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

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.

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.

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.

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.