| 摘要 |
PURPOSE:To enable the very high sensitive development, without entirely depressing the contrast by developing the resist material with a solvent mixture composed of a cyclic ether which has a four-six membered cyclic ring structure and is a good solvent for the titled resist, and a poor solvent for the titled resist. CONSTITUTION:In the development of the positive type radiation resist material composed of a copolymer obtd. by copolymerizing alpha-methylstyrene or its derivative, and an another comonomer capable of forming the positive type resist material, the mixed solvent composed of the cyclic ether which is the good solvent for the prescribed copolymer and has the four-six membered cyclic ring structure, and the poor solvent for said copolymer, is used to the developer. The more content of the cyclic ether which is the prescribed good solvent is high, the higher sensitive development becomes possible, but, the film of the unexposed part becomes remarkably thin, and the gamma-value of the titled resist is also reduced. On the contrary, when the content of the prescribed poor solvent in the resist is too large, the sensitive of the titled resist depressed. Thus, the mixed ratio of the cyclic ether of the prescribed good solvent and the prescribed poor solvent is a range of 5/95-95/5 vol. ratio, preferably 10/90-90/10 vol. ratio. |
