Use of variable RF generator to control coil voltage distribution
AssigneeApplied Materials, Inc.
InventorBradley O Stimson
Life of this patent
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Abstract
In a plasma deposition system for depositing a film of sputtered target material on a substrate, the output of an RF generator coupled to a coil for generating a plasma can be varied during the deposition process so that heating and sputtering of the RF coil can be more uniform by “time-averaging” RF voltage distributions along the RF coil.
Claims33
A semiconductor fabrication process for sputtering material onto a substrate, the process comprising:
- energizing a coil of said material, which is carried by a semiconductor fabrication chamber, using an RE signal from an RF generator, said chamber having a plasma generation area within said chamber, and a target of said material for sputtering, said coil positioned to couple energy into said plasma generation area to ionize said sputtered target material to form a layer of said sputtered target material on said substrate;
- and
- changing a frequency of said RF signal so as to shift voltage distributions along said coil by an angular distance of at least 15 degrees.
A semiconductor fabrication process comprising:
- energizing a coil carried by a semiconductor fabrication chamber at RF frequencies, said chamber having a plasma generation area within said chamber, said coil positioned to couple energy into said plasma generation area to maintain a plasma in said plasma generation area;
- and
- changing the frequency of said energizing in a predetermined sequence so as to shift voltage distributions along said coil in a predetermined sequence of locations along said coil.
A semiconductor fabrication process comprising:
- energizing a coil carried by a semiconductor fabrication chamber at RE frequencies, said chamber having a plasma generation area within said chamber, said coil positioned to couple energy into said plasma generation area to maintain a plasma in said plasma generation area;
- and
- changing the power level of said energizing in a predetermined sequence so as to shift voltage distributions along said coil in a predetermined sequence of locations along said coil.
A semiconductor fabrication process, comprising:
- energizing a coil at RE frequencies, said coil being carried by a semiconductor fabrication chamber having a plasma generation area within said chamber, said coil positioned to couple energy into said plasma generation area to maintain a plasma in said plasma generation area, said coil having a plurality of voltages distributed along said coil;
- and;
- cyclicly and continuously shifting said RE frequency to cyclicly and continuously shift said distribution of voltages along said coil.
A semiconductor fabrication process, comprising:
- energizing a coil at RE frequencies, said coil being carried by a semiconductor fabrication chamber having a plasma generation area within said chamber, said coil positioned to couple energy into said plasma generation area to maintain a plasma in said plasma generation area, said coil having a plurality of voltages distributed along said coil;
- and
- cyclicly and continuously shifting the power level of said energizing to cyclicly and continuously shift said distribution of voltages along said coil.
A semiconductor fabrication process for processing a substrate, the process comprising:
- generating a cyclical RE signal having a variable frequency which shifts between at least three values in each cycle;
- and
- applying said RE signal to a coil carried within a chamber and positioned to couple energy into a plasma generation area within said chamber to maintain a plasma in said plasma generation area, said cyclical RE signal time-averaging voltage distributions along said coil while said substrate is processed.
A semiconductor fabrication process for processing a substrate, the process comprising:
- generating an RE signal;
- applying said RE signal to a coil carried within a chamber and positioned to couple energy into a plasma generation area within said chamber to maintain a plasma in said plasma generation area, wherein said RE signal causes said coil to have a plurality of voltage values distributed along said coil;
- and
- shifting the frequency of said RE signal between a plurality of values sufficiently different to shift said voltage value distribution in a predetermined path along said coil to thereby time-average voltage value distributions along said coil while said substrate is processed.
Dependencies are inferred from the claim text.