Fabrication of PZT actuated cantilevers on silicon-on-insulator wafers for a RF microswitch.

A processing scheme for fabricating Pb(ZrxTi1-x)O3 thin film actuated silicon cantilevers using silicon-on-insulator wafers is described. Such piezoelectrically actuated cantilevers are being investigated for RF microswitches. The microswitch design specification requires the Pb(ZrxTi1-x)O3 thin film to be at least 1μm thick to achieve the adequate deflection at an operating voltage of 10V. A two-stage dry-wet etching process was developed to reliably pattern the 1μm Pb(ZrxTi1-x)O3 film. To release the Pb(ZrxTi1-x)O3 cantilevers on silicon-on-insulator wafers it is necessary to perform deep silicon etching from both sides of the wafer. The Pb(ZrxTi1-x)O3 thin film was prepared by sol-gel method. The piezoelectric coefficient d31 was calculated as 14pC/N.