HYSTERESIS BEHAVIOR IN 85-NM CHANNEL-LENGTH VERTICAL N-MOSFETS GROWN BY MBE

Vertical n-MOSFET's with channel lengths of 85 nm have been grown by M BE. For drain-to-source voltages V-DS > 3.3 V, these transistors exhib it hysteresis behavior similar to the reported behavior of fully deple ted SOI-MOSFET's. Our results also show a gate voltage controlled turn -off of the drain current when the transistor is operating in the hyst eresis mode. We have analyzed this behavior in vertical -MOSFET's usin g 2-D device simulation and our results show a threshold value for the hole concentration across the source-channel junction which is requir ed for the forward biasing of this junction. For a transistor operatin g in the hysteresis mode, we show that the potential barrier height fo r electron injection across the source-channel junction increases for increasing negative gate voltages during retrace. This results in a ga te controlled turn-off of the drain current for SOI and vertical n-MOS FET's operating in the regenerative mode.