Extinguishing arcs in a plasma chamber

Patent metadata

Field	Value
Publication number	US-10002749-B2
Application number	US-201514742960-A
Country	US
Kind code	B2
Filing date	Jun 18, 2015
Priority date	Dec 18, 2012
Publication date	Jun 19, 2018
Grant date	Jun 19, 2018

Abstract

An arc extinguishing method for extinguishing arcs in a plasma chamber of a plasma system, comprising providing a plasma operating power during a plasma operation to the plasma chamber for generating plasma in the plasma chamber and carrying out a plasma-processing process using the generated plasma, by generating an analog signal by a digital-to-analog converter (DAC) and amplifying the generated analog signal on an amplifier path, monitoring, by an arc detection device, the plasma system for arcs, and in response to detecting an occurrence of an arc, controlling the DAC by the arc detection device such that the generated analog signal by the DAC is modified.

First claim

What is claimed is:

1. A method of extinguishing arcs in a plasma chamber of a plasma system, the method comprising:
providing a plasma operating power during a plasma operation to the plasma chamber for generating plasma in the plasma chamber and carrying out a plasma-processing process using the generated plasma, by generating an analog signal by a digital-to-analog converter (DAC) and amplifying the generated analog signal on an amplifier path;
monitoring, by an arc detection device, the plasma system for arcs; and
in response to detecting an occurrence of an arc, controlling the DAC by the arc detection device such that the generated analog signal by the DAC is modified,
wherein controlling the DAC comprises:
controlling an arc management circuit by the arc detection device; then
controlling the DAC by the arc management circuit.

2. The method of claim 1 , comprising:
in response to detecting the occurrence of an arc, controlling one or more DACs by the arc detection device.

3. The method of claim 1 , wherein providing a plasma operating power comprises:
providing a high-frequency power with a frequency of more than 1 MHz; and
controlling the DAC to generate the analog signal with the same frequency.

4. The method of claim 1 , wherein monitoring the plasma system for arcs comprises:
recording a signal associated with at least one of: a first power supplied to the plasma, a second power reflected by the plasma, a current flowing into the plasma, and a voltage applied to the plasma; and
generating an arc detection signal based on the recorded signal.

5. The method of claim 4 , comprising:
converting the recorded signal into digitized values by an analog-to-digital converter (ADC);
supplying the digitized values to a logic circuit;
evaluating, by the logic circuit, the digitized values; and
generating, by the logic circuit, the arc detection signal based on a result of the evaluation.

6. The method of claim 5 , comprising:
sampling the recorded signal by the ADC with a frequency of more than 1 MHz; and
clocking the logic circuit with a clock signal with a frequency of more than 1 MHz.

7. The method of claim 5 , comprising:
clocking the ADC and the logic circuit with a same clock signal.

8. The method of claim 1 , comprising:
during an arc extinguishing operation, supplying the plasma chamber with an arc extinguishing power that is smaller than the plasma operating power,
wherein the plasma operating power and the arc extinguishing power are generated at least in part by:
controlling the DAC based on monitoring the plasma system for arcs; and
amplifying the analog signal of the DAC on the amplifier path to provide at least a part of the plasma operating power or the arc extinguishing power.

9. The method of claim 8 , comprising:
controlling one or more additional DACs based on monitoring the plasma system for arcs; and
amplifying respective analog signals of the one or more additional DACs on respective subsequent amplifier paths for the one or more additional DACs to at least a part of the plasma operating power or the arc extinguishing power.

10. The method of claim 9 , wherein the analogue signals of at least two of the DACs are differently amplified on the respective amplifier paths or amplified with different cycle times.

11. The method of claim 1 , comprising:
generating a digital signal by multiplying a signal data value stored in a digital data memory and an amplitude data value stored in an amplitude data memory,
wherein the analog signal is generated from the digital signal by the DAC, supplied to the amplifier path, and amplified on the amplifier path into a high-frequency power signal.

12. The method of claim 11 , comprising:
changing the amplitude data values stored in the amplitude data memory to switch from generating the plasma operating power to generating an arc extinguishing power for an arc extinguishing operation.

13. The method of claim 12 , wherein the DAC is supplied with a same series of digital values during the plasma operation and during the arc extinguishing operation.

14. The method of claim 1 , comprising:
generating a different analog signal by the DAC during an arc extinguishing operation than during the plasma operation.

15. The method of claim 1 , comprising:
supplying the DAC with a different reference signal during the plasma operation than during an arc extinguishing operation.

16. The method of claim 1 , comprising:
in response to detecting the occurrence of an arc, reducing the plasma operating power to an arc extinguishing power in one of a stepped way and a ramped way.

17. A method of extinguishing arcs in a plasma chamber of a plasma system, the method comprising:
providing a plasma operating power during a plasma operation to the plasma chamber for generating plasma in the plasma chamber and carrying out a plasma-processing process using the generated plasma, by generating an analog signal by a digital-to-analog converter (DAC) and amplifying the generated analog signal on an amplifier path;
monitoring, by an arc detection device, the plasma system for arcs;
in response to detecting an occurrence of an arc, controlling the DAC by the arc detection device such that the generated analog signal by the DAC is modified; and
during an arc extinguishing operation, supplying the plasma chamber with an arc extinguishing power that is smaller than the plasma operating power,
wherein the plasma operating power and the arc extinguishing power are generated at least in part by:
controlling the DAC based on monitoring the plasma system for arcs; and
amplifying the analog signal of the DAC on the amplifier path to provide at least a part of the plasma operating power or the arc extinguishing power.

18. A method of extinguishing arcs in a plasma chamber of a plasma system, the method comprising:
providing a plasma operating power during a plasma operation to the plasma chamber for generating plasma in the plasma chamber and carrying out a plasma-processing process using the generated plasma, by generating an analog signal by a digital-to-analog converter (DAC) and amplifying the generated analog signal on an amplifier path;
monitoring, by an arc detection device, the plasma system for arcs;
in response to detecting an occurrence of an arc, controlling the DAC by the arc detection device such that the generated analog signal by the DAC is modified; and
supplying the DAC with a different reference signal during the plasma operation than during an arc extinguishing operation.

Assignees

• Trumpf Huettinger Gmbh Co Kg

Inventors

• Grede Andre
• Krausse Daniel
• Labanc Anton
• Thome Christan
• Vidal Alberto Pena

Classifications

• H01J37/32064

  Circuits specially adapted for controlling the arc discharge (for plasma torches H01H1/36) · CPC title

• H01J37/32944 Primary

  Arc detection · CPC title

• H01J37/3299

  Feedback systems · CPC title