Patent Application
20110053081
This application claims the benefit of Korean Patent Application No. 10-2009-0081181, filed on Aug. 31, 2009, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a positive typed photosensitive composition that may prevent a warpage phenomenon of a semiconductor wafer from occurring in a semiconductor manufacturing process, and have excellent ductility.
2. Description of the Related Art
In general, most photosensitive compositions used in a semiconductor process may exhibit a positive type, because an exposed portion is dissolved in an alkali aqueous solution by ultraviolet exposure. The composition may include a resin dissolved in the alkali aqueous solution, a photosensitive compound that is insoluble in the alkali aqueous solution and is sensitive to ultraviolet light, and other additives.
As an example of the resin dissolved in the alkali aqueous solution, a polyamide derivative may be given. This resin may be transformed into polyamide and polybenzoxazole by heat, thereby exhibiting characteristics of a heat-resistant resin. In a conventional art, a composition not having photosensitivity may be used, however, in recent years, there arises a tendency to prefer a composition having photosensitivity for the purpose of process simplification. As high integration is accelerated with a development in semiconductor manufacturing techniques, packing technologies may proceed toward a significantly complex process, unlike to conventional packing technologies. A high-lamination packing technology of at least two layers may be adopted from a simple single-dimensional packing technology of the conventional art. The high-lamination packing technology may be a technique of maximizing a chip capacity in comparison to a chip size. In this instance, a volume of a chip thickness may be reduced by abrading a rear surface of a wafer during the semiconductor manufacturing process in order to minimize a chip thickness having been increased due to lamination of layers. When the chip thickness is finally reduced down to 40 μm or less by abrading the rear surface of the wafer, a warpage phenomenon of the wafer may occur. This warpage phenomenon may be exhibited due to different linear expansion coefficients depending on a difference between materials used in a front surface and the rear surface of the wafer. When the warpage phenomenon significantly occurs, manipulation of the wafer in a following process may be inconvenient, and errors may also frequently occur, thereby reducing a yield.
An aspect of the present invention provides a positive typed photosensitive composition that may prevent a warpage phenomenon of a semiconductor wafer from occurring in a semiconductor manufacturing process and have excellent ductility.
According to an aspect of the present invention, there is provided a positive typed photosensitive composition including a polyamide derivative being represented by
where R1 and R2 independently represent a bivalent to hexavalent aryl group with at least two carbon atoms, R3 represents either a hydrogen atom or an alkyl group with 1 to 20 carbon atoms, R4 represents either an alkyl group having a linear structure or an aryl group having a linear structure, R5 represents any one of a bivalent to hexavalent aryl group with at least two carbon atoms, an alkyl group having a linear structure, and an aryl group having a linear structure, k and l independently represent an integer of 10 to 1000, n and m independently represent an integer of 0 to 2 (n+m>0), and X represents either a hydrogen atom or an aryl group with 2 to 30 carbon atoms.
Additional aspects, features, and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the invention.
According to exemplary embodiments, when a positive typed photosensitive composition is used in a semiconductor manufacturing process, occurrence of a warpage phenomenon of a semiconductor wafer may be prevented, and the wafer may be easily manipulated in the semiconductor manufacturing process, and thereby a semiconductor process efficiency may be improved.
Hereinafter, a positive typed photosensitive composition according to exemplary embodiments will be described in detail.
The positive typed photosensitive composition according to an exemplary embodiment may have high sensitivity, and minimize occurrence of a warpage phenomenon of a wafer after forming a film. The positive typed photosensitive composition may include a polyamide derivative, a diazonaphthol compound, and other additives. As examples of the additive, there may given a crosslink catalyst, an adhesive aid, a surfactant, an anti-corrosion agent, and the like. The polyamide derivative may be represented by
where R1 and R2 independently represent a bivalent to hexavalent aryl group with at least two carbon atoms, R3 represents either a hydrogen atom or an alkyl group with 1 to 20 carbon atoms, R4 represents either an alkyl group having a linear structure or an aryl group having a linear structure, R5 represents any one of a bivalent to hexavalent aryl group with at least two carbon atoms, an alkyl group having a linear structure, and an aryl group having a linear structure, k and l independently represent an integer of 10 to 1000, n and m independently represent an integer of 0 to 2 (n+m>0), and X represents either a hydrogen atom or an aryl group with 2 to 30 carbon atoms.
In this instance, R4 may have a linear structure, and may represent either an alkyl group with 20 carbon atoms or less having at least one alkenyl group or an aryl group with 20 carbon atoms or less having at least one alkenyl group. Also, R5 may include a compound identical to that of R1 or R4. That is, R1, R4, and R5 may have an identical chemical structure.
As examples of a compound of R1, there may given compound groups which are represented by Chemical Formulas 2 to 22 below, and the compound groups may be used alone or in combination of the compounds.
In the above Chemical Formula 16, R4 may be any one of a hydrogen atom, a halogen atom, a hydroxyl group, carboxyl group, a thiol group, an alkyl group with 1 to 10 carbon atoms, and an aryl group with 1 to 10 carbon atoms.
In addition, in the above Chemical Formula 1, as examples of a compound of R2, there may be given the compound groups represented by Chemical Formulas 23 to 37 below, and the compound groups may be used alone or in combination thereof
In the above Chemical Formula 33, R5 may be any one of a hydrogen atom, a halogen atom, a hydroxyl group, carboxyl group, a thiol group, an alkyl group with 1 to 10 carbon atoms, and an aryl group with 1 to 10 carbon atoms.
In addition, in the above Chemical Formula 1, as examples of a compound of R4, there may be given the compound groups represented by Chemical Formulas 38 to 41 below, and the compound groups may be used alone or in combination thereof.
In the above Chemical Formulas 38 to 41, R7 and R8 may independently represent a hydrogen atom, or an alkyl group, Y may represent an alkyl group with 2 to 12 carbon atoms, and m and n may represent a natural number of 1 to 12.
The polyamide derivate (Chemical Formula 1) according to an exemplary embodiment may increase ductility of a polymer using a monomer corresponding R4. Due to the ductility of the polymer, the warpage phenomenon of the wafer occurring in a semiconductor wafer manufacturing process may be minimized. However, when a chain length of the monomer corresponding to R4 is too long, and a used amount of the R4 is relatively great, a glass transition temperature (Tg) of the polymer may be reduced. Accordingly, the chain length of the monomer (R4) may be preferably in a range where a number of carbon atoms is less than 20. Also, R4 may be preferably used in an amount of 2 mol % to 10 mol % based on the whole polyamide derivative.
In polymer synthesis of the above Chemical Formula 1, to adjust a molecular weight and to improve storage stability of a product, an amine group of a main chain of a polymer may be preferably replaced with a chemically stable functional group. There may be various methods of replacing the amine group with the functional group, however, the amine group may be preferably replaced with an amide group. For example, as examples of a compound that is reacted with the amine group to generate the amide group, there may be given an alkylcarbonyl chloride derivative, an alkenylcarbonyl chloride derivative, an alkinylcarbonyl chloride derivative, an alkylsolfonyl chloride derivative, an arylsolfonyl chloride derivative, an alkyl group-containing acid anhydride derivative, an aryl group-containing acid anhydride derivative, an alkenyl group-containing acid anhydride derivative, and the like. However, when using the alkylcarbonyl chloride derivative and the alkenylcarbonyl chloride derivative that have a significantly high chemical reaction speed, the alkylcarbonyl chloride derivative and the alkenylcarbonyl chloride derivative may be reacted with another functional group as well as the amine group of the polymer main chain, and thereby by-products may be disadvantageously generated.
In the above Chemical Formula 1, X may be a hydrogen atom, or a compound group represented by Chemical Formulas 42 to 51 below. However, the present may not be limited thereto, and thus a mixture of two or more compounds may be used as X.
In the above Chemical Formula 50, R6 may represent an alkyl group with 1 to 10 carbon atoms or an aryl group with 1 to 10 carbon atoms. That is, an amine group of a main chain may be replaced with an amide group using at least one of the above compounds.
The polymer represented by the above Chemical Formula 1 may be generally manufactured by a condensation reaction. The condensation reaction may be performed such that a dicarboxylic acid derivative is transformed into a dichloride derivative using thionyl, and is subjected to the condensation reaction with a diamine derivative under a basic catalyst. A reaction temperature of the condensation reaction may not be particularly limited, however, may be preferably about 80° C. or less. When the reaction temperature of the condensation reaction is too high, by-products may be generated to deteriorate a development speed or UV transmittance, and the like. However, when the reaction temperature thereof is −10° C. or less, a reaction speed may be significantly reduced. A reaction mixture of the condensation reaction may be slowly dropped on a pure material to have the reaction mixture precipitated after the condensation reaction is completed, thereby obtaining a polymer compound of a solid particle type. When a molecular weight of the polymer is relatively great, a used amount of an acid anhydride derivative or a sulfonxyl chloride derivative capable of being reacted with an amine functional group is increased, thereby adjusting the molecular weight of the polymer.
The diazonaphthol compound of the photosensitive compound according to an exemplary embodiment may be obtained by reacting a phenol derivative including at least two hydroxy groups with a diazonaphthol sulfonic chloride derivative under an amine catalyst. The diazonaphthol compound may be represented by
where n and m independently represent an integer of 0 to 5 (n+m>0), Z represents an aryl group with 12 to 40 carbon atoms, DNQ represents by Chemical Formulas 52 or 53 below, and R7 represents any one of a hydrogen atom, an alkyl group with 1 to 12 carbon atoms, and an alkylcarbonyl group with 1 to 12 carbon atoms.
In the above Chemical Formula 51, a ratio of DNQ:R7 may be 1:4 to 20:1. When the ratio of the DNQ:R7 is too high, a sensitivity may be reduced, and when the ratio thereof is too low, a perpendicularity of a pattern may be deteriorated. When using an i-line exposurer, a phenol derivative having no ultraviolet absorbance at 365 nm may be preferably used. When the ultraviolet absorbance is relatively high, the perpendicularity of the pattern may be deteriorated. Examples of the diazonaphthol compound may be represented by Chemical Formulas 54 to 61 below, and the present invention is not limited thereto.
where DNQ represents a compound group expressed by a hydrogen atom, an alkylcarbonyl group, and the compound represented by the above Chemical Formula 52 or 53, and R8 represents a methyl group or a naphthoquinonediazide sulfoxy group (—ODNQ) (the DNQ being a compound group expressed by a hydrogen atom, an alkylcarbonyl group, and the compound represented by the above Chemical formula 52 or 53).
The diazonaphthol compound may be used in a mixture of compounds. A benzophenone derivative may be preferably used in terms of sensitivity, however, may not be preferably used in terms of the perpendicularity of the pattern. However, when the benzophenone derivative is mixed in a small amount thereof, and used, the sensitivity may be slightly improved instead of deteriorating the perpendicularity. In general, in terms of a UV sensitivity, an 1,2-naphthoquinone-2-diazide-4-sulfonic acid ester derivative may be preferably used rather than an 1,2-naphthoquinone-2-diazide-5-sulfonic acid ester derivative. The diazonaphthol compound may be preferably used in an amount of 5 to 30 parts by weight based on 100 parts by weight of the polyamide compound. When a used amount of the diazonaphthol compound is less than 5 parts by weight, a dissolution suppressing effect is insignificant to have a difficulty in pattern formation, and when the used amount thereof is more than 30 parts by weight, a film thickness loss is significantly increased after a thermal crosslinking is performed.
In forming a pattern, the pattern may be basically formed only using the polyamide compound, the diazonaphthol compound, and a solvent. However, as semiconductor devices are highly integrated, a composition having a high resolution, a high sensitivity, and a less thickness change after the thermal crosslinking is performed may be required. In order to obtain a composition having the high resolution, the high sensitivity, and a minimal thickness change without deteriorating other physical properties, another additive other than the polyamide compound and the diazonaphthol compound may be required. As an example of the additive, a general low molecular phenol compound may be used. The low molecular phenol compound may be easily obtained, however, have a relatively low thermal stability, and thereby a formed pattern may not be maintained when the thermal crosslinking is performed at a high temperature of about 300° C. or more. In order to overcome this problem, a phenol derivative including a methylol functional group and a separate thermal crosslinking agent may be extensively used. When the thermal crosslinking agent is separately used, the thermal stability may be maintained, however, a ductility of a film subjected to the thermal crosslinking may be deteriorated.
In a process of forming the pattern, bis(4-hydroxyphenyl)fluorine represented by Chemical Formula 62 below may be used in order to prevent an unexposed portion from being dissolved in a developer after being exposed. The bis(4-hydroxyphenyl)fluorine may increase the thermal stability after hardening the pattern in addition to preventing the unexposed portion from being dissolved in the developer.
In a recent process of manufacturing the semiconductor device, a relatively low temperature may be needed when forming a polyimide film or a polybenzoxazole film. This is to maximize a semiconductor manufacturing yield by minimizing a thermal impact exerted on the semiconductor device. A stable film may be obtained by heating a polyimide precursor or a polybenzoxazole precursor at about 350° C. for 30 minutes or more. According to the present invention, a compound in which an acid is generated by heat may be added, thereby reducing a crosslinking temperature by 20° C. or more. As an example of the compound in which the acid is generated by heat, there may be given a bivalent-alkyltoluene sulfonate. When the bivalent-alkyltoluene sulfonate is decomposed by a relatively low heat, a scum may occur in an exposed portion when forming the pattern, and when the bivalent-alkyltoluene sulfonate is decomposed by a relatively high heat, effects of the bivalent-alkyltoluene sulfonate may be insignificant. As an example of a bivalent-alkyl arylsulfonate, 2-propyl sulfonate, cycloalkyl sulfonate, 2-hydroxy cyclohexyl sulfonate, and the like may be given, however, the present invention may not be particularly limited thereto. As a used amount of the bivalent-alkyl arylsulfonate, 0.01 to 5% within the whole composition may be appropriate. When the used amount thereof is insufficient, effects thereof may be insignificant, and when the used amount thereof is excessive, an adverse influence may be exerted on a shape of the pattern and an exposed energy.
In manufacturing the composition according to the present invention, a silane coupling agent may be used in order to achieve an adhesive force with a substrate, or a diaminosiloxane monomer of less than 5% may be used in a polymer main chain. When the diaminosiloxane monomer of the polymer main chain of 5% or more is used, a heat resistance may be deteriorated. As examples of the silane coupling agent, there may be given vinyl trimethoxy silane, {3-(2-aminoethylamino)propyl}trimethoxy silane, 3-aminopropyltrimethoxy silane, N-methylaminopropyltrimethoxy silane, 3-glycidoxy-propyltrimethoxy silane, 3-glycidoxy-propyltriethoxy silane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxy silane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, N-(1,3-dimethylbutylidene)-3-(triethoxysilane)-1-propanamine, N,N-bis(3-trimethoxysilyl) propylethylamine, N-(3-trimethoxysilylpropyl)pyrrole, ureidopropyltrimethoxy silane, (3-triethoxysilylpropyl)-t-butylcarbamate, N-phenylaminopropyltrimethoxysilane, and 3-isocyanatepropyltrimethoxysilane. Of these, 3-glycidoxy-propyltrimethoxy silane and 3-glycidoxy-propyltriethoxy silane, ureidopropyltrimethoxy silane may be superior. A used amount of silane coupling agent may be preferable in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the polyamide compound. When the used amount thereof is less than 0.5 parts by weight, an adverse influence may be exerted on improvement of the adhesive force, and when the used amount thereof is greater than 10 parts by weight, pattern formation may be suppressed, or the scum may be generated.
An etching process may be performed to remove a lower passivation layer after patterning using the composition according to the present invention. In this instance, to prevent corrosion of an exposed aluminum layer or a conductive wiring layer, an anti-corrosion agent may be added. As a representative example of the anti-corrosion agent, there may be given a catechol derivative, a pyrogallol derivative, an alkyl gallate derivative, and the like in which a hydroxyl group is adjacent to a phenyl group. For example, the present invention is not particularly limited thereto as long as derivatives of catechol, alkyl catechol, alkoxy catechol, pyrogallol, alkyl pyrogallol, alkoxy pyrogallol, alkyl gallate, and the like in which the hydroxyl group is adjacent to the phenyl group. The anti-corrosion agent may be preferable used in an amount of 0.01 to 10% based on the whole composition. When a used amount of the anti-corrosion agent is less than 0.01%, an anti-corrosion function may be deteriorated, and when the used amount thereof is more than 10%, an amount of loss of the film may be significantly increased when developing.
In addition, a surfactant may be used to improve coating physical properties, and an antifoaming agent may be used to remove foam.
According to the present invention, the composition may be provided by dissolving the above described compositions in the solvent. As examples of the solvent, there may be given gamma-butyrolactone, N-methylpyrrolidone, N,N-dimethylacete amide, dimethylsulfoxide, cyclohexane, 2-heptanone, propylene glycol monomethyl ether acetate, methyl isobutyl ketone, ethylene glycol diethyl ester, ethylene glycol dimethyl ester, ethyllactate, and the like, and the present invention may be not particularly limited thereto. The solvent may be used alone or in a mixture of two or more thereof.
A method of forming a pattern using the composition according to the present invention will be herein described in detail. Compositions may be uniformly dissolved in a solvent. Next, this solution may be filtered, and coated on a silicon wafer or a glass substrate using spin coating, spray coating, roll coating, and the like to have a desired thickness. The coated substrate may be heated to 50° C. to 150° C. using a hot plate or infrared to thereby dry the solvent to be removed. A film of the composition generated on the substrate may be subjected to an exposure processing using any one of an i-line exposurer, an h-line exposurer, and a g-line exposurer. The substrate including a mask pattern may be developed, washed, and dried to obtain a pattern. As a developer used in the developing process, tetramethylammonium hydroxide may be used, however, the present invention is not particularly limited thereto as long as a compound exhibits basic properties. To transform the obtained pattern into a polyimide compound or a polybenzoxazole compound, the obtained pattern may be put in an oven at a temperature of about 280° C. or more, and heated for several tens of minutes. The obtained film may be used as an interlayer insulating film of a semiconductor or display process, or used as an intermediate protective layer in a packaging process.
The composition according to the present invention may have a superior coating uniformity and a high resolution when developing, while having high sensitivity, and may minimize a shrinkage when a crosslinking is performed.
Hereinafter, the present invention will be described in detail by examples. It is to be understood, however, that these examples are for illustrative purpose only, and are not construed to limit the scope of the present invention. In this instance, an organic timber having been subjected to a dehydration process may be used, and a synthesis of a polymer may be performed under a nitrogen atmosphere.
In a flask of 0.5 L including an agitator and a thermometer mounted therein, 60 g (0.232 mol) of 4,4-oxybisbenzoic acid was added in N-methylpyrrolidone (NMP) 240 g, and agitated and dissolved. Next, the flask was cooled down to 0° C., and thionyl chloride 110 g (0.9246 mol) was dropped on the flask to have a dropped product reacted for one hour, thereby obtaining a 4,4-oxybisbenzoyl chloride solution.
NMP 400 g was put in a flask of 1 L including an agitator and a thermometer mounted therein, 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane 85 g (0.2321 mol) was added in the flask, and agitated and dissolved. Next, pyridine 39 g (0.4930 mol) was added in the flask, and 5-norbonen-2,3-dicarboxylic acid anhydride 8 g (0.0487 mol) and the synthesized 4,4-oxybisbenzoyl chloride were slowly dropped on the flask. Next, a dropped product was agitated at room temperature for one hour. Next, a solution obtained through the above described process was added in three liters of water to obtain a precipitate. Next, the obtained precipitate was filtered, washed, and vacuum-dried to obtain a polyamide A of 110 g. In this instance, the obtained polyamide had an average molecular weight in terms of polystyrene of 18,500.
NMP 400 g was put in a flask of 1 L including an agitator and a thermometer mounted therein, 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane 75.5 g (0.209 mol) and 4,7,10-trioxa-1,13-tridecanediamine 5 g (0.023 mol) were added in the flask, and agitated and dissolved. Next, pyridine 39 g (0.4930 mol) was added in the flask, and 5-norbonen-2,3-dicarboxylic acid anhydride 8 g (0.0487 mol) and the synthesized 4,4-oxybisbenzoyl chloride were slowly dropped on the flask. Next, a dropped product may be agitated at room temperature for one hour. Next, a solution obtained through the above described process was added in three liters of water to obtain a precipitate. Next, the obtained precipitate was filtered, washed, and vacuum-dried to obtain a polyamide B of 119 g. In this instance, the obtained polyamide had an average molecular weight in terms of polystyrene of 15,600.
Polyamide C of 110 g was obtained in the same way as the above described synthesis example 1, except that 4,4′-ethylene-di-M-toluidine 5.5 g (0.023 mol) was used instead of using 4,7,10-trioxa-1,13-tridecanediamine 5 g (0.023 mol). In this instance, the obtained polyamide had an average molecular weight in terms of polystyrene of 24,000.
Dimethyl-3,3′,4,4′-diphenyl ether-tetracarboxylic acid anhydride 60 g (0.1934 mol), methyl alcohol 2 (0.0198 mol), triethylamine 2 g (0.0198 mol), and NMP 120 g were added in a flask of 1 L including an agitator and a thermometer mounted thereon, and were agitated and reacted at room temperature for four hours to obtain a di-n-methyl-3,3′,4,4′-diphenyl ether-tetracarboxylate solution. Next, the flask was cooled down to about 0° C., thionyl chloride 70 g (0.5884 mol) was dropped on the flask to have a dropped product reacted for two hours, thereby obtaining a dimethyl-3,3′,4,4′-diphenyl ether-tetracarboxylate dichloride solution.
NMP 260 g was put in a flask of 1 L including an agitator and a thermometer mounted thereon, 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane 65 g (0.1775 mol) was added, and these reactants were agitated to be dissolved. Next, pyridine 35 g (0.4425 mol) was added to the flask, and the dimethyl-3,3′,4,4′-diphenyl ether-tetracarboxylate dichloride solution was slowly dropped on the flask for 30 minutes, and these reactants were agitated for one hour at room temperature. Three liters of water was added to a solution obtained through the above described process to obtain a precipitate. Next, the obtained precipitate was filtered, washed, and vacuum-dried to obtain polyamidate D 128 g. In this instance, the polyamidate had an average molecular weight in terms of polystyrene of 19,200.
NMP 260 g was put in a flask of 1 L including an agitator and a thermometer mounted thereon, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane 58.5 g (0.160 mol) and 4,4′-ethylene-di-M-toluidine 4.3 g (0.0178 mol) were added to the flask, and these reactants were agitated to be dissolved. Next, pyridine 35 g (0.4425 mol) was added to the flask, and the dimethyl-3,3′,4,4′-diphenyl ether-tetracarboxylate dichloride solution was slowly dropped on the flask for 30 minutes, and these reactants were agitated for one hour at room temperature. Three liters of water was added to a solution obtained through the above described process to obtain a precipitate. Next, the obtained precipitate was filtered, washed, and vacuum-dried to obtain polyamidate E 105 g. In this instance, the polyamidate had an average molecular weight in terms of polystyrene of 22,000.
In a round flask, tri(4-hydroxyphenyl)ethane 50 g, 1,2-naphthoquinonediazide-5-sulfonyl chloride 87 g, and acetic anhydride 17 g were dissolved in dioxane 800 g, and was cooled using ice water. Next, triethylamine 59 g was slowly dropped on this solution at the same temperature, and the solution was agitated for eight hours at room temperature. Next, the agitated solution was dropped on an excess amount of deionized water to obtain a precipitate. Next, the obtained precipitate was filtered, washed, and vacuum-dried at about 40° C. for 48 hours to thereby obtain sulfonic ester 95 g.
In the synthesis example 1, 1,2-naphthoquinonediazide-4-sulfonyl chloride 87 g was used instead of using 1,2-naphthoquinonediazide-5-sulfonyl chloride 87 g to thereby obtain sulfonic ester 91 g.
Using a photosensitive composition including the polymer synthesized in each of the synthesis examples 2, 3, and 5 (examples 1 to 4) and the comparative synthesis examples 1 and 2, a patterning process was performed, and a degree of warpage (beding) and a result of the patterning process were observed.
The synthesized polymer, the diazonaphthol compound, and various additives were dissolved in gamma-butyrolactone, acting as a solvent, to be 40 wt %, and particulate foreign substances were removed using 0.5 um filter. Next, a filtered filtrate was rotation-coated on a silicon wafer of eight inches to have a thickness of 10 um. In this instance, to completely remove the solvent, a baking was performed on the wafer at about 130° C. for 60 seconds. In the wafer, a film was subjected to a crosslinking in an oven of about 350° C. for 30 minutes, and a rear surface of the wafer was abraded using an abrasive to have a wafer thickness of 50 um. Here, obtained results were divided into good, fair, and poor in comparison with an existing degree of warpage.
Observation of Patterning
The filtered filtrate was rotation-coated on the silicon wafer of eight inches to have a wafer thickness of 10 um. In this instance, to completely remove the solvent, a baking was performed on the wafer at about 130° C. for 60 seconds. The coated wafer was exposed using an exposure, and developed using tetramethylammonium hydroxide 2.38 wt %. A resolution of the developed wafer was observed using a scanning electron microscope (SEM). As for a thickness of the wafer, a film thickness after and before the exposing was observed using a nano spec. A scum remaining on a bottom of a developed portion was observed using the SEM. A pattern type was divided into good, fair, and poor taking pattern perpendicularity and mask-shaped solid into account. Chemical formulas 63 to 65 below respectively represented an additive A, an additive B, and an additive C.
Although a few exemplary embodiments of the present invention have been shown and described, the present invention is not limited to the described exemplary embodiments. Instead, it would be appreciated by those skilled in the art that changes may be made to these exemplary embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1020090081181 | Aug 2009 | KR | national |
