Arrays of Miniaturized Plasma Sources Individually Regulated by Vertical Structures

Applications

Miniaturized plasma sources are used in plasma processing equipment, plasma displays, avionics systems, and biological decontamination. Non-thermal plasmas are of importance in high-power lasers, synthesis of nanomaterials, and electromagnetic reflectors and absorbers.

Problem Addressed

Plasmas are generally created by generating free electrons and ions through super-heating. However, in a non-thermal plasma, the electrons are significantly hotter than the ions and neutrals. This temperature distribution, in combination with high pressure, results in collision and radiative processes that are important in a wide range of applications and that would otherwise only be possible to attain at extreme environmental conditions. Previous plasma generators have been unable to produce non-thermal, high pressure plasmas in large volumes due to instabilities which limit their practical utility. Miniaturized plasma sources with vertical structures generate stable, high pressure plasmas in large volumes.

Technology

A microplasma generator is made of elongated semiconductor structures in a spatially defined cavity. A microplasma is generated whenever a voltage is applied across the elongated semiconductor structure. A gate electrode lies adjacent to the semiconductor, outside the microplasma cavity, separated by an insulating material. This gate electrode is configured such that a saturation current is altered when the voltage is applied. A series of generators may be arranged in a way that applying a voltage along the longitudinal axis will generate microplasma within the spatially defined cavities.

Advantages

  • Miniature plasma sources keep breakdown voltage low at atmospheric pressures
  • High surface-to-volume ratio maintains plasma stability
  • Power-efficient current regulation makes it possible to operate the device with higher yield
  • Modular architecture achieves uniform and steady array operation