Characterization of the surface potential of PZT-films for an electrostatic printing process

The materials investigated in this paper are PZT thick films on polycrystalline Al₂O₃-substrates metallized with a Pt-electrode. The uniformly polarized films were locally polarized in the opposite direction with a metallic electrode as well as with an electron beam in the SEM. The surface potential resulting from the latent charge image at the film surface was measured after polarization and after contrast enhancement by corona charging. Furthermore, the potential contrast could be visualized in the SEM at small accelerating voltages and minimal sample currents. The depth profile of the polarization perpendicular to the film surface was measured by the pyroelectric laser intensity modulation method (LIMM). The influence of film inhomogeneities on the surface potential is discussed