Unified Capture Scheme for Small Delay Defect Detection and Aging Prediction

Small delay defect (SDD) and aging-induced circuit failure are both prominent reliability concerns for nanoscale integrated circuits. Faster-than-at-speed testing is effective on SDD detection in manufacturing testing, which is always implemented by designing a suite of test signal generation circuits on the chip. Meanwhile, the integration of online aging sensors is becoming attractive in monitoring aging-induced delay degradation in the runtime. These design requirements, if implemented in separate ways, will increase the complexity of a reliable design and consume more die area. In this paper, a unified capture scheme is proposed to generate programmable clock signals for the detection of both SDDs and circuit aging. Our motivation arises from the observations that SDD detection and online aging prediction both need to capture circuit response ahead of the functional clock. The proposed aging-resistant design method enables the offline test circuit to be reused in online operations. Reversed short channel effect is also exploited to make the underlying circuit resilient to process variations. The proposed scheme is validated by intensive HSPICE simulations. Experimental results demonstrate the effectiveness in terms of low area, power, and performance overheads.