Patent ID: 9048068
Filing Date: 2015-06-02
Classification: H01J

Abstract:
1. An electron beam device, comprising: a beam emitter for emitting a primary electron beam; an objective electron lens for focusing the primary electron beam onto a specimen, the objective lens defining an optical axis; a magnetic beam separator having a magnetic element as the only deflecting element, wherein the magnetic beam separator has a first dispersion and separates a signal electron beam from the primary electron beam; and a dispersion compensation element having a second dispersion and arranged upstream of the magnetic beam separator along the primary electron beam, wherein the dispersion compensation element adjusts the second dispersion independently of an inclination angle of the primary electron beam to compensate for the first dispersion, and wherein the dispersion compensation element comprises a first deflector and a second deflector, wherein the first deflector is a magnetic deflector and the second deflector is an electrostatic deflector, wherein the first and second deflectors are adapted for deflecting the electron beam in mutually opposite directions such that dispersions of the first and second deflectors do not cancel each other.