Tunable light grating integrated with high-voltage driver IC for image projection display

This paper presents a monolithic integration technique of MEMS grating light valves with high-voltage (40 V) driver circuits that target for image projection display devices. Driver circuits were prepared on an 8-mum-thick SOI (Silicon-on- Insulator) wafer by the DMO S (Double-diffused Metal Oxide Semiconductor) processes, after which the MEMS grating were integrated in the identical SOI layer by post-processing using the DRIE (Deep Reactive Ion Etching). In our work, optical light angle is modulated by changing the period of the MEMS grating pixel by means of electrostatic actuation. Optical diffraction angles of 6.6deg (OFF-state) and 3.3 deg (ON-State) were obtained with drive voltage of 0 V and 40 V, respectively.