Photoresist Composition

Assignee International Business Machines Corporation (Armonk, NY) 

A new family of perfluoroacrylate and methacrylate based positive and negative tone photoresist compositions activated at 193 run has been prepared by free radical homo-or co-polymerization of acrylate or methacrylate derivatives. Polymeric agents prepared in this manner had Mn s between 5,000 and 50,000 daltons and were readily soluble in organic solvents. 

Preparation of l,14-Trifluoro-2-Trifluoromethyl-2,5-Pentanediol (Preferred) and l,14-Trifluoro-2-Trifluoromethyl-2,4-Pentanediol 

Preparation of l,l,l-Trifluoro-2-Trifluoromethyl-2-Hydroxy-5-Pentyl Methacrylate 

A reaction vessel containing n-butyllithium (0.944 mol 1.6M in hexane) was treated with the Step 1 product dissolved in 300 ml of THF at such a rate that the reaction temperature did not exceed 15°C and then stirred 2 hours. Methacryloyl chloride (0.52 mol) dissolved in 200 ml of anhydrous THF was added dropwise over 1 hour at 10°C, and the mixture was stirred overnight at ambient temperature. The mixture was next diluted with 500 ml of diethyl ether, washed twice with 500 ml of saturated aqueous NH4CI and brine, and dried with MgS04. The product was isolated in 79% yield by distillation at 74° C at 1.0 mmHg (0.5 g of phenothiazine was added to the pot prior to distillation). 

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The sulfonic acid moiety has been iacorporated iato a variety of nonfluofinated polymeric materials (111). Chain-end sulfonated polymers are produced by the reaction of sultones with polymeric organolithiums (112). Polymeric sulfonic acids such as these are iacorporated ia positive-working photoresist compositions (113). 

A number of a-aryl-A-alkyl nitrones and contrast enhancement compositions, which can be used to make contrast enhancement layer photoresist composites (230, 231), and inhibitors of free radical polymerization of monomers in nonexposed regions of the photoresist layer at selective actinic radiation (232). Histidine was used as a catalyst in the synthesis of a, A-diaryl nitrones in situ (233). To study diphenylborate chelates with mono- and bidentate ligands, a series of hydroxyl-containing nitrones have been synthesized (Fig. 2.7) (234-237). 

Optically active polymerizable isosorbide derivatives, (II) and ( ), were prepared by Koyama et al. (3) and used in photoresist compositions. 

Antireflective siloxane polymers coating compositions consisting of the reaction product of 2-(3,4-epoxycyclohexyl)-ethyl-trimethoxysilane, phenyltri-methoxysilane, methyltrimethoxysilane, and water were prepared by Zhang et al. (4) and used in photoresist compositions that were sensitive at 157 nm. 

Maeda et al. (3) prepared florinated norbomane copolymers, (VI), which were effective in photoresist compositions. 

Crosslinked positive photoresist compositions, (V), were prepared by Ogata et al. (5), which exhibited a significant change in alkali solubility prior to exposure and formed fine patterns with a high level of resolution. 

The ammonia or amine photothermally liberated from a cobalt(III) complex can be used to crosslink a carbonyl-containing polymer. One such complex is (120), which can be used in a photoresist composition where the non-crosslinked polymer is dissolved away, leaving a negative image in hardened polymer.246... 

Photoresist compositions based on compound (4) have shown excellent adhesion on copper-laminated resin plates <81JAP8167844>. 

Additional polymerizable perfluoromethacrylates and polybornenes, (1) and (11), respectively, were prepared by Inoue [1] and used in photoresist compositions. 

Hydrophobic fluorine-containing polymerizable cyclic olefin derivatives have been prepared that are transparent to irradiation at 160 nm or less. These monomers have excellent development characteristics and appear useful as components in a base resin of photoresist compositions. 

Photoresist compositions consisting of pentafluoromethylvinyl carbonate derivatives, (II), were prepared by Yoon [2] and used in photosensitive polymers for exposure to light sources having a dominant wavelength of less than 157 nm. Perfluorovinyl ether, (III), monomers were prepared by DiPietro [3] and used in lithographic photoresist polymer compositions. 

A norbornene terpolymer containing a lactone or sulton substituent has been prepared that is effective in photoresist compositions in the 193 and 157 nm ranges in photolithography. An improvement in etch resistance was also observed. 

Methacrylate-styryl terpolymers, (Vll), and perfluoronorbomene copolymers prepared by Taylor [5] were used in photoresist compositions and were effective at 157 nm and used in short wavelength imaging. 

Photoresist compositions have been prepared that consist of silsesquioxanes containing sulfonamide substituents. These materials are useful in multilayer resist systems that provide contrast upon exposure to photogenerated acid. 

Photoresist compositions containing fluorinated silicon components within a silsesquioxane resin, (V), were prepared by the author [4] and Barclay [5] that exhibited reduced outgasing when exposed to laser radiation, including ArF exposures. 

A wider choice of components of the photoresist compositions and solvents to be used as developers. 

Attempts have been made over time to improve the physical properties of novolacs. The use of phenol formaldehyde resins prepared in alkaline medium in photoresist compositions is mentioned in a Kalle Co. AG patent. The use of polyvinyl ethers in combination with novolacs to impart stickiness and plasticization action to the latter was patented by Christensen. Steinhoff, Isaacson, and Roelants of the Shipley Company mention the use of vinyl ethers in a patent on roller coating. Lower alkyl polyvinyl ethers, such as methyl, ethyl, butyl, and isobutyl, are added to novolac resins to improve coating flexibility and adhesion to metal surfaces as well as to improve resistance to mildly alkaline solutions. The use of styrene, methyl styrene, and styrene-maleic anhydride copolymers in combination with novolac was mentioned in several patents of both Shipley and Kalle Co. AG. When novolac is copolymerized with maleic anhydride, a resin that is readily soluble in alkaline solutions is obtained. ... 

C.G. Willson, U. Okoroanyanwu, and D. Medeiros, Photoresist compositions comprising norbornene derivative pol3miers with acid labile groups, U.S. Patent No. 6,103,445 (2000). 

The dissolution behavior of copolymers in aqueous base is of primary importance in photoresist performance. As microlithography continues to decrease in exposure wavelength and the minimum feature size required from photoresist compositions decreases below 0.20 pm, control of macromolecular architecture will play an increasingly significant role. That is, how does the random, alternating or "blocky nature of the matrix polymer effect its solubility in aqueous base. It has been well documented for novolac based photoresists that the molecular weight distribution... 

A Woolam Variable Angle Scanning Ellipsometer (VASE) was used to measure the Cauchy coefficients of the photoresist compositions. The photoresist... 

Kawabe, Y Kokubo, T. Positive-working photoresist composition. Eur. Pat. Appl. EP 385442, 1990 Chem. Abstr. 1991,114, 237657. 

Aoki, T. Kajiwara, T. Manufacture of printed circuit boards and photoresist compositions with good resolution, adhesiveness, and releasabUity therefor. Jpn. Kokai Tokkyo Koho JP 2005031583, 2005 Chem. Abstr. 2005,142, 210269. 

Nunomura, M. Hashimoto, M. Kasuya, K. Sasaki, M. Positive-working photoresist composition and patterning method using same. Jpn. Kokai Tokkyo Koho JP 05173327, 1993 Chem. Abstr. 1994,121, 46621. 

Toshimitsu, E. Negative-working photoresist compositions for blue-violet rays, and photoresist films. Jpn. Kokai Tokkyo Koho JP 2006058597, 2006 Chem. Abstr. 2006,144, 243414. 

Kawabe, Y. Uenishi, K. Kokubo, T. Positive-working photoresist compositions providing high resolution pattern. Jpn. Kokai Tokkyo Koho JP 04296754, 1992 Chem. Abstr. 1993,118, 222918. 

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