US 12,092,565 B2
Non-destructive inspection and manufacturing metrology systems and methods
Manjusha Mehendale, Morristown, NJ (US); Marco Alves, Newark, NJ (US); and Robin Mair, West Chicago, IL (US)
Assigned to Onto Innovation Inc., Wilmington, MA (US)
Appl. No. 17/613,318
Filed by Onto Innovation Inc., Wilmington, MA (US)
PCT Filed May 22, 2020, PCT No. PCT/US2020/034350
§ 371(c)(1), (2) Date Nov. 22, 2021,
PCT Pub. No. WO2020/237198, PCT Pub. Date Nov. 26, 2020.
Prior Publication US 2022/0228973 A1, Jul. 21, 2022
Int. Cl. G01N 21/17 (2006.01)
CPC G01N 21/1702 (2013.01) 18 Claims
OG exemplary drawing
 
1. A method of characterizing a sample through opto-acoustic metrology by switching functionality associated with a pump beam and a probe beam, the method comprising:
generating a first acoustic wave by directing a first pump pulse to a surface of a sample;
generating a second acoustic wave by directing a first probe pulse to the surface of the sample after a first duration of time from the first pump pulse, wherein the first probe pulse reflects off the sample and is altered by the first acoustic wave;
after a second duration of time after the first probe pulse reflects off the surface of the sample, directing a second pump pulse to the surface of the sample, wherein the second pump pulse reflects off the sample and is altered by the second acoustic wave; and
using the reflected first probe pulse to determine a first characteristic of the sample and the reflected second pump pulse to determine a second characteristic of the sample.