Monolithic integration of NEMS tunable color filter and LSI driver circuits

This paper presents a NEMS (Nano Electro Mechanical System) tunable color filter integrated with MOS driver circuits on an SOI (Silicon on Insulator) wafer. The NEMS electrostatic actuator could be designed a high mechanical resonance frequency with a relatively low drive voltage. The sub-wavelength grating and MOS driver circuits were made in a top and a substrate layer of the SOI wafer, respectively. The tiny anchors and pre-fabricated MOS transistors were covered by parylene N during the sacrificial release process using buffered hydrofluoric acid. Various structural colors depended on the pitch of the sub-wavelength grating were observed from integrated NEMS-LSI chip and NEMS TEG area. The color tuning from yellow to green was demonstrated at 20 V operation.