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

Abstract

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 °C to 360 °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.