Patent ID: 7816648
Filing Date: 2010-10-19
Classification: H01J

Abstract:
1. An electron interferometer comprising: a source of an electron beam; a condenser optical system for irradiating a specimen with the electron beam emitted from the source; a specimen holder for holding the specimen that is irradiated with the electron beam; an imaging lens system for imaging the specimen; and a device for observing or recording the specimen image; wherein: an objective lens of the imaging lens system, which is located on the downstream side in a traveling direction of an electron beam relative to a position at which the specimen is placed on an optical axis of an electron beam, is a lens formed of two stages of lens systems whose focal length can be independently controlled, said objective lens including: an upper biprism located in a plane that is orthogonal to an optical axis at a position of an image plane of the specimen, said image plane being determined on the downstream side of the objective lens formed of the two stages of lens systems; and a lower biprism located in a plane that is parallel to the plane in which the upper biprism is located on the downstream side in a traveling direction of an electron beam relative to a position of the upper biprism on the optical axis through one or a plurality of lenses among the imaging lens systems; and by independently applying the voltage to each of the upper biprism and the lower biprism, an electron beam is deflected in an identical plane of an electron optical system including an optical axis, said deflection plane.