A study of the contact resistance in the vias of a metal-insulator-metal system and its effect on the behavior of integrated circuits

Fabrication methods developed, designed to mimic those of current integrated circuit production lines, led to mean values of via contact resistances of approximately 3 x to the 8th power ohm-square centimeters. These values are more than an order of magnitude less than previous published values for comparable dimensions. A model was developed which explains the experimental results. Assuming an ideal interface, that is, a via with a perfect metal/metal junction, a contact resistance in the range 1 to 50 x -10 to the 10th power ohm-square centimeters is predicted depending on the via geometry (rectangular or circular).