VSS-Bias-Based Measurement of Random Telegraph Noise in Hybrid SRAM PUF after Hot Carrier Injection Burn-in

Abstract

In this paper, a method to observe random telegraph noise in a hybrid SRAM PUF array is presented. This allows low-cost observation of RTN in a number of bitcells by applying VSS bias voltages to measure their temporal mismatches. Also, the changes in RTN amplitude after hot carrier injection burn-in, which is used for PUF stabilization, have been measured and analyzed. Experimental results from a 130-nm CMOS test chip show that the average RTN amplitude across 80-run measurements increases from 1.46 mV before HCI to 9.72 mV after 18-min HCI. The maximum RTN amplitude also increases from 10.13 mV to 84.50 mV. These results indicate that RTN is not an omittable factor especially for a PUF using a hot carrier injection-based stabilization technique and should be carefully considered when deciding the burn-in strategy.