JPH031143A - Positive type photoresist composition - Google Patents

Abstract

PURPOSE:To provide the compsn. which ahs a high resolution and is large in the change of a developing speed with respect to a change of an exposure in particular, i.e. large in r value and with which beautiful patterns are obtain able by incorporating a specific arom. anino compd., phenolic compd. and amino group-contg. polyvalent phenolic compd. which are respectively specific into the compsn. CONSTITUTION:The arom. amino compd. expressed by formula I, the phenolic compd. expressed by formula II and the amino group-contg. polyvalent phenolic compd. obtd. by bringing at least one kind of the aldehydes selected from alkyl aldehyde and aryl aldehyde into condensation reaction. In the formulas, R is 1 to 9C alkyl group or halogen atom; respective Rs may be the same as or different from each other; p is 1 or 2 integer; q is 0, 1 or 2 integer. The compsn. which has the high resolution and is large in the change of the developing speed with respect to the change of the exposure in particular, i.e. large in the r value and with which the beautiful patterns are obtainable is obtd. in this way.

Description

Detailed Description of the Invention (&) Object of the Invention (Industrial Application Field) The present invention relates to a positive photoresist composition for forming an etching protective film in photolithography, particularly for semiconductor integrated circuits,
The present invention relates to a positive photoresist composition suitable for use in manufacturing magnetic bubble memory devices, steel clad plates for grid/grid wiring, etc.

(Prior Art) Photolithography is used in the manufacture of semiconductor integrated circuits, magnetic bubble memory elements, steel plates for printed wiring, and the like. In addition to the conventional radiation sources for lithography, ranging from visible light to ultraviolet light, deep ultraviolet light, and short-wavelength sources, in recent years, electron beams, ion beams, and X-rays also began to be used.

There are two types of photoresists for forming an etching protective film in IJ) photography: negative type and I-type.Positive type photoresists have better resolution than negative photoresists. Positive photoresists are made from a photosensitizer that changes from an insoluble state to a soluble state in a dialkaline aqueous solution by irradiation with light, energy beams, or particle beams, and a polyhydric compound made from phenol or alkylphenol and formaldehyde. Used in combination with phenol (i.e. Norac resin).

In recent years, with the miniaturization of flat surfaces formed by lithography, positive photoresists are also required to have higher performance.
Attempts have been made to improve the properties of cresol by changing the isomer ratio of cresol and co-condensing it with alkylphenols other than cresol.
No. 2542, 4I Publication No. 61-275748, etc.). Moreover, with the recent increase in the degree of integration of integrated circuits,
A high degree of fineness is required for the 9 turf to be formed, and 1μ
It has become necessary to accurately depict patterns of less than m, and simple changes in the type of alkylphenol or isomer ratio are no longer sufficient.

(Problems to be solved by the invention) The present invention is directed to a positive photoresist that has excellent resolution, that is, can easily draw highly fine turns, and in particular has a large change in development speed with respect to changes in exposure amount. It is an object of the present invention to provide a positive photoresist composition which has a large so-called r value and which can provide a clean 7-dimensional pattern.

That is, the type 4 Fo)V cyst composition of the present invention is -
(In the formula, R is an alkyl group having 1 to 9 carbon atoms or a halodane atom, and each R may be the same or different. q is a number of 0, 1, or 2. ) and an aromatic amino compound represented by
is an alkyl group having 1 to 9 carbon atoms or an atom,
Each R may be the same or different. p must be a number of 1 or 2, and q is 0. The number is l or 2. )
Most of the compositions contain an amino group-containing polyhydric phenol compound obtained by a condensation reaction between a phenol compound represented by the formula and at least one aldehyde selected from alkyl aldehydes and aryl aldehydes.

The amino group-containing polyhydric 7-ethyl compound which is an essential component of the positive photoresist composition of the present invention is composed of the above-mentioned 7-mino aromatic compound (4), the above-mentioned phenol compound (B), and an alkyl aldehyde. and at least 1111 aldehydes selected from aryl aldehydes in the presence of a recognized catalyst.

The molar ratio of the aromatic amino compound (8/phenol compound Φ) in this reaction is selected from the range of 70/30 to 1/99. Further, the reaction ratio of these compounds and aldehyde is such that the total number of moles of aromatic amino compound and phenol compound is in the range of 0.8 to 50 moles, preferably 1.0 to 30 moles per mole of aldehyde. It is.

This reaction is carried out at 50-180°C, preferably 60-150°C.
℃ temperature for 1 to 8 hours. After the reaction is completed, the acid catalyst is distilled off, washed with water, or neutralized with an alkali, and then distilled for dehydration, deaminated compounds, and phenol removed, or a water-insoluble solvent is added and washed with water. If distillation is performed to remove the solvent, the desired amino group-containing polyhydric phenol compound can be obtained. The above-mentioned distillation for removing amino compounds, removing phenol, removing solvents, etc. is preferably carried out at a temperature of 230° C. or lower.

Examples of the raw material aromatic amino compound include aniline, aniline having an alkyl substituent having 1 to 9 carbon atoms (for example, each toluidine of Og m − + p−,
2.3-, 2.4-, 2.5-, 2.6-, 3
゜4-, 3.5-dimethylaniline, O-*m
-p- each aminonorobylbenzene), and 10r
Substituted aniline/(9, for example, chloroaniline, noromoaniline, etc.).

Further, as the raw material phenol (B), for example, phenol as a -valent phenol, phenol having an alkyl substituent having 1 to 9 carbon atoms (for example, O"" *
each cresol of ill -r p-, 2.3-, 2.
4, 2.5-, 2.6-, 3.4-, 3.5-xylenol, 2.6-//P globylphenol, 2,6-)-t@rt-butylphenol, 4- nonylphenol, etc.), resorcinol as dihydric phenol, dihydric phenol having an alkyl substituent having 1 to 9 carbon atoms (e.g. 2-methylresorcinol, 5-methylresorcinol, etc.), a and halogen-substituted phenols (e.g. bromophenol, 2-methylresorcinol, etc.), , 6-dichlorophenol, 3-bromo-5-chlorophenol, etc.).

Examples of the raw material alkylaldehyde include formaldehyde, acetaldehyde, and norobilaldehyde.

In addition, the aryl alkaline raw material includes substituents such as benzaldehyde, hydroxyl groups, etc.
B? Aromatic aldehydes with 7N atoms (e.g. salicylaldehyde, p-hydroxybenzaldehyde, vanillin, 3-hydroxybenzaldehyde, 2-hydroxy-3-nitro(nzaldehyde, 4-chloro-2-
Examples include hydroxybenzaldehyde, 4-bromo-3-hydroxybenzaldehyde, and 3-f-bromo-4-hydroxybenzaldehyde.

Examples of acid catalysts for reactions include sulfuric acid and hydrochloric acid.

Mineral acids such as nitric acid, hydrogen bromide, perchloric acid, etc., sulfonic acids such as 9radluene sulfo/acid, penze/sulfonic acid,
Examples include calgenic acids such as oxalic acid, succinic acid, malonic acid, monochloroacetic acid, and dichloroacetic acid. The amount of the acid catalyst used varies depending on the reaction conditions, but is usually 0.01 to 20 parts by weight, preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the phenol.

This condensation reaction does not necessarily require a solvent, but can be carried out using a solvent such as penze, toluene, xine, glyme, glyme, and alcohol having 3 to 12 carbon atoms.

The amino group-containing polyhydric phenol in the present invention is particularly preferably one obtained by such reaction and having a number average molecular weight of about 300 to 5000 as determined by 9GPC chromatography.
Those with other molecular weights can also be used.

The photoresist composition of the present invention contains as an essential component the amine group-containing polyhydric phenol produced by K as described above, but this composition further contains a photosensitizer as an essential component. It is. The photosensitizer is
Any substance can be used as long as it transforms the photorenost composition into a state 11 that is insoluble in an aqueous alkaline solution when irradiated with electron beams, ion beams, X-rays, deep ultraviolet rays, ultraviolet rays, or visible light. The photosensitizer is
Examples include Φ]7zoanodo compounds and alkyl sulfo/compounds, but in the case of optical exposure, chino/diazide compounds are particularly preferred.

Quinonediat compounds are also effective for use with 1*, electron beam, Io7bi-A, X@, and deep ultraviolet light.

Examples of the quinonediazide compound of the photosensitizer include low-molecular and high-molecular compounds containing a naphthoquino/cyanodo group and a penzoquinone noazodo group, such as naphthoquinone cyacytosulfone chloride and a low molecular compound having a hydroxyl group of penzoquinone, such as Hydroquinone, resorcinol, phlorogluci/, 2,4-sohydroxypenzofe7,
Examples include 2+314-trihydroxybenzophenone, and examples of polymeric compounds having hydroxyl groups include 7-enol type mi, polyhydroxystyrene, and the like. In addition, the amino group-containing polyhydric phenol compound described above in the present invention can be used as a compound to be condensed with na-7-toquinone so-anodosulfonic acid chloride or pe/zoquinone-noanodosulfonic acid chloride.

The amount of the photosensitizer added in the 7 Otre ε Nost composition of the present invention is 10
A range of 15 to 50 parts by weight is desirable relative to 0 parts by weight.

In addition to the amino group-containing polyhydric phenol compound and the photosensitizer, the photoresist composition of the present invention may optionally contain additional additives, such as for improving the adhesion of the composition film. Resins, plasticizers, pigments, dyes (light absorbers), etc. can be added.

The photoresist composition of the present invention is usually used after being dissolved in a suitable solvent. The solvent is preferably one that provides a uniform and smooth photoresist coating after evaporation of the solvent at a suitable drying rate.

Such solvents include, for example, ethyl cellosolve acetate, methyl cellosolzoacetate, ethyl selon!
, methyl selonulp, butyl methyl acetate butyl ketone, xylene, etc.

The photoresist composition of the present invention dissolved in the above-mentioned solvent is used to form a predetermined etching resistor using the photoresist composition of the present invention.

After coating the object to be etched and heating and drying it under appropriate conditions, the coating film is exposed to electron beams, ion beams, and X-rays.
The resist is exposed to UV rays, deep ultraviolet rays, ultraviolet rays, visible light, etc., and subjected to in-situ processing to form a predetermined resist/four turns. As the developer, an alkaline aqueous solution can be used, such as an aqueous solution of an inorganic alkali such as hydroxide, potassium hydroxide, or an aqueous solution containing an organic alkali such as tetramethylammonium hydroxide or choline. Further, in addition to the alkaline substance, a surfactant or the like may be added to the developer.

(Examples etc.) Below, polyhydric phenol synthesis examples, examples, and comparative examples are given and further detailed.

Polyhydric phenol synthesis example 1 Aniline 935L was added as an aromatic amine compound in a reactor with a reflux condenser, a stirrer, a thermometer, and a dropping tube exposed to light.
(1 mol), m-cresol 5 as a phenolic compound
4Q (5 mol) and p-cresol 432P (4 mol)
, and U 371=formaldehyde aqueous solution 568p
(7 mol) was added, the contents were heated to 80°C with stirring, and concentrated hydrochloric acid (15%) was added dropwise. The mixture was slowly added dropwise and the temperature was raised to 95° C. while controlling to avoid excessive heat generation, and the mixture was allowed to react at the same temperature for 3 hours.

Next, the reflux condenser of the reactor was replaced with a cooling separator, the temperature of the system was raised to 150''C, and an additional 5ml
Hydrochloric acid, water, unreacted aniline, and cresol were distilled off to obtain an amino group-containing polyhydric phenol compound (Nogelac resin 9855).The comparison point of this resin was determined by microscopy. The temperature was 115°C.

Polyhydric phenol synthesis example 2 As an aromatic amine compound, m-) Louis-)/214? (
2 mol), m-cresol 43 as a phenolic compound
2% (4 moles) and p-cresol 432? (4 moles)
was used, and otherwise in the same manner as in Synthesis Example 1 to obtain amide 7 group-containing polyhydric phenol 10305'-. The softening point of this resin by microscopy was 110°C.

Polyhydric phenol synthesis example 3 m-toluidi>' 2145 as an aromatic amine compound
4 (2 mol), the phenolic compound Toshiteri Vsol 6487 (6 mol), and Resorcinol 220? (2
Amine group-containing polyhydric phenol 885y- was obtained in the same manner as in Synthesis Example 1 except that amine group-containing polyhydric phenol 885y- was used.

The softening point of this resin by microscopy was 130°C.O Polyhydric Phenol Synthesis Example 4 Aniso7186 as an aromatic amino compound? (2 moles)
, 3,5-dimethylphenol 9767 (8 mol) was used as the phenol compound, and otherwise the procedure was the same as in Synthesis Example 1, to prepare amide 7-group-containing polyhydric phenol 888? I got it. The softening point of this resin by microscopy was 124°C.

Polyhydric phenol synthesis example 5 In a reactor similar to that used in synthesis example 1, anisoy93y (i mol) as an aromatic amino compound, m-cresol 5401 (5 mol) as a phenolic compound, and p-
Cresol 4327 (4 mol) and salicylaldehyde=11 (6.5 mol) as an aldehyde were added, and the contents were heated to 80° C. with stirring. Next, 22y of concentrated hydrochloric acid was slowly added dropwise from the dropping tube, and the temperature was raised to IIO'c while controlling to prevent excessive heat generation, and the reaction was allowed to proceed at the same temperature for 3 hours.

Next, the reflux condenser of the same reactor was replaced with a cooling separator, and the temperature inside the system was raised to 150 °C, and further heated to 190 °C under reduced pressure of 5 m) (g) to remove hydrochloric acid, water, and unreacted aniline. and cresol were distilled off to obtain 1392p of amino group-containing polyhydric phenol.The softening point of this resin as determined by microscopy was 146°C.

The polyhydric phenol synthesis example is a synthesis example of a polyhydric phenol that does not contain amide 7 groups. m-Cresol 540 as a phenol compound without using any amine compound? (5 mol), p-cresol 432p (4 mol), and 3 as aldehyde.
7% formaldehyde aqueous solution 51154 (6.3 mol)
Polyhydric phenol 785? was prepared in the same manner as in Synthesis Example 1 except that 't- was used. I got it.

The softening point of this resin by microscopy was 120°C0 Examples 1 to 5 Polyhydric phenol compounds produced in Synthesis Examples 1 to 5 107
For naphthoquino/-(1,2)-soanodoh(2)
- Condensation reaction product of 5-sulfo/acid chloride and 2.3.4-trihydroxybenzophenone 3.5y-Dissolved in total acetic acid ethylene glycol monoethyl ether to prepare a photorenost solution. The resin concentration was adjusted to a concentration (35%) at which a dry coating film of 1.2 μm was obtained when applied under the following coating conditions.

This photoresist solution was filtered through a 0.2 μm filter to remove foreign matter, and then coated on a silicon substrate at 4000 rpm using a spin coater. The obtained wafer was placed in a clean oven at 80°C for 30
After drying for several minutes, use a 350W ultra-high pressure mercury lamp as the light source. Exposure was performed for 5 seconds through a patterned mask.

Next, development was carried out at 21° C. for 60 seconds using commercially available 7spray AZ (trade name, Silagray Co., Ltd.) as a developer.

After development, plot the development speed and exposure amount for each step,
The r value defined by the following formula was determined. The results are shown in Table 1.

r=(tow Rs-1mg R1)/(Log
E2-togEx) In the formula, E is the exposure amount, R is the development speed of the exposed area, and when the exposure amount of the exposed area changes from El to El, the development speed changes from R1 to R, Ic.

The larger the r value, the larger the change in development speed with respect to the change in exposure amount, and the better the sharpness of the flat turns.

Comparative Example Using the polyhydric phenol containing no amine group obtained in Synthesis Example 6, a photoresist was produced in the same manner as in Examples 1 to 5, and coated on a silicon substrate in the same manner.
After drying, it was exposed and developed.

The results were as shown in Table 1.

Table (0) Effects of the Invention The positive photoresist composition of the present invention has an excellent degree of solubility, and in particular has a large r value, which means that the development speed changes greatly with respect to changes in the exposure amount, resulting in a clean turn pattern. is obtained.

Claims (4)

[Claims] (1) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R is an alkyl group having 1 to 9 carbon atoms or a halogen atom, and each R may be the same or different. (q is a number of 0, 1 or 2) and the general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R is an alkyl group having 1 to 9 carbon atoms or A phenol compound represented by a halogen atom, each R may be the same or different from each other, p is a number of 1 or 2, and q is a number of 0, 1 or 2) A positive photoresist composition containing an amino group-containing polyhydric phenol compound obtained by a condensation reaction with at least one aldehyde selected from , alkyl aldehydes, and aryl aldehydes. (2) The positive photoresist composition according to claim 1, which contains a quinonediazide compound. (3) Phenol compounds include ortho-cresol, meta-cresol, para-cresol, dimethylphenol (2,
3-, 2, 4-, 2, 5-, 2, 6-, 3, 4- or 3, 5-isomers, or any mixture of these isomers), resorcin or any mixture thereof The positive photoresist composition according to claim 1 or 2. (4) The positive photoresist composition according to claim 1, 2, or 3, wherein the aldehyde is salicylaldehyde, parahydroxybenzaldehyde, vanillin, or any mixture thereof.