Surface Modification and Measurement Using a Scanning Tunneling Microscope With a Diamond Tip

Abstract

Scanning Tunneling Microscopy is used to modify and measure the surface of magnetic media disks. A very rugged diamond tip allows continued scanning after it has severely scratched or punched the surface. Three techniques are used. First a manual method of penetrating the surface using a stand-alone head makes a scratch of essentially uncontrollable length and depth. Then the normal head is used to cause surface penetration by removing the bias voltage while scanning. Better control is obtained as regards the location and depth of the indentation. Excellent control of indentation location and depth can be obtained by using a new software developed by the STM manufacturer to push the tip into the surface with the piezoelectric scanner. The control of the indentations and their subsequent measurement may make the STM a useful tool as a hardness tester for ultra-thin films, on the order of a few tens of nanometers.