通过酸扩散聚合以得到的光致抗蚀剂组合物来控制短长度而得到的高分子化合物-β-N-酰基内酰胺衍生物，对-β-内酰胺衍生物由下式作为原料表示的通式表示的N-酰基 （式中，R表示氢原子，甲基或三氟甲基，W表示亚烷基或亚环烷基，n表示0或1）和光聚合引发剂 R，R，R和R可具有在每个独立地表示氢原子，烷基，环烃基或酰氧基的氧原子。但是，1）R和R，R和R是任何位置连接 即，即使形成取代或未取代的环，2）R和R被连接到，并且可以形成一个取代或未取代的环，该环可包含在任意的位置的氧原子，和，3）R，R，R和R 所有同时氢原子 如果不是）

A polymer compound obtained by polymerizing an acid diffusion to the resulting photoresist composition to control short length -β- N- acyl lactam derivatives, to the N- acyl -β- lactam derivative represented by the general formula represented by the following formula as a raw material It provides photoresist compositions containing, and the polymer compound.

(In the formula, R ¹ represents a hydrogen atom, a methyl group, or trifluoromethyl. W represents an alkylene group or a cycloalkylene. N ^{is. R 2, R 3, R} 4 and R ⁵ represents 0 or 1 each independently represents a hydrogen atom, an alkyl group, cyclic hydrocarbon group or an acyloxy group. However, 1) R ² and R ^3, R ⁴ and R ⁵ are connected by a substituted or unsubstituted which may have an oxygen atom at an arbitrary position and to form a polycyclic ring, 2) R ³ and R ⁴ are connected to and form a substituted or unsubstituted ring which may contain an oxygen atom at an arbitrary position, ^{and, 3) R 2, R 3} , R 4 , and all of R ⁵ at the same time it is not a hydrogen atom)