27.4 Physically Unclonable Function in 28nm FD801 Technology Achieving High Reliability for AEC-Q100 Grade 1 and 1SO26262 ASIL-B

Protection of information is of paramount importance in today's digital age. Physically Unclonable Functions (PUFs) are considered a secure method for security key generation because they generate responses that exist only during operation. A challenge regarding the use of PUFs is to achieve high reliability. Therefore, various schemes such as temporal majority voting [2], [3], [4], spatial majority voting [1], BCH [1], [3], and burn-in [3], are applied to improve the stability of the responses. While a recent paper proposed a method of oxide-break to achieve zero error [5], it is controversial if it is a real PUF since the response value (i.e. the status of the oxide-break) can be observed by reverse engineering. Automotive is an application area where reliability is particularly important, as failures may lead to critical accidents. To satisfy the reliability of AEC-Q100 Grade 1, functionality under −40-to-125°C in ambient temperature (Ta) must be guaranteed, even considering the aging effects on a chip. To satisfy IS026262 ASIL-B, the fault coverage must be over 90%. This paper shows a PUF satisfying both AEC-Q100 Grade 1 and IS026262 ASIL-B, where our testing temperatures cover −40-to-150°C in junction temperature (Tj) to compensate for the increased thermal heat within the SoC package.