JPH01100537A - Pattern forming material - Google Patents

Abstract

PURPOSE:To provide a material effective for fine working of a substrate having steps by modifying a phenolic resin, which contains an alkali soluble resin and quinone diazide compd. and in which the alkali soluble resin consists of a phenol compd. and aldehyde compd., by a specific silicone compd. CONSTITUTION:This pattern forming material is formed by modifying the phenol resin, which consists of the alkali soluble resin and the quinone diazide compd. and in which the alkali soluble resin consists of the phenol compd. and aldehyde compd., by the silicone compd. having the basic structure expressed by formula I-III. In formulas (I), (II), (III), at least one of the substituents is a functional group; (a)-(f) are >=1 integer. The pattern forming material which is effective for fine working of the substrate having steps and has the excellent resistance to RIE of oxygen is thereby obtd.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a positive pattern forming material, and in detail,
Semiconductor device, magnetic bubble memory device.

It relates to fine pattern forming materials necessary for manufacturing integrated circuits and the like.

<Prior Art> Photolithography is used as an important means in the production of semiconductor devices, magnetic bubble memory devices, and the like. In photolithography, light diffraction,
It is known that resolution decreases when the resist film is thick due to effects such as reflection from the substrate. Therefore, if the thickness of the resist is reduced in order to obtain a high-resolution pattern, there is a problem that the resistance of the resist becomes insufficient in subsequent steps. Furthermore, the substrate surface processed by photolithography is not necessarily flat;
Since the film often has various uneven steps, a sufficient film thickness is required to cover these steps.

It is difficult to satisfy these conflicting demands with a single-layer resist process, and in order to solve this problem, a pattern forming method using a three-layer resist has been proposed by Bell.
) Institute of J.M., Moran (J.

M, Moran) et al. In the three-layer resist process, the lower layer is an organic polymer film that can be removed by oxygen RIE (reactive ion etching), and the middle layer is an oxygen RIE film such as polysilicon or silicon dioxide.
This forms an inorganic film that is difficult to remove, and a resist film that forms a pattern on top.

The upper resist film is irradiated with a desired pattern and developed to obtain the desired pattern. Next, use this upper layer as a mask,
The pattern is transferred to the intermediate layer of the inorganic film by dry etching. Finally, using the intermediate layer pattern as a mask, the oxygen R
Transfer the pattern to the underlying organic polymer film using IE,
A thick organic polymer film pattern is formed. As described above, three-layer structure resists have difficult problems, such as complicated processes and the need to form the intermediate inorganic film to be thin and prevent pinholes from forming.

<Problems to be Solved by the Invention> An object of the present invention is to solve the above-mentioned drawbacks of the prior art, to provide the above-mentioned three-layer resist process that is particularly effective for microfabrication of substrates having steps, and that is resistant to oxygen RIE. It is an object of the present invention to provide a positive pattern forming material which is particularly suitable for use in a two-layer structure resist process and which has both the roles of an upper layer and an intermediate layer.

<Means for Solving the Problems> According to the present invention, the phenol resin comprising an alkali-soluble phenol resin and a quinonediazide compound, and the alkali-soluble resin comprising a phenol compound and an aldehyde compound, is divided by ÷S i −0+r+S i −
0 → " (■) Or, the basic skeleton is (provided that at least one of the substituents in (1), (III) and (III) is a functional group and 1alblcl
dle and f are integers of 1 or more) A pattern forming material is provided that is modified with a silicone compound.

The alkali-soluble resin used in the present invention is a silicone-modified phenol resin consisting of a phenol compound and aldehydes.

Examples of the phenolic compound used in the above phenolic resin include phenol, cresol, xylenol, ethylphenol, phenylphenol, resorcinol,
Pyrocatechol, hydroquinone, bisphenol A,
Examples of pyrogallol and aldehydes include porno, aldehyde, acetaldehyde, benzaldehyde, and terephthalaldehyde.

The silicone compound used for modifying the phenolic resin in the present invention has the basic skeleton (I), (IF) or (
I[[), and the functional group is
Examples include halogen, hydroxyl group, carboxyl group, alkoxy group, or groups having these functional groups (eg, halogenated alkyl group, hydroxyalkyl group, carboxyalkyl group, etc.). These functional groups are (I), (
It is necessary that at least one of II) or (m) be present, otherwise the object of the present invention cannot be achieved. Note that groups other than functional groups are hydrocarbon residues or hydrogen that may contain appropriate elements, such as alkyl groups.

Examples include aryl groups, aralkyl groups, alkenyl groups, polyoxyalkyl groups, substituted alkyl groups, and substituted aryl groups.

Representative examples of silicone compounds include general formulas (1') and (n'
), (III').

RI General formula (1') R3-(-5t-0-)a-RA
In the formula, R1, R2; an alkyl group, an aryl group, an aralkyl group.

Alkenyl group, polyoxyalkyl group, substituted alkyl group, substituted aryl group R3; halogen, hydroxyl group, carboxyl group, alkoxy group, halogenated alkyl group, hydroxyalkyl group, carboxyalkyl group, alkyl group, aryl group, aralkyl group, alkenyl group, polyoxyalkyl group, substituted alkyl group, substituted aryl group R4; hydrogen, alkyl group, halogenated alkyl group.

Hydroxyalkyl group, carboxyalkyl group, trialkylsilyl group a; integer R2R4 of ≧1, where R1, R2, R3, R4, R5; halogen, hydroxyl group, carboxyl group, alkoxy group, halogenated alkyl group,
Hydroxyalkyl group, carboxyalkyl group, aryl group, aralkyl group.

Alkenyl group, polyoxyalkyl group, substituted alkyl group, substituted aryl group R6; hydrogen, alkyl group, halogenated alkyl group.

hydroxyalkyl group, carboxyalkyl group, trialkylsilyl group, c: an integer of ≧1, where R+ +R2, R31R4, Rs+Rs: alkyl group, aryl group.

Aralkyl group, alkenyl group, polyoxyalkyl group,
Substituted alkyl group, substituted aryl group th, R8, R+, R
+G+ alkyl group, aryl group, aracyl group, alkenyl group, polyoxyalkyl group, substituted alkyl group, substituted aryl group, halogen, hydroxyl group, carboxyl group, alkoxy group, halogenated alkyl group, hydroxyalkyl group, carboxyalkyl group d, e, f; Integer of ≧1 In general formula (■2), R1 and R2 are methyl group, ethyl group, phenyl group, benzyl group, vinyl group, polyethylene oxide group R3 is chlorine, hydroxyl group, carboxyl group , methoxy group.

Ethoxy group, chlorinated methyl group, chlorinated propyl group, hydroxymethyl group, hydroxyethyl group, hydroxypropyl group, carboxymethyl group, carboxyethyl group, methyl group, ethyl group, phenyl group, benzyl group, vinyl group.

The polyethylene oxide group R4 includes hydrogen, methyl group, ethyl group, halogenated methyl group, halogenated propyl group, hydroxymethyl group, hydroxyethyl group, hydroxypropyl group, carboxymethyl group,
Examples include carboxyethyl group, trimethylsilyl group, and triethylsilyl group.

R1, R2, R3, R4, and R5 in the general formula (■') are chlorine, hydroxyl group, carboxyl group, and methoxy group.

Ethoxy group, chlorinated methyl group, chlorinated propyl group, hydroxymethyl group, hydroxyethyl group, hydroxypropyl group, carboxymethyl group, carboxyethyl group, methyl group, ethyl group, phenyl group, benzyl group, vinyl group.

polyethylene oxide group As R6, Hydrogen, methyl group, ethyl group, chlorinated methyl group.

Chlorinated propyl group, hydroxymethyl group, hydroxyethyl group, hydroxypropyl group.

Carboxymethyl group, carboxyethyl group.

Examples include trimethylsilyl group and triethylsilyl group.

In the general formula (■'), RI, R2, R3, Rz, Rs, Re are methyl group, ethyl group, phenyl group, benzyl group, vinyl group, polyethylene oxide group R7, R8, R9, RI[l Examples include chlorine, hydroxyl group, carboxyl group, and methoxy group.

Ethoxy group, chlorinated methyl group, chlorinated propyl group, hydroxymethyl group, hydroxyethyl group, hydroxypropyl group, carboxymethyl group, carboxyethyl group, methyl group, ethyl group, phenyl group, benzyl group, vinyl group.

polyethylene oxide group Examples include.

The reaction for obtaining a silicone-modified product from a phenol resin and a silicone compound utilizes the reactivity of the hydroxyl group of the phenol resin and the functional group of the silicone compound. For example, the reaction between a silicone compound having a hydroxyl group or an alkoxy group as a functional group and a phenol resin results in an etherified silicone modified product, and the reaction between a silicone compound having a carboxyl group and a phenol resin results in an esterified silicone modified product. Can be done. These etherification reactions and esterification reactions can be carried out according to conventional methods.

The content of Si in the silicone modified product is usually 5% by weight or more, preferably 10% by weight or more. Oxygen RIE resistance is insufficient at 5% by weight of no grooves.

The quinonediazide compound used in the present invention is not particularly limited, but includes, for example, 1,2-benzoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonesiasito-4-sulfonic acid ester, 1. 2-naphthoquinonediazide-5-sulfonic acid ester, 2.1-
naphthoquinone cyato-4-sulfonic acid ester, 2.
Examples include 1-naphthoquinone cyasito-5-sulfonic acid ester.

These exemplified quinonediazide compounds are described in Photoresist J, 50. (1975) by McGraw-Hill Incorporated, New York, by DeForest, Photoresist J, 50.
e-ForestrPhotoresistJ, 50.
(1975).

McGrow-Formerly II Inc., (New York
), Gentabe Nagamatsu, Hideo Inui, Photosensitive Polymer J, 11
7. (1980), Kodansha (Tokyo), etc.

The blending amount of these quinonediazide compounds is 10 to 100 parts by weight, preferably 20 to 70 parts by weight, based on 100 parts by weight of the alkali-soluble resin. If it is less than 10 parts by weight, it will be impossible to form a pattern, and if it exceeds 100 parts by weight, the sensitivity will be significantly lowered and undeveloped areas will likely remain in exposed areas.

The pattern forming material of the present invention is used by dissolving the above-mentioned alkali-soluble resin and quinonediazide compound in a solvent.
Examples of solvents include ketones such as acetone, methyl ester ketone, and cyclohexanone, glycol ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether, cellosolve esters such as methyl cellosolve acetate and ethyl cellosolve acetate, toluene, xylene, etc. Examples include aromatic hydrocarbons. These can be used alone, but 2
More than one type may be mixed and used.

Furthermore, the pattern forming material of the present invention may contain, if necessary,
Surfactants, storage stabilizers, sensitizers, anti-striation agents, etc. can also be added.

As the developer for the pattern forming material of the present invention, an alkaline aqueous solution is used. Specifically, sodium hydroxide lx,
Potassium hydroxide, sodium silicate.

Inorganic alkalis such as ammonia, ethylamine.

Primary amines such as propylamine, diethylamine,
Tertiary amines such as dipropylamine, tertiary amines such as trimethylamine and triethylamine, alcohol amines such as diethylethanolamine and triethanolamine, tetramethylammonium hydroxide,
Examples include aqueous solutions of quaternary ammonia 11 salts such as trimethylhydroxyethylammonium hydroxide and tetraethylammonium J1 hydroxide.

Furthermore, if necessary, add methanol or
Appropriate amounts of water-soluble organic solvents such as ethanol, propatool, and ethylene glycol, surfactants, and resin dissolution inhibitors can be added.

<Effects of the Invention> Thus, according to the present invention, it is possible to obtain a pattern forming material that is effective in microfabrication of substrates having steps and has excellent resistance to oxygen RIE, as compared to the prior art.

<Example> The present invention will be described in more detail with reference to Examples below. Note that parts and percentages in Examples and Comparative Examples are based on weight unless otherwise specified.

Example 1 50 g of rn-cresol novolak resin and 200 g of methyl isobutyl ketone were charged into a reactor, and after thorough stirring to dissolve the resin, 0.4 g of tetraethyl titanate (15-g) was added. After the temperature of this reactor was raised and the resin solution started to reflux, 50 g of silicone compound No. 1 in Table 1 below was added and kept under reflux for 5 hours. Next, methyl isobutyl ketone was distilled off under reduced pressure, and the product was taken out from the reactor and cooled to obtain 104 g of resin. As a result of GPC (gel permeation chromatography) measurement of the above resin, Mw=5600. As a result of X-ray fluorescence analysis, the silicon content was 10%.

100 parts of the above resin, 23 parts of a quinonediazide compound in which 70% or more of the -OH groups of 2,3.4-) lyhydroxybenzophenone are esters of 1,2-naphthoquinonediazide-5-sulfonic acid, and ethyl cellosolve acetate. The solution was dissolved in 450 parts and filtered through a 0.1 μm Teflon filter (manufactured by Millibore) to prepare an upper layer resist solution.

First, commercially available positive photoresist AZ-1350J (
Silapray) was coated on a silicon wafer with a spinner, then baked at 200°C for 30 minutes to a thickness of 1.5 μm.
A lower layer film of m was formed. Next, the above-mentioned upper layer resist was applied with a spinner onto the silicon wafer on which the AZ-1350J lower layer film was formed, and then baked at 85°C for 30 minutes to form an upper layer resist with a thickness of 0.6 μm. did.

This exposure wafer was exposed using an FPA-1550 (manufactured by Canon) stepper and a test reticle, and exposed at 23°C with a tetramethylammonium hydroxide aqueous solution.
The upper resist film was developed by a dipping method for 1 minute to obtain a positive pattern.

Using this upper layer resist as a mask, oxygen RIE (pressure 2 x 1.0-3 Torr, oxygen flow rate 20 SCCM, power 400 W, RF frequency 13.
56M) (z, electrode temperature 10°C) to transfer the pattern to the lower layer film.

When the patterned wafer was taken out and inspected under an optical microscope, it was found that the lower layer that was not covered by the upper layer on which the test pattern was formed had been completely removed.

The film thickness of the part covered by the upper layer on which the test pattern was formed was 1.8 μm or more when measured with a film thickness meter Alpha Step-200 (manufactured by Tenco), and the pattern faithfully reflected the test pattern of the reticle. was able to form.

Example 2 50 g of resin consisting of m-cresol, p-cresol, 2,5-xylenol and formaldehyde and N in Table 1
50 g of the silicone compound No. 2 was reacted in the same manner as in Example 1 to obtain 103 g of resin. GP of the above resin
As a result of C measurement, Mw=4500, and as a result of X-ray fluorescence analysis, the silicon content was 12%.

100 parts of the above resin, 23 parts of a quinonediazide compound in which 90% or more of the 10H groups of 2,3.4-)lyhydroxybenzophenone are esters of 1,2-naphthoquinonediazide-4-sulfonic acid, fluorine-based surfactant 0.1
part was dissolved in 450 parts of ethyl cellosolve acetate, and 0
．． It was filtered through a 1 μm microfilter to prepare an upper layer resist solution.

When the above resist was patterned under the same conditions as in Example 1, the film thickness of the portion covered by the upper layer on which the test pattern was formed was 1.9 μm or more, and the pattern faithfully reflected the test pattern of the reticle. was able to form.

Example 3 Resin 50 consisting of resorcinol and formaldehyde
g and 45 g of silicone compound N063 in Table 1 were reacted in the same manner as in Example 1 to obtain 98 g of resin. As a result of GPC measurement of the above resin, MW=6500. As a result of X-ray fluorescence analysis, the silicon content was 10%.

100 parts of the above resin, 70% or more of the 10H groups of 2,3,4,4'-tetrahydroxybenzophenone are 1,2-
20 parts of a quinonediazide compound which is an ester of naphthoquinonediazide-5-sulfonic acid, 0 fluorine surfactant
．． Dissolve 1 part in 450 parts of cyclohexanone to give a diameter of 0.1 μm.
A resist solution for the upper layer was prepared by filtration through a Teflon filter.

When the above resist was patterned under the same conditions as in Example 1, the film thickness of the portion covered by the upper layer on which the test pattern was formed was 1.8 μm or more, and a pattern that faithfully reflected the test pattern on the reticle was obtained. was able to form.

Example 4 50 g of a resin consisting of m-cresol, p-cresol, pyrogallol and formaldehyde and 50 g of silicone compounds No. 4 in Table 1 were reacted in the same manner as in Example 1 to obtain 103 g of resin.

As a result of GPC measurement of the above resin, Mw = 4700°X
As a result of line fluorescence analysis, the silicon content was 9%.

' 100 parts of the above resin, 70% or more of the 10H groups of 2,3,4,4'-tetrahydroxybenzophenone are 1,2
-Naphthoquinone diazide 20 parts of a quinone diazide compound, which is an ester of 5-sulfonic acid, was dissolved in 450 parts of ethyl cellosolve acetate, and the solution was filtered through a 0.1 μm Teflon filter to prepare a resist solution.

The resist solution was applied onto a silicon wafer using a spinner, and then baked at 80° C. for 30 minutes to form a resist film with a thickness of 1 μm, which was used as a wafer for exposure. This exposure wafer was exposed using an FPA-1550 stepper and a test reticle, and the resist film was developed in an aqueous solution of trimethylhydroxyethylammonium hydroxide at 23°C for 1 minute using the immersion method, and then in ion-exchanged water for 1 minute.
A positive pattern was obtained by rinsing for 0 seconds.

The patterned wafer was taken out and the resolution was examined using a scanning electron microscope JSM-T330 (manufactured by JEOL Ltd.), and it was found that the resolution was good down to 0.9 μm. The wafer on which this pattern was formed was etched by oxygen RIE using a dry etching device ILD-4013T, and as a result, the remaining film rate was 70%.

Example 5 Resin 50 consisting of pyrogallol and pol-11 aldehyde
g and 45 g of silicone compound No. 5 in Table 1 were reacted in the same manner as in Example 1 to obtain 97 g of resin. As a result of GPC measurement of the above resin, Mw=5800. As a result of X-ray fluorescence analysis, the silicon content was 11%.

100 parts of the above resin, 25 parts of a quinonediazide compound in which 70% or more of the 10H groups of 2,3,4-trihydroxybenzophenone are esters of 1,2-naphthoquinonediazide-5-sulfonic acid, 0 fluorine-based surfactants .2 parts were dissolved in 450 parts of ethyl cellosolve acetate, and 0
．． It was filtered through a 1 μm microfilter to prepare an upper layer resist solution.

When the above resist was patterned under the same conditions as in Example 1, the film thickness of the portion covered by the upper layer on which the test pattern was formed was 1.9 μm or more, and the pattern faithfully reflected the test pattern of the reticle. was able to form.

Comparative Example Resin consisting of m-cresol, p-cresol and forno, aldehyde 100 parts, 70% or more of the 10H groups of 2,3.4-)lihydroxyhenzophenone are 1.2
-Naphthoquinone diazide 23 parts of a quinone diazide compound, which is an ester of 5-sulfonic acid, was dissolved in 450 parts of ethyl cellosolve acetate, and filtered through a 0.1 μm Teflon filter to prepare an upper layer resist solution.

When the above resist was patterned under the same conditions as in Example 1, the film thickness of the part covered by the upper layer where the test pattern was formed was 0, and the pattern of the part of the reticle where the test pattern was formed was exposed to oxygen. It was found that it was completely removed by RIE.

Margin below Table 1

Claims (1)

[Scope of Patent Claims] 1. Comprising an alkali-soluble resin and a quinonediazide compound, and the alkali-soluble resin is a phenolic resin composed of a phenol compound and an aldehyde compound, and the basic skeleton is ▲ mathematical formula, chemical formula, table, etc. ▼(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) Or, the basic skeleton is ▲There are mathematical formulas, chemical formulas, tables, etc.▼(III) (However, in (I), (II), and (III) At least one of the substituents is a functional group, a, b, c, d, e
and f is an integer of 1 or more) A pattern forming material characterized in that it is modified with a silicone compound.