US 9,810,643 B1
System and method for defect detection using multi-spot scanning
Amir Shoham, Nes-Ziyyona (IL); Yoav Berlatzky, Beit Govrin (IL); and Haim Feldman, Nof-Ayalon (IL)
Assigned to APPLIED MATERIALS ISRAEL LTD., Rehovot (IL)
Filed by Applied Materials Israel, Ltd., Rehovot (IL)
Filed on Sep. 25, 2013, as Appl. No. 14/37,304.
Claims priority of provisional application 61/705,568, filed on Sep. 25, 2012.
Int. Cl. G01N 21/956 (2006.01)
CPC G01N 21/95607 (2013.01) 13 Claims
OG exemplary drawing
 
1. A system, comprising:
a radiation source adapted to generate a beam of coherent radiation;
traveling lens optics adapted to focus the beam to generate first, second and third spots on a surface of a sample and to scan the spots together over the surface;
a controller operatively coupled to the traveling lens optics, the controller being configured to transmit a signal to the traveling lens optics to cause the traveling lens optics to generate the first, second and third spots;
a collimating lens disposed between the radiation source and the traveling lens optics, the collimating lens being adapted to collimate the beam;
collection optics adapted to collect the radiation scattered from the first, second and third spots and to focus the collected radiation to generate a pattern of interference fringes;
a detection unit adapted to detect changes in the pattern of interference fringes; and
a processing device adapted to reconstruct phase and amplitude data of a near field radiation in proximity to the surface of the sample from the detected changes in the pattern of interference fringes; and classify defects on the surface of the sample using the reconstructed phase and amplitude data.