Temperature-Dependent Characteristics and Electrostatic Threshold Voltage Tuning of Accumulated Body MOSFETs

Narrow-channel accumulated body nMOSFET devices with p-type side gates surrounding the active area have been electrically characterized between 100 and 400 K with varied side-gate biasing ( ${V}_{\text {side}}$ ). The subthreshold slope (SS) and drain induced barrier lowering (DIBL) decrease and threshold voltage ( ${V}_{t}$ ) increases linearly with reduced temperature and reduced side-gate bias. Detailed analysis on a 27 nm $\times $ 78 nm (width $\times $ length) device shows SS decreasing from 115 mV/dec at 400 K to 90 mV/dec at 300 K and down to 36 mV/dec at 100 K, DIBL decreasing by approximately 10 mV/V for each 100 K reduction in operating temperature, and ${V}_{t}$ increasing from 0.42 to 0.61 V as the temperature is reduced from 400 to 100 K. ${V}_{t}$ can be adjusted from ~0.3 to ~1.1 V with ~0.3 V/V sensitivity by depletion or accumulation of the body of the device using ${V}_{\text {side}}$ . This high level of tunability allows electronic control of ${V}_{t}$ and drive current for variable temperature operation in a wide temperature range with extremely low leakage currents (<10⁻¹³ A).