KR19980087522A - Radiation Sensitive Compositions Containing Novel Polymers - Google Patents

Abstract

The present invention relates to a photoresist composition containing the novel polymer mixture. The mixture consists of a novolak resin and a polyvinyl phenol resin, wherein one or more polymers are replaced with groups that are inert to the acid environment. When the polymer mixture of the present invention is used in a photoresist composition, the developability is improved by exposing the photoresist to i-line radiation.

Description

Radiation Sensitive Compositions Containing Novel Polymers

The present invention relates to the use of the novel polymers and the new polymers for photoresist compositions having the ability to form submicron sized high resolution features.

Photoresist is a photosensitive film used to transfer an image to a substrate. These form a negative image or a positive image. After coating the photoresist to a substrate, the coating is exposed to an active energy source such as ultraviolet light through a patterned photomask to form a latent image on the photoresist coating. The photomask has a region through which active radiation is transmitted and a region through which no radiation is transmitted. A photomask pattern, consisting of areas that are transmitted and areas that are not, defines the desired image that can be used to transfer the image to the substrate. A relief image is provided by developing a latent image pattern in the resist coating. The use of photosensitive resists is described in the literature; Deforest, Photoresist Materials and Processes, McGraw Hill Book Company, New York (1975) and Moreau, Semconductor Lithography, Principles, Practices and Materials, Plenum Press, New York (1988).

Known photoresists can provide shapes including resolutions and sizes suitable for many existing commercial applications. However, there is a need for new photoresists that can provide submicron sized images for many other applications.

Very useful photoresist compositions are described in US Pat. No. 5,128,232 to Thackeray et al. This patent describes, among other things, the use of resist resin binders comprising copolymers of non-aromatic cyclic alcohol units and phenol units. The photoresist described is described as being particularly suitable for exposure to deep U.V. (DUV) radiation. As will be appreciated by those skilled in the art, DUV radiation means exposing the photoresist to radiation having a wavelength of about 350 nm or less, more typically about 300 nm or less.

Particularly suitable groups of DUV photoresist groups are copolymers consisting of non-aromatic cyclic alcohol units and phenol units to expose to resin binders, photoacid generators or photobase generators and active radiation and to complete curing. A composition comprising one or more other materials that, when heated, require curing or crosslinking of the composition. Preferred compositions are acid curable photoresists comprising photoacid generators, resin binders comprising non-aromatic cyclic alcohol units and phenolic units, and amine based crosslinkers such as melamineformaldehyde resins (trade name; Cymel, manufactured by American Cyanamid). to be. Such acid curable resists are described in several documents, including European Patent Nos. 0 164 24 and 0 232 972, and US Pat. No. 5,128,232, and the conventional activated acid curable photoresist compositions described herein and methods of use thereof. Is incorporated herein by reference.

One of the important characteristics of the photoresist is the resolution of the image. Photoresist images developed to have lines on the vertical sidewalls that do not exceed 1 micron in width are preferred for transferring fine line images to the substrate. Many factors are involved in forming a high resolution image. One of these factors includes the phenomenon of photoresist images. The developing step preferably removes all photoresist coatings of the desired site so that no residue is present on the substrate. The side wall of the developed image should be at right angles and smooth. All photoresist existing between the channels in the photoresist image that does not form microbridging should be removed. The term microcrosslinking refers to a series of fine tendrils or strands of unremoved photoresist that pass between adjacent photoresist shapes in the developed photoresist coating. The required thin line image resolution can be obtained by exposing the photoresist composition to DUV, but full phenomena can be achieved when using other exposure energies such as i-line exposure at 365 nm for the photoresist composition described above. Turned out to be absent.

The invention described herein encompasses the use of the blends in polymer blends and in photoresist suitable for in particular i-line exposure (ie exposure to active radiation of 365 nm). When using resin blends, the photoresist of the type commonly used for DUV imaging is developed flawlessly.

Negative functional photoresist according to the present invention is an acid or base generating agent, a crosslinking agent activated by an acid or base, and an alkali soluble resin blend of novolak resin and polyvinylphenol resin, wherein at least one Resin, preferably polyvinylphenol resin, has a portion of a ring substituted with a hydroxyl group blocked with an inert blocking group). The term inert, as used in connection with the blocking group, refers to a state that is not chemically reactive in the presence of acids or bases produced during exposure and baking of the photoresist composition.

The positive working photoresist according to the invention is similar in composition to the negative functional composition and is a dissolution inhibiting means activated by an acid or base generating agent, a photogenic acid or base and an alkali soluble according to the invention. Resin blends. Dissolution inhibiting means may be in the form of acid labile groups substituted in one or both alkali-soluble resins or in the form of dissolution inhibitors added or both.

When the resin binder mixture of the present invention is exposed at 365 nm, the reason why it is developed flawlessly and microcrosslinking is removed is unknown. Since the inert blocking group reduces the number of sites that can be reacted during processing of the photoresist composition, in fact, for the negative functional photoresist, the inert blocking group is used for at least one member of the resin binder. It is not contemplated that microcrosslinking can be essentially removed while at the same time obtaining high resolution images.

The polymer blends used in the photoresist compositions according to the invention are mixtures of novolac resins and polyvinyl phenolic resins, wherein at least one polymer is blocked in part of its pendant hydroxyl group with an inert blocking group and has a blocking group Mole% of the unit in the form of the resin is in the range of 1 to 30 mol%, preferably 5 to 15 mol%). The terms novolak resins and polyvinyl phenol resins are included within the scope of their copolymers including cyclic alcohols and phenols, as described in US Pat. No. 5,128,232, which is incorporated herein by reference.

Conventional novolak resins and methods of preparing poly (vinylphenol) resins used as photoresist binders are well known in the art and described in the foregoing literatures. Novolak resins are thermoplastic condensation products of phenols and aldehydes. Examples of phenols suitable for condensation with aldehydes, especially formaldehyde, to form novolak resins include phenol, m-cresol, o-cresol, p-cresol, 2,4-xyleneol, 2,5-xyleneol, 3,4-xyleneol, 3,5-xyleneol and thymol. The acid catalyzed condensation reaction forms a suitable novolak resin that can vary in molecular weight from 500 to 100,000 daltons. Preferred novolak resins commonly used to form photoresist are cresol formaldehyde condensation products.

Poly (vinylphenol) resins are thermoplastic polymers which can be formed by block polymerization, emulsion polymerization or solution polymerization of the corresponding monomers in the presence of a cationic catalyst. Useful vinylphenols for preparing poly (vinylphenol) resins can be prepared, for example, by hydrolysis of commercial coumarins or substituted coumarins and then decarboxylation of the resulting hydroxy cinnamic acid. Useful vinylphenols can also be prepared by dehydrating the corresponding hydroxy alkyl phenols or by decarboxylating the hydroxy cinnamic acid produced by reacting substituted or unsubstituted hydroxybenzaldehyde with malonic acid. Preferred poly (vinylphenol) resins prepared from such vinylphenols have a molecular weight of about 2,000 to 100,000 daltons.

As noted above, the terms novolak resins and polyvinyl phenol resins include polymers of phenols and non-aromatic cyclic alcohols, similar in structure to novolak resins and poly (vinylphenol) resins. Such polymers can be formed by several methods. For example, in a conventional method of preparing polyvinyl phenol resins, cyclic alcohol is added to the reaction mixture as a comonomer during the polymerization reaction and then carried out according to standard methods. The cyclic alcohol is preferably aliphatic but may contain one or two double bonds. The cyclic alcohol is preferably very close to the structure of the phenol reactant. For example, when the resin is polyvinyl phenol, the comonomer is vinyl cyclohexanol.

Preferred methods of forming the copolymer include the reaction of partially hydrogenating the preformed novolak resin or the preformed polyvinyl phenol resin. The hydrogenation reaction uses a hydrogenation process that is recognized in the art and, for example, the phenolic resin solution is heated to a reducing catalyst (e.g., platinum or palladium coated carbon substrate or preferably Raney nickel) at elevated temperature and pressure. It can be done by passing. Specific conditions depend on the polymer to be hydrogenated. More particularly, the polymer is dissolved in a suitable solvent such as ethyl alcohol or acetic acid and then the resulting solution is contacted with the finely divided Raney nickel catalyst to react at atmospheric pressure of about 100 to 300 ° C. and about 50 to 300 or more. The finely divided nickel catalyst may be a nickel-on-silica catalyst on silica, a nickel-on-alumina catalyst on alumina or a nickel-on-carbon catalyst on carbon, depending on the resin to be hydrogenated. It is believed that the hydrogenation reaction reduces the double bonds in some phenolic units, thereby forming random copolymers of phenolic units or cyclic alcohol units whose percentages vary depending on the reaction conditions used.

Preferred polymeric binders formed from poly (vinylphenol) or novolak resins

expression

And

A unit having a structure selected from the group consisting of: wherein unit (1) is a phenolic unit, unit (2) is a cyclic alcohol unit, Z is an alkylene bridge having 1 to 3 carbon atoms, and A is 1 to C Halo, such as lower alkyl, chloro or bromo of 3, a substituent in a substituted aromatic ring replacing hydrogen, such as alkoxy, hydroxyl, nitro, amino, etc. of 1 to 3, a is 0 to 4, and B is Hydrogen, halo such as lower alkyl having 1 to 3 carbon atoms, chloro or bromo, substituents such as alkoxy having 1 to 3 carbon atoms, hydroxyl, nitro, amino, and the like, provided that at least three of the B substituents are hydrogen; Is an integer from 6 to 10, x is 0 to 1.0 as the mole fraction of unit (1) in the polymer, and in some cases where a copolymer is desired, preferably 0.50 to 0.99 and more preferably 0.70 to 0.90 , Y includes the mole fraction of units (2)}.

According to the present invention, some hydroxyl groups substituted on one or more polymers specified above are blocked with suitable inert blocking groups. Under these circumstances, each polymer having a blocking group follows one of the following two formulas.

In the above formula, A, a, B, b, Z are as defined above, -OG is an inert blocking group, x is the mole fraction of phenolic units in the polymer and 0.1 to 0.99, preferably 0.50 to 0.95, y Is a mole fraction of phenolic units wherein the hydroxyl group is substituted with an inert blocking group -OG, 0.01 to 0.30 mole percent, x 'is the mole fraction of cyclic alcohol units in the polymer, and y' is a hydroxyl group being an inert blocking group- Molar fraction of cyclic alcohol units in the polymer, substituted with OG, x + x 'is from 0.5 to 1.0, y + y' is equal to 1- (x + x ') and is from 0 to 0.7, x' + y Is 0.01 to 0.30, preferably 0.05 to 0.15, and x + x '+ y + y' is 1. The ratio of x 'to y' is not critical but is preferably equal to the ratio of x to y.

All blocking groups are suitable that are inert to the acid or base produced at elevated temperatures used to bake the photoresist coating and do not interfere with the photolithographic reaction. Typical examples of suitable blocking groups include alkoxy groups such as methoxy, ethoxy, propoxy, n-butoxy, secondary-butoxy, tert-butoxy and the like, formula RCOO-, wherein R is preferably methyl, Alkyl esters of 1 to 4 carbon atoms, such as ethyl, propyl, isopropyl and butyl, secondary-butyl, tert-butyl, etc.), methanesulfonyl ester, ethanesulfonyl ester, propanesulfonyl ester, benzenesul Sulfonyl acid esters, such as phonyl esters, toluene-sulfonyl esters, and the like.

Regarding the above formula, the present invention is also applicable to novolak polymers and poly (vinylphenol) s, but not to copolymers having cyclohexanol units. In this embodiment of the invention, y and y 'in the formula above are zero.

According to the invention, the photoresist binder comprises the resin blends described above, wherein at least one resin of the blend has an inert blocking group. The blend may be a polyvinyl phenol or copolymer having cyclohexanol units or a novolak resin or copolymer having a cyclohexanol group, wherein at least one component of the blend has an inert blocking group. The ratio of polyvinyl ether resin to novolak resin can vary within wide limits. The weight ratio of polyvinyl ether resin to novolak resin is preferably 1:10 to 10: 1, more preferably 4: 6 to 6: 4. In a preferred embodiment of the invention, the inert blocking group is present only in the copolymer of polyvinyl phenol having polyvinyl phenol or cyclohexanol units. In the most preferred embodiment, two resins are used in the same amount.

The method of replacing the inert blocking group with the resin is not critical and does not form part of the present invention. Preferred methods include the step of alkaline condensation reaction using a compound which is combined with the preformed copolymer and hydroxyl group to form a blocking group. For example, if the blocking group is a preferred sulfonic acid ester, halogenated sulfonic acid is added to the polymer solution and a suitable base and the mixture is stirred with normal heating. Various bases can be used in the condensation reaction, including hydroxides such as sodium hydroxide. The condensation reaction is usually carried out in an organic solvent. As will be apparent to those skilled in the art, various free solvents are suitable. Preference is given to ethers (eg diethyl ether, tetrahydrofuran) and ketones (eg methyl ethyl ketone and acetone). Conditions suitable for the condensation reaction are determined based on the components used. For example, a mixture of sodium hydroxide, methanesulfonic acid and partially hydrogenated poly (vinylphenol) is stirred at about 70 ° C. for about 15 to 20 hours. The percent substitution of the polymer binder to the blocking group is controlled by the amount of blocking group precursor condensed with the polymer. The percent substitution at the hydroxyl site of the polymer binder can be easily identified by proton NMR and ¹³ C NMR.

When a hydroxide base such as sodium hydroxide is used as the condensation reaction catalyst, it has been found that the blocking group is mainly added to the phenolic hydroxyl group which is more reactive than the cyclic alcohol group of the polymer binder specified above. This is because in most cases, only the phenolic group of the binder is bound to the blocking group as defined above and the cyclic alcohol group contains very few blocking groups. By using stronger bases such as alkyl lithium reagents, blocking groups can be added to both the phenolic and cyclic alcohol units of the binder.

The polymeric binders described above are used in acid or base curable photoresist systems comprising, as additional components, acid or base generators and crosslinkers for negative functional photoresist resists or dissolution inhibitors for positive functional photoresist resists.

The acid generator compounds used in the mixture may be selected from a wide range of compounds known to produce acids or bases upon exposure to actinic radiation. One preferred class of radiation-sensitive composition according to the present invention is a composition using polymers of phenols and cyclic alcohols having acid labile groups as binders and using ο-quinone diazide sulfonic acid esters as radiation sensitive optical acid generator components. to be. The most frequently used sensitizer in such compositions is naphthoquinone diazide sulfonic acid, which is incorporated herein by reference (Kosar, Light Sensitive System, John Wiley Sons, 1965, pp. 343-352). These photosensitizers form acids that react to radiation of different wavelengths in visible light over X-rays. Thus, the photosensitizer selected depends in part on the wavelength used for exposure. By selecting an appropriate photoresist, the photoresist can be imaged by DUV, electron beam, laser or any other active radiation commonly used to image the photoresist. Preferred photosensitizers include 2,1,4-diazonaphthoquinone sulfonic acid esters and 2,1,5-diazonaphthoquinone sulfonic acid esters.

Other useful acid generators include nitrobenzyl esters and s-triazine derivatives. Suitable s-triazine acid generators are described, for example, in US Pat. No. 4,189,323, which is incorporated herein by reference. Triazine acid generators constitute a preferred embodiment of the present invention.

Halogenated nonionic, optical acid generating compounds such as 1,1-bis [p-chlorophenyl] -2,2,2-trichloroethane (DDT), 1,1-bis [p-methoxyphenyl] -2,2,2-trichloroethane, 1,2,5,6,9,10-hexabromocyclododecane, 1,10-dibromodecane, 1,1-bis [p-chlorophenyl] -2,2-dichloroethane, 4,4-dichloro-2- (trichloromethyl) benzhydrol (keltan), hexachlorodimethyl sulfone, 2-chloro-6- (trichloromethyl) pyridine, ο, ο- Diethyl-ο- (3,5,6-trichloro-2-pyridyl) phosphothioate, 1,2,3,4,5,6-hexachlorocyclohexane, N (1,1-bis [ p-chlorophenyl] -2,2,2-trichloroethyl) acetamide, tri [2,3-dibromopropyl] isocyanurate, 2,2-bis [p-chlorophenyl] -1,1 Nonionic optical acid generators are suitable, including dichloroethylene, tri [trichloromethyl] s-triazine and their isomers, analogs, homologs, and other compounds. Suitable optical acid generators are also described in European Patent Nos. 0164248 and 0232972, both of which are incorporated herein by reference.

Particularly preferred acid generators for DUV exposure include 1,1-bis (p-chlorophenyl) -2,2,2-trichloroethane (DDT), 1,1-bis (p-methoxyphenyl) -2,2 , 2-trichloroethane, 1,1-bis (chlorophenyl) -2,2,2 trichloroethanol, tris (1,2,3-methanesulfonyl) benzene and tris (trichloromethyl) triazine .

Onium salts are also suitable acid generators. Onium salts with weak nucleophilic anions have been found to be particularly suitable. Examples of such anions are divalent to valent metals or nonmetals (e.g., B, P and As, as well as Sb, Sn, Fe, Bi, Al, Ga, In, Ti, Zr, Sc, D, Cr, Hf And Cu) halogen complex anions. Examples of suitable onium salts are the diaryl-diazonium salts and the onium salts of Groups Va B, Ia B and I of the periodic table (e.g., halonium salts, quaternary ammonium salts, phosphonium salts, arsonium salts, aromatic sulfonium salts) , Sulfoxium salt or selenium salt). Examples of suitable preferred onium salts are found in US Pat. Nos. 4,442,197, 4,603,101 and 4.624,912, which are incorporated herein by reference.

Another suitable acid generator group is sulfonated esters, including sulfonyloxy ketones. Suitable sulfonated esters, including benzoin tosylate, tert-butylphenyl alpha- (p-toluenesulfonyloxy) -acetate and tert-butyl alpha- (p-toluenesulfonyloxy) -acetate, are described in the literature. ; Photopolymer Science and Technology, vol. 4. No. 3, 337-340 (1991), incorporated herein by reference.

Crosslinkers used in the negative functional photoresist of the present invention are crosslinkers which are activated by the production of acids or bases upon exposure to active radiation. Typical crosslinkers include polymers that crosslink in the presence of an acid catalyst and heat. Various various aminoplasts or phenoplasts can be used with low molecular weight polymers or compounds containing a large number of hydroxyl, carboxyl, amide or imide groups. Suitable aminoplasts include urea-formaldehyde, melamine-formaldehyde, benzoguanamide-formaldehyde, glycoluril-formaldehyde resins and mixtures thereof. The mixture may also include phenoplasts and latent formaldehyde producing compounds. Such latent formaldehyde generating compounds include s-trioxazine, N (2-hydroxyethyl) oxazolidine and oxazolidinylethyl methacrylate. Examples of suitable further materials are described in the aforementioned European Patents 0164248 and 0232972 and in US Pat. No. 5,128,232.

Preferred crosslinkers are amine crosslinkers such as melamine-formaldehyde resins, including those marketed under American Cyanamide under the trade name Simel.

Positive functional photoresist contains a dissolution inhibiting mechanism. Such mechanisms may be in the form of pendant acid labile groups bonded to at least a portion of the hydroxyl groups of the resin binder or in the form of discrete acid labile dissolution inhibitors added to the photoresist composition. In use, upon exposure to active radiation, the optical acid generator produces an acid photoproduct. The photoproduct provides a zone of exposure of resists with higher solubility in the developer by catalyzing the deprotection reaction of the acid labile group of the resin to separate polar functional groups such as carboxyl (see Lamola et al., Chemically Amplified Resists). , Solid State Technology, 53-60 (August 1991), incorporated herein by reference).

When the dissolution inhibiting mechanism is in the form of an acid labile group substituted in the polymer backbone, the acid labile group can be condensed to the polymer backbone in the same condensation reaction used to condense the inert blocking group to the backbone. The inert blocking group can also be substituted with the resin at the same time as the acid labile blocking group by providing a solution containing a mixture of reactants comprising the inert blocking group and the acid labile blocking group. Each of these concentrations substituted on the resin can be controlled by their concentration in the reaction solution. However, when the acid labile group and the inert blocking group are substituted with the resin, it is preferable to substitute the inert blocking group with the resin sequentially, that is, first, and then with the acid labile blocking group, rather than at the same time.

Alternatively, resin binders having inert blocking groups are used with dissolution inhibitors having substituted acid labile groups. In this embodiment of the invention, the dissolution inhibitor does not dissolve the resin. Upon exposure to actinic radiation, the acid labile blocking group is converted into a polar group by the photo-generating acid to dissolve the resin in the alkaline developer.

The dissolution inhibitor used may be any alcohol backbone used to form photoactive compounds known in the art. Such alcohols include, for example, hydroquinone, resorcinol, 2,4-dihydroxy benzophenone, 2,3,4-trihydroxybenzophenone, 2,4,6-trihydroxy benzophenone, 2, 3,4,4'-tetrahydroxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2,3,4,2'-4-pentahydroxybenzophenone, 2,3, 4,2 ', 6-pentahydroxybenzophenone, 2,3,4,3,4', 3-hexahydroxybenzophenone, 2,4,6,3,4 ', 3-hexahydroxy chlorobenzo Phenone and 2,3,4,3 ', 4,3-hexahydroxy-3-benzoyl benzophenone, bis (3,4-dihydroxyphenyl) methane, 2,2, -bis (2,4-di Hydroxyphenyl) propane and 2,2-bis (2,3,4-trihydroxyphenyl) propane, bis (2,4-dihydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl Methane, 2,2-bis (2,4-dihydroxyphenyl) propane, 2,2-bis (2,3,4-trihydroxyphenyl) propane, resorcinol, pyrogallol, glucinol, 2 , 4-dihydroxyphenylpropyl acetone, 2, 4-dihydroxyphenyl-N-hexyl ketone, 2,3,4-trihydroxyphenyl-N-hexyl ketone, 3,4,3-trihydroxybenzoic acid ester, bis (2,4-dihydroxy benzoyl ) Methane, bis (2,3,4-trihydroxybenzoyl) methane, bis (2,4,6-trihydroxybenzoyl) methane, p-bis (2,3-dihydroxybenzoyl) benzene, ethylene glycol Di (3,4,5-trihydroxybenzoate), 1,4-butanediol- (3,4,3-trihydroxybenzoate), 1,8-octanediol, di- (3,4,3 -Trihydroxybenzoate), polyethylene glycol and the like.

When exposing the dissolution inhibitor in the presence of an acid generator, the acid labile group reacts with the hydroxy group of the alcohol to convert the alcohol into a dissolution inhibitor. In this aspect of the invention, the dissolution inhibitor is mixed with a resin blend having an inert blocking group in an amount sufficient to insolubilize the resin. In general, the weight ratio of resin to dissolution inhibitor is 2: 1 to 15: 1, more preferably 5: 1 to 9: 1. In one embodiment of the present invention, it should be understood that the photoresist may be formulated using a resin having an inert blocking group and an acid labile group together with a dissolution inhibitor having an acid labile group.

The photoresist composition of the present invention preferably contains a strong acid having _a pK _a of 9 or more, preferably 11 to 15. The base used in practice is not so important as long as it has the required pK _a value. Preferred kinds of bases suitable for the photoresist of the present invention include quaternary ammonium hydroxide having 1 to 8 carbon atoms in the substituent. Examples of quaternary ammonium hydroxides include tetramethyl ammonium hydroxide, tetraethyl ammonium hydroxide, dimethyldiethyl ammonium hydroxide and tetrabutyl ammonium hydroxide. The base may be added to the photoresist composition in a relatively small amount (eg, 0.1-5% by weight of the photoactive generator, more preferably 0.2-1% by weight).

The compositions of the present invention are typically prior art for preparing photoresist compositions, except that some of the polymer binders having blocking groups as described above are partially substituted with conventional resins used to form such photoresists. Manufactured according to the process. The composition of the present invention comprises the components of the composition glycol glycol (e.g. 2-methoxyethyl ether (diglyme), ethylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monomethyl ether), cellosolve ester ( For example, it is formulated as a coating composition by dissolving in a suitable solvent such as methyl cellosolve acetate), aromatic hydrocarbons (eg toluene or xylene) or ketones (eg methyl ethyl ketone). Typically, the solids content of the composition is about 5 to 35 weight percent of the total amount of radiation sensitive composition.

The composition of the present invention is used according to a generally known procedure through exposure, and the development conditions can be changed according to the improvement of the luminous flux and the change of solubility in development. The liquid coating composition according to the invention is applied to the substrate by spin coating, immersion coating, roller coating or other conventional coating methods. For spin coating, the solids content of the coating solution can be adjusted to provide the desired film thickness based on the particular spin apparatus used, the viscosity of the solution, the speed of the spinner and the spinning time.

The composition is applied to a substrate commonly used in a process comprising coating a photoresist. For example, the composition can be applied to silicon or silicon dioxide wafers for making microprocessors and other integrated circuit devices. Aluminum-aluminum oxide and silicon nitride wafers may also be coated on the photocurable compositions of the invention as planar layers or multilayers according to procedures recognized in the art.

After the photoresist is coated on the surface, the solvent is preferably removed by heating and drying until the photoresist coating becomes non-tacky. Thereafter, it is imaged through a mask in a conventional manner. The photoactive resist system is exposed to a sufficient amount to effectively activate the photoactive component to produce a patterned image on the resist coating, in particular the exposure energy is typically about 10 depending on the components of the exposure apparatus and the photoresist composition. To 300 mJ / cm 2.

A wide range of activating radiation can be suitably used to expose the optical acid or base generating compositions of the invention, including radiation having a wavelength in the range from 240 to 700 nm. As noted above, the compositions of the present invention are particularly suitable for deep ultraviolet exposure. The spectral response of the composition according to the invention can be broadened by adding the appropriate radiation sensitive compound to the composition, as will be apparent to those skilled in the art.

After exposure, the film film of the composition is preferably baked at about 70 to about 140 ° C. Thereafter, the film is developed. Polar developer, preferably inorganic alkali (e.g. sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, sodium silicate, sodium metasilicate), quaternary ammonium hydroxide solution (e.g. tetra- Alkyl ammonium hydroxide solution), various amine solutions (e.g. ethyl amine, n-propyl amine, diethylamine, di-n-propyl amine, triethyl amine or methyldiethyl amine), alcohol amines (e.g. Negative functionalities are provided by the use of an aqueous developer, such as diethanol amine or triethanol amine), cyclic amines (eg pyrrole, pyridine) and the like. The concentration of the developer can be further increased by using the modified resin according to the present invention as compared to the resins used in the prior art in such compositions. Typically, the concentration of the developer may exceed 0.2 N TMAH and may typically be as high as 0.3 N TMAH, preferably 0.26 N TMAH.

After the photoresist coating is developed on the substrate, the developed substrate is selectively processed in the baking region of the resist, for example, by chemically etching or plating the baked substrate region of the resist in accordance with procedures known in the art. can do. Suitable etchant for making microelectronic substrates (eg, silicon dioxide wafers) include gas plasma and hydrofluoric acid etching solutions. The composition according to the present invention has a very high resistance to such an etchant, which makes it possible to produce high resolution shapes comprising lines of submicron width. After this processing step, the resist can be removed from the processed substrate using known stripping procedures.

The present invention is illustrated by the following examples. The following two examples illustrate mesylation of preformed poly (vinylphenol) resins.

Example 1

In a 2-liter three-necked flask, 795 ml of acetone and 250.0 g of poly (vinylphenol) (MARUKA LYNCUR M grade, Maruzen Petrochemical Co., LTD.) Are mixed until completely dissolved. Then 45.3 g of methane sulfonylchloride are added and a solution containing 44.0 g of triethyl amine and 85 ml of acetone is added dropwise over 30 minutes. While the base is added, the batch temperature is raised to 30 ° C. and left at this temperature for 1 hour 15 minutes. To provide pure product free of metals, 307 g of Amberlite IRN 77 was added to the reaction mixture, and then 242 g of Amberlite IRN 77 and 242 g of Dowex SBR OH were added to the reaction mixture, followed by stirring while maintaining the mixture at 30 ° C. do. Both ion exchange resins are washed thoroughly with demineralized water and dehydrated with acetone before use. After 1 hour 30 minutes of contact, the ion exchange resin was filtered off and the product precipitated with 3.5 liters of demineralized water. The precipitate is collected in a filter, washed with demineralized water and dried under vacuum at 50 ° C. to give 253 g of polymer. As a result of analysis by ion chromatography, the polymer contains less than 1.0 ppm methane sulfonic acid and less than 5 ppm chloride.

Example 2

50 g of preformed polyvinyl phenol are metered into a 300 ml three-neck round bottom flask equipped with a mechanical stirrer and paddle, nitrogen inlet and addition funnel on top. 150 ml of acetone are added to the round bottom flask with vigorous stirring through the addition funnel. Dissolve the polymer completely. 4.84 g of triethylamine is added in a rapid dropwise manner while stirring. The reaction solution should be the same color as the polymer. 5.22 g of mesyl chloride is added dropwise while stirring. The color should fade slowly. The reaction solution is stirred for 1 hour at room temperature under positive nitrogen flow. During the reaction, IRN-150 ion exchange resin beads are metered into the beaker. The metered beads are transferred to a molten funnel rinsed with water. The beads are immersed in water and then left to stir with occasional stirring for 5 to 10 minutes. The water is removed by vacuum filtration and then repeated with additional water. Again the water is filtered off and acetone is added to allow the beads to immerse. Acetone is filtered off and repeated with additional acetone. Once conditioned, the beads are placed in acetone until added to the reaction flask. When the reaction time is complete, acetone is filtered off and the beads are added to the reaction solution with gentle stirring (washing with a limited amount of acetone). Stir gently at room temperature for 2 hours. The reaction solution is transferred through a molten funnel to filter the beads. Wash the beads with acetone. The filtered reaction solution is transferred to a separating funnel. The reaction solution is added to deionized water with vigorous stirring. The polymer is filtered using Whatman 42 filter paper. Dry with an aspirator. Transfer to a Pyrex tray or crystallization dish and air dry overnight. Dry for 24 hours at 100 ° C. under vacuum.

Examples 3 to 7 below illustrate the resolution obtained when developing a negative tone resist using a conventional phenolic binder upon exposure to i-line radiation. The materials and processes used are described below and the compositions are expressed in parts by weight. The composition is dissolved prior to coating and then filtered to 0.2 μm with a Teflon filter. In all embodiments, the stability or performance of the resist is unacceptable.

Example 3

Example 3 illustrates the use of a low molecular weight p-cresol novolak binder polymer.

10% p-cresol, formaldehyde condensed

Novolac formed from 90% m-cresol 22.69

Hexamethoxymelamine Isomer Mixture 2.97

Triazine D 0.34

Sylwet 7604 0.04

Ethyl lactate 73.96

The chemical formula of triazine D is as follows.

The 1.03 μm film is softbaked at 110 ° C. for 60 seconds, exposed to GCA 0.55NA, 0.54 σ i-line stepter, post exposure bake at 100 ° C. for 60 seconds and developed in 0.26N TMAH developer at 21 ° C. in a single puddle process. . The sizing luminous flux is 136 mJ / cm 2 and the resolution is 0.375 μm. The resist profile has an unacceptable triangular shape.

Example 4

Example 4 illustrates the use of a novolak binder polymer with a high content of p-cresol.

60% p-cresol, 5.5% 2,3-xyleneol,

Novolac formed from formaldehyde condensed 34.5% m-cresol 22.69

Hexamethoxymelamine Isomer Mixture 2.97

Triazine D 0.34

Sylwet 7604 0.04

Ethyl lactate 73.96

The formula of triazine D is as set forth above. The 1.03 μm film is softbaked at 110 ° C. for 60 seconds, exposed to GCA 0.55NA, 0.54 σ i-line stepter, post exposure bake at 100 ° C. for 60 seconds and developed in 0.26N TMAH developer at 21 ° C. in a single puddle process. . The sizing luminous flux is 41 mJ / cm 2 and the resolution is 0.375 m. The resist profile has an unacceptable triangular shape.

Example 5

Example 5 illustrates the use of a binder polymer formed from aromatic aldehyde phenolic polymers.

M-cresol condensed with benzaldehyde and salicyaldehyde 22.69

Hexamethoxymelamine Isomer Mixture 2.97

Triazine D 0.34

Sylwet 7604 0.04

Ethyl lactate 73.96

The formula of triazine D is as set forth above. Particles formed in the resist and could not be used for subsequent testing.

Example 6

Example 6 illustrates the use of a binder polymer formed from aromatic aldehydes and another triazine.

From m-cresol condensed with benzaldehyde and salicyaldehyde

Phenolic Polymer Formed 22.69

Hexamethoxymelamine Isomer Mixture 2.97

Triazine E 0.34

Sylwet 7604 0.04

Ethyl lactate 73.96

The chemical formula of triazine E is as follows.

A 1.03 μm film was softbaked at 110 ° C. for 60 seconds, exposed to GCA 0.55NA, 0.54 σ i-line stepter, post exposure bake at 100 ° C. for 60 seconds, and developed in a 0.26N TMAH developer at 21 ° C. in a single puddle process. do. The sizing luminous flux is 190 mJ / cm 2 and the resolution is 0.5 μm. Excellent resolution

Example 7

Example 7 illustrates the use of a polyvinylphenol binder without blocking groups.

Poly (4-vinylphenol) molecular weight = 6000 21.81

Hexamethoxymelamine Isomer Mixture 2.86

Triazine D 0.33

Sylwet 7604 0.04

Ethyl lactate 74.97

Particles formed in the filtered resist and could not be used for subsequent testing.

Examples 8 to 10 below illustrate the resolution obtained when developing a negative tone resist using a blend of phenolic binders that do not contain a blocking group bound to some hydroxyl moieties by exposure to i-line radiation. do. The materials and processes used are described below and the compositions are expressed in parts by weight. The composition is dissolved prior to coating and then filtered to 0.2 μm with a Teflon filter. In all embodiments, the stability or performance of the resist is unacceptable.

Example 8

Example 8 illustrates the use of a binder polymer blend of novolac and poly (4-vinylphenol).

10% p-cresol, formaldehyde condensed

Novolac formed from 90% m-cresol 17.27

Poly (4-vinylphenol) 11.51

Hexamethoxymelamine Isomer Mixture 4.4

Triazine E 1.75

Sylwet 7604 0.07

Propylene Glycol Methyl Ether Acetate 65.0

The chemical formula of triazine E is as set forth above. The 1.00 μm film was softbaked at 110 ° C. for 60 seconds, exposed to GCA 0.55NA, 0.54 σ i-line stepter, post exposure baked at 90 ° C. for 60 seconds, and developed in 0.26N TMAH developer at 21 ° C. in a single puddle process. do. The sizing luminous flux is 148 mJ / cm 2 and the resolution is 0.6 mu m or more. Serious microcrosslinking defects are formed between the separated patterns at intervals of 0.5 μm or less. The resolution is not excellent.

Example 9

Example 9 illustrates the use of a binder polymer blend of novolac and hydrogenated polyvinylphenol resin.

10% p-cresol, formaldehyde condensed

Novolac formed from 90% m-cresol 17.27

Poly4-vinylphenol-co-4-vinylcyclohexanol (ratio 9: 1) 11.51

Hexamethoxymelamine Isomer Mixture 4.4

Triazine E 1.75

Sylwet 7604 0.07

Propylene Glycol Methyl Ether Acetate 65.0

The chemical formula of triazine E is as set forth above. The 1.00 μm film was softbaked at 110 ° C. for 60 seconds, exposed to GCA 0.55NA, 0.54 σ i-line stepter, post exposure baked at 90 ° C. for 60 seconds, and developed in 0.26N TMAH developer at 21 ° C. in a single puddle process. do. The sizing luminous flux is 120 mJ / cm 2 and the resolution is at least 0.6 μm. Serious microcrosslinking defects are formed between the separated patterns at intervals of 0.5 μm or less. The resolution is not excellent.

Example 10

Example 10 illustrates the use of a binder blend of novolac and hydrogenated polyvinylphenol.

10% p-cresol, formaldehyde condensed

Novolac 20.91 formed from 90% m-cresol

Poly (4-vinylphenol-co-4-vinylcyclohexanol), (ratio 9: 1) 5.23

Hexamethoxymelamine isomer mixture 4.34

Triazine E 0.47

Sylwet 7604 0.07

Propylene Glycol Methyl Ether Acetate 65.0

The chemical formula of triazine E is as set forth above. The 1.00 μm film was softbaked at 110 ° C. for 60 seconds, exposed to GCA 0.55NA, 0.54 σ i-line stepter, post exposure baked at 105 ° C. for 60 seconds, and developed in 0.26N TMAH developer at 21 ° C. in a single puddle process. do. The resolution is 0.475 mu m. No microcrosslinking defects were observed. Excellent resolution

Examples 11 to 13 below contain novolak (1) and poly (4-vinylphenol-co-4-vinylcyclohexanol) (2) containing a blocking group bound to some hydroxyl moiety Illustrates the improved performance obtained when developing negative tone resists using blends of phenolic binders when exposed to i-line radiation. The materials and processes used are described below and the compositions are expressed in parts by weight. The composition is dissolved prior to coating and then filtered to 0.2 μm with a Teflon filter. In all embodiments, the performance and resolution of the resist are greatly improved compared to Examples 1-8.

Example 11

Example 11 illustrates the use of a 2: 1 binder polymer blend of low molecular weight p-cresol novolac and 11% mesylated polyvinyl phenol resin.

10% p-cresol, formaldehyde condensed

Novolac formed from 90% m-cresol 15.21

11% mesylated-poly (4-vinylphenol-co-4-vinylcyclohexanol)

(Monomer ratio 9: 1) 7.49

Hexamethoxymelamine Isomer Mixture 2.97

Triazine D 0.34

Sylwet 7604 0.04

Ethyl lactate 73.96

The formula of triazine D is as set forth above. The 1.03 μm film is softbaked at 110 ° C. for 60 seconds, exposed to GCA 0.55NA, 0.54 σ i-line stepter, post exposure bake at 100 ° C. for 60 seconds and developed in 0.26N TMAH developer at 21 ° C. in a single puddle process. . The sizing luminous flux is 65 mJ / cm 2. The resolution is 0.40 mu m. A small amount of scum defects is observed. The resolution is excellent.

Example 12

Example 12 illustrates the use of a 2: 1 binder polymer blend of high molecular weight p-cresol novolac with 11% mesylated polyvinyl phenol.

60% p-cresol, 5.5% 2,3-xyleneol, formaldehyde condensed

Novolac formed from 34.5% m-cresol 15.18

11% mesylated-poly (4-vinylphenol-co-4-vinylcyclohexanol)

(Monomer ratio 9: 1) 7.51

Hexamethoxymelamine Isomer Mixture 2.97

Triazine D 0.34

Sylwet 7604 0.04

Ethyl lactate 73.96

The formula of triazine D is as set forth above. A 1.03 μm film was softbaked at 110 ° C. for 60 seconds, exposed to GCA 0.55NA, 0.54 σ i-line stepter, post exposure bake at 100 ° C. for 60 seconds, and developed in a 0.26N TMAH developer at 21 ° C. in a single puddle process. do. The sizing luminous flux is 35 mJ / cm 2. The resolution is 0.40 mu m. The resolution is excellent. No defects were observed in the resist.

Example 13

Example 13 illustrates the use of a 1: 2 binder polymer blend of high molecular weight p-cresol novolac with 11% mesylated polyvinyl phenol.

60% p-cresol, 5.5% 2,3-xyleneol, formaldehyde condensed

Novolac 7.51 formed from 34.5% m-cresol

11% mesylated-poly (4-vinylphenol-co-4-vinylcyclohexanol)

(Monomer ratio 9: 1) 15.18

Hexamethoxymelamine Isomer Mixture 2.97

Triazine D 0.34

Sylwet 7604 0.04

Ethyl lactate 73.96

The formula of triazine D is as set forth above. The 1.03 μm film is softbaked at 110 ° C. for 60 seconds, exposed to GCA 0.55NA, 0.54 σ i-line stepter, post exposure bake at 100 ° C. for 60 seconds and developed in 0.26N TMAH developer at 21 ° C. in a single puddle process. . The sizing luminous flux is 35 mJ / cm 2. The resolution is 0.375 mu m. Excellent resolution No defects were observed in the resist.

Example 14 below illustrates the performance obtained when developing a negative tone resist using a polyvinyl phenol binder with an inert blocking group when exposed to i-line radiation. The materials and processes used are described below and the compositions are expressed in parts by weight. The composition is dissolved prior to coating and then filtered to 0.2 μm with a Teflon filter.

Example 14

11% mesylated-poly (4-vinylphenol-co-4-vinylcyclohexanol)

(Monomer ratio 9: 1) 22.68

Hexamethoxymelamine Isomer Mixture 2.97

Triazine D 0.34

Sylwet 7604 0.04

Ethyl lactate 73.96

The formula of triazine D is as set forth above. The 1.03 μm film is softbaked at 110 ° C. for 60 seconds, exposed to GCA 0.55NA, 0.54 σ i-line stepter, post exposure bake at 100 ° C. for 60 seconds and developed in 0.26N TMAH developer at 21 ° C. in a single puddle process. . The sizing luminous flux is 14 mJ / cm 2. The resolution is 0.40 mu m. Although the shape of the cross section and the side wall angle are inferior to those of the resists of Examples 10 and 11, the resolution is excellent.

Consideration for Examples 4-14

The resist of Example 4 contained only a novolak binder polymer and the resist of Example 14 contained only 11% mesylated-poly (4-vinylphenol-co-4-vinylcyclohexanol, monomeric ratio 9: 1). do. Examples 12 and 13 contain a blend polymer blend containing the above two polymers in ratios of 2: 1 and 1: 2, respectively. A close look at the performance of the resist, including cross-sectional shape, thickness retention, defects and sidewall angles, showed the best performance in the 1: 2 to 2: 1 blend of binder polymer. It is observed that even when the novolak binder polymer contains more p-cresol monomer, the performance is further improved. Thus, a 1: 1 blend of two binder polymers is selected for the next few experiments described in the Examples below.

Examples 15-18 below show negative tone corrosion using a blend of phenolic binders containing a novolak (1) and a poly (4-vinylphenol) (2) containing a blocking group bound to some hydroxyl moiety Illustrates the improved performance obtained when developing a film by exposure to i-line radiation. In these examples, the degree of mesylation of the polymer varies. The materials and processes used are described below and the compositions are expressed in parts by weight. The composition is dissolved prior to coating and then filtered to 0.2 μm with a Teflon filter. In all embodiments, the performance and resolution of the resist are greatly improved compared to Examples 1-8.

Example 15

Example 15 illustrates the use of a 1: 1 binder polymer blend of high molecular weight p-cresol novolac and 14% mesylated polyvinyl phenol.

60% p-cresol, 5.5% 2,3-xyleneol, formaldehyde condensed

Novolac 10.91 formed from 34.5% m-cresol

14% Mesylated-Poly (4-Vinylphenol) 10.91

Hexamethoxymelamine Isomer Mixture 2.86

Triazine D 0.33

Sylwet 7604 0.04

Ethyl lactate 74.97

The formula of triazine D is as set forth above. The 1.00 μm film was softbaked at 110 ° C. for 60 seconds, exposed to GCA 0.55NA, 0.54 σ i-line stepter, post exposure baked at 100 ° C. for 60 seconds, and developed in 0.26N TMAH developer at 21 ° C. in a single puddle process. do. The resolution is 0.42 mu m. The resulting features are very dross and some microcrosslinking is observed between very small gaps.

Example 16

Example 16 illustrates the use of a 1: 1 binder polymer blend of high molecular weight p-cresol novolac and 16% mesylated polyvinyl phenol.

60% p-cresol, 5.5% 2,3-xyleneol, formaldehyde condensed

Novolac 10.91 formed from 34.5% m-cresol

16% Mesylated-Poly (4-Vinylphenol) 10.91

Hexamethoxymelamine Isomer Mixture 2.86

Triazine D 0.33

Sylwet 7604 0.04

Ethyl lactate 74.97

The formula of triazine D is as set forth above. The 1.00 μm film is softbaked at 110 ° C. for 60 seconds, exposed to GCA 0.55NA, 0.54 σ i-line stepter, post exposure bake at 100 ° C. for 60 seconds and developed in 0.26N TMAH developer at 21 ° C. in a single puddle process. . The resolution is 0.40 mu m. The resulting features are very dross and some microcrosslinking is observed between very small gaps.

Example 17

Example 17 illustrates the use of a 1: 1 binder polymer blend of high molecular weight p-cresol novolac and 19% mesylated polyvinyl phenol.

60% p-cresol, 5.5% 2,3-xyleneol, formaldehyde condensed

Novolac 10.91 formed from 34.5% m-cresol

19% Mesylated-Poly (4-Vinylphenol) 10.91

Hexamethoxymelamine Isomer Mixture 2.86

Triazine D 0.33

Sylwet 7604 0.04

Ethyl lactate 74.97

The formula of triazine D is as set forth above. The 1.00 μm film is softbaked at 110 ° C. for 60 seconds, exposed to GCA 0.55NA, 0.54 σ i-line stepter, post exposure bake at 100 ° C. for 60 seconds and developed in 0.26N TMAH developer at 21 ° C. in a single puddle process. . The resolution is 0.40 mu m. The resulting shape has very little tailings.

Example 18

Example 18 illustrates the use of a 1: 1 binder polymer blend of high molecular weight p-cresol novolac and 21% mesylated polyvinyl phenol.

60% p = cresol, 5.5% 2,3-xyleneol, formaldehyde condensed

Novolac 10.91 formed from 34.5% m-cresol

21% mesylated-poly (4-vinylphenol) 10.91

Hexamethoxymelamine Isomer Mixture 2.86

Triazine D 0.33

Sylwet 7604 0.04

Ethyl lactate 74.97

The formula of triazine D is as set forth above. The 1.00 μm film is softbaked at 110 ° C. for 60 seconds, exposed to GCA 0.55NA, 0.54 σ i-line stepter, post exposure bake at 100 ° C. for 60 seconds and developed in 0.26N TMAH developer at 21 ° C. in a single puddle process. . The resolution is less than 0.40 mu m. The resulting shape is free from tailings.

Consideration of Example 8 and Examples 15 to 18

Comparing the results from Examples 8 and 15 to 18, the resistivity of the resist groups dramatically improved as the degree of blocking of hydroxyl groups in the polymer increased. The microcrosslinking defect problem very clearly observed in poly (4-vinylphenol): novolak binder mixtures is reduced and eliminated as the degree of blocking in poly (4-vinylphenol) increases from 0 to 13% to 21%. . Certainly in this system, approximately 21% of the phenolic moieties are removed by binding inert groups to sufficiently prevent microcrosslinking. Other cross-sectional defects, including tailings, are similarly reduced.

The fact that these results show similar lithographic performance when compared to similar binder blends containing 11% mesylated-poly (4-vinylphenol-co-4-vinylcyclohexanol, monomer ratio 9: 1) binder polymer. It is interesting to note. In this case, 11% of the (acidic) vinyl phenol moieties are blocked with inert groups, and the addition of possible (acidic) vinylphenol moieties in the polymer because the binder contains vinylcyclohexanol comonomers (which are much less acidic). 10% of are removed. Thus a total of 21% of the available phenolic hydroxyl moieties in the polyvinylphenol are removed from the binder component in the desired material.

Examples 19 and 20 below are negative tones using blends of phenolic binders containing novolak (1) and poly (4-vinylphenol) (2) containing blocking groups bound to some hydroxyl moieties. Illustrates the improved performance obtained when strong bases are added to resists and developed by exposure to i-line radiation. The materials and processes used are described below and the compositions are expressed in parts by weight. The composition is dissolved prior to coating and then filtered to 0.2 μm with a Teflon filter. In all embodiments, the performance and resolution of the resist is greatly improved compared to all the preceding embodiments.

Example 19

Example 19 illustrates the use of a 1: 1 binder polymer blend of high molecular weight p-cresol novolac and 21% mesylated polyvinyl phenol containing quaternary ammonium hydroxide.

60% p-cresol, 5.5% 2,3-xyleneol, formaldehyde condensed

Novolac 10.72 formed from 34.5% m-cresol

21% Mesylated-Poly (4-Vinylphenol) 10.72

Hexamethoxymelamine Isomer Mixture 2.81

Triazine D 0.25

Sylwet 7604 0.04

Ethyl lactate 75.46

Tetrabutylammonium Hydroxide 0.09

The formula of triazine D is as set forth above. The 1.00 μm film was softbaked at 110 ° C. for 60 seconds, exposed to GCA 0.55NA, 0.54 σ i-line stepter, post exposure baked at 100 ° C. for 60 seconds, and developed in 0.26N TMAH developer at 21 ° C. in a single puddle process. do. The sizing luminous flux is 80 mJ / cm 2. The resolution is 0.30 to 0.32 mu m. The shape is well formed so that there is no residue and the angle of the wall is almost vertical. Excellent resolution and process latitude.

Example 20

Example 20 illustrates the use of a 1: 1 binder polymer blend of high molecular weight p-cresol novolac containing 11% mesylated, hydrogenated polyvinyl phenol containing quaternary ammonium hydroxide.

60% p-cresol, 5.5% 2,3-xyleneol, formaldehyde condensed

Novolac 10.72 formed from 34.5% m-cresol

11% mesylated-poly (4-vinylphenol-co-4-vinyl

Cyclohexanol, monomer ratio 9: 1) 10.72

Hexamethoxymelamine Isomer Mixture 2.81

Triazine D 0.25

Sylwet 7604 0.04

Ethyl lactate 76.46

Tetrabutylammonium Hydroxide 0.09

The formula of triazine D is as set forth above. The 1.00 μm film is softbaked at 110 ° C. for 60 seconds, exposed to GCA 0.55NA, 0.54 σ i-line stepter, post exposure bake at 100 ° C. for 60 seconds and developed in 0.26N TMAH developer at 21 ° C. in a single puddle process. . The luminous flux is 80 mJ / cm 2. The resolution is 0.30 to 0.32 mu m. The shape is well formed so that there is no residue and the angle of the wall is almost vertical. Excellent resolution and process latitude.

Examples 21-27 are phenolic binders containing different optical acid generators containing poly (4-vinylphenol) (2) containing a blocking group bonded to the novolak (1) and some hydroxyl moieties. It can be used in conjunction with a blend of to illustrate the development by exposure to i-line radiation. The materials and processes used are described below and the compositions are expressed in parts by weight. The composition is dissolved prior to coating and then filtered to 0.2 μm with a Teflon filter. In all embodiments, the performance and resolution of the resist is greatly improved compared to all the preceding embodiments.

Examples 21-27

The composition used in each of the above examples is as follows:

60% p-cresol, 5.5% 2,3-xyleneol, formaldehyde condensed

Novolac 12.473 formed from 34.5% m-cresol

Hexamethoxymelamine Isomer Mixture 3.268

Optical acid generator 0.287

Sylwet 7604 0.06

Ethyl lactate 71.349

Tetrabutylammonium Hydroxide 0.09

Example Optical acid generator Beam (Eo) resolution Remarks 21 PAG E 28mJ / ㎠ 0.40 No tailings 22 PAG D 34 0.375 No tailings 23 PAG DG 30 0.325 No tailings 24 PAG A 48 0.375 No tailings 25 PAG PPP 13 0.375 No tailings 26 PAG K 310 Not observed 27 PAG N 195 Not observed

The chemical formula of triazine not given above is as follows.

PAG DG

PAG A

PAG PPP

PAG K

PAG N is an onium salt but its structure is unknown.

The following claims do not limit the particular aspects set forth in the above examples.

Photoresist compositions comprising the novel polymer mixtures according to the invention provide improved developability when developed upon exposure to i-line radiation to develop flawlessly and eliminate microcrosslinking defects.

Claims (28)

An aqueous alkali soluble phenolic resin mixture comprising a polyvinyl phenolic resin and a novolak resin and a component selected from the group consisting of photoacid generators, crosslinkers and dissolution inhibitors, wherein the at least one resin is a pendant hydroxyl group thereof In which at least 0.1 mole% of the compound is substituted with an inert group in an acid environment, and the weight ratio of the polyvinyl phenol resin to the novolak resin in the mixture is from 1:10 to 10: 1. The photoresist composition of claim 1, wherein the composition is negative functional and comprises a crosslinking agent. The photoresist composition of claim 1, wherein the composition is positive functional and comprises a dissolution inhibitor. The photoresist composition of claim 3, wherein the dissolution inhibitor is an acid labile group on at least one alkali-soluble resin backbone in the mixture. The photoresist composition of claim 3, wherein the dissolution inhibitor is an additional component added to the photoresist composition. The photoresist according to claim 1, wherein the hydroxyl group of the phenol resin is a phenolic hydroxyl group and the amount of the hydroxyl group substituted with an inert blocking group is 0.1 to 30 mol% of the total phenolic hydroxyl groups in the polymer blend. Composition. The photoresist composition of claim 1, wherein the at least one resin in the polymer mixture is a copolymer of phenol and cyclohexanol. The photoresist composition of claim 1, wherein at least one resin in the polymer mixture is a hydrogenated phenolic resin. The photoresist composition of claim 8, wherein less than 50% of the phenolic groups of the hydrogenated resin are hydrogenated. The photoresist composition of claim 8, wherein the percentage of hydrogenated groups is 1-30%. The photoresist composition of claim 8, wherein the hydrogenated resin is a hydrogenated polyvinyl phenol resin. The photoresist composition of claim 1, wherein the amount of hydroxyl groups in the polymer mixture, which reacts to form blocking groups, is from 1 to 10 mole percent of the total hydroxyl groups. The photoresist composition of claim 1, wherein the ratio of polyvinyl phenol resin to novolak resin is 4: 6 to 6: 4. 7. The photoresist composition of claim 6, wherein the mole% of the hydroxyl group substituted with the inert blocking group is 0.05 to 0.35 mole%. 7. The photoresist composition of claim 6, wherein the mole% of the hydroxyl group substituted with the inert blocking group is 0.15 to 0.30 mole%. The photoresist composition of claim 1, wherein the inert blocking group is substituted for the novolak resin. The photoresist composition of claim 1, wherein the inert blocking group is substituted for the polyvinyl phenol resin. The photoresist composition of claim 1, wherein the inert blocking group is substituted for both resins. The photoresist composition of claim 1, wherein the inert blocking group is selected from the group consisting of an alkoxy group, an alkyl ester of the formula RCOO-, wherein R is an alkyl group having 1 to 4 carbon atoms, and a sulfonyl acid ester. 13. The photoresist composition of claim 12, wherein the inert blocking group is a sulfonyl ester group. The photoresist composition of claim 1, wherein the polyvinyl phenol resin is a compound of formula 1 and the novolak resin is a compound of formula 2. Formula 1 Formula 2 In the above formula, Z is an alkylene bridge having 1 to 3 carbon atoms, A is lower alkyl having 1 to 3 carbon atoms, halo, alkoxy having 1 to 3 carbon atoms, hydroxyl, nitro or amino, a is 0 to 4, B is hydrogen, lower alkyl of 1 to 3 carbon atoms, halo, alkoxy, hydroxyl, nitro or amino of 1 to 3 carbon atoms, provided that at least three of the B substituents are hydrogen; b is an integer from 6 to 10, x is from 0.1 to 0.99 as molar fraction of phenolic units in the polymer, y is the mole fraction of the phenolic unit in which the hydroxyl group is substituted with the inert blocking group OG, x 'is the mole fraction of cyclic alcohol units in the polymer, y 'is the mole fraction of cyclic alcohol units in the polymer, wherein the hydroxyl group is substituted with an inert blocking group OG, x + x 'is 0.5 to 1.0, y + y 'is equal to 1- (x + x'), x '+ y' is 0.01 to 0.30, x + x '+ y + y' is 1, The ratio of novolak resin to polyvinyl phenol resin is 1:10 to 10: 1. 22. The photoresist composition of claim 21, wherein x '+ y' is 0.05 to 0.30. 23. The photoresist composition of claim 22, wherein x and y are each at least 0.01. The photoresist composition of claim 21 wherein x is from 0.99 to 0.70 and y is from 0.02 to 0.10. The photoresist composition of Claim 1 containing a strong base whose pK _a is nine or more. The photoresist composition of claim 25, wherein pK _a is 11-15. 27. The photoresist composition of claim 25, wherein the base is quaternary ammonium hydroxide. 27. The photoresist composition of claim 25, wherein the quaternary ammonium hydroxide is tetrabutyl ammonium hydroxide.