JPH0328849A - Positive type photoresist composition - Google Patents

Abstract

PURPOSE:To obtain a photoresist composition adaptable to half-micron lithography using light in the visible or near ultraviolet wavelength region by adding a nonphotosensitive specified compound to a naphtaquinonediazido-novolak type photoresist. CONSTITUTION:The photoresist composition contains an alkalisoluble resin and the photosensitive agent having a naphthoquinonediazido group and as an additive the compound represented by formula I in which Ar<1> is benzene, naphthalene, benzophenene, or their alkyl derivatives freed of (m + n) H atoms on the ring; Ar<2> is an alkyl derivative or the like; X is -NR-, -O-, or the like; R is H or alkyl; m is an integer of 0 - 5; and n is an integer of 1 - 5, thus permitting the obtained photoresist to be superior in resolution and other various characteristics and applicable to development of super LSI and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates generally to radiation-sensitive positive-working photoresist compositions, and more particularly to a composition comprising an alkali-soluble resin and eight λ-naphthoquinone diazide groups. The present invention relates to an improvement in a positive photoresist composition containing a photosensitizer having the following properties.

[Conventional technology]

It is generally said that the increase in the degree of integration of semiconductor integrated circuits is progressing at a speed of V times every three years. Taking J-CDRAM as an example, full-scale production of one with a memory capacity of 1M focus has now begun. Along with this, the requirements for photolithography technology, which is essential for the production of integrated circuits, are becoming stricter year by year. For example, /M bit}D
The production of RAM requires 1 μm level ring graphing technology, and even more highly integrated 'IM. /AM
In bit DRAMK, each O. gμ. 1,o
．． It is expected that lithography technology at the sμm level will be required.

In this photolithography technique, most of the resists conventionally used are negative resists obtained by adding a pisazide compound as a crosslinking agent to cyclized polyisoprene rubber. However, this type of resist has a limited resolution due to swelling during development, and it is difficult to obtain a resolution of 3 μm or more.

Positive photoresists can meet the above requirements. Positive-working photoresists contain both an alkali-soluble resin and a photosensitive material, generally a compound containing the challenged naphthoquinone diazide group. When irradiated with ultraviolet light, naphthoquinone diazide absorbs ultraviolet rays as shown in the formula below, produces ketene through carbene, reacts with water present in the system, and becomes indenyluponic acid, which is dissolved in the alkaline aqueous solution of the developer. .

H,? Since positive photoresists use an alkaline aqueous solution as a developing solution, unlike negative photoresists, the resist does not swell, making it possible to improve resolution.

Therefore, positive photoresists have emerged as resists that are generally non-swellable and have high resolution compared to negative photoresists, and have been widely used in the manufacture of VLSIs. However, in recent years, the b-sub ■ Chron level, %
K.O. It has become clear that conventional positive photoresists cannot meet the demands for resolution at the jμm level. That is, in conventional positive photoresists, an alkali-soluble novolac resin and a l. Cornafthoquinone diazido! Most of the compositions have a sulfonic acid ester as a main component, but positive photoresists containing this co-component as a main component have o.
It was only suitable for mass production at the level of gμ doors, and was not suitable for half-micron phosphorography.

Lithography technologies that can be used for half-micron lithography include X-ray phosphorography and electron beam lithography, but the former has noticeable lag from both sides of the node and resist, while the latter is difficult to mass produce due to throughput. cannot correspond to

Therefore, conventional exposure technology can be utilized, exposure can be performed using light in the visible and near ultraviolet regions, and it is also compatible with half-micron lithography, in other words, the resolution is 0.
．． There has been a strong desire to develop a resist with a good pattern profile for 6μ or more doors.

[Problem to be solved by the invention]

An object of the present invention is to provide a resist composition that solves the problems of the prior art and is compatible with half-micron lithography using light in the visible and near ultraviolet regions.

[Means to solve the problem]

In order to solve these problems, the present inventors have made intensive studies and found that by adding a specific compound that does not have photosensitivity to a naphthoquinonediazide novolak resist, 9.o. It was discovered that a positive type photoresist composition having a resolution of bμm or more, a good pattern profile, and other properties equivalent to or better than conventional ones can be obtained, and the present invention has been made. It's arrived.

That is, the gist of the present invention is an alkali-soluble resin and 1,
A positive photoresist composition comprising a photosensitizer having a u-naphthoquinonediazide group is characterized in that it contains a compound represented by the following general formula (L) as an additive.

0 (In the formula, Ar' represents benzene, naphthalene, penzophenone, or an alkyl derivative thereof from which five hydrogen atoms on the ring are removed, and Ar" is U (In the formula, Ar1 is benzene, naphthalene, penzophenone. Or, these alkyl derivatives are obtained by removing a hydrogen atom having a valence of 10^ on the ring, and Ar2 represents.X represents -NR--01 or -S1, which may be the same or different. Often, R represents a hydrogen atom or an alkyl group, m represents an integer of o - r, and n represents an integer of /~!, /≦m+n≦6.) Hereinafter, the present invention will be explained in detail. .

In the present invention, the following general formula (1) 0 is shown. X represents -NR--01 or -S1, which may be the same or different, and R represents a hydrogen atom or an alkyl group. m represents an integer of θ to S, n represents an integer of 7 to 5, and /≦m+n≦6. ) is added as an additive.

The amount of the additive added is preferably 0.0% of the total solid content of the photoresist composition. /~koθ weight%, more preferably O. S~/S weight κ. Addition amount is 0. If the amount is less than /weight κ, the effect of improving resolution and pattern profile will be small, and if the amount added is more than 2 ozB%, it may cause deterioration of the pattern profile, which is not preferable.

Examples of the additives include (A) phenols, dihydrocarbons, Roxybenzenes, trihydroxybenzenes, thiophenols, benzenedithiols, anilines, benzenediamines, anophenols, aminobenzenethiols, naphthales 4, dihydroxynaphthalenes, naphthalenethiols, diaminonaphthalenes, Examples include esters or amides obtained by reacting aminonaphthols, hydroxybenzophenones, or aminobenzophenones with (B) sulfonic acids or derivatives thereof.

Specifically, for example, CA) includes phenol, o-
Cresol, m-cresol t p-cresol. Coethyl 7-enol, 3-ethylphenol, q-ethylphenol, o-n-propylphenol. p-n
-7' oral virphenol, 0- inglovirphenol, p-improvirphenol, p-n-7
'f-butylphenol, 〇1 sec-butylphenol, p
- sec-butylphenol, m-tert-butylphenol, r)-tert-butylphenol, p
-tertbutylphenol. p-n-amylphenol, p-tert-amylphenol, pll-
Hebutylphenol*ptert-octylphenol, p-nonylphenol, . 2. J-Simethylphenol. Ko. Goodimethylphenol. Mu! Dimethylphenol, co,6-dimethylphenol, . 7.4'-dimethylphenol, 3,s-dimethylphenol, gouinbrobyrn-cresol. S-Inglovir-m-cresol, 6-isoprobyl-m-cresol, . 2, A-diimprobylphenol, co, c. 6-trisec-butylphenol, co. 4l, J
-} tert-butylphenol; catechol,! , J-dihydroxybenzene, hydroquinone r'' Ccrt monomethylcatechol, J-methylcatechol, 84-dihydroxy-g-methylbenzene, /.J-dihydroxy-4-methylbenzene, t
, 3-cyhydroxy-3-methylbenzene, J. l
I-cyhydroxy-7-methylbenzene, . y. s-hydroxyethylbenzene, co-dihydroxyethylbenzene, coutert-octylresorcinol; birogallol, l. 3. s-}lyhydroxybenzene. l,co. 4l-trihydroxybenzene, F
- tert - 7'f/I/Hio jj role: thiophenol, 0-}luenethiol. m-} toluenethiol, p-toluenethiol, thioxylenol tptert-phthylthiophenol; toluene-j4
-dithiol,1,! -benzenethiol; aniline;
N-improvylaniline, O-isopropylaniline. p-isobrobylaniline *N-n-phthylaniline, p-n-7” thylaniline, p-sec-7
"Tylaniline% p-n-hexylaniline, co, 3
-xylidine, co, terxylidine, 4,S-xylidine, 4.6-xylidine, J,+-xylidine, 3.3
-xylidine, m-xylidine, p-xylidine, ○1 toluidine, m-}leucine. p-Toluidine; O-phenylenediamine, m-7enylenediamine, p-phenylenediamine, ! -Diamino 101ki? Ren;0
-aminophenol, m-aminephenol, p-a■
Nophenol+m--1-Thylaminophenol, Guaminol-m-Cly 7'', 6-amino-m-cresol, 5-amino-〇-cresol, 4-
Amino-p-cresol, J-ethylamino-p-cresol. 2-aminobutylphenol; o-aminobenzenethiol; α-na7}-/L1,
β-naphthol;/. J-dihydroxynaphthalene, /
l4t-dihydroxynaphthalene, /. terdihydroxynaphthalene, l,6-dihydroxynaphthalene, 7.
7-Dihydroxynaphthalene,! ．． ，? -dihydroxynaphthalene. 2.7-dihydroxynaphthalene; J-naphthalenethiol; l,s-diaminonaphthalene, 1,
g-diaminonaphthalene, j,J-diaminonaphthalene; 3-amino l-naphthol, ! -Aminoconaphthol, 6-aminoconaphthol. g-aminocona7tol; co-hydroxybenzophenone, q-
Hydroxybenzophenone, 1,2'-dihydro? xypenzophenone, co, cudihydroxybenzophenone, 414'-dihydroxybenzophenone, u,
J, 4'-monotrihydroxybenzophenone, 2,+1,
II'-}rihydroxybenzophenone, J+2'g, C'-tetrahydroxybenzophenone, Co, 3k.
Cutetrahydroxybenzophenone, . 2, J, λ1, y/-pentahydroxybenzophenone; J
．． Examples include 3'-diaminobenzophenone, 3,'l-diaminobenzophenone, +,lI'-diainobenzophenone, and (B) includes benzenesulfone H
, p-}Luenesulfonic acid io }Luenesulfonic acid, ethylbenzenesulfonic acid, probylbenzenesulfonic acid, mesitylenesulfonic acid, l-naphthalenesulfonic acid, conaphthalenesulfonic acid, or derivatives thereof.

In the present invention, a novolank resin or polyhydroxystyrene is usually used as the alkali-soluble resin. Preferably 0-cresol. -Cresol. p
-1 resol or m-cresol, p-cresol, nopolac resin condensed with formaldehyde
- Novorasoc resin is used, which is obtained by condensing cresol and xylenol alone or in combination with formaldehyde. More preferably, a mixture of 5o-cresol, m-cresol, p-cresol within the range shown in Figure 4, or m-creso-A1, p-cL/sol, xylenol within the range shown in Figure 4. Novolac resins are used which are prepared by condensing a mixture within the range with formaldehyde.

Rose formaldehyde may be used instead of formaldehyde.

Condensation is usually carried out using carboxylic acids such as oxalic acid and citric acid, hydrochloric acid,
It is carried out using a mineral acid such as sulfuric acid or phosphoric acid or a Lewis acid as a catalyst. As xylenol, λ,S-xylenol or Jj-xylenol is preferably used.

The weight average molecular weight of the alkali-soluble resin is a polystyrene equivalent value (GPC measurement), /. 0 0 0~/!
;,000,Good IL<is 1,! 00~/θ, 0 0 0
Those are preferably used.

In addition, in the present invention, examples of the photosensitizer containing l',21naphthoxy/'diazide group include. 2. J. 821 naphthoquinonediazide-3''-sulfonic acid ester of trihydroxybenzophenone If 〈is 8=1 nanotoquinonediazide-y-sulfonic acid ester, .;l
, J. ! ．． 〆-tetrahydroxybenzonoenone 1,. 2-naphthoquinone diazidoter sulfonic acid ester or /9-naphthoquinone diazido q-sulfonic acid ester, l or. 2. J. lI. ．． ! ．．
〆-bentahyde-benzonoenone, con-naphthoquinone diazide-j-snorefonic acid, or/. 11 naphthoquinone cyadi}'-&-sulfonic acid ester, etc. are used. The average esterification rate used is preferably 30% or more.

The mixing ratio of the alkali-soluble resin and photosensitizer is usually expressed as the ratio of naphthoquinone diazide groups in the total solid content. As an index thereof, the number of milligram equivalents of naphthoquinonediazide groups in the solid content/y will be expressed and referred to as the Ω ratio. In the case of the present invention, the Q factor is preferably 0. ．． 2~/. 0
, more preferably 0.3 to 0. ? are used.

Usually, they are used by dissolving them in an appropriate solvent. The solvent is not particularly limited as long as it has sufficient solubility for the photosensitizer, resin, sulfonic acid ester, or sulfonic acid amide and provides good coating properties; Cellosolve solvents such as selonnorev, ethylcellonorb, methyl cellosolve acetate, ethyl cellosolve acetate, ester solvents such as butyl acetate, amyl acetate, highly polar solvents such as dimethylformamide, dimethylacetamide, N-methino 1 novirolidone, Alternatively, mixed solvents thereof, or those to which aromatic hydrocarbon water Ak'll'a is added may be used.

The developing solution for the positive photoresist composition of the present invention includes inorganic anoleka such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia. ethylamine, 11-probylamine-1. Secondary amines such as diethylamine, di-n-propylamine, triethylamine, N. J-class amines such as N-diethylmethylamine, quaternary ammonium salts such as tetramethylammonium hydroxide, trimethylhydroxyethylammonium hydroxide, or those to which alcohol, surfactant, etc. are added. can be used.

The positive photoresist composition of the present invention is useful not only for the production of ultra-1, SI, but also for general IC production, mask production, and offset printing.

〔Example〕

Next, the present invention will be explained in more detail by citing examples.
The present invention shall not be limited in any way by the embodiments unless it exceeds the gist of the invention.
It's not something to be hated.

Synthesis Example / (Synthesis of tri(halatoluenesulfonyl)benzene) Labyrogallol + 2.32? Add triethylamine 7.1, If (76
mmol) was added dropwise at room temperature, and the reaction was carried out in a room for g hours after the completion of the dropwise addition. After the reaction was completed, the reaction solution was filtered through a gold suction door to separate the precipitated gold salt. This P solution F was dropped into 700 ml of water to crystallize the reaction product, and the precipitated solid gold I4 was separated, washed with water, and dried for 7 min. 0? Tri(balatoluenesulfonylnobenzene) gold was obtained.

Synthesis Example 2 (Synthesis of novolak resin) m-cresol/guco has y<i. 3 comorno, p-cresol/90.09 (/.74 mol), co,! -xylenol/&/. Or (mixture of eight kota morno under stirring 9
Heated to 7°C. This is a 37mm% formalin aqueous solution!
713? (As formaldehyde, a solution of J.QO Molino's oxalic acid/0.Off (0.079 mol) was added dropwise, and after the dropwise addition was completed, the S was heated at 9/-94t℃.
Allowed time to react. After the reaction was completed, water and unreacted heptamer were distilled off under reduced pressure while gradually increasing the bath volume (final liquid temperature/6°C, 10mtprHg). The product was allowed to cool and F
/+f novolak resin was obtained. This nopolanok resin'
Weight average molecular weight (Mw) as analyzed by iGPc
was 1,700.

Synthesis Example 3 (Synthesis of photosensitizer) 2+J,4I,41'-tetrahydroxybenzophenone/7.2? (CuO mmorno, octaconaphthoquinonediazide-5-sulfonyl chloride SA.+t
2 (co/0 mmol) to 8 g dioxane l deθml,
It was dissolved in a mixed solvent of N-methylpyrrolidone syml.

To this, triethylamine 2 (co/0 mmol) was added dropwise over a period of 0.S hours without stirring, and the mixture was further stirred for 0.5 hours. Separate P, wash with water and dry, A7.'l
An esterified product of t was obtained. In the obtained product, three hydroxyl groups were esterified on average.

Example/Tri(balatoluenesulfonyl)benzene θ synthesized in Synthesis Example 1. 2θlIg, synthesis example. The novolac resin y, o o ti synthesized in Step 2 and the photosensitizer 8θ01 synthesized in Synthesis Example 3 were mixed with ethylcerone lupacetate l2. A photoresist composition was prepared by dissolving the solution in θ9 and passing through a precision sieve using Teflon paper (O.X μm). This photoresist composition was coated onto a silicon wafer with a diameter of S inch to a thickness of 822 μm using a spin coating device (manufactured by Dainippon Screen Manufacturing Co., Ltd.), and pre-painted on a hot plate at 9 k°C/min. After that, use a reduction projection exposure device (
Manufactured by GCA; DSW, NA=θ. 3g) and exposed to light using a 2311 weight polytetramethylammonium hydroxide aqueous solution at 23°C! Developed for θ seconds. The obtained resist pattern was observed with a scanning electron microscope (manufactured by Akashi Seisakusho ■), and the resolution was defined as the minimum line and space pattern size that was sharply resolved.

The results are shown in Table 1 and Figure 3.

Example co The mixing ratio of tri(paratoluenesulfonyl)benzene synthesized in Synthesis Example 1, novolak resin button synthesized in Synthesis Example λ, and photosensitizer synthesized in Synthesis Example 3 was changed as shown in Table 1. Except for the above, a photoresist composition was prepared and evaluated in the same manner as in Example. The results are shown in Table 1 and Figure 3.

Comparative Example/ Example 1 using the novolac resin synthesized in Synthesis Example 2 and the photosensitizer synthesized in Synthesis Example 3 (see Table 7 for the mixing ratio)
A photoresist composition was prepared and evaluated in the same manner as described above. The results are shown in Table 1 and Figure 3.

When the sulfonic acid ester was added again, the pattern profile was poor and the resolution was low. On the other hand, when the sulfonic acid ester synthesized in Synthesis Example 1 was added, both the pattern profile and resolution were good, and the NA value used in the mass production process of recent VLSIs was θ. lI
The use of the above-mentioned exposure apparatus was sufficient to cope with micron phosphorography.

Note 1) Resolution is defined as the minimum pattern size that can be resolved with a sharp pattern shape.

[Effects of the Invention] The composition of the present invention has excellent resolution, sensitivity, residual film rate,
A photoresist with excellent properties such as heat resistance can be obtained, and can be used very suitably for the development of VLSI and the like.

[Brief explanation of drawings]

Figures 1 and 2 are triangular coordinates showing preferred component ranges of the novolac resin used in the present invention. FIG. 3 is a cross-sectional view showing the pattern profile of O-6 μm line ● and ● space obtained in Examples 1 and 2 of the present invention and Comparative Example. In FIG. 3, (a) shows the pattern profile obtained in Example t, (b) shows the pattern profile obtained in Example C, and (C) shows the pattern profile obtained in Comparative Example/. Applicant Mitsubishi Kasei Corporation Representative Patent Attorney Hasegawa = (and one other person)

Claims (1)

[Claims] (1) A positive photoresist comprising an alkali-soluble resin and a photosensitizer having a 1,2-naphthoquinonediazide group, characterized by containing a compound represented by the following general formula (I) as an additive. A positive photoresist composition. ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・(I) (In the formula, Ar^1 is benzene, naphthalene, benzophenone, or an alkyl derivative thereof, with m+n hydrogen atoms on the ring removed. and Ar^2 indicates ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or these alkyl derivatives.X is -NR-
, -O- or -S-, which may be the same or different, and R represents a hydrogen atom or an alkyl group. m represents an integer of 0 to 5, n represents an integer of 1 to 5, 1≦m
+n≦6. )