| abstract |
An onium salt capable of generating an acid having an appropriate strength and low diffusion, and a chemically amplified positive resist composition containing the onium salt. An onium salt of formula (1) and a chemically amplified positive resist composition containing the same. (Wherein, X 1 and X 2 are each independently a methylene group, an ether bond, etc .; L is a sulfonate ester bond, etc .: R 1 and R 2 are each independently a monovalent hydrocarbon group; m 1 And m 2 are each independently an integer of 0 to 2; m 3 is 0 or 1; n 1 is an integer of 1 ≦ n 1 ≦ 5 + 2m 1 ; n 2 is an integer of 0 ≦ n 2 ≦ 4 + 2m 2 ; n 3 is an integer of 0 ≦ n 3 ≦ 8 + 4 m 3 ; A + is a specific sulfonium cation, etc.) [Selection figure] None |