Suppression of Self-Pulsing Regime of DC-driven Microplasma Discharge

Reference #: 01196

The University of South Carolina is offering licensing opportunities for an instability suppressor circuit for self-pulsing DC driven micro-plasma discharge.

Background:

Micro-plasmas are plasmas of small dimensions, often within tens to thousands of micrometers in size. They are widely used for attaining non-thermal and non-equilibrium discharge at atmospheric and higher pressures since their small size is able to inhibit ionization overheating instability through rapid cooling.  However, they are susceptible to instability from external disturbances, with external driving circuits being the main source. The oscillation in the negative differential resistance (NDR) region varies from few hundreds to thousands of kHz. However, the effectiveness and reliable operation of DC micro-plasma devices depends on stable discharge condition. Though parallel plates, pin-plates and micro hollow cathode discharge (MHCD) geometry are the most widely used configurations to obtain a stable discharge for a wide range of current and pressures. The instability in the NDR region is unavoidable though not absolute. The challenge is therefore to extend the stable region of operation of a DC driven micro plasma discharge, hence extending the discharge current range of atmospheric and high pressure micro plasma discharge.

Invention Description:

The subject invention is an instability suppressor circuit for self-pulsing DC driven micro-plasma discharge with a view to extending the stable region of operation. Over a range of pressure and electrode separation distance, it is able to successfully suppress self-pulsing of the discharge, extending the normal glow regime to lower currents.

Potential Applications:

The current invention eliminates the instability of atmospheric pressure and high pressure discharges so that its application can be extended over a broader range of operating conditions.

In the field of plasma enhanced chemical vapor deposition (PECVD), plasma aided micro-patterning the smallest feature size is dictated by smallest discharge current at which a stable discharge can be attained. The current invention increases the stable operation mode of DC driven micro-plasma from extremely low to high current. Thus enhancing the regime of operation.

Advantages and Benefits:

Currently there are no existing technology that is aimed at suppressing the instability of atmospheric and high pressure. The invention employs a simple external circuit configuration that is inexpensive to implement. 

Patent Information: