| abstract |
The invention provides a novel resin having a bismuth structure and a method for producing the same, which has high carbon concentration, high heat resistance, high solvent solubility, wet process, and can be used as a multilayer photoresist. A novel underlayer film forming material for a photoresist underlayer film which is excellent in heat resistance and etching resistance of a lower layer film, a method for forming a pattern using the material, and the like. The resin of the present invention has a structure represented by the following general formula (1). □ (In general formula (1), R3 and R4 are each independently a benzene ring or a naphthalene ring, a ruthenium skeleton or a carbon atom bond of a bridgehead of a (b) benzofluorene skeleton and other aromatic rings. The carbon atom of the aromatic ring of the ruthenium skeleton or the (b) benzofluorene skeleton is bonded to the carbon atom of the bridgehead of the other anthracene skeleton or (b) benzofluorene skeleton). |