US 11,749,495 B2
Bandpass charged particle energy filtering detector for charged particle tools
Youfei Jiang, Milpitas, CA (US); and Michael Steigerwald, Milpitas, CA (US)
Assigned to KLA Corp., Milpitas, CA (US)
Filed by KLA Corporation, Milpitas, CA (US)
Filed on Oct. 5, 2021, as Appl. No. 17/494,784.
Prior Publication US 2023/0104558 A1, Apr. 6, 2023
Int. Cl. H01J 37/244 (2006.01); H01J 37/28 (2006.01); H01J 37/05 (2006.01); H01J 37/147 (2006.01)
CPC H01J 37/244 (2013.01) [H01J 37/05 (2013.01); H01J 37/1471 (2013.01); H01J 37/28 (2013.01); H01J 2237/0492 (2013.01); H01J 2237/2448 (2013.01); H01J 2237/24475 (2013.01)] 35 Claims
OG exemplary drawing
 
1. A system configured to detect charged particles from a specimen, comprising:
a first repelling mesh positioned in a path of charged particles from a specimen and configured to repel the charged particles having an energy that is lower than a first predetermined energy;
a second repelling mesh configured to repel the charged particles that pass through the first repelling mesh and have an energy that is lower than a second predetermined energy;
a first attracting mesh configured to attract the charged particles that pass through the first repelling mesh, are repelled by the second repelling mesh, and have an energy that is higher than the first predetermined energy and lower than the second predetermined energy;
a first detector configured to generate output responsive to the charged particles that pass through the first attracting mesh; and
a computer subsystem configured to systematically alter potentials applied to the first repelling mesh, second repelling mesh, and first attracting mesh to thereby systematically alter the first and second predetermined energies, to compare the output generated by the first detector for at least two of the systematically altered potentials, and to select the potentials applied to the first repelling mesh, second repelling mesh, and first attracting mesh for a process performed on the specimen based on results of comparing the output.