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1. (WO2018160778) LAYER-TO-LAYER FEEDFORWARD OVERLAY CONTROL WITH ALIGNMENT CORRECTIONS

Pub. No.:    WO/2018/160778    International Application No.:    PCT/US2018/020341
Publication Date: Sat Sep 08 01:59:59 CEST 2018 International Filing Date: Fri Mar 02 00:59:59 CET 2018
IPC: G03F 7/20
G03F 9/00
H01L 21/027
Applicants: KLA-TENCOR CORPORATION
Inventors: DEMIRER, Onur N.
PIERSON, William
SMITH, Mark D.
NABETH, Jeremy
GARCIA-MEDINA, Miguel
YAP, Lipkong
Title: LAYER-TO-LAYER FEEDFORWARD OVERLAY CONTROL WITH ALIGNMENT CORRECTIONS
Abstract:
A process control system includes a controller configured to generate a reference overlay signature based on one or more overlay reference layers of a sample, extrapolate the reference overlay signature to a set of correctable fields for the exposure of a current layer of the sample to generate a full-field reference overlay signature, identify one or more alignment fields of the set of correctable fields, generate an alignment-correctable signature by modeling alignment corrections for the set of correctable fields, subtract the alignment-correctable signature from the full-field reference overlay signature to generate feedforward overlay corrections for the current layer when the one or more overlay reference layers are the same as the one or more alignment reference layers, generate lithography tool corrections based on the feedforward overlay corrections, and provide the lithography tool corrections for the current layer to the lithography tool.