(hydroxyphenyl)maleimide-isobutylene copolymer, the ratio of the structural unit represented by formula (1), that is, the ratio of l to (1+m+n) is 0.
2<Il/(1+m+n)<0.8,
Especially 0.25<Il/C1+mI-n)<0.6
It is preferable that

In addition, the above-mentioned N-(hydroxyphenyl)maleimide-isobutylene copolymer has a number average molecular weight (Mn) of 1+ 000 to 1 as determined by gel permeation chromatography (GPC method) using monodisperse polystyrene as a standard.
500,000, especially 4,000 to 200,000
It is preferable to use the following from the viewpoint of sensitivity, resolution, heat resistance, film performance, adhesion to the substrate, etc.

Further, as the N-(hydroxyphenyl)maleimide-isobutylene copolymer, the glass transition temperature (Tg
) is 1 (i0 to 260°C, particularly 170 to 250°C).

The above N-(hydroxyphenyl)maleimide-isobutylene copolymer is a new compound, for example, a copolymer obtained by copolymerizing water-harvesting maleic acid and isobutylene and aminophenol in an organic solvent. In response,
It can be produced by a method of converting part or all of the maleic anhydride component into an N-(hydroxyphenyl)maleamic acid component and then carrying out a cyclization dehydration reaction.

Further, suitable novolak resins constituting the positive photoresist composition of the present invention are alkali-soluble novolak resins obtained by addition-condensation reaction of phenols and formaldehyde; examples thereof include phenol formaldehyde novolak resins, O - Cresol formaldehyde novolak resin, rn-cresol formaldehyde novolank resin, p-talesol formaldehyde novolank resin, novolak obtained by addition condensation reaction of formaldehyde and a mixture of two or more selected from phenol and cresol isomers. Examples include JIA fat and phenol-modified xylene resin.

The above-mentioned novolak resin is made of gt-dispersed polystyrene (with a weight average molecular weight of 5 as determined by GPC method).
00 to 20,000, particularly preferably 1,000 to 10,000.If the hexaweight average molecular weight is less than 500, sufficient coating performance cannot be obtained. Poor solubility.

Suitable quinonediazide compounds constituting the positive photoresist composition of the present invention include naphthoquinonediazide sulfonic acid esters and henzoquinonediazide sulfonic acid ester m. These quinonediazide sulfonic acid esters In can be obtained, for example, by reacting naphthoquinonediazide sulfonic acid chloride or henzoquinonediazide sulfonic acid chloride with a compound having a functional group capable of a condensation reaction with an acid chloride, such as a hydroxyl group or an amine group. Examples of the above-mentioned compounds having a hydroxyl group or an amino group include phenol, p-methoxyphenol, hydroquinone, resorcinol, 2,4-
Examples include dihydroxybenzophenone, 2,3,4-trihydroxyhensiphenone, gallic acid alkyl ester, aniline, diphenylamine, phenol-formaldehyde novolank resin, cresol-formaldehyde novolank resin, and the like.

The ratio of the total of the N-(hydroxyphenyl)maleimide-isobutylene copolymer and the novolak resin to the quinonediazide compound is +111 to 1 part by weight of the quinonediazide compound. The total amount of the isobutylene copolymer and the novolac resin is 1-10 parts by weight, especially 1-10 parts by weight.
Preferably, the amount is 6 parts by weight.

In addition, the N (hydroxyphenyl)maleimide-
The ratio of the isobutylene copolymer and the novolac resin described in ■■ is such that the N-(hydroxyphenyl)maleimide-isobutylene copolymer is used in a ratio of 10 double star type 6 or more, particularly 15 weight by weight, to the novolak resin. It is preferable to use the above.

The positive photoresist composition of the present invention is soluble in an organic solvent, and is generally used as a solution (resist solution) dissolved in an organic solvent at a ratio of 1 to 50% by weight, preferably 5 to 30% by weight. The organic solvent can be used to uniformly dissolve each component of the positive photoresist composition of the present invention, apply it to the surface of a substrate such as silicon or aluminum, and then evaporate the organic solvent. Preferable examples are ketone solvents such as acetone, methyl ethyl ketone, and cyclohexanone, cellosolve solvents such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, and ethyl cellosolve acetate. . The above aqueous solvents may be used alone or in combination of two or more.

The above resist solution may contain plasticizers, dyes,
Other resins, various inhibitors, adhesion improvers, etc. can be added.

According to the positive photoresist composition of the present invention, by preparing the resist solution as described above, it is possible to form a fine pattern having flexibility and good film performance, for example, in the following manner.

That is, first, the above-mentioned resist solution is applied to a substrate and dried to remove the organic solvent. The coating on the substrate can be performed using, for example, a spin code (rotary coating) or the like. Further, the coating film is dried preferably at 120"C by methods such as hot air drying, far infrared drying, and drying on a hot plate.
Hereinafter, it is more preferable to carry out the heating at 100°C or lower. At this time, the pressure may or may not be reduced.

After drying, a mask is placed in close contact with the coating film, and a light beam is irradiated using, for example, an ultra-high pressure mercury lamp, a low-pressure mercury lamp, etc., and then this is developed by a method such as spraying a developing solvent or immersing it in a developing solvent, The exposed portion is melted and removed to form a fine pattern. As the developing solvent, a weak alkali aqueous solution such as thorium hydroxide, potassium hydroxide, sodium metasilicate, tetramethylammonium hydroxide or the like having a concentration of 5% by weight or less can be used.

Further, a substrate can be etched using the positive photoresist composition of the present invention and the pattern formed as described above as a mask.

〔Example〕

Below are examples of synthesis of the N-(hydroxyphenyl)maleimide-isobutylene copolymer that is a component of the positive photoresist composition of the present invention, examples of the present invention, and the positive photoresist composition of the present invention. The present invention will be explained in more detail by giving examples of use in which fine patterns are formed and lithographic printing plates and printed wiring boards are produced using the present invention.

Synthesis Examples 1 to 4 Maleic anhydride-isobutylene copolymer and aminophenol shown in Table 1 below were dissolved in 150 ml of dehydrated dimethylformamide, reacted at 80°C, and reacted with N.
- After producing the (hydroxyphenyl)maleamic acid copolymer, 12g of trilobylamine as a catalyst.
and by adding 45 ml of toluene as an azeotropic solvent, 14
The cyclization and dehydration reaction was carried out at 0°C. After the reaction is complete, the polymer is precipitated with ethyl ether, and tetrahydrofuran? Purified by dissolution-ethyl ether precipitation at 100 °C for 24
N having the physical properties shown in Table 1 below after drying under vacuum for an hour
-(Hydroxyphenyl)maleimide-isobutylene copolymers were obtained.

Examples 1 to 6 and Comparative Example 1 According to the conditions shown in Table 2 below, N-C hydroquinphenyl)maleimide-isobutylene copolymer, m-talesol formaldehyde novolank resin (IIf average molecular star: 3, 200) and naphthoquinone as a photosensitizer.
Resist by dissolving the condensation reaction product of (1,2)-diazide-(2)-5-sulfonic acid chloride and 2.3.4-trihydroxohenzophenone in ethyl cellosolve) 8
Each solution was prepared in 14 batches.

In addition, under the conditions shown in Table 2 below, m-cresol formaldehyde novolank resin and naphthoquinone-(1,2)-diazide-C2)-5-sulfonic acid chloride and 2,3,4-trihydroxyhen as a photosensitizer were used. A resist solution was prepared by dissolving the condensation reaction product with siphenon in ethyl cellosolve and used as a comparative example.

Test pieces were prepared as described below using the resist solution of Goret et al., and a bending resistance test was conducted on these test pieces according to the bending resistance test method described below.

(Preparation of test piece) A grained aluminum plate of 50 mm x 50 mm and P7 size of 0.21 was thoroughly washed and dried, and the above resist solution was spin-coated onto the aluminum plate and dried. to form a coating film with a thickness of approximately 2 μm (see Table 2 below). Next, this is immersed in a 1% sodium metasilicate aqueous solution for 1 minute and stirred, then washed with water and dried to obtain a test piece. Three test pieces are prepared for each of the 8 resist solutions.

(Bending resistance test method) Using a bending tester specified in JIS K 5400 (general paint test method), the above test piece was bent 180 degrees around a mandrel with a certain diameter, and the coating film at the bent part was However, since the diameter of the mandrel of the above tester is 10 mm or less, for the bending resistance test in the case of a mandrel with a diameter of 20 mm, one
The test was conducted by bending 80 degrees.

The bending resistance is so good that it can withstand small diameter mandrels.

The results of the above bending resistance test are shown in Table 2 below.

This result was 911 for two or more of the three test pieces.
When peeling was not observed, it was indicated as ○, and when it was observed, it was indicated as ×, and this was used as an index of the flexibility of the coating film.

Usage Examples 1 to 4 Each of the resist solutions prepared in Examples 2, 4, 5, and 6 was applied to a silicon wafer at 300 Or.

Spin coat with p, a+, dry at 80°C for 20 minutes,
A coating film having a thickness of about 1/jm (see Table 3 below) was obtained.

Next, a chrome mask with a pattern is closely attached to the above coating film, and a wavelength of 300
~500n+* light (UV light) was irradiated onto the coating film through the chrome mask and exposed for the time shown in Table 3 below. Add this to 2 of tetramethylammonium hydroxide.
% aqueous solution, and the exposed areas were melted and removed to form a fine pattern. When the developed patterns were observed under an electron microscope, a repeating pattern of 1.0 μm lines/spaces was formed with high accuracy. It also had good adhesion to the substrate and had excellent film properties with no cracks or pinholes.

Furthermore, the γ value and sensitivity to UV light of the positive photoresist composition of the present invention used were measured as follows. The results are shown in Table 3 below.

-T value: A coating film made of the positive photoresist composition of the present invention is prepared as described above, and this coating film is exposed and developed. By varying the amount of light irradiation, the relationship between the amount of light irradiation and the resist film thickness after development (normalized residual film thickness) is measured. From the measurement results, the horizontal axis shows the irradiation f (logarithm) of the light beam, and the vertical axis shows the remaining 11
A curve obtained by calculating the ratio of the resist film thickness after development to the film thickness of the coating film was taken as a characteristic curve, and a numerical value indicating the slope of the rising portion of the curve was determined and used as the γ value.

- Sensitivity: In the measurement of the above characteristic curve (γ value), the irradiation amount when the residual film was O was defined as the sensitivity.

Table 3 Usage Example 5 After thoroughly washing and drying a grained aluminum plate with a thickness of 0.2 mff1, the resist solution prepared in Example 2 was spread on the aluminum plate using a spinning cloth, and dried. A positive PS lithographic plate with a film thickness of 2 μm was prepared.

Next, a halftone dot positive film was densely placed on this PSS lithographic plate, and exposed for 50 seconds through the above halftone dot positive film from a distance of 7Qcm using a 3KW ultra-high pressure mercury lamp. After soaking and stirring for a minute, the exposed area was dissolved and removed, and washed with water to obtain a fixed image with an accuracy of 100 lines per 1 cm.
It has excellent flexibility, is easy to use with fatty printing inks, and can be used for offset printing as a lithographic printing plate in the presence of dampening water.

Use Example 6 The resist solution prepared in Example 6 was spin-coated onto a printed wiring board on which copper foil with a thickness of 35 μm was laminated, and dried to obtain a coating film with a thickness of 1.5 μm. Next, a positive film was closely attached to this coating film, and the film was exposed to light for 100 seconds from a distance of 70 cm using a 3KW ultra-high pressure mercury lamp through the positive film, and then immersed in a 1% aqueous solution of sodium metasilicate for 1 minute with stirring. The exposed portion was dissolved and removed and washed with water to form a resist film on the printed wiring board. After drying, the copper foil was etched with ferric chloride solution (40B;), and then
The resist film was melted and peeled off with a 4% sodium hydroxide aqueous solution at 40°C to obtain a printed wiring board.

〔Effect of the invention〕

The positive photoresist composition of the present invention has good film properties with flexibility, excellent adhesion to a substrate and heat resistance, and can be developed with an alkaline aqueous solution, so there is no risk of swelling ( , capable of forming fine photoresist patterns with high precision, printed wiring boards, I)
In addition to being used for the production of S-lithography and photo-letter printing, it can also be used for forming ordinary wiring patterns, ICJ? ) It can be used in the production of integrated circuits such as LSI, and can be widely used in fields such as the photographic industry, the printing industry, and the electronic industry.

Claims (1)

[Claims] Formula (I) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ Formula (II) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, the ratio of n and (l + m) and the ratio of l and ( l+m) are 0.01<n/(l+m)≦10 and 0.1≦l/l+m≦1, respectively. A positive photoresist composition comprising a copolymer, a novolak resin, and a quinonediazide compound as a photosensitizer.