| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an acetal compound having a high dissolution contrast in organic solvent development and useful as a monomer for a base resin of a high sensitive photoresist material, a polymer obtained from the acetal compound, a resist material containing the polymer as a base resin, and a pattern forming method using the resist material. <P>SOLUTION: The acetal compound is expressed by formula (1). In a photoresist film 10 comprising a polymer comprising repeat units obtained from the acetal compound and an acid generator, when an image is formed by positive/negative reversal in development by an organic solvent, the dissolubility of an unexposed part is high and the dissolubility of an exposed part is low, whereby the dissolution contrast becomes high. In formula (1), R<SP POS="POST">1</SP>is a hydrogen atom, methyl or trifluoromethyl; R<SP POS="POST">2</SP>is a straight, branched or cyclic monovalent 1-10C hydrocarbon group; R<SP POS="POST">3</SP>and R<SP POS="POST">4</SP>are each independently a hydrogen atom or a straight, branched or cyclic monovalent 1-10C hydrocarbon group; R<SP POS="POST">2</SP>and R<SP POS="POST">3</SP>may bond to each other to form an aliphatic hydrocarbon ring together with carbon atoms to which they bond; X<SP POS="POST">1</SP>and X<SP POS="POST">2</SP>are each independently a single bond or a straight or branched divalent 1-4C hydrocarbon group; R<SP POS="POST">5</SP>is a straight, branched or cyclic monovalent 1-15C hydrocarbon group; and k<SP POS="POST">1</SP>is an integer of 1 to 3. <P>COPYRIGHT: (C)2012,JPO&INPIT |
