Aromatic hydrocarbon resin and composition for forming underlayer film for lithography

A composition for forming an underlayer film for lithography comprising an aromatic hydrocarbon resin obtained by reacting an aromatic hydrocarbon represented by the formula (1) and an aldehyde represented by the formula (2) in the presence of an acidic catalyst:

• wherein R represents hydrogen or an alkyl group having from 1 to 4 carbon atoms;
• l and m each represents a number of 1 to 3;
• and A represents a number of from 0 to 1, provided that when any of 1 and m is 2 or more, plural groups represented by R may be the same as or different from each other,
• wherein X represents hydrogen, an alkyl group having from 1 to 10 carbon atoms, an aryl group having from 6 to 10 carbon atoms, a cyclohexyl group, a hydroxyl group, a formyl group or a carbonyl group;
• p and q each represents a number of from 1 to 3;
• and B represents a number of from 0 to 2, provided that when any of p and q is 2 or more, plural groups represented by X may be the same as or different from each other;
• an organic solvent;
• and
• at least one member selected from the group consisting of an acid generator and a crosslinking agent.