IP Library Granted Patent US 7,385,197
Granted Patent B2
US 7,385,197 · App. 11/175,390 · Granted Jun 10, 2008

Electron beam apparatus and a device manufacturing method using the same apparatus

Assignee: Ebara Corporation
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Quick Facts
Patent No.
US 7,385,197
App. No.
11/175,390
Granted
Jun 10, 2008
Kind
B2
Abstract

Disclosed is an electron beam apparatus, in which a plurality of electron beams is formed from electrons emitted from an electron gun 21 and used to irradiate a sample surface via an objective lens 28 , said apparatus comprising: a beam separator 27 for separating a secondary electron beams emanating from respective scanned regions on the sample from the primary electron beams; a magnifying electron lens 31 for extending a beam space between adjacent beams in the separated plurality of secondary electron beams; a fiber optical plate 32 for converting the magnified plurality of secondary electron beams to optical signals by a scintillator and for transmitting the signals; a photoelectric conversion device 35 for converting the optical signal to an electric signal; an optical zoom lens 33 for focusing the optical signal from the scintillator into an image on the photoelectric conversion device; and a rotation mechanism 36 for rotating the photoelectric conversion device 35 around the optical axis.

Claims (34)

1. An electron beam apparatus comprising:

an electron irradiation optics for irradiating a plurality of primary electron beams onto a sample surface;

a scanning deflector for performing a scanning operation with said plurality of primary electron beams across the sample surface;

a beam separator for separating secondary electron beams emanating from respective scanned regions on the sample from said primary electron beam;

a magnifying electron lens for magnifying a distance between any two beams of the plurality of secondary electron beams that have been separated by said beam separator;

an optical output converter for converting the plurality of magnified secondary electron beams to optical signals;

a photoelectric conversion device for converting said optical signal to an electric signal;

an optical magnifying lens for magnifying said optical signal from said optical output converter into an image on said photoelectric conversion device; and

a multi-aperture plate disposed in front of said photoelectric conversion device and having a plurality of apertures formed therethrough, said aperture having an aperture area that is large in a peripheral region.

2. An electron beam apparatus comprising:

an irradiation optical system for focusing a primary electron beams onto a sample surface via an objective lens;

an image projection optical system including at least two-stage of deflectors, an magnifying lens and an aperture for detecting secondary electrons emanating from the sample;

a wobbler application circuit for applying a wobbler to an exciting or an excitation voltage of said magnifying lens subject to axial alignment;

an image formation system for forming an image separated by the wobbler in synchronization with the x- and y-directional scanning according to a signal from the electron beam transmitted through said aperture, while carrying out the x- and y-directional scanning by at least one of the deflectors in the at least two-stage of deflectors; and

a deflector controller operable to control the other one of said at least two-stage of deflectors to minimize the separation of the image for the purpose of adjusting the optical axis so that a principal ray having exited from said objective lens is directed through a central region of said magnifying lens and through said aperture.

3. An electron beam apparatus comprising:

an irradiation optical system for focusing a primary electron beam onto a sample surface via an objective lens;

an image projection optical system for focusing secondary electrons emanating from the sample into an image on a detection surface, said image projection optical system having at least two-stage of deflectors, a magnifying lens and an aperture;

an optical output converter for converting the secondary electron image formed by said image projection optical system to an optical signal;

an optical member for extracting said optical signal into an atmosphere side, in which a plane disposed in a vacuum side of said optical member defines an optical output converter and an output surface of the optical signal disposed in the atmosphere side defines a curved surface;

a wobbler application circuit for applying a wobbler to an exciting or an excitation voltage of said magnifying lens subject to axial alignment;

an image formation system for forming an image separated by the wobbler in synchronization with the x- and y-directional scanning according to a signal from the electron beam transmitted through said aperture, while carrying out the x- and y-directional scanning by at least one of the deflectors in the at least two-stage of deflectors; and

a deflector controller operable to control the other one of said at least two-stage of deflectors to minimize the separation of the image for the purpose of adjusting the optical axis so that a principal ray having exited from said objective lens is directed through a central region of said magnifying lens and through said aperture.

4. An electron beam apparatus comprising:

an irradiation optical system for focusing a primary electron beam onto a sample surface via an objective lens;

an image projection optical system for focusing secondary electrons emanating from the sample into an image on a detection surface;

an optical output converter for converting the secondary electron image formed by said image projection optical system to an optical signal;

an optical member for extracting said optical signal into an atmosphere side, in which a plane disposed in a vacuum side of said optical member defines an optical output converter and an output surface of the optical signal disposed in the atmosphere side defines a curved surface;

wherein said objective lens comprises:

a magnetic lens including an inner magnetic pole and an outer magnetic pole with a magnetic gap produced by said inner and said outer magnetic poles defined in the sample side; a pipe made of ferrite and disposed inside said inner magnetic pole; and a deflector disposed inside said pipe made of ferrite.

5. An objective lens for focusing an electron beam onto a sample surface, comprising:

a magnetic lens including an inner magnetic pole and an outer magnetic pole with a magnetic gap produced by said inner and said outer magnetic poles defined in the sample side;

a substantially cylindrical pipe made of ferrite and disposed inside said inner magnetic pole; and

a deflector disposed inside said pipe made of ferrite.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 12, 2005
From: NAKASUJI, MAMORU; NOJI, NOBUHARU; SATAKE, TOHRU; MURAKAMI, TAKESHI; SOBUKAWA, HIROSI; KAGA, TORU; HATAKEYAMA, MASAHIRO
To: EBARA CORPORATION
Reel/Frame 017075/0609 →
Priority Claims (3)
JP 2004-201736 · Jul 8, 2004 · national
JP 2004-213083 · Jul 21, 2004 · national
JP 2004-246468 · Aug 26, 2004 · national
Continuity (1)
Related Publication 20060016989A1 · Jan 26, 2006