Highly Reliable Physical Unclonable Functions using Memristor Crossbar with Tunneling Conduction

In this work, we present highly reliable operations of physical unclonable function (PUF) using the pristine state of Al2 O3/TiOx memristor crossbar arrays. The device stack is optimized in terms of stoichiometry and thickness to obtain temperature-independent $I-V$ properties. A strong PUF with a large $(\sim 10 ^{17})$ number of challenge-response pairs is demonstrated based on the crossbars, and the bit-error rate (BER) was experimentally verified less than 1% (0.896% at 80 °C) without correction methods thanks to tunneling conduction. In addition, the uniformity, diffuseness, and uniqueness of the PUF are evaluated ~50%, and its randomness is verified through both NIST tests and machine learning attacks, confirming robust security property.