Patent · US Active

Method of detecting a particle and a lithographic apparatus

US8405825B2 · kind B2 · utility

0Cited by

1References

12Claims

0Family size

Assignee

ASML NETHERLANDS B.V. · NL

Inventors

Luigi Scaccabarozzi · Valkenswaard, NL
Vadim Yevgenyevich Banine · Deurne, NL
Christian Wagner · Rosenheim, DE

Key dates

Filing date	Oct 14, 2010
Grant date	Mar 26, 2013
Priority date	—
Expiry date	May 14, 2031

Classification

Technology area (CPC G)Physics
CPC primaryG01N2021/95676
WIPO fieldMeasurement
WIPO sectorInstruments

Abstract

A detector detects radiation from a mask to form an image, but the focal plane of the image is in front of the mask. Any particles arranged on the mask will be in focus. However, the pattern on the mask will be out of focus. It is therefore possible to detect the existence and location of particles on a mask having an arbitrary pattern. The depth of field of the detector is small and the focal plane is no further from the surface of the patterning device than two times the depth of field.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.