An Ultracompact Switching-Voltage-Based Fully Reconfigurable RRAM PUF With Low Native Instability

Abstract

In this brief, an ultracompact and highly reliable physical unclonable function (PUF) is presented based on the mainstream resistive random access memory (RRAM) devices. With the entropy originating from the switching voltage between the high-resistance state (HRS) and the low-resistance state (LRS), the proposed RRAM PUF can be generated during the RRAM's standard SET operation, leading to minimized design overhead. In addition, different from the previous implementations where the adopted RRAM PUF cells are dedicated to the “PUF” function, the proposed RRAM PUF is fully reconfigurable between the “PUF” function and the normal memory function. Moreover, the proposed implementation is validated using a standard 0.13-μm CMOS process plus customized postprocessing dedicated to RRAM devices. Featuring a normalized PUF cell area of 108F <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , the native instability (i.e., unstable bits) is measured to be as low as 0.28% at the normal condition. With the operating temperature varying from -50 °C to 150 °C and the supply voltage varying from 4 to 6 V, the averaged bit error rate (BER) is reported to be as low as 0.06% and 0.095%, respectively.