Process and fabrication of a lead zirconate titanate thin film pressure sensor

Lead zirconate titanate (PZT) ferroelectric material is highly attractive f or sensor and actuator device applications. Static pressure sensor structur es were fabricated using sol-gel deposited PZT spin coated onto Pt/SiO2/Si substrates, with the platinum layer forming the bottom electrode. A subsequ ent platinum layer deposited onto the PZT formed the device top electrode. The resultant Pt/PZT/Pt/SiO2/Si stacks were patterned with photoresist and defined by ion beam milling and reactive ion etching in a HC2CLF4 plasma to form electrical capacitor structures. Capacitance measurements were perfor med on 200 mu mX200 mum and 300 mu mX300 mum dimension structures over the frequency range 0.12-100 kHz. Capacitance remained relatively unchanged ove r this frequency range, with a magnitude corresponding to its predicted val ue along with a low dissipation factor (0.02), thus verifying the high qual ity of the device structures. The device is intended to measure pressure in the range of 10 000-100 000 psi.