International Technology Center

The University of North Carolina at Chapel Hill

North Carolina State University

Kobel Steel Usa, Inc.

William McClure Hooke

Mark Alan Ray

Allen Richard Martin

Gary Elder McGuire

Brian Rhys Stoner

Brian Douglas Schultz

Steven P Bozeman

Bradley E Williams

Jeffrey T Glass

Roy E Fauber

Sean Washburn

Michael J Kelly

Tobin L Munsat

A plasma generating system. A pair of electrodes are spaced apart by an electrode gap. A source of a gas adapted to place the gas in the electrode gap. A power generating circuit is coupled to the electrodes to generate an electric field across the electrodes so as to initiate a plasma discharge within the electrode gap. The power generating circuit has adequate capacity to maintain a sufficient electric field across the gap during the plasma discharge to allow a plasma impedance to self-tune to the plasma generating system. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.

Self-tuned dielectric barrier discharge

A method of generating a glow discharge plasma involves providing a pair of electrodes spaced apart by an electrode gap, and having a dielectric disposed in the electrode gap between the electrodes; placing the electrodes within an environment, wherein the electrode gap can be provided with a gas or gas mixture containing carbon at a specified pressure; and applying a rapid rise time voltage pulse across the electrodes to cause an extreme overvoltage condition, wherein the rapid rise time is less than a plasma generation time so that the extreme overvoltage condition occurs prior to current flow across the electrode gap. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.

Pulsed dielectric barrier discharge

A dielectric barrier plasma discharge device consistent with certain embodiments of the present invention has a pair of electrodes spaced apart by an electrode gap. A dielectric is disposed between the electrodes. The electrode gap is provided with a gas at a specified pressure. A rapid rise time voltage pulse generator produces a voltage pulse across the electrodes to cause an extreme overvoltage condition, wherein the rapid rise time is less than a plasma generation time so that the extreme overvoltage condition occurs prior to current flow across the electrode gap. Due to the high voltages and high current densities, the product yields an extremely high instantaneous power density. This extreme overvoltage condition is also believed to lead to production of shock waves and runaway free electrons. The resulting plasma can be utilized to carry out many potential tasks including, but not limited to etching, deposition, and sterilization. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.

A method of generating a fast-rise time voltage step to produce an overvoltage condition for a dielectric barrier plasma discharge involves providing a pair of electrodes spaced apart by an electrode gap and at least one dielectric disposed in the gap; generating fast-rise time voltage step such that the rise time to achieve said overvoltage condition is equal to or less than the time required to generate the plasma thereby establishing the overvoltage condition prior to current flow across said electrode gap. Power from storage capacitor banks discharge into the electrode gap through a switch. The switch is capable of standing-off voltage sufficient to create the overvoltage condition when the switch is open. The discharge current pulse across the said electrode gap is terminated by charging properties of the said dielectric(s) in the said electrode gap. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.

A plasma system is disclosed comprising a vessel suitable for containing a plasma at a pressure of at least about 100 mtorr, a plasma gas in the vessel at a pressure of at least 100 mtorr, an antenna with a substantially planar face positioned adjacent a portion of the vessel for applying an electromagnetic field to the plasma gas to thereby generate and maintain a plasma, and means for applying an external magnetic field to the plasma gas other than the field generated by the antenna, and having a component in a direction substantially perpendicular to the planar face of the antenna.

Electrode designs for high pressure magnetically assisted inductively

A method for plasma processing includes using a relatively high magnetic field and a relatively high pressure to create a first plasma region adjacent a window of a processing chamber having a lower radiation absorption and a second plasma region adjacent a substrate holder having a higher radiation absorption. Accordingly, a cooler plasma region is created adjacent the window to prevent contaminants from being etched from the window and adjacent chamber surface, and hotter plasma region is created adjacent the substrate to increase the processing rate. Additionally, the relatively high pressure of the processing gas, preferably greater than about 10 Torr and more preferably greater than about 100 Torr, increases the density of the plasma thereby increasing the processing rate. Alternatively, a high magnetic field and a high pressure create a radiation absorption region which is on the order of centimeters thick, for example 5-10 centimeters thick. Preferably, a uniform magnetic field creates uniform absorption in the absorption region.

Method for plasma processing at high pressure

A method and apparatus for enhancing the nucleation of diamond by pretreating a substrate by electrically biasing a diamond film adjacent the substrate while exposing the substrate and the thus biased diamond film to a carbon-containing plasma. The bias pretreatment may be maintained for a time period in the range of about 1 hour to 2 hours to achieve a high diamond nucleation density. Alternatively, the biasing may be continued until diamond film formation is indicated by a change in reflectivity of the surface of the substrate. The biasing pretreating may be used to nucleate diamond heteroepitaxially on a substrate having a surface film formed of a material having a relatively close lattice match to diamond, such as .beta.-silicon carbide. The apparatus includes a laser reflection interferometer to monitor the surface of the substrate. The laser reflection interferometer is used to monitor growth of the diamond film and cooperates with a controller to control the processing parameters during the diamond growing process.

Growing community of inventors

Chapel Hill, NC, United States of America

William McClure Hooke