Patent ID: 11908657
Assignee: ZHONGKE JINGYUAN ELECTRON LIMITED
Field: Measurement (Instruments)
Classification: CPC H  G | IPC G  H

Claim 0:
1. A scanning electron microscope device for a sample to be detected, which is configured to project an electron beam to a surface of the sample to generate backscattered electrons and secondary electrons, comprising:
an electron beam source configured to emit along an optical axis thereof the electron beam;
a deflection mechanism, comprising:
a first deflector located downstream of the electron beam source; and
a second deflector located downstream of the first deflector, and
an objective lens assembly, comprising:
an excitation coil which is energized to create a magnetic field; and
a magnetic yoke, formed by a magnetizer material as a housing which opens towards the sample, and comprises:
a hollow body defining an internal chamber where the excitation coil is accommodated; and
at least one inclined portion extending inward from the hollow body at an angle with reference to the hollow body and directing towards the optical axis,

with an end of the at least one inclined portion being formed into a pole piece, wherein the deflection mechanism further comprises a compensation electrode in a form of a closed shape that is a curved surface profile that is centrally hollowed and centrally symmetric with respect to the optical axis, which compensation electrode is located between the pole piece and the surface of the sample and is configured to adjust a focusing position of the electron beam at which the electron beam is focused, in a condition of excitation thereof with a voltage being applied thereon, by adjusting the voltage, and wherein the curved surface profile includes a surface that is more proximate to the pole piece being constructed as a cambered surface having a uniform radius.