Color filter process for CMOS image sensor process is divided into micro-lens and color layer steps. And the structure of color layers is made by building up photo resist(PR). Then, color is distinguished by color pattern of image sensor after light induced transmits through the pattern built. So negative PR is generally used for the structural characteristic in color filter process. Negative PR needs high-dose which results in deactivation effect by oxygen radical. In this paper, the experiment was developed by reducing oxygen radical and the process in order to pattern by reduced dose was acquired