Electron beam system using multiple electron beams
AssigneeFEI Company
InventorsRobert L. Gerlach, Paul P. Tesch, Walter Skoczylas
Life of this patent
Estimating the term…
Abstract
A charged particle beam system uses multiple electron columns to increase throughput. One or more multiple electron emitters are in one or more vacuum sealable gun chambers to allow the gun chamber to be replaced with electrons guns having emitters that have been previously conditioned so that the system does not need to be out of service to condition the newly installed emitters.
Claims39
An electron beam system for directing multiple electron beams toward a target, comprising:
- a system vacuum chamber containing the target;
- one or more intermediate vacuum chambers, each in selective communication with the system vacuum chamber through a group of vacuum isolation valves;
- multiple electron gun chambers positioned within each of the one or more intermediate vacuum chambers, each electron gun chamber including an electron source and a gun chamber vacuum isolation valve for vacuum isolating the gun chamber so that the intermediate chamber can be opened to replace an electron gun chamber without exposing the interior of the remaining electron gun chambers to air and the group of isolation valves allowing the intermediate chamber to be vacuum isolated from the system chamber to allow opening the system chamber without exposing the interior of other intermediate chambers to air.
An multiple electron beam system for directing multiple electron beams toward a target, comprising:
- a system vacuum chamber containing a target;
- one or more intermediate vacuum chambers, each in selective communication with the system vacuum chamber through one or more vacuum isolation valves;
- and
- one or more electron guns positioned within each of the one or more intermediate vacuum chambers.
A sealable electron gun chamber comprising:
- an electron gun including:
- an emitter for emitting electrons;
- a suppressor adjacent to the emitter for suppressing the unwanted emission of electrons;
- and
- an extractor for extracting electrons from the emitter;
- a vacuum housing containing the electron gun;
- and
- a vacuum isolation valve in the path of electrons when emitted by electron gun, the vacuum isolation valve sealing the vacuum housing when closed and allowing the emitted electrons to pass out of the vacuum housing when opened, the sealable electron gun chamber allowing the electron gun to be conditioned and sealed before being placed into an electron beam system.
The sealable electron gun chamber of 20 further comprising a vacuum pump for evacuating the vacuum housing.
The sealable electron gun chamber of 20 in which the electron gun further comprises a gun lens for focusing the electrons emitted by the emitter.
The sealable electron gun chamber of 20 further comprising one or more additional electron guns, each additional electron gun including an emitter, a suppressor, and an extractor.
The sealable electron gun chamber of 20 in which the emitter is conditioned and the vacuum isolation valve is closed to maintain the emitter in the conditioned state.
An electron beam system including multiple electron sources, comprising:
- a system vacuum chamber including a target;
- and
- one or more gun vacuum chambers, each gun vacuum chamber including one or more electron guns and capable of being separately sealed, thereby allowing one of the electron chamber guns to be replaced with without exposing the other electron guns to air and allowing a gun chamber to be preconditioned, sealed, and inserted into the electron beam system, thereby eliminating the requirement to condition the electron gun within the electron beam system.
A method of replacing one or more electron sources in an electron beam system including a sealable electron gun chamber having a vacuum isolation valve, the method comprising:
- evacuating a sealable gun chamber containing one or more electron sources;
- conditioning the one or more electron sources;
- sealing the sealable gun chamber;
- inserting the sealed gun chamber into an electron beam system;
- unsealing the sealable gun chamber, thereby providing a path for one or more electron beam from the one or more electron sources to a target.
A method of replacing an electron source in a multiple electron beam system including multiple intermediate chambers, each containing multiple electron gun chambers, the multiple intermediate chambers including one or more vacuum valves for isolating the intermediate chamber from a system chamber including a target, the multiple electron gun chambers each positioned within one of the intermediate chambers and each having a vacuum isolation valve for sealing the electron gun chamber within the intermediate chamber, the method comprising:
An electron beam system including multiple electron columns, comprising:
- multiple electron guns;
- and
- multiple electron columns, each column including lower deflection elements, the lower deflection elements for the multiple electron columns being formed from the same sheet of metal with insulator and deflection plate inserts and capable of being biased to provide fine focusing of the electron columns.
In an electron beam system including deflectors for deflecting an electron beam and an objective lens for focusing the electron beam, a method of finely focusing electron columns in a charged particle beam system comprising applying a relatively small voltage to deflectors that are positioned above the objective lens.
An electron gun comprising
- an emitter for emitting electrons;
- an extractor for applying an extraction voltage to extract electrons from the emitter, the extractor being at an extraction electrical potential in relation to the emitter;
- a suppressor for suppressing the emission of undesirable electrons;
- and
- a gun lens first element that is separate from the emitter, suppressor, and extractor element, and is maintained at approximately the same potential as the extractor.
Dependencies are inferred from the claim text.