초록 ▼

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

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.

대표청구항 ▼

The invention claimed is: 1. 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 el

The invention claimed is: 1. 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. 2. The magnetic-field-superposed electron gun according to claim 1, further comprising; a magnetic coil placed in the proximity of the electron source and being detachably attachable from an atmosphere side, instead of said permanent magnet. 3. 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. 4. 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. 5. The charged particle beam apparatus according to claim 4, further comprising: a third nonevaporative getter pump provided on the bore of the column in the second vacuum chamber.