Process and circuit for the bipolar pulse-shaped feeding of energy into low-pressure plasmas

US6005218A · kind A · utility

Assignee

• Fraunhofer-Gesellschaft zur förderung der angewandten Forschung e.V. · DE

Inventors

• Hendrik Walde · Fort Collins, US
• Jonathan Reschke · Dresden, DE
• Klaus Goedicke · Dresden, DE
• Torsten Winkler · Radeberg, DE
• Volker Kirchhoff · Dresden, DE
• Peter Frach · Radeberg, DE

Key dates

• Filing date: Aug 11, 1997
• Grant date: Dec 21, 1999
• Expiry date: Aug 11, 2017

Classification

• Technology area (CPC H): Electricity
• CPC primary: H05H1/46
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

A process and circuit for the bipolar pulse-shaped feeding of energy into low-pressure plasmas is provided. Within an average time period, a power which is to be as high as possible is to be fed into the low pressure discharge. In each polarization, the same power is to be fed although the impedance differs considerably. In a system for plasma and surface treatment techniques having at least two electrodes and one power supply, the outputs of at least two potential-free direct current supplies are switched such that an output of one direct current supply is conductively connected with an output of the same polarity of the other direct current supply. By means of a switch which is connected with each feed line to the electrodes and whose other outputs are led in a combined manner to the other outputs of the direct current source, these switches are operated via a timing generator in synchronism with the pole changing frequency. The switches are opened up in the event of the occurrence of an arcing. The process is used for the bipolar pulse sputtering for depositing electrically insulating layers on workpieces. Preferably, such layers are used for a mechanical protection, protection …