Detecting an arc occuring during supplying power to a plasma process

A plasma power supply for supplying a plasma process in a plasma chamber with a power, the plasma power supply comprising:

• a DC source;
• an output signal generator connected to the DC source;
• a first signal sequence measurement device for measuring a first signal sequence present between the DC source and the output signal generator;
• a second signal sequence measurement device for measuring a second signal sequence present at an output of the output signal generator;
• and
• a controller connected to the first and second signal sequence measurement devices and configured to receive the first signal sequence and the second signal sequence, the controller comprising:
• a reference signal sequence generator configured to generate a reference signal sequence based on one of the first and second signal sequences, and
• a comparator configured to compare the reference signal sequence and the other of the first and second signal sequences that has not been used to determine the reference signal sequence, and to generate a detection signal if the reference signal sequence and the other of the first and second signal sequences cross.

A device for a plasma power supply for supplying a plasma process in a plasma chamber with a power, the device comprising:

• a reference signal sequence generator configured to generate a reference signal sequence based on one of a first signal sequence present between a DC source and an output signal generator and a second signal sequence present at an output of the output signal generator, the plasma power supply including the DC source and the output signal generator;
• and
• a comparator configured to:
• compare the reference signal sequence and the other of the first and second signal sequences which has not been used to determine the reference signal sequence, and
• generate a detection signal if the reference signal sequence and the other of the first and second signal sequences cross.