Reliability mechanism of the unprogrammed amorphous silicon antifuse

The electrical properties of the unprogrammed metal electrode amorphous silicon antifuse has been characterized. A model is proposed for the reliability mechanism. During a voltage stress, the leakage current through the antifuse creates localized states which increase the leakage current from 1 nA to tens of nA. The effect eventually saturates and can be annealed out. The amorphous silicon antifuse does not have a catastrophic failure mechanism such as the Time Dependent Dielectric Breakdown found in dielectric antifuses. The increase in the amorphous silicon antifuse leakage current is predictable and reproducible. The increase does not effect the reliability of the Field Programmable Gate Array which uses this antifuse as a programmable interconnect. The FPGA product has been stressed for 200 million equivalent device hours with a 7.0 volt static burn in with no failures.<
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