Fast Measurement of BTI on 28nm Fully Depleted Silicon-On-Insulator MOSFETs at Cryogenic Temperature down to 4K
Lauriane Contamin, M. Cassé, X. Garros, F. Gaillard, M. Vinet, Philippe Galy, A. Juge, Emmanuel Vincent, S. De Franceschi, Tristan Meunier
Abstract
We report preliminary results on bias temperature instabilities (BTI) on 28FDSOI MOS transistors from 300K to 4K with ultra-fast measurements. Common models describe BTI as a temperature-activated effect. Consequently, BTI is expected to be suppressed at cryogenic temperature. However, our measurements show that some BTI degradation remains even at 4K, underlying another degradation mechanism that becomes predominant at low temperature for both PBTI and NBTI. We offer insight into its characteristic temperature and time scales. We study the effect of the back-gate voltage, and show that its use can mitigate BTI degradation. Finally, an anomalous signal is observed in small PMOS devices, which can be caused by a trapping from the gate that is revealed at low temperature.