DEPOSITION PROCESS STUDY OF CHROMIUM-OXIDE THIN-FILMS OBTAINED BY DC MAGNETRON SPUTTERING

The study of the deposition process of chromium oxide thin films (Cr2O 3) by magnetron sputtering is the main purpose of this work. A pure ch romium target biased by a d.c. voltage is sputtered in a reactive atmo sphere of argon and oxygen. A systematic study of the deposition param eters like oxygen partial pressure has made it possible to follow with precision the mechanisms of target poisoning. On each part of the hys teresis loop, the amount of reacting oxygen and the number of sputtere d chromium atoms have been calculated. It has been compared with the r esults of X-ray photoelectron spectroscopy analysis. The evolution of the crystallization of the coatings has been studied depending on subs trate temperature by X-ray diffraction analysis. An optimal operating point for deposition of stoichiometric oxide coatings has been determi ned. In these conditions, for temperatures above 300 degrees C, the fi lms consist of pure well-crystallized Cr2O3 and present the characteri stic green colour of bulk Cr2O3.