Sharp switching, hysteresis-free characteristics of Z2-FET for fast logic applications

A logic switch for integrated circuits is demonstrated experimentally in advanced FDSOI (Fully Depleted SOI). The Z² -FET (Zero Impact Ionization and Zero Subthreshold Slope FET) is a band-modulation device that shows remarkable performance in terms of ON/OFF current ratio and sharp switch (~ 1 mV/decade). The Z² -FET capability for ESD protection and capacitorless DRAM has already been documented. However, the presence of an inherent hysteresis effect has inhibited so far fast logic applications. A new generation of Z² -FETs with single or dual ground-plane has been fabricated with Ultra-Thin Body and Buried Oxide (UTBB) SOI technology. We demonstrate that fast pulses on the gate result in hysteresis-free switching: the device turns ON and OFF at same gate bias. Systematic measurements reveal the key roles of the device parameters and bias on the speed of operation.