Closed loop control
A method of controlling a reactive deposition process and a corresponding assembly and/or apparatus are described. The method includes providing power to a cathode with a power supply, providing a voltage set point to the power supply, receiving a power value correlating the power provided to the cathode, and controlling a flow of a process gas in dependence of the power value to provide a closed loop control for the power value.
1. A method of controlling a reactive deposition process, comprising:
providing power to a cathode with a power supply;
providing a voltage set point to the power supply;
receiving a power value of the actual power provided to the cathode from the power supply; and
controlling a flow of a process gas based on the power value to provide a closed loop control.
2. The method according to claim 1 , wherein the power provided to the cathode is MF power.
3. The method according to claim 1 , wherein the voltage set point is an upper limit for the power supply.
4. The method according to claim 1 , wherein the voltage set point is configured to operate the cathode in a transition mode.
5. The method according to claim 1 , wherein the received power value is stabilized by controlling the flow of process gas.
6. The method according to claim 1 , wherein the process gas comprises oxygen.
7. The method according to claim 1 , further comprising:
receiving an actual voltage value of the voltage provided by the power supply and monitoring a deposition mode based upon the actual value.
8. A closed loop control assembly configured for a reactive deposition process in a deposition apparatus having a chamber and a cathode therein, comprising:
a power supply connected to the cathode for providing power to the cathode;
a gas supply configured for providing a process gas into the chamber; and
a controller connected to the power supply for providing a voltage set point to the power supply and for receiving a power value of the actual power provided to the cathode from the power supply, wherein the controller is further connected to the gas supply for controlling a gas flow of the process gas based on the power value.
9. The assembly according to claim 8 , wherein the power supply is a MF power supply.
10. The assembly according to claim 8 , wherein the power supply is configured to provide the power with an oscillation frequency of 1 kHz to 200 kHz.
11. The assembly according to claim 8 , wherein the controller contains a program code adapted for controlling the flow of the process gas based on the power value to provide a closed loop control.
12. The assembly according to claim 11 , wherein the voltage set point is an upper voltage limit.
13. A deposition apparatus for reactive deposition of a layer on a substrate comprising:
a chamber for depositing the layer on the substrate therein;
a cathode for generating a plasma in the chamber; and
a closed loop control assembly configured for a reactive deposition process in a deposition apparatus having the chamber and the cathode therein, the closed loop assembly comprising:
a power supply connected to the cathode for providing power to the cathode;
a gas supply configured for providing a process gas into the chamber; and
a controller connected to the power supply for providing a voltage set point to the power supply and for receiving a power value of the actual power provided to the cathode from the power supply, wherein the controller is further connected to the gas supply for controlling a gas flow of the process gas based on the power value.
14. The method according to claim 1 , wherein the power provided to the cathode is MF power with an oscillation frequency of 1 kHz to 200 kHz.
15. The method according to claim 4 , wherein the voltage set point is configured to operate the cathode in a transition mode.
16. The method according to claim 1 , wherein the process gas comprises oxygen, wherein the oxygen flow is controlled.
17. The assembly according to claim 11 , wherein the power supply is a MF power supply having a DC generator and an oscillator.