Microplasma Field Effect Transistors

Abstract

Micro plasma devices (MPD) with power gains are of interest in applications involving operations in the presence of ionizing radiations, in propulsion, in control, amplification of high power electromagnetic waves, and in metamaterials for energy management. Here we review and discuss MPDs with an emphasis on new architectures that have evolved during the past 7 years. Devices with programmable impact ionization rates and programmable boundaries are developed to control the plasma ignition voltage and current to achieve power gain. Plasma devices with 1-10 μm gaps are shown to operate in the sub-Paschen regime in atmospheric pressures where ion-assisted field emission results in a breakdown voltage that linearly depends on the gap distance in contrast to the exponential dependence dictated by the Paschen curve. Small gap devices offer higher operation frequencies at low operation voltages with applications in metamaterial skins for energy management and in harsh environment inside nuclear reactors and in space. In addition to analog plasma devices, logic gates, digital circuits, and distributed amplifiers are also discussed.Index Terms-Plasma devices; atmospheric-pressure plasmas; glow discharge devices; power amplifiers; terahertz switches I. INTRODUCTIONPlasmas are extensively studied during the past century [1]. Their applications in large-scale devices for fusion, and small-scale devices in switches are well accomplished and developed. Here, we concentrate on cold plasmas that can be easily generated in a small (< 1 mm 3 ) volume with moderate electrical powers of less than 5 Watts and discuss their applications in devices similar to diodes, MOSFETs and digital and analog three-terminal devices with power gains for amplification of signals. Except in distributed plasma devices and in magnetic field sensors, we only consider non-magnetized plasmas. For the most part, we assume that the plasma is quasi-neutral and it is generated at atmospheric pressures that range from 0.6 to 1.1 atmosphere.Microplasma devices have received a renewed attention in the past 5-7 years owing to their potential applications in harsh environment. Important features that make plasma devices attractive are: a) their very large off-to-on resistance ratios (10 10 Ω/0.1 Ω), b) the ability to conduct very large currents, c) the ability to operate at very high temperatures (can be as high as 1000 o C), d) improved operation in the presence of ionizing radiation, e) the ability to traverse shortest "electrical" distance between their anode and cathode (this property can be used to solve "shortest" path problems) [2], and f) the ability to form programmable electrically conducting paths making them suitable for reconfigurable antennas and circuits [3]. MPDs are also being explored in developing chip-scale electron beam accelerators and a 100 GeV electron accelerators has already been demonstrated [4].Microplasma devices are currently used in displays [5], light sources [6], ionization devices for chemical analysis [7], material processing [...