Development of micromechanical and optical devices incorporating depositedPZT films

This paper reports the results of a 3 year Brite-Euram (III) programme aime d at extending the functionality of micromechanical and optical devices uti lising both thin and thick film PZT technologies: a oscillatory gyroscope w ith a resolution of 0.2 degrees /s, signal bandwidth of 30Hz @-3dB and dime nsions of 20-25 mm(2), a valve-less diffuser micropump capable of 0.05ml/mi n. and 3.5kPa maximum flow and pressure, a planar waveguide optical switch with insertion loss <1dB and switching time <1msec, and an integrated IR de tector array with NETD <100 mK. Cantilever test structures indicate that d( 31) for these films is <similar to>70 pC/N. Thinner films, <1<mu>m, have be en developed for the integrated IR detector array which have a pyroelectric coefficient similar to 250 muC/m(2)/K and F-D similar to1.5x10(-5) Pa-1/2. Laser crystallization of PZT using a pulsed excimer laser system has been successfully demonstrated. This is particularly significant for integration of PZT with active circuitry where post-processing temperatures must be ke pt below about 550 degreesC.