The present invention provides a sulfonium salt of the formula (Ia)
a polymeric compound comprising a structural unit of the formula (Ib)
and a chemical amplification type positive resist composition comprising (A) an acid generator comprising at least one compound selected from the group consisting of a sulfonium salt of the formula (Ia), a polymeric compound comprising a structural unit of the formula (Ib), and a sulfonium salt of the formula (Ic); and
(B) resin which contains a structural unit having an acid labile group and which itself is insoluble or poorly soluble in an alkali aqueous solution but becomes soluble in an alkali aqueous solution by the action of an acid.
本发明提供了一种公式(Ia)的
硫鎓盐,包括一个结构单元的聚合物化合物的公式(Ib),以及一种
化学放大型正性光刻胶组合物,包括(A)至少选择自
硫鎓盐的公式(Ia)、一个结构单元的聚合物化合物的公式(Ib)和
硫鎓盐的公式(Ic)组成的酸发生剂;以及(B)含有酸敏感基团的结构单元的
树脂,本身在碱性
水溶液中不溶或难溶,但在酸的作用下变得可溶于碱性
水溶液。