We study the dielectric degradation phenomena of ultrathin SiO2 films using conducting-AFM spectroscopy in a vacuum (1×10-5 Pa). In successive current-voltage characteristics, a change of the carrier transport (from Fowler-Nordheim tunneling to direct tunneling) and current instability (which is due to a change in conductance of leakage path by isolated traps) are observed before `breakdown'. As an example of a possible application of conducting-AFM spectroscopy, we investigate a change in conductivity at a `breakdown' area.
Applied Physics A: Materials Science & Processing
- Pub Date:
- PACS: 07.79.Lh;