Remote plasma mixer
First Claim
1. A plasma generator in a semiconductor processing reactor, comprising a microwave choke including quarter-wavelength shorted coaxial conductors, the shorted coaxial conductors defining a choke enclosure, the enclosure filled with a solid material having a dielectric constant greater than about 3.
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Accused Products
Abstract
A remote plasma generator, coupling microwave frequency energy to a gas and delivering radicals to a downstream process chamber, includes several features which, in conjunction, enable highly efficient radical generation. In the illustrated embodiments, more efficient delivery of oxygen and fluorine radicals translates to more rapid photoresist etch or ash rates. A single-crystal, one-piece sapphire applicator and transport tube minimizes recombination of radicals in route to the process chamber and includes a bend to avoid direct line of sight from the glow discharge to the downstream process chamber. Microwave transparent cooling fluid within a cooling jacket around the applicator enables high power, high temperature plasma production. Additionally, dynamic impedance matching via a sliding short at the terminus of the microwave cavity reduces power loss through reflected energy. At the same time, a low profile microwave trap produces a more dense plasma to increase radical production. In one embodiment, fluorine and oxygen radicals are separately generated and mixed just upstream of the process chamber, enabling individually optimized radical generation of the two species.
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Citations
22 Claims
- 1. A plasma generator in a semiconductor processing reactor, comprising a microwave choke including quarter-wavelength shorted coaxial conductors, the shorted coaxial conductors defining a choke enclosure, the enclosure filled with a solid material having a dielectric constant greater than about 3.
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5. A microwave plasma generator in a semiconductor processing reactor, comprising:
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a microwave power source;
a microwave energy waveguide extending from the energy source at a first end to a second end;
an microwave cavity in communication with the second end of the waveguide;
a gas carrier tube extending from an upstream gas source through the cavity; and
a cooling jacket surrounding the carrier tube within the cavity, the cooling jacket filled with a perfluorinated cooling fluid transparent to microwave energy. - View Dependent Claims (6, 7, 8, 9)
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10. A plasma generator comprising a hollow sapphire tube extending from a gas source through a microwave cavity to a process chamber, the tube including an elbow joint defining an angle of greater than about 35°
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- View Dependent Claims (11, 12, 13, 14)
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15. A remote plasma generator for generating a plasma within a gas carrier tube upstream of a process chamber, the generator comprising:
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a microwave energy generator;
a microwave energy pathway from the generator, including;
an isolator module in communication with the generator, the isolator module configured to protect the energy generator from reflected power;
a waveguide communicating at a proximal end with the isolator module; and
a microwave cavity communicating at a proximal end with a distal end of the waveguide, the cavity including a gas influent port and a radical effluent port, a sliding short defining a variable distal end of the microwave cavity, the sliding short dynamically controlled to match impedance of the microwave cavity with the waveguide. - View Dependent Claims (16, 17)
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18. A dual plasma source downstream reactor, comprising:
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a first plasma source cavity;
a first plasma energy source coupled to the plasma source cavity;
a first gas carrier tube extending through the first plasma source cavity;
a second plasma source cavity;
a second plasma energy source coupled to the plasma source cavity;
a second gas carrier tube extending through the first plasma source cavity;
a plasma mixer chamber in fluid communication with each of the first gas carrier tube and the second gas carrier tube downstream of first and second plasma source cavities; and
a process chamber downstream of and in fluid communication with the mixer chamber. - View Dependent Claims (19, 20, 21, 22)
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Specification