POSITIVE TYPE RADIATION-SENSITIVE RESIN COMPOSITION

Abstract: A positive type radiation-sensitive resin composition which comprises a l,2-quinonediazide compound and an alkali-soluble novolac resin produced by poly­ condensing phenols represented by the formulas (I) and (II) in a molar ratio of (I)/(II) of l/99 to l00/0 with a carbonyl compound: wherein R¹ and R², which may be the same or different, represent hydroxyl groups, hydrogen atoms, alkyl groups, aryl groups, aralkyl groups, alkenyl groups, halogen atoms, alkoxy groups, alkoxycarbonyl groups, aroxycarbonyl groups, alkanoyloxy groups, aroyloxy groups, acyl groups, cyano groups or nitro groups, wherein R³, R⁴ and R⁵, which may be the same or different, represent hydrogen atoms, alkyl groups, aryl groups, aralkyl groups, alkenyl groups, halogen atoms, alkoxy groups, alkoxycarbonyl groups, aroxycarbonyl groups, alkanoyloxy groups, aroyloxy groups, acyl groups, cyano groups or nitro groups. The above positive type radiation-­ sensitive resin composition is excellent in dry-etching resistance, resolution and heat resistance, and appropriate as a positive type resist for producing integrated circuits in which a resist pattern is formed, and also as a positive type resist for producing a mask.

Description: This invention relates to a positive type radiation-sensitive resin composition, and more particularly to a positive type radiation-sensitive resin composition particularly suitable as a resist or producing integrated circuits, which composition is sensitive to radiations such as ultraviolet rays, far-ultraviolet rays, X-rays, electron beams, molecular beams, gamma-rays, synchrotron radiations, proton beams and the like. JP-A-5984238 discloses a photosensitive novolak resin composition for a lithographic printing plate. The composition is high in sensitivity and leaves the non-image part of the printing plate clean after development. EP-A-0054258 discloses a photosensitive novolak resin composition which has excellent resistance to chemicals, a long press-life, excellent alkali-solubility and difficult to form scumming. The resists which have heretofore been used in the production of integrated circuits include negative type resists comprising a cyclized rubber and a bisazide compound, and positive type resists comprising an alkali-soluble novolac resin and a 1,2-quinonediazide compound. When the negative type resist is irradiated with a light, the bisazide compound liberates a nitrogen to become a nitrene, which three-dimensionally crosslinks the cyclized rubber. However, the light-irradiated portions are not completely cured, and therefore, the resist pattern is greatly swollen in a developing solution consisting of an organic solvent, whereby the resolution of tie resist pattern becomes low. This is disadvantageous. On the other hand, the positive type resist comprises an alkali-soluble novolac resin and an alkali-insoluble 1,2-quinonediazide compound and hence is difficult to dissolve in a developing solution consisting of an aqueous alkaline solution and is hardly swollen. Accordingly, the 1,2-quinonediazide compound contained in the light-irradiated portion is converted into a carboxylic acid. Therefore, when the irradiated resist is developed with a developing solution consisting of an aqueous alkaline solution, the light-unirradated portions which form a resist pattern are very small in solubility change, and therefore, a resist pattern is obtained which is faithful to the mask and has a high resolution. Thus, in recent years during which higher integration of integrated circuits has been required, such positive type resists having an excellent resolution have often been used. Also, attempts to enhance the resolution of resists have been made by not only improving the characteristics of resists, but also improving the method of producing integrated circuits, for example, changing the wet etching method, which has heretofore been the main current, to a dry etching method. However, this dry etching method requires etching the substrate with reactive ions. Therefore, the temperature of the substrate rises during the etching, and the resist pattern undergoes thermal deformation to reduce the dimension accuracy. In addition, highly reactive fluorine ions, chlorine ions and the like impair the resist pattern. This is disadvantageous. Commercially available novolac resin-based positive type resists have heretofore been evaluated to be resistant to such severe dry etching as compared with other resists. However, they cannot be said to be fully satisfactory. An object of this invention is to provide a positive type radiation-sensitive resin composition having an improved dry etching resistance and also having an improved resolution and thermal resistance. Other objects and advantages will become apparent from the following description. According to the invention, there is provided a positive type radiation-sensitive resin composition which comprises 100 parts by weight of an alkali-soluble resin and 5 to 100 parts by weight of a 1,2-quinonediazide compound represented by the formula (I): wherein R¹ to R¹⁰, which may be the same or different, represent hydroxyl groups, 1,2-quinonediazidesulfonyl groups, hydrogen atoms, alkyl groups having 1 to 4 carbon atoms, alkoxy groups having 1 to 4 carbon atoms, halogen atoms, cyano groups, nitro groups, acyl groups having 2 to 5 carbon atoms and aralkyl groups having 7 to 9 carbon atoms, and wherein the number (n) of the hydroxyl groups in the formula (I) is O or an integer of 1 to 9, the number (m) of the 1,2-quinonediazidesulfonyl groups in the formula (I) is an integer of 1 to 10 and 5 ≦ n + m ≦ 10. In the definitions of R¹ to R¹⁰ in the formula (I), the 1,2-quinonediazidesulfonyl groups include, for example, 1,2-naphthoquinonediazide-5-sulfonyl, 1,2-naphthoquinonediazide-4-sulfonyl and 1,2-benzoquinonediazide-4-sulfonyl; the alkyl groups having 1 to 4 carbon atoms include, for example, methyl, ethyl, propyl and butyl; the alkoxy groups having 1 to 4 carbon atoms include, for example, methoxy, ethoxy, propoxy and butoxy; the halogen atoms include, for example, chlorine and bromine; the acyl groups having 2 to 5 carbon atoms include, for example, acetyl, propyonyl, butyryl and valeryl; and the aralkyl groups having 7 to 9 carbon atoms include, for example, benzyl, phenethyl and phenylpropyl. The 1,2-quinonediazide compounds represented by the formula (I) used as a photosensitizer in the Composition are produced by reacting a 1,2-quinonediazide with a polyhydroxy compound represented by the formula (II): wherein R¹¹ to R²⁰ which may be the same or different, represent hydroxyl groups, hydrogen atoms, alkyl groups having 1 to 4 carbon atoms, alkoxy groups having 1 to 4 carbon atoms, halogen atoms, cyano groups, nitro groups, acyl groups having 2 to 5 carbon atoms or aralkyl groups having 7 to 9 carbon atoms, and the number (ℓ) of the hydroxyl groups in the formula (II) is 5 ≦ ℓ ≦ 10, in the presence of a basic catalyst. The polyhydroxy compound represented by the formula (II) includes, for example, 2,3,4,2',4'-pentahydroxybenzophenone, 2,3,4,2',5'-pentahydroxybenozophenone, 2,3,4,2',6'-pentahydroxybenzophenone, 2,3,4,3',4'-pentahydroxybenzophenone, 2,3,4,3',5'-pentahydroxybenzophenone, 2,3,4,2',3',4'-hexahydroxybenzophenone, 2,3,4,3',4',5'-hexahydroxybenzophenone, 2,3,4,2',4',6'-hexahydroxybenzophenone, 2,4,6,2',4'-pentahydroxybenzophenone, 2,4,6,2',5'-pentahydroxybenzophenone, 2,4,6,2',6'-pentahydroxybenzophenone, 2,4,6,3',4'-pentahydroxybenzophenone, 2,4,6,3',5'-pentahydroxybenzophenone, 2,4,6,3',4',5'-hexahydroxybenzophenone, 2,4,6,2',4',6'-hexahydroxybenzophenone, 2,3,4,5,2'-pontahydroxybenzophenone, 2,3,4,5,3'-pentahydroxybenzophenone, 2,3,4,5,4'-pentahydroxybenzophenone, 2,3,4,5,2',4'-hexahydroxybenzophenone, 2,3,4,5,2',5'-hexahydroxybenzophenone, 2,3,4,5,2',6'-hexanydroxybenzophenone, 2,3,4,5,3',4'-hexahydroxybenzophenone, 2,3,4,5,3',5'-hexahydroxybenzophenone, 2,3,4,5,2',3',4'-heptahydroxybenzophenone, 2,3,4,5,3',4',5'-heptahydroxybenzophenone, 2,3,4,5,2',4',6'-heptahydroxybenzophenone, 2,3,4,2',4'-pentahydroxy-5-methylbenzohenone, 2,3,4,2',4'-pentahydroxy-5-ethylbenzophenone, 2,3,4,2',4'-pentahydroxy-5-n-propylbenzophenone, 2,3,4,2',4'-pentahydroxy-5-n-butylbenzophenone, 2,3,4,2',5'-pentahydroxy-5-methylbenzophenone, 2,3,4,2',5'-pentahydroxy-5-n-propylbenzophenone, 2,3,4,2',6'-pentahydroxy-5-methylbenzophenone, 2,3,4,2',6'-pentahydroxy-5-n-propylbenzophenone, 2,3,4,3',4'-pentahydroxy-5-methylbenzophenone, 2,3,4,3',4'-pentahydroxy-5-n-propylbenzophenone, 2,3,4,3',5'-pentahydroxy-5-methylbenzophenone, 2,3,4,3',5'-pentahydroxy-5-n-propylbenzophenone, 2,3,4,2',-3',4'-hexahydroxy-5-methylbenzophenone, 2,3,4,2',3',4'-hexahydroxy-5-n-propylbenzophenone, 2,3,4,3',4',5'-hexahydroxy-5-methylbenzophenone, 2,3,4,3',4',5'-hexahydroxy-5-n-propylbenzophenone, 2,3,4,2',4',6'-hexahydroxy-5-methylbenzophenone, 2,3,4,2',4',6'-hexahydroxy-5-n-propylbenzophenone, 2,3,2',3',4'-pentahydroxy-4-methoxybenzophenone, 2,3,2',3',4'-pentahydroxy-4-ethoxybenzophenone, 2,3,2',3',4'-pentahydroxy-4-n-propoxybenzophenone, 2,3,2',3',4'-pentahydroxy-4-n-butoxybenzophenone, 2,3,3',4',5'-pentahydroxy-4-methoxybenzophenone, 2,3,3',4',5'-pentahydroxy-4-n-propoxybenzophenone, 2,3,2',4',6'-pentahydroxy-4-methoxybenzophenone, 2,3,2',4',6'-pentahydroxy-4-n-propoxybenzophenone, 2,3,4,2',4'-pentahydroxy-5-chlorobenzophenone, 2,3,4,2',4'-pentahydroxy-5-bromobenzophenone, 2,3,4,2',6'-pentahydroxy-5-chlorobenzophenone, 2,3,4,2',6'-pentanydroxy-5-bromobenzophenone, 2,3,4,3',4',-5'-hexahydroxy-5-chlorobenzophenone, 2,3,4,3',4',5'-hexahydroxy-5-bromobenzophenone, 2,3,4,2',4'-pentahydroxy-5-cyanobenzophenone, 2,3,4,3',4',5'-hexahydroxy-5-cyanobenzophenone, 2,3,4,2',4'-pentahydroxy-5-nitrobenzophenone, 2,3,4,3',4',5'-hexahydroxy-5-nitrobenzophenone, 2,4,3',-4',5'-pentahydroxy-5-acetylbenzophenone, 2,4,3',4',5'-pentahydroxy-5-benzoylbenzophenone, 2,3,4,3',4',5'-hexahydroxy-5-acetylbenzophenone, 2,3,4,3',4',5'-hexahydroxy-5-benzoylbenzophenone, 2,4,3',4',5'-pentahydroxy-5-benzoylbenzophenone, 2,3,4,3',4',5'-hexahydroxy-5-benzoylbenzophenone and the like. These polyhydroxy compounds may be used alone or in admixture of two or more. The above-mentioned 1,2-quinonediazide include, for example, 1,2-quinonediazidesulfonyl halides such as 1,2-naphthoquinonediazide-5-sulfonyl chloride, 1,2-napnthoquinonediazide-4-sulfonyl chloride, 1,2-benzoquinonediazide-4-sulfonyl chloride and the like. These 1,2-quinonediazides may be used alone or in admixture of two or more. The amount of the 1,2-quinonediazide compound used based on the compound represented by the formula (II) is appropriately adjusted depending upon the number of the hydroxyl groups in the compound of the formula (II) and is usually 0.1 to 1 mole per mole of the hydroxyl group of the compound of the formula (II) though not critical. The basic catalyst includes, for example, amines such as trimethylamine, triethylamine, tripropylamine, pyridine, tetramethylammonium hydroxide and the like and also inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate and the like. The amount of the basic catalyst used is usually 0.8 to 2 moles, preferably 1 to 1.5 moles, per mole of the 1,2-quinonediazide compound. In the above-mentioned reaction, a reaction medium is usually used, which includes, for example, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and the like; cyclic ethers such as dioxane, tetrahydrofuran and the like; cyclic ketones such as cyclopentanone, cyclohexanone and the like; amides such as N,N-dimethylformamide, N,N-dimethylacetamide and the like; esters such as γ-butyrolactone, ethylene carbonate, propylene carbonate and the like; pyrrolidone; N-methylpyrrolidone; and water. The amount of the reaction medium used is usually 100 to 1,000 parts by weight per 100 parts by weight of the compound of formula (II). Also, the reaction temperature is usually -30 to +60°C, preferably 0 to 40°C in the above reaction. The compound of the formula (I) used in the Composition includes, for example, 2,3,4,2',4'-pentahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,2',5',-pentahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,2',6'-pentahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,3',4'-pentahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,3',5'-pentahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,2',3',4'-hexahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,3',4',5'-hexahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,2',4',6'-hexahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,4,6,2',4'-pentahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,4,6,2',5'-pentahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,4,6,2',6'-pentahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,4,6,3',4'-pentahydroxybenzophenone-1,2-nabhthoquinonediazide-5-sulfonic acid ester, 2,4,6,3',5'-pentahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulsonic acid ester, 2,4,6,3',4',5'-hexahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,4,6,2',4',6'-hexahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,5,2'-pentahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,5,3'-pentahydroxybenzophenone-1,2-naphthaoquinonediazide-5-sulfonic acid ester, 2,3,4,5,4'-pentahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,5,2',4'-hexahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,5,2',5'-hexahydroxybenzophenone-1,2-naphthoquinonediazide-5- sulfonic acid ester, 2,3,4,5,2',6'-hexahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,5,3',4'-hexahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,5,3',5'-hexahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,5,2',3',4'-heptahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,5,3',4',5'-heptahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,5,2',4',6'-heptahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,2',4'-pentahydroxy-5-methylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,2',4'-pentahydroxy-5-ethylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,2',4'-pentahydroxy-5-n-propylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,2',4'-pentahydroxy-5-n-butylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,2',5'-pentahydroxy-5-methylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,2',5'-pentahydroxy-5-n-propylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,2',6'-pentahydroxy-5-methylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,2',6'-pentahydroxy-5-n-propylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,3',4'-pentahydroxy-5-methylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,3',4'-pentahydroxy-5-n-propylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,3',5'-pentahydroxy-5-methylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,3',5'-pentahydroxy-5-n-propylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,2',3',4'-hexahydroxy-5-methylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,2',3',4'-hexahydroxy-5-n-propylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,3',4',5'-hexahydroxy-5-methylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,3',4',5'-hexahydroxy-5-n-propylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,2',4',6'-hexahydroxy-5-methylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,2',4',6'-hexahydroxy-5-n-propylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,2',3',4'-pentahydroxy-4-methoxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,2',3',4'-pentahydroxy-4-ethoxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,2',3',4'-pentahydroxy-4-n-propoxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,2',3',4'-pentahydroxy-4-n-butoxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,3',4',5'-pentahydroxy-4-methoxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,3',4',5'-pentahydroxy-4-n-propoxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,2',4',6'-pentahydroxy-4-methoxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,2',4',6'-pentahydroxy-4-n-propoxybenzophenone-1,2-naphthoquinone diazide-5-sulfonic acid ester, 2,3,4,2',4'-pentahydroxy-5-chlorobenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,2',4'-pentahydroxy-5-bromobenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,2',6'-pentahydroxy-5-chlorobenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,2',6'-pentahydroxy-5-bromobenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,3',4',5'-hexahydroxy-5-chlorobenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,3',4',5'-hexahydroxy-5-bromobenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,2',4'-pentahydroxy-5-cyanobenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,3',4',5'-hexahydroxy-5-cyanobenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,2',4'-pentahydroxy-5-nitrobenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,3',4',5'-hexahydroxy-5-nitrobenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,4,3',4',5'-pentahydroxy-5-acetylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,4,3',4',5'-pentahydroxy-5-benzoylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,3',4',5'-hexahydroxy-5-acetylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,3',4',5'-hexahydroxy-5-benzoylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,4,3',4',5'-pentahydroxy-5-benzylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,3',4',5'-hexahydroxy-5-benzylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,2',4'-pentahydroxybenzophenone-1,2-naphthoquinonediazide-4- sulfonic acid ester, 2,3,4,2',6'-pentahydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3,4,3',4',5'-hexahydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,4,6,2',6'-pentahydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,4,6,3',4',5'-hexyhydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3,4,5,4'-pentahydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3,4,5,2',6'-hexahydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3,4,5,3',4',5'-heptahydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3,4,2',4'-pentahydroxy-5-methylbenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3,4,2',6'-pentahydroxy-5-methylbenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3,4,3',4',5'-hexahydroxy-5-methylbenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3,3',4',5'-pentahydroxy-4-methoxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3,4,3',4',5'-hexahydroxy-5-chlorobenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3,4,3',4',5'-hexahydroxy-5-acetylbenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3,4,3',4',5'-hexahydroxy-5-benzoylbenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3,4,2',6'-pentahydroxybenzophenone-1,2-benzoquinonediazide-4-sulfonic acid ester, 2,3,4,3',4',5'-hexahydroxybenzophenone-1,2-benzoquinonediazide-4-sulfonic acid ester, 2,4,6,3',4',5'-hexahydroxybenzophenone-1,2-benzoquinonediazide-4-sulfonic acid ester, 2,3,4,3',-4',5'-hexahydroxy-5-methylbenzophenone-1,2-benzoquinonediazide-4-sulfonic acid ester, 2,3,3',4',5',-pentahydroxy-4-methoxybenzophenone-1,2-benzoquinonediazide-4-sulfonic acid ester, 2,3,4,3',4',5'-hexahydroxy-5-benzoylbenzophenone-1,2-benzoquinonediazide-4-sulfonic acid ester and the like. In the Composition, the amount of the compound represented by the formula (I) contained is 5 to 100 parts by weight, preferably 10 to 50 parts by weight, per 100 parts by weight of the alkali-soluble resin. When this amount is less than 5 parts by weight, the amount of a carboxylic acid produced owing to the 1,2-quinonediazide compound absorbing radiation becomes small, and hence, patterning becomes difficult. When the amount is more than 100 parts by weight, the irradiation with a radiation for a short period of time does not enable the whole of the 1,2-quinonediazide compound to be decomposed, and the development with a developing solution consisting of an aqueous alkaline solution becomes difficult. In the Composition, it is possible to add other 1,2-quinonediazide compounds in such an amount as not to impair the properties of the final product. The alkali-soluble resin used in the Composition includes, for example, alkali-soluble novolac resins. This alkali-soluble novolac resin is prepared by addition -condensing phenols with carbonyl compounds in the presence of an acid catalyst. The alkali-soluble resins used in the Composition include alkali-soluble novolac resins, and in addition thereto, for example, polyhydroxystyrene, its derivatives, styrene-maleic anhydride copolymer, polyvinyl hydroxy-benzoate, carboxyl-containing (meth)acrylate resins and the like. These alkali-soluble resins may be used alone or in admixture of two or more. In the Composition, a sensitizer may be contained in order to increase the sensitivity as resist. The sensitizer includes, for example, 2H-pyrido[3,2-b]-1,4-oxazin-3-[4H]-ones, 10H-pyrido[3,2-b]-[1,4]-benzothiazines, urazoles, hydantoins, barbituric acids, glycine anhydrides, 1-hydroxybenzotriazoles, alloxans, maleimides and further sensitizers described in Japanese Patent Publication Nos. 12,242/73 and 35,402/73, Japanese Patent Application Kokai (Laid-open) Nos. 37,641/83 and 149,042/83 and the like. The amount of the sensitizer contained is usually not more than 100 parts by weight, preferably 4 to 60 parts by weight, per 100 parts by weight of the 1,2-quinonediazide compound. Moreover, the Composition may contain a surface active agent and the like for improving coatability, for example, striation, and the developability of the radiation-irradiated portion after the formation of the dry coating. The surface active agent includes nonionic surfactants, for example, polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether and the like; polyoxyethylene alkyl phenol ethers such as polyoxyethylene octyl phenol ether, polyoxyethylene nonyl phenol ether and the like; polyethylene glycol difatty acid esters such as polyethylene glycol dilaurate, polyethylene glycol distearate and the like; fluorine-containing surfactants such as F Top EF 301, EF 303 and EF 352 (these are products of Shin Akita Kasei K.K.), Megafac F 171 and F 173 (these are products of DANINIPPON INK & CHEMICALS), Fluorad FC 430 and FC 431 (these are products of Sumitomo 3M Limited), Asahi Guard AG 710 and Surflon S-382, SC 101, SC 102, SC 103, SC 104, SC 105 and SC 106 (these are products of Asahi Glass Co., Ltd.), and straight chain-like fluorine-containing surfactants having fluorinated alkyl groups or perfluoroalkyl groups as described in Japanese Patent Application Kokai (Laid-Open) No. 178,242/82 and the like; organosiloxane polymer KP 341 (a product of Shin-Etsu Chemical Co., Ltd.); and acrylic or methacrylic (co)polymer Polyflow No. 75 and No. 95 (these are products of Kyoeisha Yushikagaku Kogyo K.K.) and the like. The amount of these surface active agents contained is usually not more than 2 parts by weight, preferably not more than 1 part by weight, per 100 parts by weight of the solids content of the Composition Also, the Composition may contain a coloring agent for visualizing the latent image in the radiation-irradiated portions and for reducing the adverse effect of halation during irradiation with a radiation, or may contain an adhering aid for improving the adhesiveness to substrate. In addition, the Composition may, if necessary, contain a storage stabilizer, anti-foaming agent and the like. The Composition is prepared by dissolving an alkali-soluble resin, a 1,2-quinonediazide compound and various compounding agents in the necessary amounts in a solvent and filtering the resulting solution through a filter having a pore diameter of, for example, about 0.2µm. The solvent used in this case includes, for example, glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether and the like; cellosolve esters such as methyl cellosolve acetate, ethyl cellosolve acetate and the like; ketones such as methyl ethyl ketone, cyclohexanone and the like; and esters such as ethyl acetate, butyl acetate, methyl lactate, ethyl lactate and the like. These solvents may be used alone or in admixture of two or more. Moreover, a high boiling solvent may be added such as an aromatic hydrocarbon, for example, toluene, xylene or the like; an ether, for example, benzyl ethyl ether, dihexyl ether or the like; a glycol ether, for example, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether or the like; a ketone, for example, acetonylacetone, isophorone or the like; a fatty acid, for example, caproic acid, caprylic acid or the like; an alcohol, for example, 1-octanol, 1-nonanol, benzyl alcohol or the like; an ester, for example, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, ethylene carbonate, propylene carbonate, phenyl cellosolve acetate or the like; or a lactone, for example, γ-butyrolactone, δ-valerolactone or the like. In coating the Composition on a silicon wafer or the like, for example, a 5 to 50% by weight solution of the Composition is applied to the substrate by a spin coating, flow-coating, roll-coating or the like. The developing solution for the Composition is an aqueous alkaline solution prepared by dissolving in water an inorganic alkali such as sodidum hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium meta-silicate, ammonia water or the like; a primary amine such as ethylamine, n-propylamine or the like; a secondary amine such as diethylamine, di-n-propylamine or the like; a tertiary amine such as triethylamine, methyldiethylamine or the like; an alcoholamine such as dimethylethanolamine, triethanolamine or the like; a quaternary ammonium salt such as tetramethylammonium hydroxide, tetramethylammonium hydroxide or the like or a cyclic amine such as pyrole, piperidine, 1,8-diazabicyclo(5,4,0)-7-undecene, 1,5-diazabicyclo(4,3,0)-5-nonane or the like. When preparing an integrated circuit in which the use of a developing solution containing a metal is objected to, it is preferred to use an aqueous alkaline solution of a quaternary ammonium salt or a cyclic amine. The developing solution may further contain an appropriate amount of an aqueous organic solvent, for example, an alcohol such as methanol, ethanol or the like, and a surface active agent. The positive type radiation-sensitive resin composition of this invention is excellent in dry-etching resistance, resolution and heat resistance, and particularly useful as positive type resists for producing integrated circuits in which a resist pattern is formed by irradiation with a radiation such as a visible light, a ultraviolet ray, a far-ultraviolet ray, an X-ray, a molecular beam, an ion ray, an electron beam, a γ-ray or the like, and also useful as a positive type resist for producing a mask. This invention is further explained in more detail below referring to Examples. In the Examples, the number of the 1,2-quinonediazidesulfonyl groups in 1,2-quinonediazide compounds represented by the formula (I) Used is an average value of the reaction product. Example 1 (1) Into a 500-ml separable flask equipped with a stirrer, a dropping funnel and a thermometer were charged 11.2 g of 2,3,4,2',6'-pentahydroxybenzophenone and 34.5 g of 1,2-naphthoquinonediazide-5-sulfonic acid chloride (referred to hereinafter as NQD) in a molar ratio of 1:3, and further, to the resulting solution was added 240 g of dioxane, after which the resulting mixture was stirred to form a solution. Separately, 14.3 g of triethylamine was charged into the dropping funnel. The separable flask was immersed in a water bath adjusted to 30°C, and when the internal temperature reached a constant temperature of 30°C, the triethylamine was dropwise added to the solution so gradually that the internal temperature did not exceed 35°C. Subsequently, the triethylamine hydrochloride salt was removed by filtration, and the filtrate was poured into a large amount of dilute hydrochloric acid, upon which 2,3,4,2',6'-pentahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid triester was precipitated. The 1,2-quinonediazide compound recovered by filtration was dried a whole day and night in a vacuum-drier adjusted to 40°C. The yield was 98%. (2) Into a 300-ml separable flask equipped with a stirrer charged 20 g of an alkali-soluble novolac resin produced by polycondensing a cresol mixture of m-cresol/ p-cresol (6/4 by mole) with formaline, 5 g of the above 2,3,4,2',6'-pentahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid triester, 60 g of ethylcellosolve acetate and 15 g of γ-butyrolacetone, and the resulting mixture was well stirred at room temperature to form a solution. The solution thus formed was filtered through a membrane filter having a pore diameter of 0.2 µm to prepare a solution of the Composition of this invention. This solution was spin-coated on a silicon wafer having a silicon oxide film by means of a spinner, and thereafter, pre-baked at 90°C for 2 minutes to form a resist layer having a thickness of 1.2 µm. Subsequently, the resist layer was exposed to light through a pattern mask using a stepper for 0.45 seconds, and then developed with a 2.2% by weight aqueous TMA solution for 60 seconds. The resist pattern thus obtained was observed by means of a scanning electron microscope to find that no undeveloped portion, namely no developing residue was recognized in the adhesion portion between the substrate and the resist pattern and that a resist pattern having a line width of 0.8 µm was resolved. Comparative Example 1 The same procedure as in Example 1 (2) was repeated, except that 2,3,4-trihydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid triester was substituted for the 2,3,4,2',6'-pentahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid triester to prepare a solution of a resist composition. In the same manner as in Example 1 (2), this solution was applied to a silicon wafer having a silicon oxide film and then exposed to light for 65 seconds through a pattern mask using a stepper and thereafter developed with a 2.4% by weight aqueous TMA solution. The resist pattern thus obtained was observed by means of a scanning electron microscope to find that resolution was possible till a line width of 1.1µm, but a developing residue was recognised in the portion at which the resist pattern contacted the substrate. Examples 2 to 7 In the same manner as in Example 1 (1), 2,4,6,3',4',5'-hexahydroxybenzophenone, 2,3,4,5,4'-Pentahydroxybenzophenone or 2,3,4,3',4',5'-hexahydroxy-5-methylbenzophenone was reacted with NQD, triethylamine and dioxane to synthesize the 1,2-quinonediazide compounds shown in Table 1. Subsequently, the same procedure as in Example 1 (2) was repeated, except that these 1,2-quinonediazide compounds and an alkali-soluble novolac resin produced by polycondensing a cresol mixture of m-cresol/p-cresol (4/6 by mole) with formaldehyde were used to prepare solutions of the Composition. In the same manner as in Example 1 (2), the solutions thus obtained were applied to a silicon wafer having a silicon oxide film and exposed to light for the periods of time shown in Table 1 through a pattern mask using a stepper, and then developed with a 2.4% by weight aqueous TMA solution. The resist patterns thus obtained were observed by means of a scanning electron microscope to find that the resolutions of the resist patterns were high as shown in Table 1 and no developing residue was recognized. Example No. 1,2-Quinonediazide compound Exposure time (sec) Resolution (µm) 2 2,4,6,3',4',5'-Hexahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid tetraester 0.38 0.8 3 2,3,4,3',4',5'-Hexahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid tetraester 0.42 0.8 4 2,3,4,5,4'-Pentahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid triester 0.55 0.9 5 2,3,4,3',4',5'-Hexahydroxy-5-methylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid triester 0.48 0.8 6 2,3,4,3',4',5'-Hexahydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid tetraester 0.60 0.9 7 2,3,4,3',4',5'-Hexahydroxy-5-methylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid tetraester 0.58 0.8 Examples 8 to 11 The same procedure as in Example 1 (2) was repeated, except that the alkali-soluble novolac resin obtained by polycondensing a cresol mixture of m-cresol/p-cresol (6/4 by mole) with formaline was replaced with the alkali-soluble novolac resins produced by polycondensing a cresol mixture shown in Table 2 with formaline, to prepare solutions of the Composition of this invention. In the same manner as in Example 1 (2), the solutions thus obtained were applied to a silicon wafer having a silicon oxide film and then exposed to light through a pattern mask for the period of time shown in Table 2 using a stepper, and then developed with a 2.4% by weight aqueous TMA solution. The resist patterns thus obtained were observed by means of a scanning electron microscope to find that the resolutions of the resist patterns were high as shown in Table 2, and no developing residue was recognised. Example No. Novolac resin (molar ratio of cresols charged) Exposure time (sec) Resolution (µm) 8 m-Cresol/p-Cresol (7/3) 0.37 0.8 9 m-Cresol/3,5-Xylenol (7/3) 0.48 0.9 10 m-Cresol/p-Cresol/2,2-Bis-(p-hydroxyphenylpropane) (6/2/2) 0.55 0.9 11 α-Naphthol/2,5-Xylenol (6/4) 0.85 0.8 Examples 12 to 14 Into a 500-ml separable flask equipped with a stirrer, a dropping funnel and a thermometer were charged 2,3,4,3',4',5'-hexahydroxybenzophenone (referred to hereinafter as HHBP), NQD, triethylamine and dioxane in the amounts shown in Table 3 and subjected to reaction in the same manner as in Example 1 (1) to synthesize 1,2-quinonediazide compounds. Subsequently, the same procedure as in Example 1 (2) was repeated, except that the 1,2-quinonediazide compounds thus obtained and alkalisoluble novolac resins produced by polycondensing a cresol mixture of m-cresol/p-cresol (4/6 by mole) with formaline were used to prepare solutions of the Composition of this invention. In the same manner as in Example 1 (2), the solutions thus obtained were applied to a silicon wafer having a silicon oxide film and then exposed to light for the period of time shown in Table 3 through a pattern mask using a stepper, and then developed with on aqueous TMA solution having a concentration as shown in Table 3. The resist patterns thus obtained were observed by means of a scanning electron microscope to find that the resolutions of the resist patterns were high as shown in Table 3, and no developing residue was recognised.

Claims: A positive type radiation-sensitive resin composition which comprises 100 parts by weight of an alkali-soluble resin and 5 to 100 parts by weight of a 1,2-quinonediazide compound represented by the formula (I): wherein R¹ to R¹⁰, which may be the same or different, represent hydroxyl groups, 1,2-quinonediazidesulfonyl groups, hydrogen atoms, alkyl groups having 1 to 4 carbon atoms, alkoxy groups having 1 to 4 carbon atoms, halogen atoms, cyano groups, nitro groups, acyl groups having 2 to 5 carbon atoms and aralkyl groups having 7 to 9 carbon atoms, and wherein the number (n) of the hydroxyl groups in the formula (I) is O or an integer of 1 to 9, the number (m) of the 1,2-quinonediazidesulfonyl groups in the formula (I) is an integer of 1 to 10 and 5 ≦ n + m ≦ 10. The positive type radiation-sensitive resin composition according to claim 1, wherein R¹ to R¹⁰ in the formula (I) are hydroxyl groups, 1,2-naphthoquinonediazide-5-sulfonyl groups, hydrogen atoms or alkyl groups having 1-4 carbon atoms, the number (n) of the hydroxyl groups in the formula (I) is O or an integer of 1 to 9, the number (m) of the 1,2-quinonediazidesulfonyl groups in the formula (I) is an integer of 1 to 10 and 5 ≦ n + m ≦ 10. The positive type radiation-sensitive resin composition according to claim 1, wherein the 1,2-quinonediazidesulfonyl group for R¹ to R¹⁰ in the formula (I) is selected from the group consisting of 1,2-napthoquinonediazide-5-sulfonyl group, 1,2-naphthoquinonediazide-4-sulfonyl group and 1,2-benzoquinonediazide-4-sulfonyl group. The positive type radiation-sensitive resin composition according to claim 1, wherein the 1,2-quinonediazidesulfonyl group for R¹ to R¹⁰ in the formula (I) is a 1,2-naphthoquinonediazide-5-sulfonyl group. The positive type radiation-sensitive resin composition according to claim 1, wherein the 1,2-quinonediazide compound represented by the formula (I) is produced by reacting a 1,2-quinonediazide with a polyhydroxy compound represented by the formula (II): wherein R¹¹ to R²⁰, which may be the same or different, represent hydroxyl groups, hydrogen atoms, alkyl groups having 1 to 4 carbon atoms, halogen atoms, cyano groups, nitro groups, acyl groups having 2 to 5 carbon atoms or aralkyl groups having 7 to 9 carbon atoms, and the number (ℓ) of the hydroxyl groups in the formula (II) is 5 ≦ ℓ ≦ 10, in the presence of a basic catalyst. The positive type radiation-sensitive resin composition according to claim 5, wherein the amount of 1,2-quinonediazide used is 0.1 to 1 mole per equivalent of the hydroxyl group in the compound of the formula (II). A positive type radiation-sensitive resin composition as claimed in claims 1,2,3,4,5 or 6 for the production of an integrated circuit, wherein the alkali-soluble resin is a resin prepared by polycondensing a phenol mixture consisting essentially of 20-30 mole % of resorcinol and 80-70 mole % of at least one of m-cresol or 3,5-xylenol, with acetaldehyde. The positive type radiation-sensitive resin composition according to claim 7, wherein the phenol mixture consists essentially of 20-25 mole % of resorcinol and 80-75 mole % of m-cresol and 3,5-xylenol in which the molar ratio of m-cresol to 3,5-xylenol is 64-49/16-26. A positive type radiation-sensitive resin composition as claimed in claims 1,2,3,4,5 or 6 for the production of an integrated circuit wherein the alkali-soluble resin is a resin prepared by polycondensing a phenol mixture consisting essentially of 100-30 mole % of pyrogallol and 0-70 mole % of at least one m-cresol or p-cresol, with at least one member selected from the group consisting of formaldehyde, acetaldehyde and acrolein. A positive type radiation-sensitive resin composition as claimed in claims 1,2,3,4,5 or 6 for the production of an integrated circuit, wherein the alkali-soluble resin is a resin prepared by polycondensing a phenol mixture consisting essentially of 30-70 mole % of phloroglucinol and 70-30 mole % of at least one of p-cresol or 2,5-xylenol, with at least one of benzaldehyde or p-hydroxybenzaldehyde.

Inventors: HARITA, YOSHIYUKI, HONDA, KIYOSHI, HOSAKA, YOSHIHIRO, NOZUE, IKUO, TAKATORI, MASASHIGE
Applicants: JAPAN SYNTHETIC RUBBER CO., LTD.
Application year: 1986
Main classification: G03F7
IPC codes: G03F7