Patent ID: 8729466
Filing Date: 2014-05-20
Classification: H01J

Abstract:
1. An apparatus for forming an aberration-corrected, energy-filtered image from a blurred and unfiltered image in an electron microscope, the apparatus comprising: a first electron beam source configured to generate a first illumination electron beam with lower energy; a second electron beam source configured to generate a second illumination electron beam with higher energy; an objective lens configured to illuminate and image a specimen; a first energy-dispersive device configured to: a second energy-dispersive device positioned between the second electron source and first energy-dispersive device that bends the high-energy component of the electron beam at less of an angle in comparison to the bending angle of the low-energy component of the electron beam, such that the high- and low-energy electron beam components exit said second energy-dispersive device at different angles of trajectory; a first electron mirror configured to reflect the high electron beam exiting the second energy-dispersive device, wherein electrons entering at an angle with respect to the normal to the reflection surface of said mirror exit the mirror symmetrically with respect to said normal and at the same angle; a first plurality of electron lenses configured to converge at the reflection surface of the first electron mirror all energy components exiting the second energy-dispersive device at different angles of trajectory; a first movable knife-edge plate positioned between the second energy-dispersive device and the first electron mirror that can remove all electrons with energies higher and lower than a selected energy; a second electron mirror configured to reflect the electron beam scattered and emitted by the specimen, wherein electrons entering at an angle with respect to the normal to the reflection surface of said mirror exit symmetrically with respect to said normal and at the same angle; a third electron mirror configured to correct one or more aberrations introduced by the objective lens; a third energy-dispersive device configured to: a second movable knife-edge plate positioned between the third energy-dispersive device and the second electron mirror that removes all electrons with energies higher and lower than a selected energy; a second plurality of electron lenses configured to converge at the third energy-dispersive device all energy components of the electron beam exiting said first energy-dispersive device at different angles of trajectory; a third plurality of electron lenses configured to converge at the reflection surface of the second electron mirror all energy components of the electron beam exiting said third energy-dispersive device at different angles of trajectory; a fourth plurality of electron lenses configured to transport the electron beam exiting the third energy-dispersive device into the third electron mirror.