Electron-induced gasification reactions in the fabrication process on graphite surface using scanning tunneling microscopy

We have studied the dependence of nanofabrication on the pulse duration explicitly with scanning tunneling microscopy, using graphite as an example. It is demonstrated that, under comparable conditions, the depth of the as-generated craters has monotonic correlation with the pulse duration, while the apparent surface diameters do not show significant changes. This is believed to be direct evidence that the electron-induced gasification reaction of the carbon atoms did occur during fabrication, rather than field evaporation mechanism. The removal rate of the carbon atoms is estimated to be on the order of 10(5)/s. In addition, the characteristics of the fabrication is shown to be related to the specific reaction type. (C) 1999 American Institute of Physics. [S0021-8979(99)02916-3].