Wafer-level transfer of thermo-piezoelectric Si3N4 cantilever array on a CMOS circuit for high density probe-based data storage

Abstract

In this research, a wafer-level transfer method of cantilever array on a conventional CMOS circuit has been developed for high density probe-based data storage. The transferred cantilevers were silicon nitride (Si3N 4) cantilevers integrated with poly silicon heaters and piezoelectric sensors, called thermo-piezoelectric SisN4 cantilevers. The thermo-piezoelectric Si3N4 cantilever arrays were fabricated with a conventional p-type silicon wafer instead of a SOI wafer. Furthermore, we have developed a wafer-level cantilever transfer process, which requires only one step of cantilever transfer process to integrate the CMOS circuit with the cantilevers. Using this process, we have fabricated a single thermo-piezoelectric Si3N4 cantilever, and recorded 65nm data bits on a PMMA film. And we have successfully applied this method to transfer 34×34 thermo-piezoelectric Si3N4 cantilever arrays on a CMOS wafer. Finally, We obtained reading signals from one of the cantilevers. © 2006 IEEE.