Spatial and temporal control of ion bias voltage for plasma processing
AssigneeAdvanced Energy Industries, Inc.
InventorsDenis Shaw, Kevin Fairbairn, Daniel Carter
Life of this patent
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Abstract
Systems and methods for plasma processing are disclosed. An exemplary system may include a plasma processing chamber including a source to produce a plasma in the processing chamber and at least two bias electrodes arranged within the plasma processing chamber to control plasma sheaths proximate to the bias electrodes. A chuck is disposed to support a substrate, and a source generator is coupled to the plasma electrode. At least one bias supply is coupled to the at least two bias electrodes, and a controller is included to control the at least one bias supply to control the plasma sheaths proximate to the bias electrodes.
Claims23
A system for plasma processing, the system comprising:
- a plasma processing chamber including:
- a source to provide a plasma in the processing chamber;
- at least two separate electrical planes arranged within the plasma processing chamber to control plasma sheaths proximate to the at least two separate electrical planes;
- and
- a chuck disposed to support a substrate;
- at least one bias supply coupled to the at least two separate electrical planes, the at least one bias supply is configured to periodically apply a cycle of an asymmetric periodic voltage waveform to each of the electrical planes, wherein each cycle of the asymmetric periodic voltage waveforms includes a first portion with a voltage that increases to a first voltage level, a second portion at the first voltage level, a third portion with a negative voltage swing along a first negative voltage ramp to a second voltage level, and a fourth portion that includes a second negative voltage ramp from the second voltage level, wherein the first negative voltage ramp and the second negative voltage ramp are different;
- and
- at least one controller to control the at least one bias supply to control the plasma sheaths proximate to the at least two separate electrical planes.
A method for processing a substrate in a plasma processing chamber, the method comprising:
- producing a plasma in the plasma processing chamber;
- periodically applying a cycle of an asymmetric periodic voltage waveform to each of a plurality of separate electrical planes in the plasma processing chamber with a corresponding one of a plurality of bias supplies, each cycle of the asymmetric periodic voltage waveforms include a first portion with a voltage that increases to a first voltage level, a second portion at the first voltage level, a third portion with a negative voltage swing along a first negative voltage ramp to a second voltage level, and a fourth portion that includes a second negative voltage ramp from the second voltage level, wherein the first negative voltage ramp and the second negative voltage ramp are different;
- and
- adjusting one or more characteristics of the asymmetric periodic voltage waveforms to alter corresponding portions of a plasma sheath.
A non-transitory computer-readable medium comprising instructions stored thereon, for execution by a processor, or for configuring a field programmable gate array, to perform plasma processing, the instructions including instructions to:
- control at least one of a remote plasma source or a source generator to produce a plasma in the plasma processing chamber;
- control a plurality of bias supplies to periodically apply a cycle of an asymmetric periodic voltage waveform to each of a plurality of separate electrical planes in the plasma processing chamber with a corresponding one of the plurality of bias supplies, each cycle of the asymmetric periodic voltage waveforms include a first portion with a voltage that increases to a first voltage level, a second portion at the first voltage level, a third portion with a negative voltage swing along a first negative voltage ramp to a second voltage level, and a fourth portion that includes a second negative voltage ramp from the second voltage level, wherein the first negative voltage ramp and the second negative voltage ramp are different;
- and
- control one or more of the plurality of bias supplies to adjust one or more characteristics of the asymmetric periodic voltage waveforms to alter corresponding portions of a plasma sheath.
Dependencies are inferred from the claim text.