The influence of substrate temperature on the properties of Al, Zr and W coatings deposited by closed-field unbalanced magnetron sputtering

Closed-field unbalanced magnetron sputtering (CFUBMS) is now recognised as a technique capable of producing high quality industrially relevant coatings. As a result of this, BNFL are undertaking a major project with the aim of fully characterizing a CFUBMS system. As a part of this project, characterization studies have been carried out of the properties of Al, Zr and W coatings deposited by CFUBMS. Deposition parameters, such as target current (over the range 2A to 8A), substrate bias (-30 V to -70 V), coating pressure (0.5 mtorr to 3 mtorr) and substrate-to-target separation (80 mm to 150 mm), were varied in a systematic manner, using experiments designed using the Taguchi Method. Substrate temperatures were also measured, and were found to range from 200 degrees C to 360 degrees C. The coatings were analysed using X-ray diffraction techniques to determine grain size, micro- and macro-strains and texture. Knoop microhardness measurements were also made. The relationships between the deposition parameters, substrate temperature, and the subsequent coating properties were investigated. (C) 1998 Elsevier Science Ltd. All rights reserved.