US 11,874,605 B2
Verification metrology targets and their design
Michael E. Adel, Ya'akov (IL); Inna Tarshish-Shapir, Yokneam Ilit (IL); Shiming Wei, Shanghai (CN); and Mark Ghinovker, Yoqneam Ilit (IL)
Assigned to KLA Corporation, Milpitas, CA (US)
Filed by KLA Corporation, Milpitas, CA (US)
Filed on Jul. 6, 2020, as Appl. No. 16/921,880.
Application 16/921,880 is a continuation of application No. 15/351,995, filed on Nov. 15, 2016, granted, now 10,705,434, issued on Jul. 7, 2020.
Application 15/351,995 is a continuation of application No. PCT/US2015/053838, filed on Oct. 2, 2015.
Claims priority of provisional application 62/059,640, filed on Oct. 3, 2014.
Prior Publication US 2020/0348604 A1, Nov. 5, 2020
Int. Cl. H01L 21/66 (2006.01); G03F 7/00 (2006.01); G06F 30/00 (2020.01)
CPC G03F 7/70491 (2013.01) [G03F 7/70616 (2013.01); G06F 30/00 (2020.01); H01L 22/30 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A metrology target design method comprising:
using optical critical dimension data related to at least one designed overlay metrology target as an estimation of a discrepancy between a target model and a corresponding actual target on a wafer, wherein the optical critical dimension data is at least partially derived from a measurement, with a critical dimension metrology sensor, of at least one verification target comprising one or more overlay target features, wherein the one or more overlay target features of the at least one verification target comprise at least one of: a pitch, a segmentation and a topography which is identical to a corresponding feature of at least one overlay metrology target as the at least one designed overlay metrology target; and
adjusting a metrology target design model to compensate for the discrepancy, wherein the adjusting is carried out with respect to at least one of a critical dimension, an optical material characteristic, a film thickness, topography or presence of process variation, wherein the process variation relates to at least one of an induced topography, a deposited topography, an etched topography, or chemical mechanical planarization dishing.