Patent · US Active

Method for examining photolithographic masks and mask metrology apparatus for performing the method

US10775691B2 · kind B2 · utility

0Cited by

0References

20Claims

0Family size

Assignee

Carl Zeiss SMT GmbH · DE

Inventors

Dirk Hellweg · Langenau, DE
Markus Koch · Neu-Ulm, DE
Renzo Capelli · Heidenheim, DE

Key dates

Filing date	Sep 10, 2018
Grant date	Sep 15, 2020
Priority date	—
Expiry date	Dec 14, 2038

Classification

Technology area (CPC G)Physics
CPC primaryG03F7/70666
WIPO fieldOptics
WIPO sectorInstruments

Abstract

The invention relates to a method for examining a photolithographic mask for the extreme ultraviolet (EUV) wavelength range in a mask metrology apparatus. In this method, at least one structured region of the mask is selected, a scanner photon number in the extreme ultraviolet (EUV) wavelength range for which the mask in the lithographic production run is provided and a metrology photon number in the extreme ultraviolet (EUV) wavelength range with which the measurement is performed are determined. Next, a photon statistics examination mode is established on the basis of the scanner photon number and the metrology photon number and at least one aerial image of the at least one structured region is produced with the mask metrology apparatus.

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