Patent ID: 6949745
Filing Date: 2005-09-27
Classification: H01J

Abstract:
1. In an electron beam apparatus having an optical axis, an electron beam source for generating an electron beam directed along the optical axis, and a magnetic field lens having an axis coincident with the optical axis for focusing the electron beam onto a sample subjected to a negative voltage so that secondary electrons are emitted from the sample, the magnetic field lens comprising: a conductive cylinder surrounding a part of the optical axis to permit the passage therethrough of an electron beam from the electron beam source; a reflecting elate disposed over and surrounding the conductive cylinder; a first detector for detecting secondary electrons emitted by the sample in a direction away from the optical axis, the first detector being disposed at a position generally confronting the conductive cylinder; a second detector disposed over the conductive cylinder, at least one of the first detector and the second detector comprising a scintillation detector; a Wien filter deflector for deflecting secondary electrons emitted by the sample toward the second detector and for detection by the second detector, the Wien filter deflector being disposed on the optical axis and between the conductive cylinder and the second detector; and means for applying a negative voltage to the conductive cylinder and the reflecting plate.