5  US 2019/0243238 Al  Aug. 8, 2019  [0054]  A specific structure of the onium salt compound  represented by formula (4) when R $^{3 }$is a phenylene group or  a naphthylene group can include the ones shown below. The  present invention is not limited to these.  [Chemical Formula 8]  /  RI  Te  -continued 