Integrated High-Frequency Vacuum Field Emission Transistors

Four types of Vacuum Field Emission Transistor (VFET) will be developed for integration into GaAs MMIC amplifer circuits. All VFETs lower circuit noise, partly by substituting vacuum gaps for noisy channels in solid state devices. VFETs alsosignificantly increase device speed and power performance, moving the trade-off curve out by possibly an order of magnitude. VFETs will be integrated on the same substrates as solid-state MMICs, providing a more reliable, elegant and less expensivealternative to microwave power modules connected to MMICs. Two types of GaAs edge emitter VFET, one all-metal and one GaN edge emitter will be designed, fabricated and characterized. Integration with MMICs can be by building in the VFET at the samesubstrate layers as the MMIC, by fabricating on top of the MMIC or by bonding through flip chip and other methods.