Use of variable impedance to control coil sputter distribution
AssigneeApplied Materials, Inc.
InventorsJames van Gogh, John C. Forster
Life of this patent
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Abstract
Capacitances in an impedance-matching box for an RF coil, in a plasma deposition system for depositing a film of sputtered target material on a substrate, can be varied during the deposition process so that the RF coil and substrate heating, and the film deposition, are more uniform due to “time-averaging” of the RF voltage distributions along the RF coil.
Claims70
A semiconductor fabrication system for sputtering material onto a substrate, the system comprising;
- a semiconductor fabrication chamber having a plasma generation area within said chamber;
- said chamber having a target of said material for sputtering;
- a 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
- an impedance-matching box coupled to said coil, said impedance-matching box having a tunable variable reactance adapted to shift a voltage value distribution in a predetermined path along said coil to thereby time-average voltage value distributions along said coil.
A semiconductor fabrication system, comprising:
- a semiconductor fabrication chamber having a plasma generation area within said chamber;
- a coil positioned to couple enemy into said plasma generation area to maintain a plasma in said plasma generation area, said coil having a plurality of voltage values distributed along said coli;
- and
- means for shifting said distribution of voltage values in a predetermined path along said coil.
A semiconductor fabrication system, for use with an RF generator, comprising:
- a semiconductor fabrication chamber having a plasma generation area within said chamber;
- a coil positioned to couple energy into said plasma generation area to maintain a plasma in said plasma generation area, said coil having first and second ends and a plurality of voltage values distributed along said coil between said first and second ends wherein said first end of said colt is adapted to be coupled to said RF generator;
- a plurality of capacitors adapted to be coupled to said second end of said coil;
- and a switch having a plurality of coupling states, each state coupling a selected capacitor of said plurality of capacitors between said coil second end and ground.
A semiconductor fabrication process for sputtering material onto a substrate, the process comprising:
- energizing a coil positioned to couple energy into a plasma generation area of a semiconductor fabrication chamber to ionize sputtered target material to form a layer of said sputtered target material on said substrate;
- and
- time-averaging voltage value distributions along said coil by shifting a voltage value distribution in a predetermined path along said coil using an impedance-matching box connected to said coil, said impedance-matching box having a variable reactance.
A semiconductor fabrication process comprising:
- energizing a coil positioned to couple energy into a plasma generation area of a semiconductor fabrication chamber to maintain a plasma in said plasma generation area;
- and changing the capacitance of a blocking capacitance coupled to said coil so as to shift a voltage value distribution in a predetermined path along said coil.
A semiconductor fabrication process, comprising:
- energizing a coil positioned to couple energy into a plasma generation area of a semiconductor fabrication chamber to maintain a plasma in said plasma generation area, said coil having a plurality of voltage values distributed along said coil;
- and
- cyclicly shifting said distribution of voltage values in a predetermined path along said coil.
A semiconductor fabrication system, comprising:
- a semiconductor fabrication chamber having a plasma generation area within said chamber:
- a 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 voltage values distributed along said coil;
- and
- a voltage value distribution controller adapted to shift said distribution of voltage values in a predetermined path along said coil.
A semiconductor fabrication process comprising:
- energizing a coil positioned to couple energy into a plasma generation area of a semiconductor fabrication chamber to maintain a plasma in said plasma generation area:
- and
- shifting a voltage value distribution in a predetermined path along said coil.
A semiconductor fabrication system for sputtering material onto a substrate, the system comprising:
- a semiconductor fabrication chamber having a plasma generation area within said chamber;
- said chamber having a target of said material for sputtering a 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
- an impedance circuit coupled to said coil, said impedance circuit having a variable reactance adapted to shift a voltage value distribution in a predetermined path along said coil in response to changes in the reactance of said variable reactance to thereby time-average voltage value distributions along said coil.
A semiconductor fabrication process for sputtering material onto a substrate, the process comprising:
- energizing a coil positioned to couple energy into a plasma generation area of a semiconductor fabrication chamber to ionize sputtered target material to form a layer of said sputtered target material on said substrate;
- and
- time-averaging voltage value distributions along said coil by shifting a voltage value distribution in a predetermined path along said coil using an impedance circuit connected to said coil, said impedance circuit having a variable reactance.
Dependencies are inferred from the claim text.