Temperature-Dependent Adhesion Mechanisms of Metal and Insulator Probe-Sample Contact Pairs

This paper explores the effect of temperature on measured values of stiction, the attractive force keeping two bodies in contact, when investigating nano-scale contact pairs. Various sample and probe configurations are explored, with the probe being surface metallic (palladium) or insulating (silicon nitride) and the sample being metallic (gold) or insulating (glass). An atomic force microscope is used and pull-off force is measured as a function of temperature under both global and local heating. The findings of this work suggest that global heating leads to a more rapid reduction in stiction force compared with only probe heating, and that hydrophilicity of the surfaces being investigated dramatically affects the measured values of stiction. It was also found that metal-metal contact pairs had the smallest stiction values across the full range of conditions tested, identifying them as most favorable for mitigating the unwanted effects of stiction. Analytical models of the probe-sample adhesion match the trends of the experimental results well.