Optimization of RRAM-based physical unclonable function with a novel differential read-out method

RRAM-based physical unclonable function (PUF) leveraging the remarkable resistance variability has been proposed and experimentally demonstrated on a 1-kb one-transistor one-resistor array. In this letter, a novel differential read-out method is utilized to reduce the effect of resistance window degradation. The RRAM PUF reliability is optimized through a reliability-enhancement design and oxide stack engineering. The experimental results show that the optimized RRAM PUF demonstrates nearly ideal uniqueness with the inter-chip Hamming distance close to 50%. The reliability of the optimized RRAM PUF is improved over the prior work. The intra-chip Hamming distance is close to the ideal value 0%, which can be sustained for a lifetime of more than ten years at 80 °C. This letter demonstrates that RRAM PUF has great potential for robust lightweight security solutions in IoT applications.