US 12,347,642 B2
Scanning electron microscope
Naoya Saitoh, Yokohama (JP); and Daisuke Kubota, Yokohama (JP)
Assigned to TASMIT, INC., Kanagawa (JP)
Appl. No. 17/913,655
Filed by TASMIT, INC., Yokohama (JP)
PCT Filed Mar. 18, 2021, PCT No. PCT/JP2021/011055
§ 371(c)(1), (2) Date Sep. 22, 2022,
PCT Pub. No. WO2021/193346, PCT Pub. Date Sep. 30, 2021.
Claims priority of application No. 2020-055703 (JP), filed on Mar. 26, 2020.
Prior Publication US 2023/0109853 A1, Apr. 13, 2023
Int. Cl. H01J 37/28 (2006.01); H01J 37/147 (2006.01); H01J 37/153 (2006.01); H01J 37/21 (2006.01); H01J 37/244 (2006.01); H01J 37/26 (2006.01)
CPC H01J 37/28 (2013.01) [H01J 37/1474 (2013.01); H01J 37/153 (2013.01); H01J 37/21 (2013.01); H01J 37/244 (2013.01); H01J 37/265 (2013.01); H01J 2237/1534 (2013.01); H01J 2237/24475 (2013.01); H01J 2237/2448 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A scanning electron microscope comprising:
a stage configured to support a workpiece;
a deflector configured to deflect an electron beam to scan a target region on the workpiece with the electron beam;
a deflection controller configured to apply a scanning voltage that causes the electron beam to scan the target region and an offset voltage that shifts the electron beam from an optical axial center to the target region to the deflector; and
an electron detector configured to detect electrons emitted from the workpiece,
wherein the deflection controller is configured to correct the scanning voltage by multiplying an aberration-correcting coefficient by a command value of the scanning voltage, apply the corrected scanning voltage and the offset voltage to the deflector to cause the electron beam to scan the target region, and change the aberration-correcting coefficient and the offset voltage to allow the deflector to scan another target region with the electron beam without moving the stage.