A new concept and first development results of a PZT thin film actuator

High piezoelectric coupling coefficients of PZT-based material systems can be employed for actuator functions in micro-electro-mechanical systems (MEMS) offering displacements and forces which outperform standard solutions. Within this project a stress compensated, PZT coated cantilever concept for a 6" silicon micro machining process was developed. The actuator was designed for a tip displacement of 10 μm by a cantilever length of 200 μm - 1000 μm. Therefore, silicon bulk micro machining technique was used in combination with CSD technique. In the context of this paper the deposition and integration processes for the different materials were described. Special attention was given to the Zr/Ti ratio of the PZT thin films to obtain a high piezoelectric coefficient. Si₃N ₄ was used for stress compensation of the deposited layers. For first characterizations XRD, SEM, microscopy, stress-, hysteresis-, and CV-measurements were used