Analytical modeling of a vacuum field effect transistor (VFET)

Abstract

An analytical model has been developed for vacuum field effect transistor (VFET). Mathematical expressions for threshold voltage, drive in voltage and channel current have been derived. Threshold voltage of VFET has been obtained based on the minimum accumulation charges and minimum electric field. A drive in voltage has been modeled based on minimum current density for space charge limited emission. Analytical model of the channel current incorporates the device operating physics such as space charge limited emission and Fowler-Nordheim tunneling. Effective electric field and emission area have been determined to obtain channel current more accurately. The analytical model has been numerically verified with the practical simulated data available. Proposed model provides the opportunity to evaluate the vacuum device characteristics and determine the future projections as well. It can be a useful tool for analyzing different features of vacuum microelectronic devices.