A Novel PUF Using Stochastic Short-Term Memory Time of Oxide-Based RRAM for Embedded Applications

Abstract

RRAM suffers from poor retention with short-term memory time when using low compliance current for programing. However, the short-term memory time exhibits ideal randomness, which can be exploited as an entropy source for physically unclonable function (PUF). In this work, we demonstrated a novel PUF utilizing the stochastic short-term memory time of oxide-based RRAM. The proposed PUF was implemented on a 256Kb HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /WO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> bilayer RRAM test chip in 0.13μm logic process. The RRAM PUF is capable of regenerating >10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">20</sup> times after 10 years@115°C and the bit error rate (BER) remains <; 0.08% at the temperature of up to 115°C for the read voltage of 0.1-0.7V, exhibiting strong resiliency against environmental variations. The average inter-chip Hamming distance (HD) is 0.4999 and the average intra-chip HD is 0.0009. The energy efficiency is 0.19 pJ/bit.