| abstract |
1. Formula (Ma): [Where: The structural unit M1 is a structural unit derived from a monomer having 2 or 3 carbon atoms and having at least one fluorine atom, The structural unit M2a is represented by the formula (a): (In the formula, R 1 is substituted with a divalent hydrocarbon group having 1 to 8 carbon atoms, a hydrocarbon group or a fluorine-containing alkyl group which forms a ring which may be substituted with a hydrocarbon group or a fluorine-containing alkyl group. At least one hydrocarbon group selected from the group consisting of divalent hydrocarbon groups having an ether bond with a total of 2 to 8 carbon atoms and oxygen atoms forming a ring which may be substituted; R 2 represents a ring; Formed alkylene group having 1 to 3 carbon atoms; R 3 and R 4 are the same or different; both are divalent alkylene groups having 1 or 2 carbon atoms; n1, n2, and n3 are the same or different; And at least one structural unit forming an aliphatic monocyclic structure in the main chain represented by 0 or 1), The structural unit N is a polymer having an aliphatic monocyclic structure in the polymer main chain represented by the structural unit derived from a monomer copolymerizable with the structural units M1 and M2a. Provided is a fluorine-containing copolymer having a number average molecular weight of 500 to 1,000,000 comprising ˜99 mol%, structural unit M2a of 1 to 99 mol%, and structural unit N of 0 to 98 mol%. The fluorine-containing copolymer has excellent dry etching resistance and transparency in the vacuum ultraviolet region. |