Passive bipolar arc control system and method

An arc control system for responding to an arc in a DC reactive sputtering system, comprising:

• a sputtering chamber that houses an anode and a sputtering target formed from a target material and serving as a cathode, the target material being formed from a metallic material;
• a DC power supply to provide a cathode voltage such that a cathode current flows from the anode to the cathode;
• a capacitor-inductor filter coupled between the DC power supply and the chamber, the resonant network having a Q such that the cathode current resonates to a negative current and such that the output of the DC power supply does not vary in response to the occurrence of an arc, thereby maintaining a rate of deposition for the sputtering system;
• and
• a series connected bidirectional zener diode and a unidirectional zener diode coupled across the filter to clamp the cathode voltage to a predetermined reverse voltage when the cathode current resonates to the negative current.

A method of coating a workpiece in a DC sputtering system, comprising the steps of:

• providing a sputtering chamber having a sputtering target formed from a target material and serving as a cathode;
• supplying a direct current cathode voltage between the cathode and an anode such that current flows between the cathode and anode;
• depositing a thin film upon the workpiece;
• filtering the cathode current such that in reaction to an arc, the cathode current resonates to a reverse current level;
• and
• clamping the cathode voltage to a predetermined reverse voltage.

An arc control system for responding to an arc in a DC sputtering system, comprising:

• a sputtering chamber that houses an anode and a sputtering target formed from a target material and serving as a cathode;
• a DC power supply configured to provide a direct current cathode voltage such that a cathode current flows through the anode and the cathode, the DC power supply having an output filter that includes an output inductor and an output capacitor;
• a first circuit branch coupled across the DC power supply, the first circuit branch comprising a resonant capacitor;
• and
• a second circuit branch coupled across the DC power supply in parallel with the first circuit branch, the second circuit branch comprising a resonant inductor in series with a parallel combination of a first circuit subbranch and a second circuit subbranch, wherein the first circuit subbranch comprises the sputtering chamber and the second circuit subbranch comprises a reverse voltage clamp;
• and further wherein the resonant capacitor and the resonant inductor comprise a resonant network configured to provide a Q such that in reaction to the occurrence of an arc, the cathode current resonates to a reverse current level and wherein the reverse voltage clamp is configured to clamp the cathode voltage to a predetermined clamp voltage and further wherein the output of the DC power supply does not vary in response to the occurrence of an arc.