Gas distribution system having fast gas switching capabilities
First Claim
1. A gas distribution system for supplying gas to a plasma processing chamber including a gas distribution member having inner and outer zones which are flow insulated from each other, the gas distribution system comprising:
- a first gas passage in fluid communication with a first process gas source, the inner zone of the gas distribution member of the plasma processing chamber and a bypass line;
a second gas passage in fluid communication with the first process gas source, the outer zone of the gas distribution member of the plasma processing chamber and the bypass line;
a third gas passage in fluid communication with a second process gas source, the inner zone and the by-pass line;
a fourth gas passage in fluid communication with the second process gas source, the outer zone and the by-pass line; and
a controller connected in control communication to a plurality of fast switching valves that are operably connected to receive signals from the controller to open or close and the controller is configured so that (i) the first process gas is supplied to the inner and outer zones via the first and second gas passages, while the second process gas is supplied to the by-pass line via the third and fourth gas passages, and (ii) to change the flows of the first and second process gases so that the second process gas is supplied to the inner and outer zones via the third and fourth gas passages, while the first process gas is supplied to the by-pass line via the first and second gas passages; and
at least one first flow restrictor, at least one second flow restrictor, at least one third flow restrictor and at least one fourth flow restrictor arranged along the first, second, third and fourth gas passages, respectively, the first, second, third and fourth flow restrictors being operable to maintain an approximately constant gas pressure in a region of the first, second, third and fourth gas passages upstream of and proximate the first, second, third and fourth flow restrictors.
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Accused Products
Abstract
A gas distribution system for supplying different gas compositions to a chamber, such as a plasma processing chamber of a plasma processing apparatus is provided. The gas distribution system can include a gas supply section, a flow control section and a switching section. The gas supply section provides first and second gases, typically gas mixtures, to the flow control section, which controls the flows of the first and second gases to the chamber. The chamber can include multiple zones, and the flow control section can supply the first and second gases to the multiple zones at desired flow ratios of the gases. The gas distribution system can continuously supply the first and second gases to the switching section and the switching section is operable to switch the flows of the first and second gases, such that one of the first and second process gases is supplied to the chamber while the other of the first and second gases is supplied to a by-pass line, and then to switch the gas flows. The switching section preferably includes fast switching valves operable to quickly open and close to allow fast switching of the first and second gases, preferably without the occurrence of undesirable pressure surges or flow instabilities in the flow of either gas.
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Citations
17 Claims
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1. A gas distribution system for supplying gas to a plasma processing chamber including a gas distribution member having inner and outer zones which are flow insulated from each other, the gas distribution system comprising:
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a first gas passage in fluid communication with a first process gas source, the inner zone of the gas distribution member of the plasma processing chamber and a bypass line; a second gas passage in fluid communication with the first process gas source, the outer zone of the gas distribution member of the plasma processing chamber and the bypass line; a third gas passage in fluid communication with a second process gas source, the inner zone and the by-pass line; a fourth gas passage in fluid communication with the second process gas source, the outer zone and the by-pass line; and a controller connected in control communication to a plurality of fast switching valves that are operably connected to receive signals from the controller to open or close and the controller is configured so that (i) the first process gas is supplied to the inner and outer zones via the first and second gas passages, while the second process gas is supplied to the by-pass line via the third and fourth gas passages, and (ii) to change the flows of the first and second process gases so that the second process gas is supplied to the inner and outer zones via the third and fourth gas passages, while the first process gas is supplied to the by-pass line via the first and second gas passages; and at least one first flow restrictor, at least one second flow restrictor, at least one third flow restrictor and at least one fourth flow restrictor arranged along the first, second, third and fourth gas passages, respectively, the first, second, third and fourth flow restrictors being operable to maintain an approximately constant gas pressure in a region of the first, second, third and fourth gas passages upstream of and proximate the first, second, third and fourth flow restrictors. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A plasma processing apparatus, comprising:
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a plasma processing chamber comprising a showerhead electrode assembly including a showerhead electrode plate and having inner and outer zones which are flow insulated from each other, and a plasma confinement zone within the plasma processing chamber having a volume of about ½
liter to 4 liters; anda gas distribution system in fluid communication with the inner and outer zones of the showerhead electrode plate, the gas distribution system comprising; a first gas passage in fluid communication with a first process gas source, the inner zone of the showerhead electrode plate and a bypass line; a second gas passage in fluid communication with the first process gas source, the outer zone of the showerhead electrode plate and the bypass line; a third gas passage in fluid communication with a second process gas source, the inner zone and the by-pass line; a fourth gas passage in fluid communication with the second process gas source, the outer zone and the by-pass line; and a controller connected in control communication to a plurality of fast switching valves that are operably connected to receive signals from the controller to open or close and the controller is configured so that (i) the first process gas is supplied to the inner and outer zone, via the first and second gas passages, while the second process gas is supplied to the by-pass line via the third and fourth gas passages, and (ii) to change the flows of the first and second process gases so that the second process gas is supplied to the inner and outer zones via the third and fourth gas passages, while the first process gas is supplied to the by-pass line via the first and second gas passages; and at least one first flow restrictor, at least one second flow restrictor, at least one third flow restrictor and at least one fourth flow restrictor arranged along the first, second, third and fourth gas passages, respectively, the first, second, third and fourth flow restrictors being operable to maintain an approximately constant gas pressure in a region of the first, second, third and fourth gas passages upstream of and proximate the first, second, third and fourth flow restrictors, wherein the first process gas comprises a fluorocarbon and is operable to etch a dielectric layer on a semiconductor substrate in the chamber and the second process gas comprises a flurohydrocarbon and is effective to form a polymer deposit which protects a mask layer above the dielectric layer, and wherein the gas distribution system further comprises a controller operable to (a) substantially replace the first process gas or the second process gas in the plasma confinement zone with the other of the first process gas or the second process gas within a period of less than about 200 ms, (b) to supply the first process gas for a period of about 5 seconds to about 20 seconds and, (c) to supply the second process gas for a period of about 1 second to about 3 seconds.
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Specification