Current threshold response mode for arc management
This disclosure describes systems, methods, and apparatuses for extinguishing electrical arcs in a plasma processing chamber. Once an arc is detected, the steady state voltage provided to the plasma processing chamber can be reduced, and the current being provided to the chamber decays below a steady state value as the arc is extinguished. When the current falls to or below a current threshold, the voltage can be ramped back up bringing the voltage and current back to steady state values. This technique enables power to return to a steady state level faster than traditional arc mitigation techniques.
1. A power supply comprising:
a power controller configured to apply DC or pulsed DC power to a plasma processing chamber;
an arc management portion including a non-transitory, tangible computer readable storage medium, encoded with processor readable instructions to extinguish one or more arcs in the plasma processing chamber, the instructions including instructions for:
detecting an arc in the plasma processing chamber;
reducing, responsive to detection of the arc, a voltage provided to the plasma processing chamber to at least one reduced level;
monitoring a current provided by the power controller to detect when the current falls to a current threshold that is a percentage of a steady state current being applied to the plasma processing chamber just before the arc, and where the current threshold is less than the steady state current; and
raising, from the at least one reduced level, the voltage provided to the plasma processing chamber when the current falls to the current threshold, thereby effecting a dynamic quench period having a duration dependent upon the current.
2. The power supply of claim 1 , the arc management portion further comprising a voltage monitor and a current monitor, the current monitor configured for monitoring the current provided by the power supply.
3. The power supply of claim 1 , wherein the arc management portion includes a shunt switch disposed between a high and low voltage potential, wherein the shunt switch diverts power from the plasma processing chamber when closed, and wherein the high and low voltage potential provide power from the power controller to the plasma processing chamber.
4. The power supply of claim 3 , wherein the arc management portion includes a shunt-switch controller that controls closing and opening of the shunt switch.
5. The power supply of claim 4 , wherein the arc management portion uses the shunt-switch controller to open the shunt switch when the current provided to the plasma processing chamber falls to the current threshold.
6. A power supply comprising:
a power controller configured to apply DC or pulsed DC power to a plasma processing chamber;
an arc detection module configured to detect an occurrence of an arc in the plasma processing chamber;
an arc reduction module configured to reduce, responsive to the occurrence of the arc, a level of the power that is applied to the plasma processing chamber;
a current threshold monitor configured to detect when a current level of the power supply falls to a fixed current threshold that is a percentage of a steady state current and less than the steady state current, detection occurring during a reduced level of the power; and
a power resumption module configured to terminate a dynamic quench period by increasing the level of the power to the plasma processing chamber when the current that is applied to the plasma processing chamber falls to the current threshold.
7. The power supply of claim 6 , wherein the arc detection module includes a voltage monitor and a current monitor.
8. The power supply of claim 6 , wherein the arc reduction module includes a shunt switch disposed between a high and low voltage potential, wherein the shunt switch diverts power from the plasma processing chamber when closed, and wherein the high and low voltage potential provide power from the power controller to the plasma processing chamber.
9. The power supply of claim 8 , wherein the arc reduction module includes a shunt-switch controller that controls closing and opening of the shunt switch.
10. The power supply of claim 9 , wherein the power resumption module uses the shunt-switch controller to open the shunt switch when the current provided to the plasma processing chamber falls to the current threshold.