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US 10,853,444 B2Granted
Systems and methods for tuning an impedance matching network in a step-wise fashion
AssigneeLam Research Corporation
InventorsArthur M. Howald, John C. Valcore, Jr., Andrew Fong, David Hopkins
Life of this patent
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Abstract
Systems and methods for tuning an impedance matching network in a step-wise fashion are described. By tuning the impedance matching network in a step-wise fashion instead of directly to achieve optimum values of a radio frequency (RF) and a combined variable capacitance, processing of a wafer using the tuned optimal values becomes feasible.
Claims20
A controller comprising:
- a processor configured to:
- obtain a first input parameter value associated with an output of a radio frequency (RF) generator when an impedance matching network operates at a first capacitance value;
- initialize a model to have the first capacitance value;
- propagate the first input parameter value via the model to output a first output parameter value when the model has the first capacitance value;
- determine, using the first output parameter value and the model, an optimum capacitance value for which a reflection coefficient at an input of the model is at a minimum;
- and
- control the impedance matching network to modify the first capacitance value to be closer to the optimum capacitance value;
- and
- a memory device coupled to the processor.
6 more elements
A method comprising:
- obtaining a first input parameter value associated with an output of a radio frequency (RF) generator when an impedance matching network operates at a first capacitance value;
- initializing a model to have the first capacitance value;
- propagating the first input parameter value via the model to output a first output parameter value when the model has the first capacitance value;
- determining, using the first output parameter value and the model, an optimum capacitance value for which a reflection coefficient at an input of the model is at a minimum;
- and
- controlling the impedance matching network to modify the first capacitance value to be closer to the optimum capacitance value.
3 more elements
A plasma system comprising:
- a radio frequency (RF) generator configured to generate an RF signal;
- an impedance matching network coupled to the RF generator, wherein the impedance matching circuit is configured to receive the RF signal to output a modified RF signal;
- a plasma chamber coupled to the impedance matching circuit to receive the modified RF signal;
- and
- a host computer coupled to the RF generator, wherein the host computer is configured to:
- obtain a first input parameter value associated with an output of the RF generator when the impedance matching network operates at a first capacitance value;
- initialize a model to have the first capacitance value;
- propagate the first input parameter value via the model to output a first output parameter value when the model has the first capacitance value;
- determine, using the first output parameter value and the model, an optimum capacitance value for which a reflection coefficient at an input of the model is at a minimum;
- and
- control the impedance matching network to modify the first capacitance value to be closer to the optimum capacitance value.
8 more elements
Dependencies are inferred from the claim text.