Minimizing PVT-Variability by Exploiting the Zero Temperature Coefficient (ZTC) for Robust Delay Fault Testing
Hanieh Jafarzadeh, Florian Klemme, Jan Dennis Reimer, Hussam Amrouch, Sybille Hellebrand, Hans-Joachim Wunderlich · 2024
Process, Voltage, Temperature (PVT) variations impede the test generation for Small Delay Faults (SDFs) significantly as test patterns effective for one circuit instance may not be valid for a different one. Temperature-induced timing variations in FinFET and Gate-All-Around (GAA) technologies are especially severe due to temperature fluctuations and self-heating. Depending on the supply voltage, they show the Temperature Effect Inversion (TEI) which describes the increase of the circuit speed with increasing temperature. The Zero Temperature Coefficient (ZTC) specifies a supply voltage where TEI approaches 0, and the optimal voltage is determined, such that the effects of temperature-induced variability are minimized. Simulation results are reported, which demonstrate that test generation at the ZTC voltage leads to higher fault coverage of SDFs while using significantly less test patterns.