Charged particle beam apparatus
AssigneeHitachi High-Technologies Corporation
InventorsTakashi Ohshima, Mitsugu Sato, Soichi Katagiri
Life of this patent
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Abstract
A charged particle beam apparatus in which an electrostatic lens is used as a main focusing element to obtain a subminiature high-sensitivity high-resolution SEM, a drift tube for an electron beam is located inside a column between an electron source and a sample, and a detector for secondary electrons is located inside the drift tube. This solves the problem associated with the provision of a secondary electron detector, which heretofore has been a bottleneck in making a subminiature high-resolution SEM column.
Claims20
A charged particle beam apparatus comprising:
- a charged particle beam source;
- means for accelerating a charged particle beam emitted from the charged particle beam source;
- a drift tube which constitutes a drift zone;
- a sample stage on which a sample to be irradiated with the charged particle beam rests;
- a detector which detects secondary electrons or backscattered electrons generated from the sample irradiated with a charged particle beam;
- and
- an objective lens with an aperture through which the charged particle beam passes,
- wherein the objective lens is located between the drift tube and the sample stage;
- wherein the charged particle beam source is located outside the drift tube;
- and
- wherein the detector is located in the drift tube.
A charged particle beam apparatus comprising:
- a charged particle beam source;
- means for accelerating a charged particle beam emitted from the charged particle beam source;
- a drift tube which constitutes a drift zone;
- a sample stage on which a sample to be irradiated with the charged particle beam rests;
- a detector which detects secondary electrons or backscattered electrons generated from the sample irradiated with a charged particle beam;
- and
- an electrostatic objective lens with an aperture through which the charged particle beam passes, including electrodes facing each other,
- wherein the objective lens has a first electrode on the sample side and a second electrode on the charged particle beam source side;
- wherein means for maintaining the drift tube and the detector at the same electric potential is provided;
- wherein the sample side principal plane of the objective lens is formed between the first electrode and the sample stage;
- wherein the charged particle beam source is located outside the drift tube;
- and
- wherein the second electrode is located on the lower face of the drift tube.
A charged particle beam apparatus with at least a first column and a second column comprising:
- a sample stage on which a sample common to the first column and the second column rests;
- a column transport mechanism for moving the first column and the second column or a sample moving mechanism for moving the sample;
- the first column and the second column each including:
- a charged particle beam source;
- means for accelerating a charged particle beam;
- a drift tube which constitutes a drift zone;
- an electrostatic objective lens for irradiating the sample with the charged particle beam;
- and
- a detector which detects secondary electrons or backscattered electrons generated from the sample irradiated with the charged particle beam;
- wherein the detector is located in the drift tube;
- wherein the charged particle beam source is located outside the drift tube;
- wherein the first column and the second column are symmetrical with respect to an axis perpendicular to the sample stage surface;
- and
- wherein backscattered electrons generated by irradiation of the sample with the charged particle beam from the first column are detected by the detector of the second column.
A charged particle beam apparatus with a plurality of columns in a vacuum chamber comprising:
- a sample stage on which a sample common to the plural columns rests;
- a transport mechanism for moving the plural columns or a sample moving mechanism for moving the sample;
- the plural columns each including:
- a charged particle beam source;
- means for accelerating a charged particle beam;
- a drift tube which constitutes a drift zone;
- an electrostatic objective lens for irradiating the sample with the charged particle beam;
- and
- a detector which detects secondary electrons or backscattered electrons generated from the sample irradiated with the charged particle beam;
- wherein the charged particle beam source is located outside the drift tube;
- and
- wherein the detector is located in the drift tube.
Dependencies are inferred from the claim text.