Plasma treatment apparatus
First Claim
1. A plasma treatment apparatus comprising:
- at least first and second cathodes separated by a gap, said first cathode comprising a first exposed cathode surface, said second cathode comprising a second exposed cathode surface, and said first exposed cathode surface oriented non-parallel to said second exposed cathode surface;
a set of magnets operative to generate a magnetic field exiting from one of the cathodes and entering the other of the cathodes, thereby crossing the gap;
said magnetic field comprising a first magnetic field portion crossing the gap and passing through said first exposed cathode surface, said first magnetic field portion comprising magnetic field lines having a maximum field strength of at least 100 Gauss;
at least one anode structure positioned to create an electric field extending from the cathodes to the anode structure, at least a portion of said electric field crossing said magnetic field and forming a closed-loop electron containment region within said magnetic field, a sufficient voltage between the anode structure and the cathodes operative to form a plasma within the magnetic field when a gas is present near the containment region at a gas pressure between 0.1 and 100 mTorr; and
at least one substrate positioned to be treated by said plasma.
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Accused Products
Abstract
Magnetically enhanced glow discharge devices are disclosed for the purpose of PECVD, etching or treating a substrate in a vacuum chamber. Two cathode surfaces are separated by a gap. A mirror magnetic field emanates from the cathode surfaces and passes through the gap. An anode structure forms diverging electric fields from each cathode to the anode, where the electric fields pass through the magnetic field 360 degrees around the dipole magnetic field. A closed loop electron trap is formed by the diverging electric fields and the expanding magnetic field in the gap. With a chamber pressure in the range of 0.1 to 100 mTorr and an applied voltage between the cathode and anode surfaces, a plasma is formed in the electron trap and in the plane of the trap. By shaping the plasma poles and exposing the sides of the cathode surfaces to the substrate, the created Hall current of the plasma can be brought into direct contact with the substrate.
74 Citations
33 Claims
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1. A plasma treatment apparatus comprising:
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at least first and second cathodes separated by a gap, said first cathode comprising a first exposed cathode surface, said second cathode comprising a second exposed cathode surface, and said first exposed cathode surface oriented non-parallel to said second exposed cathode surface;
a set of magnets operative to generate a magnetic field exiting from one of the cathodes and entering the other of the cathodes, thereby crossing the gap;
said magnetic field comprising a first magnetic field portion crossing the gap and passing through said first exposed cathode surface, said first magnetic field portion comprising magnetic field lines having a maximum field strength of at least 100 Gauss;
at least one anode structure positioned to create an electric field extending from the cathodes to the anode structure, at least a portion of said electric field crossing said magnetic field and forming a closed-loop electron containment region within said magnetic field, a sufficient voltage between the anode structure and the cathodes operative to form a plasma within the magnetic field when a gas is present near the containment region at a gas pressure between 0.1 and 100 mTorr; and
at least one substrate positioned to be treated by said plasma. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17, 19, 20, 27, 28, 29, 30, 31, 32, 33)
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16. A plasma treatment apparatus comprising:
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at least two cathodes separated by a gap;
a set of magnets operative to generate a magnetic field exiting from one of the cathodes and entering the other of the cathodes, thereby crossing the gap;
at least one anode structure positioned to create an electric field extending from the cathodes to the anode structure, at least a portion of said electric field crossing said magnetic field and forming a closed-loop electron containment region within said magnetic field, a sufficient voltage between the anode structure and the cathodes operative to form a plasma within the magnetic field when a gas is present near the containment region at a gas pressure between 0.1 and 100 mTorr; and
at least one substrate positioned to be treated by said plasma;
wherein the magnetic field is asymmetrical with respect to a central axis of the gap extending between the cathodes, and wherein the electron containment region extends farther away from the central axis on one side of the gap than on the other side of the gap.
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18. A plasma treatment apparatus comprising:
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at least two cathodes separated by a gap;
a set of magnets operative to generate a magnetic field exiting from one of the cathodes and entering the other of the cathodes, thereby crossing the gap;
at least one anode structure positioned to create an electric field extending from the cathodes to the anode structure, at least a portion of said electric field crossing said magnetic field and forming a closed-loop electron containment region within said magnetic field, a sufficient voltage between the anode structure and the cathodes operative to form a plasma within the magnetic field when a gas is present near the containment region at a gas pressure between 0.1 and 100 mTorr;
at least one substrate positioned to be treated by said plasma; and
a set of ferromagnetic elements magnetically coupled to the set of magnets to provide a ferromagnetic return magnetic path, thereby enhancing the magnetic field across the gap.
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21. A plasma treatment apparatus comprising:
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at least two cathodes separated by a gap;
a set of magnets operative to generate a magnetic field exiting from one of the cathodes and entering the other of the cathodes, thereby crossing the gap;
at least one anode structure positioned to create an electric field extending from the cathodes to the anode structure, at least a portion of said electric field crossing said magnetic field and forming a closed-loop electron containment region within said magnetic field, a sufficient voltage between the anode structure and the cathodes operative to form a plasma within the magnetic field when a gas is present near the containment region at a gas pressure between 0.1 and 100 mTorr;
at least one substrate positioned to be treated by said plasma;
an enclosure extending from the cathodes around a portion of the electron containment region positioned away from the substrate; and
a source of process gas positioned within the enclosure. - View Dependent Claims (22, 23, 24, 25, 26)
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Specification