Optical disk mastering using an electron beam recorder

For the next-generation optical disk, electron beam mastering has been considered as a technique with high potential. Parameters of exposure and development processes, such as focus distance, beam current, linear velocity, and development time, have been discussed in our previous paper (2001). However, for electron beam mastering, electron backscattering is also an important problem. In this paper, we discussed how the proximity effect caused by backscattered electrons influences the exposure linewidth (FWHM) and the thickness of residual resist as track pitch decreases. We attacked this problem by raising beam voltage and changing the material of a substrate. According to experimental results, depositing a SiO₂ film or a Si₃N₄ film on a substrate can partially solve this problem.