Polarization Analyzing Image Sensor with On-Chip Metal Wire Grid Polarizer in 65-nm Standard Complementary Metal Oxide Semiconductor Process

Abstract

A polarization analyzing complementary metal oxide semiconductor (CMOS) image sensor with a fine on-chip metal wire grid polarizer in the 65-nm standard process is presented. The extinction ratio is an important characteristic for a polarizer that depends largely on the feature size of the metal wire grid pitch and the fabrication CMOS process. To improve the extinction ratio, we designed and fabricated a sensor chip in the 65-nm process. The design rules of the 65-nm process realize the fine metal wire grid pitch compared with the wavelength of visible light. Improvement of extinction ratio is expected by such a fine structure. With the fabricated sensor, an extinction ratio greater than 40 was achieved. The difference between the measured value and the simulation value of the extinction ratio, and pixel crosstalk of the fabricated sensor are discussed.