Brevet : EP2690496 - PROCÉDÉ PERMETTANT DE MESURER UNE DISTORSION D'UN OBJECTIF DE PROJECTION

Titre

PROCÉDÉ PERMETTANT DE MESURER UNE DISTORSION D'UN OBJECTIF DE PROJECTION

N° et date de publication de la demande

EP2690496 - 29/01/2014

Type de la demande

A1

N° et date de dépôt

EP12761311.5 - 21/03/2012

N° et date de priorité

CN201110068060 - 21/03/2011 ; PCT/CN2012072693 - 21/03/2012

Famille de brevets

SG192887A1 ; EP2690496A1 ; US2013335718A1 ; WO2012126364A1 ; TW201245903A ; CN102692820A

Abrégé

A method for measuring distortion of a projection objective, which includes: obtaining a plurality of first positional deviations between two groups of patterns formed respectively after two exposures performed in a same exposure field during a stepping and exposing process of the reticle stage (S21); obtaining a plurality of second positional deviations between two groups of patterns formed respectively after another two exposures performed in a same exposure field during a stepping and exposing process of the workpiece stage (S22); subtracting motional errors of the reticle stage and/or workpiece stage from each of the plurality of first and second positional deviations to obtain corresponding first and second corrected deviations (S43, S44); calculating differences each between a pair of corrected deviations (S45); and calculating the distortion of the projection objective by a fitting process (S46).