Morphological stability of Pt coatings deposited on Cr substrates

The morphological stability of coatings is an important factor for the reliability of microelectronic devices operating at elevated temperature. The focus of this work was to characterise and explain the coating degradation mechanisms of Pt–Cr coatings and thereby to find ways of extending their operating temperature range. Platinum coatings on chromium are shown to be morphologically stable up to 800 °C; at higher temperatures degradation is observed. Scanning electron microscopy of coated specimens with a systematic variation in both coating thickness and annealing temperature shows that significant grain-boundary grooving and agglomeration can occur. This has important implications for the reliability of microelectronic devices operating at elevated temperatures. - Highlights: • Degradation mechanisms for Pt–Cr coatings at high temperatures have been investigated. • A model for coating morphology degradation is proposed. • Operating temperature ranges for uniform and reliable Pt–Cr coatings are shown.