Charged particle beam apparatus
AssigneeHitachi High-Technologies Corporation
InventorsSouichi Katagiri, Takashi Ohshima, Toshihide Agemura, Mitsugu Sato, Takashi Furukawa
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Abstract
A small-sized charged particle beam apparatus capable of maintaining high vacuum even during emission of an electron beam is provided. A nonevaporative getter pump is placed upstream of differential pumping of an electron optical system of the charged particle beam apparatus, and a minimum number of ion pumps are placed downstream, so that both the pumps are used in combination. Further, by mounting a detachable coil on an electron gun part, the inside of a column can be maintained under high vacuum with a degree of vacuum in the order of 10−8 Pa.
Claims5
A magnetic-field-superposed electron gun comprising:
- a differential pumping system comprising two or more vacuum chambers coupled together via an aperture;
- a nonevaporative getter pump on an upstream side;
- an ion pump in any of the vacuum chambers on a downstream;
- an electron source on a most upstream vacuum chamber;
- a permanent magnet in the proximity of the electron source,
- wherein the permanent magnet is positioned as a center axis;
- and
- at least two different magnetic poles at axisymmetric positions with respect to the electron source as the center axis.
A charged particle beam apparatus comprising:
- a first vacuum chamber, having an electron source or ion source, on an upstream side;
- a second vacuum chamber, coupled with the first vacuum chamber via an aperture, on a downstream side,
- wherein the first vacuum chamber comprises a first nonevaporative getter pump and is absent from any ion pumps, and
- wherein the second vacuum chamber comprises a second nonevaporative getter pump and ion pump;
- and
- a column comprising the first and second vacuum chambers,
- wherein the first nonevaporative getter pump is provided on the bore of the column and a heater to heat the first nonevaporative getter pump is provided outside the column.
A charged particle beam apparatus comprising:
- first vacuum chamber, having an electron source or ion source, on an upstream side;
- a second vacuum chamber, coupled with the first vacuum chamber via an aperture, on a downstream side,
- wherein the first vacuum chamber comprises a first nonevaporative getter pump and is absent from any ion pump, and
- wherein the second vacuum chamber comprises a second nonevaporative getter pump and ion pump;
- a column comprising the first vacuum chamber and the second vacuum chamber;
- and
- an electrode, provided with a first heater, arranged between the first vacuum chamber and the second vacuum chamber,
- wherein the first nonevaporative getter pump is provided on the bore of the column and a second heater to heat the first nonevaporative getter pump is provided on the electrode.
Dependencies are inferred from the claim text.