An interconnect scheme for reducing the number of contact pads on process control chips

摘要

An approach is presented to reduce the number of pads required by electrical test structures by using a multiplexed interconnect scheme. This passive multiplexed scheme requires only two levels of interconnect and can be used for transistors, electrical verniers, yield monitoring, reliability evaluations, continuity tests, and measuring the resistance of tracks. The basic measurement procedure to access individual components is to force a voltage on one of the access pads and then ground one of the group terminals via an ammeter. While an even number of pads is not mandatory it is recommended since this maximizes the efficiency of pad usage.