Lead zirconate titanate film formation technology with spray coating method

This paper presents a three-dimensional microfabrication and integration technology for micro electro mechanical system (MEMS) smart materials that utilizes a spray coating method. Spray coating is shown to be most effective for additional deposition on nonplanar surfaces. Lead zirconate titanate (PZT) films were formed both on flat and uneven surfaces at a thickness of approximately 1 µm. Perovskite structures were formed with a suitable heat treatment and a ferroelectric P-E hysteresis loop was also obtained. This paper is the first report from our group and other researchers on the deposition of smart materials for MEMS using a spray coating method. Spray coating has been proposed as an effective three-dimensional coating method which can be used to deposit piezoelectrics, pyroelectrics and magnetics for sensors and actuators. The hydrophilic and hydrophobic properties between the substrate surface and ejected liquid are most essential factors in the spray coating method for improving film growth conditions.