Patent ID: 7232640

Claim:
A positive resist composition for electron-beam, X-ray or EUV, comprising: (a) a polymer capable of increasing its solubility in an alkali developer under action of an acid, wherein the polymer has repeating units represented by formula (I), repeating units represented by formula (II), repeating units represented by formula (III), and a molecular weight dispersion degree of 1.5 or below, (b) a compound capable of generating an acid upon irradiation with an actinic ray or radiation, and (c) a solvent: wherein L 1 to L 4 , which are the same or different, each represents a hydrogen atom, a straight-chain, branched or cyclic alkyl group or an aralkyl group, and Z represents a straight-chain, branched or cyclic alkyl group or an aralkyl group, W has the same meaning as Z and is a group having an alicyclic or aromatic group, and Z and L 1 , or W and L 4 , may be combined with each other to form a 5- or 6-membered ring, provided that the groups represented by Z and W are not the same.