(Invited) III-Nitrides for Vacuum Nanoelectronics

Abstract

Vacuum Field Effect Transistors (VFETs) are explored using wide-bandgap (III-Nitrides), VFETs avoid high power consumption caused by cathode heating in thermionic emission devices and have small turn-on voltage with potential for millimeter-wave operation. Special attention is placed on emitter design, growth of high-quality materials and evaluation of thermal propertiesProgress in Si- and III-V-based electronic devices allowed operation at high-frequencies extending well into the millimeter-wave range. Device performance is limited by carrier transport properties and parasitics which have been addressed using different semiconductor materials, shrinking of device dimensions and advanced design approaches, permitting in this way to achieve operation at several hundred GHz. Further performance advances continue to be reported but start reaching a limit. The advances made in nanotechnology together with the possibility of utilizing field- rather than thermionic-emission offer, however, the possibility of revisiting the principle of vacuum tubes. Nanoelectronic devices utilizing such approaches offer the possibility of operating at millimeter-wave frequencies. Materials used for their realization are semiconductors i.e. II-Nitrides that can be processed using well-developed technologies and nanofabrication techniques, providing therefore ways of shrinking dimensions in critical parts of the device such as for example the gap between the emitter and cathode.The paper addresses device approaches for vacuum nanoelectronics using wide-bandgap i.e. III-Nitride semiconductors. The studies rely on appropriate emitter design, growth of high-quality materials and evaluation of thermal properties that can play a critical role in device performance.