Performance optimization for on-chip sensors to detect recycled ICs

IC recycling has become a grave problem in today's globalized semiconductor industry, with potential impact to critical infrastructures. In order to mitigate this problem, various Design-for-Anti-Counterfeit (DfAC) measures have been recently proposed. In this paper, we look at DfAC strategies based on recycling sensors, most notably the ones based on a pair of ring oscillators, which rely on integrated circuit aging phenomena to detect usage of ICs in the field. We introduce a novel optimization technique that generalizes to most recycling sensors suggested so far in literature and gives manufacturers exact control over parameters that determine sensor performance, such as yield, misprediction and area overhead. A detailed analysis of various factors affecting recycling sensor performance is presented and an optimization problem is formulated and verified using simulations, in order to demonstrate the accuracy of the approach.