KR950006730B1 - Photoresist composition - Google Patents

Abstract

The photoresist composition is composed of an alkali soluble phenol novolac resin having 5-1,000 ∦/sec solution velocity w.r.t. an aqueous solution of 2.38 wt.% tetra ammonium hydroxide at 20-25 'C, a quinone diazide gp.-containing cpd. as a photosensitive agent, and a cpd. of formula (I) or (II). In the formulas, A is SO2, SO, (subtd.) alkyl, (subtd.) alkoxy, (subtd.) hydroxy alkyl or (subtd.) hydroxy alkoxy; R1-10 and R'1-6 are each H, OH, alkoxy, hydroxy alkyl or hydroxy alkoxy. The photoresist composition has a good contrast and resolution, and is used for the mfr. of semiconductors.

Description

Photoresist composition

BACKGROUND OF THE INVENTION The present invention relates to a photoresist composition, and in particular, a resist that is suitable for use in semiconductor manufacturing, has no residue, good contrast and resolution, and heat resistance that is equal to or higher than that of conventional products. It relates to a composition.

Recently, with the rapid development of the semiconductor use industry such as industrial computers, office automation equipment, personal computers, and the like, semiconductor densities are rapidly increasing in density and integration.

In order to increase the degree of integration of a semiconductor, a good resolution with a narrow pattern of lines and space (hereinafter referred to as L / S) when forming a semiconductor circuit is required. Currently, the so-called g-ray resist sensitive to g-ray (436 nm) generated from mercury lamps is mainly used for the production of 4-mega-RAM (MDRAM), but the limit of the resolution is about 0.45 μm L / S, so the 4-mega-RAM It is not suitable for the fabrication of semiconductor circuit elements of high integration. Therefore, in order to increase the resolution, the use of i-ray (365 nm), excimer laser (248 nm), X-ray, electron beam, etc., which are shorter than g-rays, is being considered, but excimer laser (248 nm), X-ray, electron beam, etc. are considered in terms of equipment. There are many problems to apply the current manufacturing process as it is. On the other hand, many studies have been conducted in that i-rays using the same mercury lamp as a light source can be applied to the current manufacturing process.

However, benzophenone-based photosensitizers widely used in g-rays have energy that must be determined to the quinonediazide group, which is a photosensitive group during exposure because it reacts and esterifies with quinonediazide because the benzophenone parent is absorbed at 365 nm. By absorbing, transparency becomes worse and resolution falls.

In order to increase the resolution and obtain a good pattern, the difference in solubility in the developer of the non-exposure part and the exposure part should be increased.

[Figure 1] Masking Effect of Resist

There are two ways to increase the a value: first, to increase the dissolution inhibiting effect in the non-exposed part, and second, to increase the dissolution rate in the exposed part.

A feature of the present invention relates to a resist composition which enhances the resolution by accelerating the dissolution rate of an exposed part, and by adding an appropriate amount of the compounds of formulas (I) and (II) to a resist solution containing an alkali-soluble resin and a photosensitive component, It is to increase the resolution by increasing the dissolution rate of the exposed portion while maintaining the remaining film ratio of. In addition, the compounds of the general formulas (I) and (II) do not absorb in the ultraviolet (Ultra-Violetray) region of 340nm to 500nm, so that the transparency of addition is not reduced.

(A in general formula (I) is: SO, SO ₂ , an alkyl group, a substituted alkyl group, an alkoxy group, a substituted alkoxy group, a hydroxyalkyl group, a substituted hydroxyalkyl group, a hydroxyalkoxy group, a substituted hydroxyalkoxy group, R _1-10 and R ' _1-6 of (I) and (II) are hydrogen, a hydroxyl group, an alkoxy group, a hydroxyalkyl group and a hydroxyalkoxy group, each of which is independent.)

In other words, the present invention relates to a positive photoresist composition containing from 0% to 50% of an alkali-soluble resin, a quinonediazide compound as a photosensitive component, and a compound represented by the general formulas (I) and (II) as a sensitizer. Preferably it is 1%-20%, and addition amount can be added or subtracted according to the kind of novolak resin. If the added amount is not suitable, the decrease in film thickness in the non-exposed part may be severe, resulting in poor residual film ratio.

Some of the compounds represented by the general formula (I) or (II) may be used as a mother compound of the quinonediazide ester compound (quinonediazide-based photosensitive agent) (Korean Patent Publication No. 1831).

However, in the present invention, it was found that the resolution can be increased by adding the compound of general formula (I) or (II) itself to a composition composed of a compound containing an alkali-soluble resin and a quinonediazide group rather than as a mother of the photosensitizer. .

Examples of the phenol novolac resins of the present invention include phenol, o-cresol, m-cresol, p-cresol, 2.5-xylenol, 3,5-xylenol, 3,4-xyl Knoll, 2,3,5-trimethylphenol, 4-t-butylphenol, 2-t-butylphenol, 3-t-butylphenol 2-ethylphenol, 3-ethylphenol, 4-ethylphenol, 3-methyl- 6-t-butylphenol, 4-methyl-2-t-butylphenol, 2-naphthol, 1.3-dihydroxy naphtharene, 1,5-dihydroxynaphtharene, 1,7-dihydroxynaphthylene and the like And condensed phenols alone or in combination of two or more in accordance with the aldehydes and the method of drawing. The photosensitizer may be any ester compound having a diazonaptoquinone group as long as the esterity is 30% to 100%.

Examples of solvents for dissolving alkali-soluble resins such as novolac resins include 2-methoxyethyl acetate, 2-ethoxyethyl acetate, cyclohexanone, ethyl lactate, ethylene glycol monomethyl ether acetate, and propylene glycol monomethyl ether. Can be used. The pattern formation was applied by a conventional method, subjected to an electrothermal treatment at 90 ° C. for 90 seconds, then exposed, and developed after heat treatment at 110 ° C. for 90 seconds.

Embodiments of the present invention are as follows. However, the present invention is not limited to the examples.

Synthesis Example 1

A mixture of 64% by weight of metacresol (90% purity) and 36% by weight of paracresol (99% purity) was added with 0.75 mole of 37% formalin solution to 1 mole of cresol in the presence of oxalic acid. After the reaction, the mixture was gradually heated under reduced pressure to extract moisture, residual monomers, and the like to obtain novolak resin A.

Synthesis Example 2

In the same manner as in Synthesis example 1, a novolak resin B having a weight average molecular weight (polystyrene equivalent) of 8,000 was obtained using methacresol having a purity of 97%.

Synthesis Example 3

Novolak resin C having a weight average molecular weight of 5,100 was obtained by setting the reaction time to 30 minutes between the two companies in the same composition and in the same manner as in Synthesis example 1.

Synthesis Example 4

A mixture of 55% by weight of metacresol (purity 97%), 35% by weight paracresol (99% purity) and 10% by weight 2,4-xylenol was polymerized in the same manner as in Synthesis Example 1 to obtain a furnace having a weight average molecular weight of 4,100. Volac resin D was obtained.

Synthesis Example 5

2,3,4,4'-tetrahydroxybenzophenone and 1,2-naphthoquinonediazide-5-sulfonyl chloride are mixed in a 1: 3.7 molar ratio, dissolved in dioxane, and then triethylamine is added. . The mixture was reacted at 10 ° C. to 25 ° C. for 1 hour, extracted with water, washed with methyl alcohol, and dried under reduced pressure at room temperature to obtain a photosensitive agent. Analysis of the liquid chromatography showed that the content of the tetrasubstituted body was 78%.

Example 1-1

10 g of novolac resin A obtained in Synthesis Example 1 and 0.5 g of a compound represented by Formula (I) were dissolved in 25 g of 2-ethoxyethyl acetate, and a solution was filtered through a 0.2 μm Teflon filter. This was applied to a thin film of 1 μm on the wafer, and after 60 seconds of heat treatment at 90 ° C., the solution was immersed in a 2.38 wt% tetraammonium hydroxide aqueous solution. 650 ms / sec.

Example 1-2

0.5 g of the compound represented by the general formula (II) was added to 10 g of novolak resin A obtained in Synthesis Example 1, and the dissolution rate was measured in the same manner as in Example 1, and it was 458 dl / sec.

Comparative Example 1

10 g of novolak resin A obtained in Synthesis Example 1 was dissolved in a solvent, and the dissolution rate was measured in the same manner as in Example 1-1. As a result, it was 380 Pa / sec.

Example 2

10 g of novolak resin B obtained in Synthesis Example 2 and 2 g of the compound represented by the general formula (I) were added, and the dissolution rate was measured in the same manner as in Example 1, and it was 2.580 Pa / sec.

Comparative Example 2

It was melt | dissolved in the novolak resin B solvent obtained by the synthesis example 2, and the dissolution rate was measured by the method similar to Example 1-1, and it was 250 kPa / sec.

Example 3

To 10 g of novolak resin C obtained in Synthesis Example 3, 1.5 g of the photosensitive agent obtained in Synthesis Example 5 and 0.5 g of the compound represented by Formula (I) were added, dissolved in 25 g of 2-ethoxyethyl acetate to form a solution. Was filtered. This was applied to an econcon wafer, subjected to electrothermal treatment, exposed for 10 seconds with UV light, and then developed by dipping in a 2.38% by weight tetraammonium hydroxide solution to measure the time that the coating film was completely melted. It was a second.

Comparative Example 3

1.5 g of the photosensitizer obtained in Synthesis Example 5 was added to 10 g of the novolak resin C obtained in Synthesis Example 3, and the dissolution rate was measured in the same manner as in Example 3, and it was 470 Pa / sec.

Example 4

1.5 g of the photosensitive agent obtained in Synthesis Example 5 and 0.5 g of the compound represented by the general formula (I) were added to 10 g of the novolak resin D obtained in Synthesis Example 4, and the dissolution rate thereof was measured in the same manner as in Example 3 to find 510 dl / It was a second.

[Comparative Example 4]

1.5 g of the photosensitizer obtained in Synthesis Example 5 was added to 10 g of the novolak resin D obtained in Synthesis Example 4, and the dissolution rate was measured in the same manner as in Example 3, and it was 267 s / sec.

Example 5

To 10 g of novolac resin C obtained in Synthesis Example 3, 1.5 g of the photosensitive agent obtained in Synthesis Example 5 and 0.35 g of the compound represented by Formula (I) were added, dissolved in 28 g of 2-ethoxyethyl acetate, and filtered through a 0.2 μm Teflon filter. The resist liquid was produced. It was spin-coated at 4,000 rpm and coated to a constant thickness, and exposed with a stepper of NA 0.5, which was preheated at 90 ° C. for 90 seconds, and then heat-treated at 110 ° C. for 90 seconds. This was developed using a puddle method with a 2.38 wt% tetraammonium hydroxide solution, and the result of observing the pattern is shown in Table 1.

[Comparative Example 5]

1.5 g of the photosensitive agent obtained in Synthesis Example 5 was added to 10 g of the novolak resin obtained in Synthesis Example 3, and the same procedure as in Example 5 was carried out.

TABLE 1

Comparison of Example 5 and Comparative Example 5

Claims (1)

Alkali-soluble phenol novolak resins and quinonediazide-containing compounds having a dissolution rate in an aqueous solution of 2.38% by weight of tetraammonium hydroxide at 20 to 25 ° C in the range of 5 to 1,000 Pa / sec, and general formula (I) or (II Photoresist composition containing a compound of Formula 1). However, by the general formula (I) A is: SO, SO _2, an alkyl group, a substituted alkyl group, an alkoxy group, a substituted alkoxy group, a hydroxy group, a substituted hydroxy group, a hydroxy alkoxy group, a substituted hydroxy and alkoxy groups, Common R _1-10 and R ' _1-6 of formulas (I) and (II) are hydrogen, a hydroxyl group, an alkoxy group, a hydroxyalkyl group, and a hydroxyalkoxy group, each of which is independent.