Real-time Monitoring Technique for High Quality Holographic Grating

摘要

The diffraction efficiency of diffraction grating lie on groove depth. In the course of exposure and development, the precision control groove depth of the holographic grating is more difficult. Based on refractive index of photoresist transforming in exposure process and groove evolving of photoresist grating in developing process, the diffraction efficiency changing was analyzed combining with electromagnetic field theory. The method for controlling groove depth of the holographic grating was presented. The relation between groove depth and diffraction efficiency in — 1 order shown below.