JPS5934532A - Radiation sensitive resist material and its manufacture - Google Patents

Abstract

PURPOSE:To form an extremely sharp and fine pattern and to obtain a resist superior in sensitivity, and dry etching resistance, by using as an effective component a polymer having a specified phenyl ether for recurring units. CONSTITUTION:A polymer represented by formula II is prepared by polymerizing a starting reaction material contg. vinylphenyl ether having formula I , R being -CH3, -CH2-CH=CH-CH3, -CH2-CH=CH3, or -CH(CH3)-CH=CH2-CH3, in the presence of cymyl cessium as a polymerization initiator. A good resist can be formed by irradiating short wavelength radiation, such as X-rays or electron beams to said obtd. radiation sensitive resist material in accordance with an image and developing it with a developing soln. of methyl ethyl ketone- ethanol, or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel negative radiation-sensitive resist material used in microfabrication techniques during the manufacturing process of solid-state devices such as semiconductor elements and integrated circuits, and a method for manufacturing the same.

Recently, demands for higher density, higher speed, and smaller integrated circuits have required the formation of fine patterns, and there is an urgent need to develop lithography technology to replace light. Therefore, microfabrication techniques using radiation having shorter wavelengths than light, such as X-rays and electron beams, have been developed. There are a wide range of performance requirements for resist materials, including sensitivity, resolution, etching resistance, especially dry etching resistance, development tolerance, post-polymerization, and stability, but conventionally developed resist materials meet all of these requirements. The performance was not satisfactory. For example, positive resists such as polymethyl methacrylate have sufficiently good resolution, but have poor sensitivity and dry etching resistance, making them difficult to use practically.
Also, negative resists such as polyglycidyl methacrylate have high sensitivity and good resistance.

However, the resolution and dry etching resistance are poor, and improvements are strongly desired.

In particular, negative resists generally have poor resolution, and there has been a desire to develop materials that exhibit high resolution.

Some of the present inventors previously reported that polystyrene with a narrow molecular weight distribution exhibits high resolution and is good as a resist material (J, Bleatr
ochem, Soa, , / +2ri(3), &4j
(z9g, z)).

As a result of further intensive research, the present inventors have discovered that a radiation-sensitive resist material containing a polymer containing a specific repeating unit as an active ingredient has higher sensitivity. It has been found that pattern formation can be achieved and other required performances such as sensitivity and dry etching resistance can also be satisfied, and the present invention has been achieved.

That is, the gist of the present invention is m general formula CI)OR [wherein R is 10H3, -OR, -0H-OH-OH,
, -cH, -C1(=(J12 or -CI((OH3
)-0'H==OH-ON (representing a) A radiation-sensitive resist material characterized in that the active ingredient is a polymer containing a repeating unit represented by
A radiation-sensitive resist material characterized in that a reaction raw material bicontaining vinyl phenyl crotyl ether is polymerized in the presence of cumyl cesium as a polymerization initiator to produce a polymer represented by the general formula (II) 3- It consists in the manufacturing method.

The present invention will be described below. The radiation-sensitive resist material used in the present invention contains a polymer containing a repeating unit represented by the general formula (I) as an active ingredient. Such polymers include polymers consisting only of repeating units represented by the general formula (I), ie, poly-guvinyl phenyl methyl ether; poly-l-vinyl phenyl crotyl ether;・Phenyl・
Allyl ether; poly-l-vinyl, phenyl-/-#
Examples include f-sil-lotyl ether and copolymers with other monomers. Copolymerizable monomers include diene-based mo/r-styrenic monomers, ie, butadiene; isoprene; l-phenylbutadiene;
3-dimethylbutadiene; styrene; P-chlorostyrene; P--10 mostyrene, etc. can be listed.

41 The polymer used in the present invention can be produced by anionic polymerization of the corresponding monomer according to a known method. In the anionic polymerization of l-vinylphenyl crotyl ether, which is one of the most suitable resist materials in the present invention, cumyl cesium was used as a polymerization initiator, and -to ℃
When polymerized as follows, a polymer with an extremely sharp molecular weight distribution can be obtained in high yield.

In the present invention, generally, a coating solution is prepared by dissolving the above-mentioned polymer and, if necessary, various known additives such as sensitizers and stabilizers in a solvent such as ethyl cellosolve acetate. Accordingly, the film thickness is usually 20,000 mm on a substrate such as a silicon wafer or a glass substrate.
A radiation-sensitive resist material is created by applying the resist material in a zero-cross pattern.

By irradiating such a radiation-sensitive resist material with short-wavelength radiation such as X-rays and electron beams according to the image, and then developing with a developer such as a mixed solution of methyl ethyl ketone and ethanol (727), A good resist can be formed.

Next, the present invention and its effects will be explained using examples.

However, the present invention is not limited to these in any way.

Synthesis Example 1 Monomer (couvinyl phenyl crotyl ether)
Synthesis is performed in the following three steps.

(1) Etherification (synthesis of 4L-acetylphenyl crotyl ether) Add ethanol, z, and thornl to the third flask, followed by P-acetylphenol/μO0 μg (/, 63.2 mol); potassium carbonate/
4<, 2.6FIC/, o3x mol); Potassium iodide/&, J-g (0.1 mol) was added and dissolved with stirring.
3. Add crotyl chloride from the dropping funnel. μg(/, 0
32 mol) and further ethanol, 2 r o ml
added. After refluxing for a period of time, suction filtration was performed, and the ethanol in the p solution was distilled off. Ether and 5% sodium hydroxide aqueous solution were added to the residue, and the mixture was shaken in a separatory funnel. After liquid separation, the ether layer was washed with water, and carbonated. After drying with potassium, the ether was distilled off and vacuum distillation was performed. A yield of 20 ml of l-acetylphenyl crotyl ether was obtained.

<2> M element (a-(α-hydroxyethyl)-phenyl crotyl ether synthesis) Sodium hydroxide 2.0 mt in methanol
g, sodium borohydride lr, ug (0,1lr7
mol) was dissolved while cooling, and after dropwise addition of guacetylphenyl crotyl ether, the solution was refluxed for μ hours. After methanol was distilled off, ether was added, washed with water, and dried over sodium sulfate.

After distilling off the ether, vacuum distillation was performed to obtain g-(α-hydroxyethyl)phenylcrotyl ether in a yield of 7%.

(3) Synthesis of dehydrated vinyl phenyl crotyl ether) Grind 0.369 potassium hydrogen sulfate and 0.1 g of t-butylcatechol in a mortar to give 7dt41-(α-hydroxyethyl)-phenylcrotyl ether 7j,!
i' was added, heated to 0℃, and
The pressure was reduced to . After almost no water has been distilled out, the reaction is stopped, ether is added, and! The mixture was washed with an aqueous solution of IJ and water, dried over 11 um of sodium sulfate, and then distilled. 4'-vinylphenyl crotyl ether was obtained in a yield of jθ%. (bp,,2 fight I(g tata~lO
1°C) 8-2 Polymerization (Anionic polymerization of Ho II-p-vinyl phenyl crotyl ether) (1) Purification of monomer This was carried out in the following three steps.

(1) Monomer and calcium hydride were stirred in a vacuum line (70-4 Hg) for 3 hours and distilled. (Dehydration, degassing) (11) Distilled benzophenone-sodium and monomer in a vacuum line (10-6 Hg) with stirring. (Impurity removal) (IiD) In a similar vacuum line, triphenylmethyl-sodium was distilled with stirring.
Lithium, lithium bromide, and monomer were distilled with stirring.

The above distillation was carried out under reduced pressure while keeping the temperature below 100°C.

(2) Solvent purification In advance, tetrahydrofuran (THF), which has been dried with calcium hydride and sodium wire, is added to the vacuum line (7
The mixture was stirred for an hour in the presence of anthracene and metal sodium pieces (0-4 Hg) and then distilled. Further, a THF solution of α-methylstyrene tetramer disodium salt was added and distilled with stirring.

(3) Overlapping Polymerization was carried out using the polymerization apparatus shown in FIG.

First, after reducing the pressure in the system to 10=tnmHg, it was disconnected from the vacuum line at position t. The inside of the system was washed with a tetrahydrofuran solution of α-methylstyrene tetramarginate 1]um salt in the reagent tank 1, collected in the recovery tank λ, and separated at the position .

Next, the polymerization initiator cumyl cesium /, /X in the reagent tank 3
/ 0-4 mol was put into the reaction tank B, and then 0 ml of the solvent tetrahydrofuran AO from the reagent tank was added while stirring.

After cooling to -7rC, the monomer (guvinylphenyl crotyl ether) t in reagent tank j,! After polymerization for 3 hours, the apparatus was opened, methanol was added to stop the reaction, and the polymer precipitate was collected separately. After drying, it was dissolved in benzene and freeze-dried. Yield: g, +g (Yield: 3%
) got the bolimata.

The molecular weight of this polymer is 7G, Po (HL manufactured by Toyo Soda Co., Ltd.
O-1.27 type). The measurement results are shown in Figure 1.

As is clear from Figure J, Mn: / /, /X/Q4,
A polymer with a sufficiently large molecular weight (Mw/Mn = 7.01) and a sharp molecular weight distribution was obtained.

Example 1 A 5% ethyl cellosolve acetate solution of Bo11 + -vinyl phenyl crotyl ether obtained in the synthesis example was prepared, purified temporarily using Ol and a membrane filter with a pore size of 2 μm, and spun onto a silicon wafer. A film thickness of 3jt00k was obtained. An electron beam (zBx
-sh, 20 KV) and measured the sensitivity curve, as a result of which FIG. 3 was obtained.

For development, the film was immersed in a 7:7 mixture of methyl ethyl ketone and ethanol for λ minutes. Remaining 11- If the irradiation amount at film thickness ro% is used as an index of sensitivity, r, o
x t o-60/cn was obtained, and this value f;7 poly, z, te + zyno value A, rxz exhibited high sensitivity characteristics about 33 times as compared to o-6a/cr&. Also γ−, 2, J+
l) The results were good. Also, the irradiation amount j, 7 X / 0
When a fine pattern with a spacing of 1 μm was formed using -60 eyebrows, an extremely sharp image was obtained. Scanning electron microscope (SE
M) The photograph is shown in the figure≠.

Next, dry etching (Plasma Therm.

HFS-3000D gas 0F4102=Rij/
r), it showed sufficient resistance.

As described above, this resist was found to be extremely excellent as a radiation-sensitive resist.

Example Copoly-govinyl phenylallyl ether was irradiated with electron beam in the same manner as in Example 1 to produce a sharp fine pattern:
/'& get f, :.

12-Example 3 yt'l) Electron beam lithography was performed in the same manner as in Example 1 using -e-hinyl φ phenyl methyl ether, and a good fine pattern was obtained.

Example Electron beam lithography was performed in the same manner as in Example 1 using poly-guvinyl phenyl-7-methylcrotyl ether to obtain a sharp fine image.

[Brief explanation of the drawing]

FIG. 1 shows a schematic diagram of the polymerization apparatus used in the synthesis examples. FIG. 2 shows the results of molecular weight measurement of the polymer obtained in the synthesis example. In the figure, curves //, /2 and 13 show the results measured for polymers polymerized at monomer concentrations of t% and 17%, respectively. FIG. 3 shows the sensitivity curve measured in Example 1. The horizontal axis shows the dose, and the vertical axis shows the film thickness after development (relative to the initial film thickness).
f ratio). Figure t shows a scanning tube 1 photomicrograph of the resist pattern obtained in Example/. /, 3, Hiro, j... Reagent tank, Otsu...
・・・・・・Reaction tank 7・・・・・・・・・Teflon stirrer Applicant Mitsubishi Chemical Industries, Ltd. agent Patent attorney Hase - and 1 other personFigure 3 1og (dose) (c/cny2) 1 A +

Claims (2)

[Claims] (1) General formula (I) R [In the formula, R is -OR, -〇H2-OH, =OH-OH
3, -0H2-OH=: C'Es2 or -0H(O
H3)-0H=0H-OH3. ] A radiation-sensitive resist material characterized by containing a polymer containing a repeating unit represented by the following as an active ingredient. (2) A radiation-sensitive product characterized in that a reaction raw material containing 4t-vinylphenyl crotyl ether is polymerized in the presence of cumyl cesium as a polymerization initiator to produce a polymer represented by the general formula (TI). Method of manufacturing resist material.