Photovoltaic effect on the conductive atomic force microscopic characterization of thin dielectric films

The authors have used front-wing conductive probes to investigate the photovoltaic effect on the conductive atomic force microscopic (C-AFM) characterization of thin dielectric films. The surface photovoltage induced by the laser beam of an atomic force microscope can enhance the electrical field across the studied dielectric film, decreasing the onset voltage of the leakage current, resulting in a modified C-AFM image with a larger current distribution. Moreover, the experimental results also revealed that the influence of the photovoltaic effect on C-AFM would be more significant for dielectric films that are grown on a substrate with a higher carrier concentration.