Constriction resistance of microcone-based contacts

Based on a recently developed semiconductor processing technique for field emitters, molybdenum cones are made on the surface of contact members to achieve low constriction resistance. A model was set up to calculate the constriction resistance of such a cone-based contact interface. The constriction resistance is obtained from the solution to a linear system of current flow equations for the contact structure. The effects of surface features such as number, size and distribution of microcontacts, and cluster area on the constriction resistance were evaluated by a computer simulation. The least-square optimization of numerical results led to an empirical expression which relates the constriction resistance to the cone radius, cone density and cluster area. The model predicts the reduction of constriction resistance as a function of cone density, and it agrees well with the experimental results