In Situ Energy Loss and Internal Friction Measurement of Nanocrystalline Copper Thin Films Under Different Temperature

Abstract

This study uses a temperature controlled capacitance-based system to measure the mechanical behaviors associated with temperature dependent energy loss in ultra-thin copper films. Copper thin films are widely used in electronic interconnections and MEMS structures; however, most studies have focused on their temperature dependent dynamic properties at larger scales. This study designed a paddle-like test specimen with Cu films deposited on the upper surface in order to investigate the in-situ temperature dependent mechanical properties of metal thin films at higher temperature up to 120 °C under high vacuum conditions at very small scales. In-Situ Energy loss was measured according to decay in the oscillation amplitude of a vibrating structure following resonant excitation. The results indicated very tight temperature dependent internal friction of ultra-thin Cu metal films.