Fabrication of a thin film micro polarization array

A thin film polarizer has been patterned and etched using reactive ion etching (RIE) in order to create 14 micron circular periodic structures. The polarization thin film has extinction ratio of 60dB in the blue and green visible spectrum and /spl sim/40db in the red spectrum. Various gas combinations for RIE has been explored and it has been experimentally determined that for a particular concentration of CF/sub 4/ and O/sub 2/ an optimum etching rate, in terms of speed and under-etching, is possible. Theoretical explanation for the optimum etching rate has been also presented. In addition, anisotropic etching with less then 0.5/spl mu/m under cutting has been achieved. Experimental results of the patterned structures under polarized light are presented.