Electric Surface Modification of Diamond Like Carbon Film

Abstract

Local surface modifications of a diamond like carbon (DLC) film are carried out by applying voltages to conductive (Au coated) AFM probes in the contact mode. The DLC is deposited on a silicon substrate by ECR sputtering. When DC voltages are applied as the probe is scanned, two types of modifications such as hollows and mounds are formed in negative bias (-3--5V). When negative voltage pulses (-15V) are applied to the probe contacting with a point on the DLC, small pits are formed. Diameters of the pits decreases with decrease of the pulse width in the range from 1000ms to 10ms. The pit formed by the voltage pulse with 10ms width has 20nm diameter.