Evaluation of interface strength of micro-dot on substrate by means of AFM

Abstract

Using atomic force microscopy (AFM), we have developed an experimental method for evaluating interface strength of a small dot on a substrate. This technique is applied to tungsten (W) dots of micrometer size on a silicon (Si) substrate. The diamond tip is dragged horizontally along the Si surface and the load is applied to the side edge of the W dot at a constant displacement rate. Both the lateral and the vertical load and displacement are continuously monitored during the test. Results show that after the tip hits the W dot, the lateral load, F l, increases almost in proportion to the lateral displacement, δ l. The W dot is abruptly separated from the substrate along the interface, and the apparent fracture energy of the interface, E d, is successfully evaluated.