Nanometer-scale distribution of field emission current from the arc-prepared carbon thin film

In this work, we used an ultrahigh vacuum (UHV) STM system with a surface treatment chamber where we prepare the carbon film by means of arc-discharge deposition of a high purity graphite rod under the same condition as in the case of the carbon coating that enhances FE characteristics. According to the STM geometrical images, the surface consists of graphite grains whose crystallinities and orientations are different, and has no sharp protrusions such as carbon nanotubes, where we cannot expect such a high field enhancement factor as to explain the improvement of the FE characteristics.