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This work presents a detailed characterization of 28 nm FDSOI CMOS process at cryogenic temperatures. Electrostatic, Analog and RF Figures of Merit (FoM) are studied. At liquid nitrogen temperatures, 30% to 200% enhancement of drain current, Id, and maximum transconductance, gm_max, values are demonstrated. Current gain cutoff frequency, fT, increase by about 85 GHz is shown. Temperature behavior of analog and RF FoMs is discussed in terms of mobility and series resistance effect. This study suggests 28 nm FDSOI as a good contender for future read-out electronics operated at cryogenic temperatures (as e.g. around qubits or in space).

A detailed study of the hot-carrier degradation in nano-scale fully depleted ultra-thin body and buried oxide n-MOSFETs is presented. The degradation mechanisms were identified based on static current-voltage measurements. The degradation of the transistor was explained by considering generation of traps at the gate dielectric/Si interface and traps located within a tunneling distance of the interface. All stress parameters are considered describing with semi-empirical relations their impact on the transistor parameters. Based on our analytical compact model, we propose an aging hot-carrier model predicting with good accuracy the device degradation stressed under different bias conditions using a unique set of model parameters. Display Omitted The hot-carrier degradation of nanoscale UTBB FD-SOI n-MOSFETs has been investigated under different drain and gate bias stress conditions.The degradation mechanisms have been identified by studying the static current-voltage characteristics measurements.The impact of the HC degradation on the device parameters has been expressed with semi-empirical models in terms of the stress time, channel length, drain bias and gate bias.Based on our analytical compact model, HC aging model is proposed enabling to predict the device degradation stressed under different bias conditions, using a unique set of few model parameters determined for each technology through measurements.

This work provides a detailed study of 28 nm fully-depleted silicon-on-insulator (FD-SOI) planar ultra-thin body and BOX (UTBB) MOSFETs for high frequency applications. All parasitic elements such as the parasitic gate and source/drain series resistances, total capacitances are extracted and their effects on RF performance are analyzed and compared with previous work on similar devices. Two main RF figures of merit (FoM) such as the current gain cut-off frequency ( f T ) and the maximum oscillation frequency ( f max ) are determined. It is shown that f T of ∼280 GHz and f max of ∼250 GHz are achievable in the shortest devices. Based on the extracted parameters, the validation of the small-signal equivalent circuit used for modeling UTBB MOSFETs is investigated by comparing simulated and measured S -parameters.

In this work self-heating and its effect on analogue device parameters are compared in 28 nm technology bulk and FDSOI MOS devices. It is shown that for self-heating characterisation in advanced MOSFETs the RF extraction technique is more suitable than the pulsed I – V . It is found that the thermal resistance is ∼3.4 times higher and the temperature rise is ∼2.5 times higher in 28 nm gate length FDSOI than in bulk. However, in spite of stronger self-heating, FDSOI devices outperform bulk over a wide frequency range. Moreover, device parameters degradation with temperature is attenuated in FDSOI transistors.