Title :
Hysteresis behavior in 85-nm channel length vertical n-MOSFETs grown by MBE
Author :
Rao, Ramgopal V. ; Wittmann, Franz ; Gossner, Harald ; Eisele, Ignaz
Author_Institution :
Fakultat fur Elektrotech., Univ. der Bundeswehr Munchen, Neubiberg, Germany
fDate :
6/1/1996 12:00:00 AM
Abstract :
Vertical n-MOSFETs with channel lengths of 85 nm have been grown by MBE. For drain-to-source voltages VDS>3.3 V, these transistors exhibit hysteresis behavior similar to the reported behavior of fully depleted SOI-MOSFETs. Our results also show a gate voltage controlled turn-off of the drain current when the transistor is operating in the hysteresis mode. We have analyzed this behavior in vertical n-MOSFETs using 2-D device simulation and our results show a threshold value for the hole concentration across the source-channel junction which is required for the forward biasing of this junction. For a transistor operating in the hysteresis mode, we show that the potential barrier height for electron injection across the source-channel junction increases for increasing negative gate voltages during retrace. This results in a gate controlled turn-off of the drain current for SOI and vertical n-MOSFETs operating in the regenerative mode
Keywords :
MOSFET; hole density; hysteresis; impact ionisation; molecular beam epitaxial growth; semiconductor device models; 2D device simulation; 3.3 V; 85 nm; MBE growth; NMOSFET; channel length; drain current; electron injection; forward biasing; gate voltage controlled turnoff; hole concentration; hysteresis behavior; n-channel device; potential barrier height; regenerative mode; source-channel junction; transistor; vertical n-MOSFET; Analytical models; Boron; Electrons; Fabrication; Hysteresis; Impact ionization; MOSFET circuits; Plasma temperature; Threshold voltage; Voltage control;
Journal_Title :
Electron Devices, IEEE Transactions on