Electrostatic trap for particles entrained in an ion beam
AssigneeAxcelis Technologies, Inc.
InventorsEric R. Harrington, Victor M. Benveniste, Michael A. Graf, Robert D. Rathmell
Life of this patent
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Abstract
A system for inhibiting the transport of contaminant particles with an ion beam includes a pair of electrodes that provide opposite electric fields through which the ion beam travels. A particle entrained in the ion beam is charged to a polarity matching the polarity of ion beam when traveling through a first of the electric fields. The downstream electrode provides another electric field for repelling the positively charged particle away from the direction of beam travel.
Claims18
A system for inhibiting transport of particles with an ion beam comprising:
- a first electrode that provides a first electric field having a first polarity opposite that of the ion beam, a particle entrained in the ion beam within the first electric field being charged to a polarity matching the ion beam;
- and
- a second electrode located downstream in a direction of travel for the ion beam relative to the first electrode, the second electrode providing an electric field having a polarity matching the-ion beam for repelling the charged particle away from the downstream direction of travel.
A system for inhibiting transport of particles with a positive ion beam comprising:
- a negative electrode that provides a negative electric field, a particle entrained in the ion beam within a region of the negative electric field being charged to a positive polarity;
- and
- a positive electrode adjacent the negative electrode in a downstream direction of travel for the ion beam, the positive electrode providing a positive electric field for repelling the positively charged particle away from the direction of travel.
An ion implantation system comprising:
- an ion source for emitting ions to treat a substrate located at an implantation station;
- an analyzing magnet system for diverting ions of an appropriate mass to an implantation trajectory;
- a trap system for inhibiting transport of particles with the diverted ions from the analyzing magnet system, the trap system comprising:
- a first electrode provides a first electric field having a first polarity opposite that of the ion beam, a particle entrained in the ion beam being charged to a polarity matching an ion beam formed of the diverted ions;
- and
- a second electrode located in a downstream direction of travel for the ion beam relative to the first electrode, the second electrode providing an electric field having a polarity opposite the first electric field for repelling the charged particle;
- and
- a substrate supported at the implantation station for treatment with ions from the trap system, whereby particle contamination at the substrate is mitigated.
A system for inhibiting transport of particles with an ion beam comprising:
- means for generating a first electric field in a path of the ion beam, a particle entrained in the ion beam when within the first electric field being charged to a polarity matching the ion beam;
- and
- means for generating a second electric field in the path of the ion beam downstream from and having a polarity opposite the first electric field to the first electric field, the second electric field urging the charged particle away from the path of the ion beam.
A method for inhibiting transport of particles with an ion beam, the method comprising the steps of:
- generating a first electric field in the path of the ion beam;
- charging particles located in the ion beam in a region of the first electric field with a polarity matching the ion beam;
- and
- generating a second electric field in the path of the ion beam downstream relative the first electric field, the second electric field having a polarity opposite the first electric field so as to repel at least some of the charged particles away from the ion beam.
Dependencies are inferred from the claim text.