In this study, photoresist stripping in semiconductor or LCD (liquid crystal display) fabrication processes using DIO$_3$, was investigated. In order to obtain the high PR stripping efficiency of DIO$_3$. we have developed new ozone-generating system with high ozone concentration and ozone-resolving system with high contact ratio. In this study, we obtained ozone gas concentrations of 11 % by new ozone-generating system, ozone-resolving efficiency of 99.5 % and maximum solubility of 130 ppm in deionized water. We applied the newly designed equipments to photoresist stripping processes and obtained similar results to SPM(sulfuric-peroxide mixture) process characteristics.?????ㄻ??????5??K?乍