Thermo-piezoelectric Si₃N₄ cantilever array on CMOS circuit for high density probe-based data storage

A novel wafer level transfer method of silicon nitride cantilever arrays on a conventional CMOS wafer has been developed for the high density usage of probe based data storage device. The cantilevers are so called thermo-piezoelectric cantilevers consist of poly silicon heaters for writing and piezoelectric sensors for reading. The cantilevers were fabricated with a commercial p-type Si wafer instead of a SOI wafer used for this application before. The wafer level transfer method presented here, consists of only one direct bonding of the wafer with cantilevers and the one with CMOS circuits. Thirty-four by thirty-four array of cantilevers were successfully transferred with this method. With a thermo-piezoelectric silicon nitride cantilever transferred with this method, 65 nm of data bits were recorded on a PMMA film. We also obtained piezo-electric reading signals from the transferred cantilevers.