Electrical Resistivity and Real Structure of Magnetron-Sputtered Carbon Films

Abstract

The resistivity and structure of DC magnetron-sputtered carbon films is studied. The film structure is examined by Raman spectroscopy, transmission electron microscopy, and electron diffraction. The films reveal prominent resistivity anisotropy relating to film structure. In the range of deposition temperatures 20–450^∘C, ordered regular aromatic rings and graphite-like clusters form. In the range 450–650^∘C, the growth mechanism changes and graphite phase forms directly on the substrate. Annealing of films in the range 50–300^∘C results in transformation of distorted aromatic rings into regular ones, and in ordering them without formation of graphite fragments. Further increase in the annealing temperature causes little changes the film structure. Ion bombardment in the range of substrate bias voltage –20 ≤ V _bias≤ –150 V decreases cluster size and results in disordering in their internal structure. At V _bias > –150 V the cluster structure tends to be more ordered towards graphitization . The results obtained open the way for deposition of carbon films with controllable electrical properties.