US 5,585,766 AGranted

Electrically tuned matching networks using adjustable inductance elements

AssigneeApplied Materials, Inc.

InventorViktor Shel

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Abstract

A plasma processing system for use in fabricating electronic devices including an RF generator; a process chamber including an electrical load which produces a plasma within the chamber when powered by the RF generator; an electronically tunable matching network connected between the RF generator and the electrical load of the process chamber, wherein during operation the matching network couples power from the RF generator into the plasma within the process chamber; and a control circuit connected to the matching network, wherein during operation the control circuit electronically adjusts the matching network so as to control a transfer of power from the RF generator into the plasma in the process chamber. The matching network includes an electronically tunable variable inductor including a core made of a material which exhibits a non-linear relationship between magnetic field intensity, H, and magnetic flux density, B. The core is configured as a closed loop defining a central opening. A magnetization coil is wound around the core so that the core forms a closed magnetic flux path for the magnetization coil. The magnetization coil includes two input terminals for coupling an electrical signal from the control circuit into the windings of the magnetization coil. There is also a primary coil formed around the outside of said closed-loop core and having input terminals for receiving a high-frequency current signal from the RF generator.

Claims45

Dependent claims

A plasma processing system for use in fabricating electronic devices, said system comprising:

an RF generator;
a process chamber including an electrical load which produces a plasma within the chamber when powered by the RF generator;
an electronically tunable matching network connected between the RF generator and the electrical load of the process chamber, wherein during operation said matching network couples power from the RF generator into the plasma within the process chamber;
and
a control circuit connected to the matching network and generating a control signal, wherein during operation said control circuit via the control signal electronically adjusts the matching network so as to control a transfer of power from the RF generator into the plasma in the process chamber,
said matching network including an electronically tunable variable inductor comprising:
a core made of a material which exhibits a non-linear relationship between magnetic field intensity, H, and magnetic flux density, B, said core configured as a closed loop defining a central opening;
a magnetization coil on said core, said magnetization coil wound around said core so as to pass through said central opening whereby said core forms a closed magnetic flux path for said magnetization coil, said magnetization coil including two input terminals for coupling the control signal from the control circuit into the windings of said magnetization coil;
and
a primary coil formed around said closed-loop core in such a way that the primary coil exhibits a variable inductance the value of which is controlled by the control signal changing the magnetic permeability of the closed-loop core, said primary coil comprising one or more loops, each of which is arranged about said core so that said magnetization coil produces a net magnitization flux through each of said one or more loops that is substantially zero, said primary coil having input terminals receiving a high-frequency current signal from the RF generator.

7 more elements

An inductance element for generating an electrically tunable inductive reactance to a high-frequency current signal, said inductance element comprising:

a core made of a material which exhibits a non-linear relationship between magnetic field intensity, H, and magnetic flux density, B, said core configured as a closed loop defining a central opening;
a first magnetization coil on said core, said magnetization coil wound around said core so as to pass through said central opening whereby said core forms a closed magnetic flux path for said magnetization coil, said first magnetization coil including two input terminals for coupling a control signal into the windings of said first magnetization coil;
and
a primary coil formed around said closed-loop core in such a way that the primary coil exhibits a variable inductance the value of which is controlled by the control signal changing the magnetic permeability of the closed-loop core, said primary coil comprising one or more loops, each of which is arranged about said core so that said magnetization coil produces a net magnetization flux through each of said one or more loops that is substantially zero, said primary coil having input terminals for receiving the high-frequency current signal.

1 more element

An inductance element for generating an electrically tunable inductive reactance to a high-frequency current signal, said inductance element comprising:

a core made of a material which exhibits a non-linear relationship between magnetic field intensity, H, and magnetic flux density, B, said core configured as a closed loop defining a central opening;
a first magnetization coil on said core, said magnetization coil wound around said core so as to pass through said central opening whereby said core forms a closed magnetic flux path for said magnetization coil, said first magnetization coil including two input terminals for coupling a control signal into the windings of said first magnetization coil;
a second magnetization coil wound around said core so as to pass through said central opening whereby said core forms a closed magnetic flux path for said second magnetization coil, second magnetization coil including two input terminals for coupling the control signal into the windings of said second magnetization coil;
and
a primary coil formed around the outside of said closed-loop core in such a way that the primary coil exhibits a variable inductance the value of which is controlled by the control signal changing the magnetic permeability of the closed-loop core, said primary coil having input terminals for receiving the high-frequency current signal, and
wherein the first magnetization coil has a first axis, the second magnetization coil has a second axis, and the primary coil has a primary axis and wherein the first and second axes are substantially perpendicular to said primary axis of the primary coil.

3 more elements

Dependencies are inferred from the claim text.