Electron beam device with dispersion compensation, and method of operating same

摘要

An electron beam device comprises: 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 beam separator having a first dispersion for separating a signal electron beam from the primary electron beam; and a dispersion compensation element. The dispersion compensation element has a second dispersion, the dispersion compensation element being adapted for adjusting the second dispersion independently of an inclination angle of the primary beam downstream of the dispersion compensation element, such that the second dispersion substantially compensates the first dispersion. The dispersion compensation element is arranged upstream, along the primary electron beam, of the beam separator.

主权项

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.