Preparation of functional PZT Films on 6 and 8 silicon wafers by high rate sputtering

Crack and void free polycrystalline Lead Zirconate Titanate (PZT) thin films in the range of 2 m to 8 m have been successfully deposited on silicon substrates using an improved set-up for a novel high rate sputtering process. An optimised, rectangular cathode geometry (width 250 mm) allows homogenous PZT deposition on temperature controlled wafers up to 200mm diameter. Deposition rates of 100nm/min to 120nm/min for uniform layers of high quality were achieved. The sputtered PZT layers show a high dielectric constant r up to 2300 and a distinct ferroelectric hysteresis loop with a remnant polarisation of 17 C/cm2 and a coercive field strength of 5.4 kV/mm. Piezoelectric coefficients d33,f of 102 to 108 pm/V have been determined using a standard aixACCT. A transverse piezoelectric module e31 = -10.9 C/m2 was measured. Experiments for structuring of deposited PZT films have started. We report results from wet etch and dry etch tests using an APS tool from the company STS.