Scanning probe microscopy was used to form local polarized domains in ferroelectric thin films by applying a voltage between the gold-coated cantilever and the conductive substrate in contact mode. Two methods of visualizing the poled areas are described. The first is to detect the piezoelectric response of the films by applying a small oscillating voltage between the probe tip and the substrate. This measurement determines the local ferroelectric polarity and domain structure directly. The second method is to measure the surface potential of the poled films using scanning Maxwell stress microscopy. This does not directly address the ferroelectric behavior of the film, but rather the potential due to surface charge. We determined the surface potential dependence on pulse voltage and duration applied to the ferroelectric film. The results demonstrate that the charged area will increase rapidly, but the surface potential will saturate as the pulse voltage and duration are increased. The resultant stable localized surface charge features indicate that lead zirconate titanate thin films are promising candidates for high-density charge storage media.

Scanning probe microscopy (SPM) was utilized to form novel nanometer‐scale memory units in organic molecular layers. One method is based on the conductivity changes induced in evaporated n‐paraffin films by imposing electric pulses. The scanning tunneling microscope (STM) image revealed clearly the formation of high‐conductive area, the spot size of which is as small as 1 nm, suggesting the creation of the extremely high‐density molecular memory over 1014 bit/cm2. Moreover, the analysis with the aid of a computer simulation demonstrated that the extraction of H atoms for n‐paraffin molecules by applying electric pulses results in the changes in the electric states as well as geometric conformation. Next, ferroelectric organic materials were utilized to construct another type of reversible molecular memory. Here, the nanometer‐scale polarization switching in ferroelectric (VDF/TrFE) films was achieved with the SPM technique by applying a positive or a negative electric voltage to the film spin‐coated on Pt substrate, and actually, several local domains with different polarities could be formed even within a small crystalite of about 200 nm in length. Finally, the possibility of creating the novel molecular memories of the next generation is discussed.