Organic–Inorganic Hybrid Thermoset-Based Dual Tone-Type Photosensitive Material

This paper describes the development of an organic–inorganic hybrid thermoset-based dual tone-type photosensitive material which can be used for the formation of both a positive tone-type pattern and a negative tone-type pattern by simply changing the patterning process. A combination of three types of solubility controls was used to realize the dual tone-type material; copolymer composition, polymer composition contents, and process conditions were optimized based on the determination of solubility in an alkaline developer. Furthermore, the proposed mechanism of the solubility changes was confirmed by 1H nuclear magnetic resonance and Fourier transform infrared analyses. Thin coating films on silicon wafers prepared similarly by the procedures to prepare positive and negative patterns (with ultraviolet exposure without any photomask, without development) and subsequent heat treatment at 230 °C showed good adhesion to the silicon wafers and high heat resistance. Since this material can form linkages with silicon wafer surfaces and can be used to form fine and complicated patterns using a wide range of exposure doses, it is expected to be applied to permanent film materials such as interlayer dielectrics and protective films for high-density semiconductor packages.