STM Study of the Effects of Etching on the Surface of Kish-Graphite

We used a scanning tunneling microscope to study how the surface of Kish-Graphite roughens with etching. We present STM images of the etched surfaces for different etch times. The roughness (rms) and the peak-to-valley height were calculated from the digitized STM signals. The roughness vs sputtering time graph shows that the roughness increases with sputtering time up to about a roughness of 1 nm, then does not change with increased etching. The peak-to-valley height is proportional to the roughness with a coefficient of 8.7.