SYSTEM AND METHOD FOR DIAGNOSING PLASMA CHAMBER
In one embodiment, a system for determining a characteristic of the plasma chamber is disclosed. The system includes an impedance matching network, a sensor, and a control circuit. The control circuit stores one or more reference values for a parameter related to a semiconductor processing tool. A current value for the parameter is determined based on a signal received from the sensor. The control circuit then determines a characteristic of the plasma chamber based on a comparison of the current value for the parameter and the one or more reference values for the parameter.
1 . A system comprising:
an impedance matching network configured to operably couple to a plasma chamber;
a sensor; and
a control circuit configured to carry out the operations of:
storing one or more reference values for a parameter related to a semiconductor processing tool, the matching network and the plasma chamber forming part of the semiconductor processing tool;
determining a current value for the parameter based on a signal received from the sensor; and
determining a characteristic of the plasma chamber based on a comparison of the current value for the parameter and the one or more reference values for the parameter.
2 . The system of claim 1 wherein the one or more reference values are a valid range of values, and the comparison of the current value and the one or more reference values comprises a determination whether the current value is outside the valid range of values.
3 . The system of claim 1 wherein the sensor is positioned at an output of the matching network.
4 . The system of claim 1 wherein the sensor is positioned internal to the matching network.
5 . The system of claim 1 wherein the sensor is positioned at an input of the plasma chamber.
6 . The system of claim 1 wherein the parameter is a load impedance at an RF output of the matching network.
7 . The system of claim 1 wherein the parameter is a voltage, a current, or a phase angle.
8 . The system of claim 1 wherein the one or more reference values are based on values determined over a prior period of time of operation.
9 . The system of claim 1 wherein the control circuit forms part of the matching network.
10 . The system of claim 1 wherein the control circuit is further configured to provide a visual or audible indication of the determined characteristic of the plasma chamber, or to cause an action to address the determined characteristic.
11 . A method of determining a plasma chamber characteristic, the method comprising:
storing one or more reference values for a parameter related to a semiconductor processing tool, the semiconductor processing tool comprising the plasma chamber and a matching network;
determining a current value for the parameter based on a signal received from a sensor coupled to the tool; and
determining a characteristic of the plasma chamber based on a comparison of the current value for the parameter and the one or more reference values for the parameter.
12 . The method of claim 11 wherein the one or more reference values are a valid range of values, and the comparison of the current value and the one or more reference values comprises a determination whether the current value is outside the valid range of values.
13 . The method of claim 11 wherein the sensor is positioned at an output of the matching network.
14 . The method of claim 11 wherein the sensor is positioned internal to the matching network.
15 . The method of claim 11 wherein the sensor is positioned at an input of the plasma chamber.
16 . The method of claim 11 wherein the parameter is a load impedance at an RF output of the matching network.
17 . The method of claim 11 wherein the parameter is a voltage, a current, or a phase angle.
18 . The method of claim 11 wherein the one or more reference values are based on values determined over a prior period of time of operation.
19 . The method of claim 11 wherein the control circuit forms part of the matching network.
20 . A semiconductor processing tool comprising:
a plasma chamber configured to deposit a material onto a substrate or etch a material from the substrate; and
an impedance matching network operably coupled to the plasma chamber;
a sensor; and
a control circuit configured to carry out the operations of:
storing one or more reference values for a parameter related to the semiconductor processing tool;
determining a current value for the parameter based on a signal received from the sensor; and
determining a characteristic of the plasma chamber based on a comparison of the current value for the parameter and the one or more reference values for the parameter.