An aluminum/SiO2/silicon−on−sapphire light valve matrix for projection displays

Abstract

A new electron−beam−addressed light valve structure has been tested which is composed of a large array of 0.002×0.002−in. 3000−Å−thick aluminized silicon dioxide electrostatically deflectable squares, suspended by a centrally located 4−5−μm−tall silicon post over a transparent sapphire substrate. The device is fabricated using conventional semiconductor processing techniques and, in particular, slits are photolithographically defined in each picture element so as to spatially separate in the schlieren stop plane the signal light produced by deflected elements from the diffraction pattern from the matrix. Experimental results include 20 lines/mm resolution, 18:1 contrast ratio, picture storage times of several months, and full erasure times of 1/30 sec.