US 11,756,761 B2
Wien filter and charged particle beam imaging apparatus
Qinglang Meng, Beijing (CN); Weiqiang Sun, Beijing (CN); and Yan Zhao, Beijing (CN)
Assigned to Zhongke Jingyuan Electron Limited, Beijing (CN), Beijing (CN)
Filed by Zhongke Jingyuan Electron Limited, Beijing (CN), Beijing (CN)
Filed on Jan. 27, 2022, as Appl. No. 17/586,706.
Application 17/586,706 is a continuation of application No. 17/006,149, filed on Aug. 28, 2020, granted, now 11,239,044.
Claims priority of application No. 201910803331.1 (CN), filed on Aug. 28, 2019.
Prior Publication US 2022/0157556 A1, May 19, 2022
Int. Cl. H01J 37/147 (2006.01); H01J 37/10 (2006.01); H01J 37/244 (2006.01); H01J 37/28 (2006.01)
CPC H01J 37/1475 (2013.01) [H01J 37/10 (2013.01); H01J 37/1477 (2013.01); H01J 37/244 (2013.01); H01J 37/28 (2013.01); H01J 2237/057 (2013.01); H01J 2237/1516 (2013.01); H01J 2237/1534 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A Wien filter, comprising a Wien filter body which comprises:
an electrostatic deflector, comprising at least one pair of electrodes, respective two electrodes in each pair of which are opposite to each other, each electrode comprising an electrode body constructed in an arc-shaped form, and respective electrode bodies of respective two electrodes in each pair of the at least one pair of electrodes being arranged concentrically with and opposite to each other in a diameter direction, and the at least one pair of electrodes being configured to generate respective electric fields by cooperation of the respective two electrodes in each pair of the at least one pair of electrodes, in the condition of respective bias voltages applied individually thereon; and
a magnetic deflector, comprising at least one pair of magnetic poles, respective two magnetic poles in each pair of which are opposite to each other, each magnetic pole comprising a magnetic pole body constructed in an arc-shaped form, and respective magnetic pole bodies of respective two magnetic poles in each pair of the at least one pair of magnetic poles being arranged concentrically with and opposite to each other in the diameter direction, and the magnetic pole bodies of the at least one pair of magnetic poles in the magnetic deflector and the electrode bodies of the at least one pair of electrodes in the electrostatic deflector being arranged concentrically and spaced apart from each other in a circumferential direction, and the at least one pair of magnetic poles being configured to generate respective magnetic fields by cooperation of respective two magnetic poles in each pair of the at least one pair of magnetic poles,
wherein a resultant electric field formed collectively by all of the respective electric fields is perpendicular to a resultant magnetic field formed collectively by all of the respective magnetic fields; and
wherein each electrode is also provided with a respective first protrusion extending radially inwards from a radial inner side of the respective electrode body thereof, and each magnetic pole is also provided with a second protrusion extending radially inwards from a radial inner side of the respective magnetic pole body thereof,
wherein the electrostatic deflector comprises the at least one pair of electrodes which are formed by a conductive material and are not multiplexed as magnetic poles, and are configured to generate the respective electric fields cooperatively when bias voltages are applied thereon respectively, and the respective electric fields are synthesized by combination of vectors into the resultant electric field of the electrostatic deflector, without generating magnetic field;
wherein the magnetic deflector comprises the at least one pair of magnetic poles which are not multiplexed as electrodes, and are configured to generate the respective magnetic fields cooperatively, and the respective magnetic fields are synthesized by combination of vectors into the resultant magnetic field of the magnetic deflector, without generating electric field;
wherein the Wien filter further comprises a regulator, the regulator comprising a pair of regulator bodies which are annular and are arranged coaxially on both sides of the Wien filter body,
wherein the pair of regulator bodies are two magnetic rings arranged coaxially on both sides of the Wien filter body and spaced apart from the Wien filter body respectively, and the magnetic rings are located and dimensioned to converge magnetic field lines at an edge of the resultant magnetic field which distributes substantially along the optical axis and would have been originally generated by the Wien filter without the regulator, so as to match the resultant electric field, along the optical axis; or
wherein the pair of regulator bodies are two electrode rings arranged coaxially on both sides of the Wien filter body and spaced apart from the Wien filter body respectively, and the electrode rings are located and dimensioned to correct a distribution of the electric field which distributes substantially along the optical axis and would have been originally generated by the Wien filter without the regulator, at an edge of the electric field where an electric field intensity has its value being close to 0, so as to match the resultant magnetic field, along the optical axis.