JPS61118741A - Photoresist material - Google Patents

Abstract

PURPOSE:To improve a contrast of an image on a copyed substrate such as a mask used in a photographically etching process of LSI by forming a specific compd. layer of N-phenylnitrone derivatives on a surface of a photoresist layer provided on a substrate to be etched. CONSTITUTION:The above described specific compd. is a compd. shown by formula I wherein Z is (R<3>)a-Q-R<4> or R<5>, Z' is -R<6>-(X)b, R, R<1>, R<2>, R<3> are each a hydrogen atom, 1-8C an (substd.) alkyl or 6-13C an (substd.) aryl group, Q is a halogen atom or a di or tri valency atom selected from O, S and N, (a) is 0, 1 or 2, R<4> is 6-13C a (substd.) aryl group, R<5> is a (substd.) heterocyclic ring contg. O, S and/or N atoms, 6-20C an aromatic hydrocarbon group, (b) is 1, 2 or 3, (n) is 0, 1 or 2, X is a halogen atom, -CN or -O-R7 group, R7 is 1-12C a (substd.) aryl group, (m) is 1 or 2, if (m) is 1, (b) is 1, 2 or 3, and X is -CO-aryl or -O-R7 group or a group shown by formula II. By applying the above described compd., the mask capable of forming a high contrast pattern is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION ``Industrial Application'' The present invention relates to a photoresist material capable of enhancing the contrast of an image of a copy such as a mask used in a photolithography process in the manufacture of integrated circuits. It is related to.

``Prior art'' Electronic components such as semiconductors, ICs, and LSIs are manufactured by drawing arbitrary circuit patterns using optical means, exposing the resist to light through a mask, developing it, and etching the substrate. There is. In recent years, as integrated circuits have become more highly integrated, patterns have become increasingly finer. For this reason, it is strongly desired to form fine/e-turns with high accuracy in the resist. However, in the above method, the resolution of the resist image is significantly affected by the diffraction of the exposing light and the scattering and reflection of the light from the surface of the underlying silicon substrate. In particular, when using a widely used projection type photolithographic apparatus, its resolution is said to be approaching its physical limit due to the wavelength of the light used for exposure. Furthermore, it is currently difficult to expect a dramatic improvement in the resolution of lenses used in these devices. However.

In recent years, a method of enhancing the contrast of an image in photoresist operation has been proposed and has made progress, as seen in Japanese Patent Application Laid-open No. 10-106-6 Hiroshi.

This method involves forming 1iI' containing a photobleaching compound adjacent to the photoresist layer and exposing it to light.
It has been described that a nitrone compound having a specific chemical structure can be used as a photobleaching compound to enhance the contrast of light that reaches the photoresist layer.

However, with some of these compounds, the desired optical density may not be obtained during prebaking, which is one of the steps normally performed in photolithography. Although the reason for this is not clear, it is also presumed that the stability and sublimation resistance of these compounds against heat are insufficient. Even if the compound does not have these drawbacks and has satisfactory performance, the raw materials used to manufacture the compound are expensive and the manufacturing process is long and complicated, making it particularly difficult to use industrially. There was a point C in terms of cost etc.

The present inventors have completed the present invention as a result of studies to overcome the above-mentioned conventional techniques.

"Problems to be Solved by the Invention" The purpose of the present invention is to provide a method for stably increasing the contrast of a resist image using a compound that does not cause a decrease in concentration even during a pre-baking process at high temperatures. .

Another purpose of the invention! The present invention provides a method for increasing the contrast of a resist image using a photobleachable compound.

"Means for Solving All Problems" The present invention provides a photoresist layer provided on a material to be etched, and further provided with a layer containing at least one compound represented by the following general formula [I]. This was achieved by using materials.

In the formula, 2 is represented by (R3)a-Q-R' or R5,
Z' is represented by -R6-(X)b.

R, R1, R2 and R3 are a hydrogen atom, a substituted or unsubstituted alkyl group having /-r carbon atoms, or a substituted or unsubstituted aryl group having 6 to /3 carbon atoms.

Q is a halogen atom or a covalent or trivalent atom selected from O, S, and N, and a represents O1/, 2.

Further, R3 may form a ring (eg, a piperidine ring, a eurolidine ring, etc.) with Q or R4.

R4 represents a substituted or unsubstituted aryl group having t to /3 carbon atoms, R5 represents a substituted or unsubstituted heterocycle containing O, N, and S, and R6 represents an aromatic hydrocarbon group having z to 2θ carbon atoms. represents. bFio.

l, λ, 3, and n represents O1/, λ.

X is selected from a halogen atom, -CN, R7, -0-R7, and a group represented by -N-8O2R7. R7 represents a substituted or unsubstituted alkyl group having 12 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, and R8 and R9 are a hydrogen atom, a substituted or unsubstituted alkyl group having 12 carbon atoms, and represents a substituted or unsubstituted aryl group having 6 to 3 carbon atoms. mVi/or ko. However, when m is 1, b takes /, 2.3, and
X is -C-aryl, -C-0-aryl, -0-R7
, -8-R7, take at least one spider. When m is 2, R,
At least one of R1, R2°R3, and R7 is a substituted or unsubstituted alkylene group or a substituted or unsubstituted arylene group to form a bis body.

Next, specific examples of compounds used in the present invention will be shown, but the present invention is not limited thereto.

Lir CH34c,.

Hiro12 ≠31 α ≠22 4Lko0 NH8O2CH3 3λ NHCOCsHt I Pr 4c+2j JA7 J! These compounds are listed in [Chemical Reviews]
cal Reviews) J Volume 1 (J4L), ≠
Pages 73-4CPj, Jan Hamer & Anthony
Maaaluso) r2)* Nttrone
It can be synthesized according to the method described in the section on synthesis of s month.

Synthesis Example 1 (Synthesis of Compound 1) p-diethylaminoinduldehyde t, 79 (0,0
3 mol) and 2.2 f (0.01 mol) of p-methanesulfonylphenylhydroxylamine were added to ethanol j0d dehydrated with molecular sieves, and the mixture was heated and stirred at RO 0C for 6 hours. Ethanol is distilled off from the brown homogeneous bath liquid, and a mixture of toluene and hexane (/:/) is added to the residue to crystallize it. When P is removed, yellow crystals are obtained. Obtained.

The melting point was 712-773°C.

Synthesis Example J (Synthesis of Compound *#) N,N'-diethyl-N,N'-(p-formylphenyl)ethylenediamine it, it<o.

012 mol) tophenylhydroxylamine/J.

If (0.12 mol) was added in ethanol 100-
Heat to reflux for 1 hour. About 10 d of ethanol is distilled off,
Upon cooling, the desired yellow crystals precipitate. Yield: 2tf Melting point: 171~/l 0C Binding agents for forming a layer containing the compound represented by the above general formula [1] include vinyl acetate polymers and copolymers with other vinyl compounds, and copolymers of these. Partial hydrolysates, copolymers of styrene or its derivatives, polymers and copolymers of acrylic acid and methacrylic esters, acetal resins, acrylonitrile-citadiene copolymers, ethyl cellulose and other hydrocarbon-soluble cellulose ethers Examples include cellulose propionate and other hydrocarbon-soluble cellulose esters, polychloropre/, polyethylene oxide, and polyvinylpyrrolidone.

Aromatic hydrocarbons (e.g.
tt-j') or mixtures thereof with aliphatic hydrocarbons (e.g. cyclohexane), halogenated aliphatic compounds (e.g. trichloroethylene, methylchloroform, etc.), alcohols (e.g. Examples include propatool, butanol, ethyl cellosolve, etc.), esters (such as cellosolve acerade, butyl acetate, etc.), and cyclohexanone.

The compound of the present invention is 1 to 100% by weight based on the binder.
The amount added is preferably 1 to 10% by weight. The compound of the present invention may be added to a mixture of the binder and the solvent, or the compound may be dissolved in the solvent beforehand and added to the binder.

The photoresist serving as the base material of the photoresist material used in the present invention is a rubber photoresist containing cyclized rubber and bisazide as main components, a phenol and/or cresol novolak resin, and at least one 0-quinonediazide compound. A positive resist or the like is used.

"Example" Next, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

Example 1 1 inch of positive photoresist HPR-10≠ (trade name, manufactured by Philip, Hito, Hunt, solid dispersion ratio 27.r weight width) containing a novolac resin and at least one O-quinonediazide Spin coating onto a silicon wafer using a spinner to a film thickness of 7.4 μm (7000y, p, m, -
0 seconds) and then heated under a N2 stream for 110 minutes to remove the solvent.

Next, a solution was prepared in which 1% by weight of the styrene aryl alcohol copolymer, 1% by weight of Compound 1, and Compound 16 were each dissolved in a toluene solvent. This solution J was applied by spinning with a spinner to a thickness of O0λ0μm.
The solvent was removed by heating to prepare Samples 1 and 2. Comparative samples that did not contain the compound of the present invention were exposed to light through a resolution cover using a reduced projection type Stellar electron beam, and the upper layer was removed with toluene. After that, ・Po5itive
LSI Developer Metal Ion F
It was developed by immersing it in a 2x diluted solution (trade name, manufactured by Philip A.) for 1 minute at 2!0 C'''C. When comparing the formed chisel turns, there was no difference in line width of 10 μm between the three samples. Although it was not noticed, at the line width of 00tμm, the resist image of the comparison sample was somewhat sagging, as if it had been overexposed.On the other hand, samples 1 and 2
The pattern is given a moderate exposure, and the resist image is 1g1
The I-wall was also nearly vertical, indicating enhanced contrast.

Example copolymethyl methacrylate solution in butyl acetate (
Solid content ratio, 6.4 weight 11 to solid content 6.7 weight i
% of the compound 3 of the present invention, and /r were prepared. This solution was spin-coated (!j00r, p, m, /j seconds) onto a blue plate glass substrate to a film thickness of λ, Oμm to create Sample 3 and Sample Hiroshi.
The mixture was heated for 0 cto minutes, and the UV-visible absorbance ratio was measured over time using a chromator. As a comparative sample, sample At- was prepared in the same manner as above except that α-(4cm diethylaminophenyl)-N-phenylnitrone (compound A) was used instead of the compound of the present invention. The results are shown in FIG.

The compound of the present invention is superior to conventional products in that the concentration decreases less even when heated and dried. Therefore, there was little variation in the shape of the resist image after development.

Example 3 A sample was prepared in the same manner as in Example 2 except that Compound 3, /r in Example- was replaced with another compound of the present invention, and the change in absorbance when heated for 30 minutes was measured. −
It was measured using a UV-vis spectrometer. The results are shown in Table 1.

Table 1 From the results, it can be seen that the compound of the present invention has a much smaller decrease in concentration than conventional compounds and is less affected by the manufacturing process, so it can stably produce the desired effect.

[Brief explanation of the drawing]

FIG. 1 shows the relationship between heating time and absorbance ratio at a heating temperature of 00C. In the figure, Q is a sample using compound example/l ≠
, Δ is Sample 3 using Compound Example 3, and Δ is Comparative Compound α-
Comparative 1tlA using (Hiro-dimethylaminophenyl)-N-phenylnitrone is shown. Patent applicant Fujisha) IL, Film Co., Ltd. drawings Jokichi (Contents: no soil changes) Sword mouth mourning time (ri') Procedural amendment work side 1.1 - Xu Li's officer 1, case display Showa j 2017 Patent Application No. λ≠Okor
No. 2, Name of the invention Photoresist material 3, Relationship with the person making the amendment Patent applicant Address 210-4 Nakanuma, Minamiashigara City, Kanagawa Prefecture Date of amendment order 5. We will submit the specification and drawing 6 of the subject of the amendment, as well as the detailed specification of the amendment and the engraving of the drawing (no changes to the content). Showa 1995, month/day 2゜Name of the invention Relationship to the photoresist material incident
Patent Applicant Address: 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture Name (520) Fuji Photo Film Co., Ltd., -p/' Contact Address: 2-26-30 Nishi-Azabu, Minato-ku, Tokyo 106 Subject of Amendment: Inventions in the Specification Column 5 of ``Detailed Description of the Invention'' and the description of ``Detailed Description of the Invention'' of the Description of Contents of the Amendment are amended as follows. (1) Correct ``tori'' in the first hiro page/hiro row to ``sei''. +21i/? page λth line

Claims (1)

[Scope of Claims] A photoresist material, comprising a photoresist layer provided on a material to be etched, and further provided with a layer containing at least one compound represented by the following general formula [I]. General formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ In the formula, Z is represented by (R^3)a-Q-R^4 or R^5, and Z' is -R^6-( X) Represented by b. R, R^1, R^2, R^3 are hydrogen atoms, carbon atoms 1 to 8
a substituted or unsubstituted alkyl group, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. Q is a halogen atom or 2 selected from O, S, and N
It is a valent or trivalent atom, and a represents 0, 1, or 2. R^4 represents a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, R^5 represents a substituted or unsubstituted heterocycle containing O, N, and S, and R^6 represents a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. represents an aromatic hydrocarbon group. b represents 0, 1, 2, 3, and n represents 0, 1, 2. X is a halogen atom, -CN
, R^7, -O-R^7, -S-R^7, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, -SO2-R^7, ▲ Mathematical formulas There are , chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas, chemical formulas,
There are tables, etc. Selected from the groups represented by ▼. R^7 represents a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms; R^8 and R^9 are hydrogen atoms; represents a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. m is 1 or 2. However, when m is 1, b is 1, 2, or 3, and X is ▲mathematical formula, chemical formula, table, etc.▼aryl, ▲mathematical formula,
There are chemical formulas, tables, etc. ▼Aryl, -O-R^7, -
S-R^7, -SO_2-R^7, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼,
▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, chemical formulas,
There are tables etc. Take at least one group represented by ▼. When m is 2, R,
At least one of R^1, R^2, R^3, and R^7 is substituted or unsubstituted alkylene or substituted or unsubstituted arylene group to form a bis body.