Treating arcs in a plasma process
An arc treatment device includes an arc detector operable to detect whether an arc is present in a plasma chamber, an arc energy determiner operable to determine an arc energy value based on an energy supplied to the plasma chamber while the arc is present in the plasma chamber, and a break time determiner operable to determine a break time based on the determined arc energy value.
1. An arc treatment device comprising:
an arc detector operable to detect whether an arc is present in a plasma chamber;
an arc energy determiner operable to determine an arc energy value based on an energy supplied to the plasma chamber while the arc is present in the plasma chamber; and
a break time determiner operable to determine a break time based on the determined arc energy value.
2. The arc treatment device of claim 1 , further comprising an input for receiving a signal associated with the plasma process,
wherein the arc detector is operable to detect whether an arc is present in the plasma chamber based on the received signal.
3. The arc treatment device of claim 1 , further comprising a data transfer arrangement operable to transfer an arc detection signal from the arc detector to a power supply controller.
4. A method of treating arcs occurring while a plasma process is being carried out in a plasma chamber, the method comprising:
detecting an arc present in the plasma chamber;
determining an arc energy value based on an energy supplied to the plasma chamber while the arc is present in the plasma chamber; and
determining a break time based on the determined arc energy value.
5. The method of claim 4 , wherein detecting the arc as present in the plasma chamber comprises:
measuring and analyzing a signal supplied by a power supply device to the plasma chamber.
6. The method of claim 4 , further comprising:
identifying a point in time when the break time starts.
7. The method of claim 6 , wherein determining the arc energy value comprises:
determining the arc energy value based on the identified point in time and a signal supplied to the plasma chamber.
8. The method of claim 4 , wherein determining the arc energy value comprises:
determining the arc energy value to be the energy supplied to the plasma chamber while the arc is present during a time interval between a start of the arc and extinction of the arc.
9. The method of claim 4 , wherein determining the arc energy value comprises:
determining the arc energy value as a portion of the energy supplied to the plasma chamber while the arc is present, during a time interval selected as one of:
an interval between time points of detection of the arc and extinction of the arc,
an interval between time points of reaction to the detection of the arc and the extinction of the arc,
an interval between a time point of the detection of the arc and a time point when an arc energy or an arc current falls under a predetermined threshold, and
an interval between a time point of reaction to the detection of the arc and a time point when the arc energy or arc current fails under the predetermined threshold.
10. The method of claim 4 , further comprising:
continually adjusting the break time.
11. The method of claim 4 , wherein determining the break time comprises:
determining the break time based on the determined arc energy value and a coefficient.
12. The method of claim 11 , further comprising:
determining the coefficient based on a quantity associated with previous arc occurrences.
13. The method of claim 11 , wherein the coefficient is one of a fixed value, a regulated value by a user, and a dynamic value calculated based on at least one of a power to the plasma process, a type of a target in the plasma process, and a length of the target.
14. The method of claim 4 , further comprising:
determining an effective break time by adding a predetermined value to the determined break time.
15. The method of claim 14 , further comprising:
determining that the determined break time is shorter than a reference time, and in response, determining the effective break time.
16. The method of claim 4 , further comprising:
choosing a beginning of the break time from a time interval between a start of the arc and extinction of the arc.
17. A plasma process power supply comprising:
a power output connectable to deliver power to a plasma chamber; and
a controller coupled to the power output and configured to:
detect a presence of an arc in the plasma chamber;
in response to detecting the presence of an arc, determine an arc energy value based on an energy supplied to the plasma chamber while the arc is present in the plasma chamber; and
interrupt the power to the plasma chamber for a period of time associated with a break time determined as a function of the determined arc energy value.
18. The plasma process power supply of claim 17 , wherein the controller comprises:
an arc treatment device including:
an arc detector operable to detect whether an arc is present in a plasma chamber;
an arc energy determiner operable to determine the arc energy value; and
a break time determiner operable to determine the break time based on the determined arc energy value; and
an output power controller coupled to the arc treatment device and operable to:
shut off the power to the plasma chamber in response to receiving from the arc detector an arc detection signal indicating the presence of an arc, and
turn on the power to the plasma chamber in response to receiving a signal indicating that the break time has elapsed.
19. The plasma process power supply of claim 18 , wherein the output power controller is configured to:
choose a beginning of the break time from a time interval between a start of the arc and extinction of the arc,
wherein the period of time is no smaller than the determined break time minus a period from the chosen beginning of the break time and a time point when the output power controller receives the arc detection signal.
20. The plasma process power supply of claim 18 , further comprising an output signal generator operable to provide the power to the plasma chamber via the power output and controllable by the output power controller,
wherein the output signal generator comprises one of an inverter and a pulse generator, and
wherein the output signal generator comprises an arc extinguisher connected to the arc detector and configured to extinguish an arc.