The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 10, 1998
Filed:
Feb. 24, 1997
Jeff C Sellers, Palmyra, NY (US);
ENI Technologies, Inc., Rochester, NY (US);
Abstract
A strike enhancement circuit for a dc power supply, which can be a switched half-bridge supply, creates a high voltage at high impedance to initiate a plasma in a plasma chamber or sputtering chamber. The strike circuit has a plurality of diode bridges that act as full-wave rectifiers or peak detectors. The transformer secondary of the power supply is connected through isolation capacitors to the ac inputs of each of the diode bridges. The dc ports of the diode bridges are stacked in series, and the combined, stacked voltage is applied across the input terminals of the plasma chamber. Each diode bridge also has a storage capacitor connected between the positive and negative dc ports. Positive and negative voltage peaks from the transformer secondary waveform are stored in the storage capacitors. The combined dc outputs applied to the plasma chamber appear as a voltage high enough to initiate a plasma discharge. Once the plasma is present, the impedance of the isolation capacitors prevents the strike circuit from providing the high strike voltage.