METHOD AND DEVICE FOR DETECTING A PLASMA IGNITION

Disclosed are a method and an apparatus for the detection of a plasma in a process chamber for the treatment of substrates. In the method, the pressure within the chamber is measured over a period of time using a pressure sensor, a sudden change in pressure is detected and an ignition or extinguishing of a plasma determined at least by means of the pressure change. The apparatus comprises a process chamber, for receiving at least one substrate, with at least one plasma generator, at least one pressure sensor which is situated so as to detect the pressure within the process chamber and output an output signal corresponding to the pressure, and at least one evaluation unit. The evaluation unit is capable of monitoring over a period of time an output signal from the pressure sensor and, on the basis of at least one sudden change in the output signal of the pressure sensor, of determining an ignition and/or an extinguishing of a plasma.