Conference paper Open Access
Kai-Hsin Chuang; Erik Bury; Robin Degraeve; Ben Kaczer; Guido Groeseneken; Ingrid Verbauwhede; Dimitri Linten
A novel physically unclonable function (PUF) utilizing the intrinsic randomness of oxide breakdown (BD) positions in CMOS transistors is presented. The advantages of this approach are studied and validated by measurements on test-chips fabricated in a commercial 40nm CMOS process. Experiments show that the required soft BDs can be reliably generated in a sufficiently short period. The randomness of the utilized mechanism shows excellent properties, required for PUF applications: an overall bias of 0.498 and inter-chip hamming distance (HD) of 0.501. Further analysis of the current distributions reveals a dependence of operating voltage on
readout resolution and window. Finally, dedicated experiments with external heating and embedded poly-heaters show that these soft BDs are stable and show no read-out errors up to operating temperatures of 600K.