The present invention provides a positive photosensitive resin composition which can form a pattern of high resolution and high residual film ratio and has high sensitivity. The method involves providing a substrate; forming a gate structure over the substrate; forming an epitaxial layer in a source and drain region of the substrate that is interposed by the gate structure; and after forming the epitaxial layer, forming a lightly doped source and drain feature in the source and drain region. The press molding preform is comprised of the optical glass. An experiment performance component runs the established number of experiments for the algorithm.