Transmission Enhancement in Coaxial Hole Array Based Plasmonic Color Filter for Image Sensor Applications

Abstract

Plasmonic color filters based on the hexagonal arrangement of coaxial hole array in aluminum have been demonstrated as a promising candidate for color filter development due to polarization and incident angle insensitivity. They also comprise a single nanometer thick metal film, demonstrate good line width, CMOS compatibility, and fine color tunability. However, the low transmittance of the coaxial hole array based filters limits their use in potential applications such as image sensors and displays. This paper introduces a new method to increase transmittance in coaxial hole array based filters by tuning localized surface plasmons and surface plasmon polaritons. In this method, coaxial holes of small diameters are filled along with a large size coaxial hole array to form a combined filter geometry with optimized parameters in aluminum film using computational techniques. The simulation results will have potential applications in CMOS image sensors, submicron pixel development, microdisplays, and liquid crystal over silicon devices.