The Operation of Partially Depleted SOI Inverters from Room Down to Liquid Helium Temperature

The operation of inverters, fabricated in a 1 ¿m partially depleted SOI CMOS technology is investigated from room temperature down to liquid helium. It is demonstrated that the transfer characteristics suffer from the floating-body anomalies, like the kink and the breakdown/latch behaviour. Additionally, at 4.2 K, hysteresis, which is related to the cryogenic (freeze-out) behaviour of the n-MOSFETs occurs. Finally, practical measures to reduce or eliminate these anomalies are discussed. Better results are obtained by using the twin-gate configuration, compared with a grounded body tie.