CHARACTERISTICS OF TRIODE MAGNETRON SPUTTERING - THE MORPHOLOGY OF DEPOSITED TITANIUM FILMS

This paper presents a modification to conventional diode magnetron spu ttering systems that results in higher ionisation rates with a consequ ent possibility of maintaining the discharge at lower pressures. The i ntroduction of a grounded or positively biased grid in front of the ta rget increases the target current substantially compared with the diod e configuration. In addition, the discharge can be maintained at a low er target voltage, thus increasing the range of deposition rate. With a low-pressure discharge maintained during him deposition, the mean fr ee path of the sputtered atoms increases. As a consequence, they reach the substrate with a high energy and, thus, a high-density film is ob tained. Therefore, by using the triode magnetron configuration and set ting the substrate temperature to 100 degrees C, it is possible to dep osit a titanium film having a similar morphology to one deposited in t he diode system at 400 degrees C. Finally, the electrode placed in fro nt of the cathode probably produces a more homogeneous spatial distrib ution of electron density, resulting in a significantly higher dischar ge stability in the triode configuration. (C) 1998 Elsevier Science S. A. All rights reserved.