| abstract |
A polymer is disclosed comprising: a first repeat unit derived from a monomer comprising a hydroxy-aryl group; a second repeat unit derived from a hydroxy-aryl group protected with an acetal or ketal group the monomer; the third repeating unit, which is derived from a (meth)acrylate monomer containing an alicyclic group; and the fourth repeating unit, which is derived from a monomer containing an acid-sensitive group, wherein the first repeating unit is A repeating unit, the second repeating unit, the third repeating unit, and the fourth repeating unit are different from each other. |