| abstract |
The present invention is a polymer having an aliphatic monocyclic structure in the polymer main chain represented by the general formula Ma, comprising 1 to 99 mol% of structural unit M1, 1 to 99 mol% of structural unit M2a, and 0 to 98 mol% of structural unit N. It provides a fluorine-containing copolymer whose number average molecular weight is 500-1 million. This fluorine-containing copolymer has excellent dry etching resistance and transparency in the vacuum ultraviolet region.n n n <Formula Ma>n n n n n n n n In the formula, the structural unit M1 is an ethylenic monomer having 2 or 3 carbon atoms, which is a structural unit derived from a monomer having one or more fluorine atoms, and the structural unit M2a forms an aliphatic monocyclic structure in the main chain represented by the following general formula (a). It is at least one structural unit, and structural unit N is a structural unit derived from the monomer copolymerizable with structural units M1 and M2a.n n n <Formula a>n n n n n n n n Wherein R 1 represents a carbon number and an oxygen number forming a ring which may be substituted with a divalent hydrocarbon group having 1 to 8 carbon atoms, a hydrocarbon group or a fluorine-containing alkyl group which may be substituted with a hydrocarbon group or a fluorine-containing alkyl group. Is at least one hydrocarbon group selected from the group consisting of divalent hydrocarbon groups having an ether bond of 2 to 8, R 2 is an alkylene group having 1 to 3 carbon atoms forming a ring, and R 3 and R 4 are Are the same or different and are all divalent alkylene groups having 1 or 2 carbon atoms, n1, n2, n3 are the same or different and all are 0 or 1; |