Residual gas analyser, and EUV lithography system having a residual gas analyser

Patent metadata

Field	Value
Publication number	US-12573604-B2
Application number	US-202318099656-A
Country	US
Kind code	B2
Filing date	Jan 20, 2023
Priority date	Jul 21, 2020
Publication date	Mar 10, 2026
Grant date	Mar 10, 2026

Abstract

A residual gas analyser ( 40 ) for analysis of a residual gas ( 30 ), in particular a residual gas in an EUV lithography system ( 1 ), includes an inlet system ( 41 ) for admission of the residual gas from a vacuum environment ( 27 a ) into the residual gas analyser, and a mass analyser ( 43 ) having a detector ( 44 ) for detecting ionized constituents ( 30 a ) of the residual gas. The residual gas analyser includes an ion transfer device ( 42 ) for transferring the ionized constituents of the residual gas to the mass analyser, the ion transfer device having an ion filtering device ( 45 ) configured for filtering at least one ionic constituent ( 30 a ) of the residual gas. Also disclosed is an EUV lithography system, in particular an EUV lithography apparatus, which includes at least one residual gas analyser configured as indicated above for analysing a residual gas in a vacuum environment of the EUV lithography system.

First claim

What is claimed is:

1 . A residual gas analyser for analysis of a residual gas, comprising:
an inlet system comprising an ion transfer device and configured to admit the residual gas from a vacuum environment into the residual gas analyser, and a mass analyser comprising a detector configured to detect ionized constituents of the residual gas, wherein:
the ion transfer device is configured to transfer the ionized constituents of the residual gas to the mass analyser, and
the ion transfer device comprises an ion filtering device configured to filter at least one ionic constituent of the ionic constituents of the residual gas based on its mass-to-charge ratio, so that the at least one ionic constituent does not enter the mass analyser.

2 . The residual gas analyser as claimed in claim 1 , in which the ion filter device is configured as a notch filter.

3 . The residual gas analyser as claimed in claim 1 , in which the ion filter device is configured as an RF-only quadrupole, an RF-only hexapole or an RF-only octopole.

4 . The residual gas analyser as claimed in claim 1 , in which the mass analyser is configured as a time-of-flight analyser.

5 . The residual gas analyser as claimed in claim 1 , in which the detector is selected from the group consisting essentially of secondary electron multipliers and microchannel plates.

6 . The residual gas analyser as claimed in claim 1 , in which the mass analyser further comprises an ion supply device at an outlet end of the inlet system, wherein the ion supply device is configured to supply further ionized constituents of the residual gas that have not been filtered by the ion filter device to the detector.

7 . The residual gas analyser as claimed in claim 1 , further comprising:
at least one ionizing device configured to ionize neutral constituents of the residual gas.

8 . The residual gas analyser as claimed in claim 7 , in which the ionizing device is disposed at an inlet end of the inlet system.

9 . The residual gas analyser as claimed in claim 7 , in which the ionizing device comprises ion optics for transferring the ionized constituents of the residual gas formed in the vacuum environment.

10 . The residual gas analyser as claimed in claim 7 , in which the ionizing device is selected from the group consisting essentially of an electron ionization device and a high-frequency plasma ionization device.

11 . An extreme ultraviolet (EUV) lithography system, arranged in a vacuum environment and comprising:
at least one residual gas analyser as claimed in claim 1 and arranged for analysis of a residual gas in the vacuum environment of the EUV lithography system.

12 . The EUV lithography system as claimed in claim 11 , further comprising:
at least one optical element configured and arranged to reflect EUV radiation, wherein an inlet end of the inlet system of the residual gas analyser is disposed at a distance of less than 5 cm from a reflective surface of the optical element.

Assignees

• Zeiss Carl Smt Gmbh

Inventors

• Schoell Achim
• Ehm Dirk
• Brachthaeuser Yessica
• Benter Thorsten

Classifications

• H01J49/421 Primary

  Mass filters, i.e. deviating unwanted ions without trapping · CPC title

• G03F7/70858

  Environment aspects, e.g. pressure of beam-path gas, temperature (pollution aspects G03F7/70916) · CPC title

• G03F7/70908

  Hygiene, e.g. preventing apparatus pollution, mitigating effect of pollution or removing pollutants from apparatus · CPC title

• G03F7/7085 Primary

  Detection arrangement, e.g. detectors of apparatus alignment possibly mounted on wafers, exposure dose, photo-cleaning flux, stray light, thermal load · CPC title