Synthesis and optical properties of EB induced refractive index lithography materials based on aliphatic polyimides

Electron beam reaction induced refractive index change of several polyimides, which are one of the most thermo stable polymers. Introducing aliphatic amine into polyimide makes the polymer transparent and colorless in the visible wavelength region due to restriction of charge transfer, as well as increase in the sensitivity to electron beam induced reaction. One of the aliphatic polyimide, PI(HPMDA/mix-DCHM), prepared form cyclohexane tetracarboxylic anhydride and diaminodicyclohexylamine, change the refractive index as large as 10(-3) for both TE and TM modes. Chemical reaction during the EB irradiation was also determined as electron beam induced aromatization. occurred.