Messverfahren, Vorrichtung und Substrat

Details

Veröffentlichungs-Nr.

EP2458441

Aktenzeichen

EP11186981

Anmeldetag

27. Oktober 2011

Veröffentlichung

19. Januar 2022

Erteilung

19. Januar 2022

Rechtsraum

EP

IPC

G03F7/20G03F9/00

Abstract

A pattern (310, 610) is formed on a substrate (W) using a lithographic step (400). The pattern includes first and second sub-patterns (312, 316; 612, 616) positioned adjacent one another on the substrate and having respective first and second periodicities. The pattern is observed (402) to obtain a combined signal (403) which includes a beat component having a third periodicity at a frequency lower than that of the first and second periodicities. A measurement of performance of the lithographic process is determined (406) by reference to a phase of the beat component (405). Depending how the sub-patterns are formed, the performance parameter might be critical dimension (CD) or overlay, for example. For CD measurement, one of the sub-patterns may comprise marks each having of a portion sub-divided by product-like features. The measurement can be made using an existing alignment sensor of a lithographic apparatus. Sensitivity and accuracy of the measurement can be adjusted by selection of the first and second periodicities, and hence the third periodicity.

Anmelder

Firma

ASML Netherlands BV

Land

🇳🇱 Niederlande

Fachgebiete