Direct Measurement of Interface Strength between Copper Submicron-Dot and Silicon Dioxide Substrate

摘要

We develop an experimental evaluation method of interface strength for ductile submicron-dots on a hard substrate without collapse of the dot. The validity is examined by a copper (Cu) submicron-dot on a silicon dioxide (SiO_2) substrate with the rigid-layer of tungsten (W), which restrains the deformation and decreases the influence of complicated stress field due to the contact of tip. The diamond tip is dragged horizontally along the SiO_2 surface and the load is applied to the side edge of the W layer at a constant displacement rate using a modified atomic force microscopy. Both the lateral and the vertical load and displacement are continuously monitored during the test. The lateral load, F_1, increases almost in proportion to the lateral displacement, δ_1, and the Cu dot with the W layer is clearly separated from the SiO_2 along the interface. The restraint by the W layer works well so that there are little damages in both the delaminated W/Cu dot and the substrate. The delamination lateral load, F_(1C), is successfully measured.