LOW-PRESSURE PLASMA SYSTEM WITH SEQUENTIAL CONTROL PROCESS

摘要

The low pressure plasma system includes a treatment chamber which is pumped out in a first process step by means of a pump. In a second process step a gas supply valve is opened in order to achieve a defined gas composition in the treatment chamber at low pressure. In a third process step a plasma generator is switched on in order to ignite a plasma in the treatment chamber. In a fourth process step a flushing valve can be opened in order to flush the treatment chamber. In a fifth process step the treatment chamber can be ventilated by way of a ventilation valve. The sequential switching element can be a rotary switch and include a zero switching position where the low pressure plasma system is off. The sequential switching element renders possible a simple embodiment of the low pressure plasma system and its intuitive operation.

主权项

1. A low pressure plasma system comprises:
a treatment chamber that can be at least in part evacuated, a gas supply valve, a plasma generator and a controller; wherein the controller comprises a vacuum electric circuit, a gas supply electric circuit and a plasma electric circuit; wherein the vacuum electric circuit controls a pump which can be connected to the low pressure plasma system and/or a pump valve of the low pressure plasma system; wherein the gas supply electric circuit controls the gas supply valve; wherein the plasma electric circuit controls the plasma generator; wherein the controller comprises a sequential switching element having switching positions that follow one another for setting process steps that follow one another; wherein the sequential switching element is embodied so as in each switching position to interrupt and to close respectively the vacuum electric circuit, the gas supply electric circuit and the plasma electric circuit by a plurality of switches that are electrically isolated from one another; wherein the sequential switching element comprises a first switching position in which the vacuum electric circuit is closed but the gas supply electric circuit and the plasma electric circuit are interrupted; wherein the sequential switching element comprises a second switching position in which the vacuum electric circuit and the gas supply electric circuit are closed but the plasma electric circuit is interrupted; wherein the sequential switching element comprises a third switching position in which the vacuum electric circuit, the gas supply electric circuit and the plasma electric circuit are closed; wherein the sequential switching element comprises in each case the plurality of switches for controlling the vacuum electric circuit the gas flow electric circuit and the plasma electric circuit, and the plurality of switches can be opened or closed one after the other; and wherein the sequential switching element is embodied so as in each switching position to close the plurality of switches of the sequential switching element, said plurality of switches being electrically isolated from one another.