Abstract
An experimental method for evaluating interface strength of a small dot on a substrate is developed using a modified Atomic Force Microscopy (AFM). This technique is applied to a tungsten (W) dot of micrometer size on a silicon (Si) substrate. A diamond tip is dragged horizontally along the Si surface and the load is applied to the side edge of the W dot under a constant displacement rate. The lateral as well as the vertical load and displacement are continuously monitored during the test. After the tip hits the W dot, the lateral load, F_l, increases in almost proportion to the lateral displacement, δ_l. The W dot is abruptly separated from the substrate along the interface. The apparent fracture energy of the interface, E_d, is successfully evaluated.
