Scanning force microscopy of domain structure in ferroelectric thin films: imaging and control

Abstract

Scanning force microscopy (SFM) has been used to perform nanoscale studies of domain structures and switching behaviour of (PZT) thin films. An SFM piezoresponse mode, based on the detection of the piezoelectric vibration of a ferroelectric sample, was shown to be suitable for high resolution imaging of ferroelectric domains in thin films. The lower limit of the piezoresponse mode imaging resolution depends on the radius of the probing tip and is estimated to be of the order of several nanometers. The effect of the film microstructure on the imaging resolution is discussed. The ability of effective control of domains as small as 50 nm by means of SFM has been demonstrated. It is shown that SFM can be used in the investigation of electrical degradation effects in ferroelectric thin films. Formation of regions with unswitchable polarization as a result of fatigue, within grains of submicron size, was experimentally observed.