STM studies of the characteristics of the surface fabrication process using chemical and electrical methods

In this report, we compare the characteristics of nanostructures on graphit e surfaces produced by oxidation processes at high temperatures and by an e lectric pulse method using STM. The craters generated by the oxidation proc ess are typically flat bottomed, indicating uniform atomic layer removals, while the electric pulse method will lead to "V"-shaped craters that could be associated with the electron diffusion characteristics. The studies of t he fabrication experiment on a 1T-TaS2 surface using STM yielded appreciabl y different results. It is observed that the threshold pulse voltage is low er than that for graphite at comparable tunneling conditions. The minimum d imension of the as-produced features is appreciably larger than those on gr aphite. Both observations indicate higher surface instability for 1T-TaS2 a s compared with graphite.