JPS61190331A - Photoresist material - Google Patents

Abstract

PURPOSE:To stably enhance a contrast of the photoresist layer by providing the photoresist layer on a material to be etched, and then by laminating a layer contg. one or more of the specific compds. shown by the formula on said obtd. layer. CONSTITUTION:The photoresist layer is provided on the material to be etched, and the layer contg. at least one of the compds. shown by the formula wherein R1 and R2 are each a hydrogen atom, an alkyl or an aryl group, X, Y and Z are each a hydrogen atom, a halogen substd. alkyl or an unsubstd. alkyl, a substd. or an unsubstd. alkoxy or allyloxy group, M<-> is an anion, is laminated on said photoresist layer to prepare the titled material. A vinylacetate polymer is used as the binding agent for forming the layer contg. the compd. shown by formula I.

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, and then etching the substrate. ing. In recent years, as integrated circuits have become more highly integrated, miniaturization of nomoturns has been progressing. For this reason, it is strongly desired that the resist be formed with fine e-turn t-accuracy. 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, the degree of elucidation is said to be approaching the physical limit due to the wavelength of the light used for exposure. At present, it is difficult to expect a dramatic improvement in the resolution of the lenses used in these devices. However, in recent years, as seen in Japanese Patent Application Laid-Open No. 1044-1044, a method of enhancing the contrast of an image in photoresist operation has been proposed and progress has been made.

In this method, a layer containing a photobleaching compound is formed adjacent to the photoresist layer, and when exposed to light, the contrast of light reaching the photoresist layer can be increased. The use of nitrone compounds with specific chemical structures has been described.

However, when these compounds are used, the desired optical density may not be obtained during pre-baking, which is one of the steps normally carried out 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 manufacture industrially. There were some difficulties in using it, such as cost.

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" An object of the present invention is to provide a method for stably increasing the contrast e of a resist image using a compound that does not cause a decrease in concentration even during a prebaking process at high temperatures.

Another object of the present invention is to provide a method for enhancing the contrast of resist images using novel photobleachable compounds.

"Means for Solving the Problems" The present invention provides a photoresist layer on a material to be etched, and further provides a layer containing at least one compound represented by the following general formula CI) on the photoresist layer. This is accomplished by using photoresist materials.

represents. R1+12 each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group (for example, methyl, ethyl,
Butyl, hexyl, tert-octyl, methoxyethyl, hydroxyethyl, methanesulfonamidoethyl,
7 carbonylethyl, acetyloxyethyl, chloroethyl, cyanoethyl, etc.), or a substituted or unsubstituted aryl group (e.g. phenyl, methylphenyl, methylphenyl, chlorphenylnato)
. X.

Y and Z each independently represent a hydrogen atom, a halogen atom (e.g. chlorine atom, bromine atom), a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group (e.g. methyl, ethyl, butyl, methoxyethyl, etc.), and Aryloxy group (e.g. methoxy, ethoxy, butoxy, phenoxy, p/4!/, /Hiroshi← page (Gihodo, 1939)
(Published in 2013) and organic carboxylic acids, and organic sulfonic acids and organic carboxylic acids are preferable. ] represents.

Again with R1 and R2! ~6-membered rings (eg, morpholine, piperidine, pyrrolidine rings, etc.) may be formed, or X and Y may form ~6-membered rings (eg, naphthalene rings, etc.).

Further, R□ or R2 and Z or Y may form a 1-4 membered ring.

Also, either R□ or R2 is an alkyl group (e.g. ethylene, propylene) or an arylene group (e.g. haphenylene)
Alternatively, a screw body may be formed by removing.

However, R1 and R2 do not take up hydrogen atoms when they are open.

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

Hs The compound of the present invention can be easily synthesized by the method described in the above-mentioned "Dye Chemistry", page 6j onwards.

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

Aromatic hydrocarbons (iF
IJ, toluene, 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., propyl esters (for example, cellosolve acerade, butyl acetate, etc.), and cyclohexanone.

The compound of the present invention is contained in an amount of j to 10Q% by weight based on the binder.
The amount added is preferably about 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-based photoresist containing cyclized rubber and bisazide as main components, 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 Example t, but the present invention is not limited thereto.

514tIIA Example 1 Polymer photoresist HPR- containing a novolac resin and at least one O-quinonediazide, manufactured by ZO Hiro (trade name, Philip, People), Inc., solids loss ratio 27. r
Weight It-φ inch Silicon wafer with film thickness /, 4μ
Rotate the coating with a spinner so that it becomes m (7000r, p,
m, -0 seconds) and heated under a N2 stream for 30 minutes to remove the solvent and then put it in toluene solvent! Weight - of styrene aryl alcohol copolymer,! A solution was prepared in which each of the 11 compounds by weight was dissolved. This solution is 0.2 thin! Samples 1 and 2 were prepared by spin coating with a spinner to a thickness of μm and heating to remove the solvent. Comparative samples that do not contain the compound of the present invention were exposed to light through a resolution cut-off turn, and the upper gold layer was removed with toluene.
SI Developer MetalIon
Free (Product name, Philip, A.) Manufactured by 1-Tot Co., Ltd.)
It was immersed in a 2-fold diluted solution at λr'C for 1 minute and developed. Comparing the formed patterns, there was no difference in the line widths of λ and θμ between the three samples, but at a line width of 0.1 μm, the resist image of the comparative sample appeared to be slightly overexposed. It was also a so-called pun. On the other hand, in the e-turn of Sample 11, the exposure seemed to be appropriate, and the side walls of the resist image were also nearly vertical, indicating that the contrast was enhanced.

Example copolymethyl methacrylate solution in butyl acetate (
A solution was prepared in which the following comparative compound At was added in an amount of 4.7% by weight based on the solid content (solid content ratio: 6.4% by weight). This solution was spin-coated (1100 r, p, m, / 7 seconds) on a blue plate glass substrate so that the film thickness was 0 μ.
After heating for a minute, changes in the absorbance ratio were measured using a UV-visible chromatometer.

Compound 3, ≦, 7 of the present invention instead of comparative compound A in the nest
．． A sample φ, t, 4.7 was prepared using 13t, and the absorbance ratio was measured in the same manner as sample 3. The results are shown in Table 1.

@Table 1 (Comparative Compound A) It can be seen that the compound of the present invention is stable, with a small decrease in concentration even when heated and dried, compared to conventional products. Therefore, there is little variation in the shape of the resist image after development, that is, in contrast enhancement.

Patent applicant: Fuji Photo Film Co., Ltd. March 1960 r/l*-47-・,,-,r 1, Indication of the case Filed on February 1985 (B) 2. Name of the invention Photo Resist material 3, relationship with the case of the person making the amendment Patent applicant name (520
) Fuji Photo Film Co., Ltd. Tel: (406) 2537 Old style) Subject of the amendment The description in the "Detailed Description of the Invention" section of the specification & Contents of the amendment The description in the "Detailed Description of the Invention" section of the specification is as follows. Correct the standard.

From ``As a sample'' on the second line of page 73 to ``Give exposure to light'' on the 10th line of the same page.
up to ``sample, contact type mask alignment device, type M
Passed through a filter using A-/l Mikasa ■)
A monochromatic light source of 0.011 m was used to provide pattern exposure of 0.0 μm and 0.02 μm. The exposure amount is λ, 0 μm and 062 μm at the bottom of the resist image of each sample viewed with a scanning electron microscope.
The width of tt was chosen as μm. ” he corrected.

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, A represents ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or R_1-O-. R_1 and R_2 each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, and X, Y, and Z each independently represent a hydrogen atom, a halogen atom substituted or unsubstituted alkyl group, Represents substituted or unsubstituted alkoxy and aryloxy groups, or ▲numerical formulas, chemical formulas, tables, etc.▼. M^- represents an anion. Also R
_1 and R_2, X and Y may form a 5- to 6-membered ring, or R_1 or R_2 and Z or Y may form a 5- to 6-membered ring. Further, either R_1 or R_2 may be an alkylene group or an arylene group to form a bis body. However, R_1 and R_2 are never hydrogen atoms at the same time.