JPS6240444A - Photoresist material - Google Patents

Abstract

PURPOSE:To obtain a stable composition giving increased contrast and superior resolution by forming a photoresist layer on a meterial to be etched and a layer contg. at least one kind of specified org. compound on the photoresist layer. CONSTITUTION:A photoresist layer is formed on a material to be etched and a layer contg. at least one kind or org. compound represented by the formula is formed on the photoresist layer. A binder used to form the layer contg. the org. compound may be a vinyl acetate polymer, a copolymer of vinyl acetate with other vinyl compound, a partial hydrolyzate of the (co)polymer, a copolymer of styrene or s styrene deriv., polyethylene oxide or polyvinylpyrrolidone. The org. compound is added to the binder by 5-100wt%, preferably 5-50wt%. A rubber-base photoresist contg. cyclized rubber and bisazide as essential components or a positive type photoresist may be used as the photoresist.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to photoresist materials capable of enhancing the contrast of images of reproduction objects such as masks used in photolithography processes in the manufacture of integrated circuits. It is.

``Prior art'' Electronic components such as semiconductors, ICs, and LSIs are manufactured by drawing an arbitrary circuit pattern 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 turns with high precision 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, Tokukai Sho! As seen in the 7th photoresist operation, a method of enhancing the contrast of an image was proposed and progress was made, as seen in the 7th Oatti-λ.

In this method, a layer containing a photobleachable compound is formed adjacent to the photoresist layer, and when exposed to light, it is possible to increase the resistance of light that reaches the photoresist layer. describes the use of nitro/compounds with specific chemical structures.

"Problems to be Solved by the Invention" However, when some of these compounds are used in a process commonly carried out in photolithography, the desired optical density may not be obtained.

This is due to poor compatibility between these compounds and the medium of the layer containing them, making it impossible to add the desired amount, or even if they are temporarily dissolved, they precipitate over time. One possible way to solve this problem is to dissolve these in a solvent with higher solubility (generally with higher polarity) and mix it with a medium. However, when these solutions are applied onto a photoresist layer that has already been applied, there is a drawback that the underlying photoresist layer is attacked by these solvents, resulting in a step difference.

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

An object of the present invention is to provide a method for increasing the contrast If of a resist image using a compound having improved solubility.

Another object of the present invention is to provide a stable contrast enhancement layer composition that does not affect the photoresist layer.

]-Next means to resolve the problem ykW4 The present invention provides a 7-otoresist 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 CI). This was achieved by using materials.

In the formula, R1 and R2 are substituted or unsubstituted alkyl groups having 1 carbon atoms, R3 is a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 carbon atoms, and 1 carbon atoms.
− represents the alkoxy fund of μ. X may be the same or different and is a norogen atom, -CN, R4, -0-R4,
-8-R4, -C-R4;

R4 represents an alkyl group having carbon number/~6, R5, R6
represents a hydrogen atom or an alkyl group having a carbon number of 1 to 2. n is taken as O1/, 21.

However, the total number of carbon atoms in R1, R2, R3, R4, R5, and R6 is 7 or more and /I or less.

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

Oe Oe Oe Oe Oe O8 These compounds are described in ``Chemical Reviews''.
cal Reviews) Jf4/ (6tl) volume, μ73-Hiroshi 5 pages, Jan Hamer & Antho (Jan Hamer & Antho
Written by Macaluso [Nitrons]
It is described in the synthesis section of es)j and can be synthesized according to the second son's method.

Synthesis Example N, N-di-n-butyltoluidine (synthesis of 11 m-toluidine s3.gy, nythylbromide-20!, 6
? , potassium carbonate/jJ's', dimethylformamide and 200 trtlf are mixed, heated to /20°C and stirred for 6 hours. The reaction mixture eI was added to water and extracted with ethyl acetate, and then the organic layer was washed with water. The organic layer was concentrated and the remaining oil was distilled under reduced pressure to obtain 102f of (1).

Boiling point iot~/Or 0C10, /Hg0μm Synthesis of dibutylamino-λ-methylbenzaldehyde (2) 179 (1) Mix with 1 Oml of dimethylamino formaldehyde and cool.

Next, a separately prepared Guillsmeyer reagent (dimethylformamide/!Omt, 1 ton of coconut chloride) is added dropwise to this solution while stirring.

After the addition is complete, the mixture is heated to zo 0c for 6 hours, cooled, and then added to water and neutralized with aqueous sodium hydroxide solution. Extract the oil with ethyl acetate, wash with water, and concentrate.

Distilling the remaining oil under reduced pressure yields (2) 70. /f
Obtained.

boiling point/! ! ~/60’C/0, J mHg.

Hiro-Methoxycarbonylphenylhydroxylamine (
3) Synthesis of Hiro-nitrobenzoic acid methyl ester t, ty was dissolved in methanol roorrtt, and then zinc powder Ir3' was added to this solution. Add. An aqueous solution of JOf ammonium chloride dissolved in this solution! ! Drop 0rnlf. After stirring for 1 hour, all inorganic matter was removed by filtration, and the mixture was extracted with ethyl acetate. When ethyl acetate was concentrated, 70.79 g of (3) was obtained as a crude product.

Synthesis of Exemplary Compound I J7. /f(2) and λtf(3) are dissolved in 1 ml of absolute ethanol and left at room temperature overnight. The precipitated crystal 't-F was collected, washed with a mixture of ethyl acetate and n-hexane, and air-dried to obtain the exemplified compound of Hiroj1.

As a binder for forming a layer containing the compound represented by the above general formula CI), vinyl acetate polymers, copolymers with other vinyl compounds, partial hydrolysates thereof, styrene, etc. or copolymers of its derivatives, homopolymers and copolymers of acrylic acid or methacrylic esters, acetal resins, acrylonitrile-butadiene copolymers, ethyl cellulose and other hydrocarbon-soluble cellulose ethers, cellulose propionate and other Examples include hydrocarbon-soluble cellulose esters, polychloroprene, polyethylene oxide, and polyvinylpyrrolidone.

Aromatic hydrocarbons (e.g.
tJfh (luene, xylene, ethylbenzene, chlorobenzene, etc.) or mixtures thereof with aliphatic hydrocarbons (e.g. cyclohexane, etc.), halogenated aliphatic compounds (e.g. trichloroethylene, methylchloroform, etc.), alcohols (e.g. Examples include propatool, butanol, ethyl cellosolve, etc.), esters (for example, selonlube acerate, butyl acetate, etc.), and cyclohexano/etc.

The compound of the present invention contains j~/θO weight i% with respect to the binder.
Preferably 1-10% by weight is added. 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 includes a rubber photoresist mainly containing cyclized rubber and bisazide gold, a phenol and/or cresol novolak resin, and at least seven 0-quinonediazide compounds. 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 7 Weighed 20 m9 of each of the compounds shown in Table 1 below to /CC or 10 CC of brown Bayerbin and added toluene to make 2♂
Dissolve for 30 minutes under ultrasound in a water bath at 0C.

If the gold does not dissolve, add toluene to the gold, apply ultrasound, and repeat this operation until the gold is completely dissolved. The amount of toluene required at this time is shown in 1effI.

As is clear from these results, it can be seen that the compounds of the present invention have dramatically improved solubility compared to conventionally used comparative compounds.

Example λ A positive photoresist (Waco) HPR,
20≠ (trade name: manufactured by Fuji Hunt Electronics Technology ■, solid content ratio λ7゜1% by weight) using a spinner with lr 700 r, p, m.

The coating was spin-coated for 720 seconds, and the solvent was removed by heating at O'C for 130 minutes under a nitrogen stream.

Nitoluene IOA: Copolymer of styrene and allyl alcohol (copolymer composition ratio: 1 mol, molecular weight approximately 2
A solution was prepared in which 0.21% of O0≠2 and 0.21% of the exemplary compound 1 of the present invention were dissolved. This solution was applied to the silicon wafer outside of the photoresist coating using a spinner.
The coating was spin-coated at 0 Or, p, m, / for 20 seconds and heated at 70'C for 20 minutes under a nitrogen stream to remove the solvent. The surface of this coating was smooth and exhibited good uniform gloss.

After cooling, this wafer was exposed to light for 0.33 seconds through a chromium-deposited glass masker having a fine pattern using a step-and-repeat exposure device with a wavelength≠J 6 nm and a residual ultraviolet radiation of 2 g 3 mW/crIL2. The exposed wafer was immersed in trichlorethylene for 60 seconds, then further immersed in fresh trichlorethylene for 16 seconds, then removed, and the Univer was dried by blowing with nitrogen. Using Waycoat, Positive Developers Par HPR-4102D developer (product name: Fuji Hunt Electronics Technology), develop for 11 seconds with a spray paddle automatic developing device, rinse with distilled water, spin out, and dry. did. The resist pattern was formed using a JSM-T 200 type scanning electron microscope manufactured by Nippon 'Poko'. The form of a rectangular island pattern of line @0-J'μ was observed and confirmed.

Example 3 Exemplary compound 7 was substituted for exemplified compound l in Example λ
fO, 27 μm, styrene-allyl alcohol copolymer fO03/,! A laminated coated silicon wafer was obtained in the same manner as in Example A except that f was used.

This uncoated sea urchin...- is the wavelength! Nomiturn light was applied for 722 seconds through a chrome mask using a mask alignment device with a 4 nm ultraviolet intensity λ and I 7 mW /α2. After treating with trichlorethylene in the same manner as in Example 1, Waycoat Positive L, S, and I were prepared.

After immersing a metal ion free developer tube (trade name: manufactured by Fuji Hunt Electronics Technology ■) in an equal amount of pure water for 60 seconds, rinsing it with distilled water for 1 second, and spinning it out using a spinner. Dry. The resist pattern formed in the same manner as in Example 2 was observed using a scanning electron microscope. Line width O1! Formation of a rectangular island pattern of μm was confirmed.

Comparative Example/Laminated coated silicone wafers were obtained in the same manner as in Example 2, using Comparative Compound 9 instead of Exemplified Compound 1 in Example λ, and toluene Q Oml: f. When I observed the surface of this coating, it was not shiny and fine crystals were dispersed and precipitated, so I was unable to carry out subsequent exposure and printing.

Comparative Example A resist pattern was prepared in the same manner as in Example C, except that the application of the toluene bath solution of the styrene-allylic alcohol copolymer and Exemplified Compound I in Example λ was omitted, and the exposure time was changed to O12 seconds. Obtained. When observed with a scanning electron microscope, the turns were trapezoidal or semicircular, and the resolution of line widths of 74 m or more was only poor.

"Effects of the Invention" In this way, the present invention provides improved solubility.
It is possible to use a parabola that provides a stable, contrast-enhanced, and sharp resolution.

Patent applicant: Fuji Photo Film Co., Ltd. Showa to March 2-0 1. Indication of the case: 1985 Patent Application No. Ho293 2, title of invention: Photoresist material 3, person making the amendment Relationship with the case: Patent applicant: Address: 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture Contact Address: 2 Nishi-Azabu, Minato-ku, Tokyo 106 Chome 26-30 No. 4, Subject of amendment The description in the "Detailed Description of the Invention" column 5 of the description and the "Detailed Description of the Invention" section of the description of the contents of the amendment is amended as follows.

l) No.? Compound example/2 on page λth line " "of " ” and correct it.

2) 1st λ page/4th line "with oil" "Oil" and correct it.

3) Page 73, line λ "Benzoic acid" "benzoic acid" and correct it.

Hiroshi) Page 13, line ♂ "crude organisms" "Composition" and correct it.

page 1, line 77 "Solve Cerato" "Solve Acetate" and correct it.

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] ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼ In the formula, R_1, R_2 are substituted or unsubstituted alkyl groups having 1 to 8 carbon atoms, and R_3 is a hydrogen atom, halogen atom, or a carbon number 1 to 4. represents a substituted or unsubstituted alkyl group or an alkoxy group having 1 to 4 carbon atoms. X may be the same or different; halogen atom, -CN, R_4, -O-R
＿４, -S-R_4, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, -SO_2-
R_4, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas,
There are chemical formulas, tables, etc. ▼▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ Selected from the groups represented. R_4 represents an alkyl group having 1 to 6 carbon atoms, and R_5R
_6 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. n takes 0, 1, or 2. However, R_1, R_2, R_3, R_4, R_5, R_
The total number of carbon atoms in 6 is 7 or more and 18 or less.