Projection exposure apparatus having a device for determining the concentration of atomic hydrogen

Patent metadata

Field	Value
Publication number	US-12306551-B2
Application number	US-202217702218-A
Country	US
Kind code	B2
Filing date	Mar 23, 2022
Priority date	Mar 23, 2021
Publication date	May 20, 2025
Grant date	May 20, 2025

Abstract

A projection exposure apparatus ( 1 ) for semiconductor lithography has a device for determining the concentration of atomic hydrogen in a plasma ( 29 ) in the region of an optical element ( 25, 25.1 ), wherein the device includes a sensor ( 32, 32.1, 32.2, 32.3, 32.4 ), In this case, the device includes a filter element ( 31, 31.1,31.2, 31.3, 31.4 ) arranged between the region of the plasma ( 29 ) and the sensor ( 32, 32.1, 32.2, 32.3, 32.4 ), wherein the filter element ( 31, 31.1,31.2, 31.3, 31.4 ) is configured to predominantly allow the passage of atomic hydrogen from the plasma ( 29 ) to the sensor ( 32, 32.1, 32.2, 32.3, 32.4 ).

First claim

What is claimed is:

1. Projection exposure apparatus for semiconductor lithography, comprising a device for determining concentration of atomic hydrogen in a plasma in a region of an optical element, wherein the device comprises:
a sensor, and
a filter element arranged between the region of the plasma and the sensor, wherein the filter element is configured to predominantly allow passage of atomic hydrogen from the plasma to the sensor, and

wherein the filter element comprises a channel-shaped region for the passage of the atomic hydrogen.

2. Projection exposure apparatus according to claim 1 ,
wherein inner sides of the channel-shaped region are at least partly formed such that there is a low recombination probability when atomic hydrogen is incident thereon.

3. Projection exposure apparatus according to claim 1 ,
wherein a ratio of length to smallest diameter of the channel-shaped region ranges between 20:1 and 4:1 at least in sections of the region.

4. Projection exposure apparatus according to claim 3 ,
wherein the ratio of the length to the smallest diameter of the channel-shaped region ranges between 8:1 and 4:1 at least in the sections of the region.

5. Projection exposure apparatus according to claim 4 ,
wherein the ratio of the length to the smallest diameter of the channel-shaped region is of the order of 6:1 at least in the sections of the region.

6. Projection exposure apparatus according to claim 1 ,
wherein the channel shaped region is aligned at an angle of >30° with respect to a polarization direction of used radiation incident on the optical element.

7. Projection exposure apparatus according to claim 1 ,
wherein the channel-shaped region has an angled configuration.

8. Projection exposure apparatus according to claim 7 ,
wherein the channel-shaped region is formed by interaction of a main body of the optical element and a housing.

9. Projection exposure apparatus according to claim 1 , wherein the optical element is a non-actuated mirror of the projection exposure apparatus.

10. Projection exposure apparatus according to claim 1 , wherein a device for producing an electric or magnetic field is arranged between the region of the plasma and the sensor.

11. Projection exposure apparatus according to claim 1 , wherein the sensor is a heat flux sensor.

12. Projection exposure apparatus for semiconductor lithography, comprising a device for determining concentration of atomic hydrogen in a plasma in a region of an optical element, wherein the device comprises:
a sensor, and
a filter element arranged between the region of the plasma and the sensor, wherein the filter element is configured to predominantly allow passage of atomic hydrogen from the plasma to the sensor, and

wherein the sensor comprises a sacrificial material which experiences etch removal when exposed to H radicals.

13. Projection exposure apparatus according to claim 12 ,
wherein the sacrificial material contains one or more of the substances Zn, Sn, Pb, In, P, C, or Si.

14. Projection exposure apparatus according to claim 13 ,
wherein the sacrificial material contains C or Si.

15. Projection exposure apparatus according to claim 12 , further comprising a device for determining the etch removal.

16. Projection exposure apparatus according to claim 15 ,
wherein the etch removal determining device is configured to carry out a transmission measurement, an ellipsometry measurement or a measurement of a frequency shift of a quartz microbalance.

17. Projection exposure apparatus according to claim 12 ,
wherein the optical element is a non-actuated mirror of the projection exposure apparatus.

18. Projection exposure apparatus according to claim 12 ,
wherein a device for producing an electric or magnetic field is arranged between the region of the plasma and the sensor.

19. Projection exposure apparatus according to claim 12 ,
wherein the sensor is a heat flux sensor.

Assignees

• Zeiss Carl Smt Gmbh

Inventors

• Ehm Dirk
• Becker Moritz

Classifications

• G03F7/70308

  Optical correction elements, filters or phase plates for manipulating imaging light, e.g. intensity, wavelength, polarisation, phase or image shift · CPC title

• G01N33/005

  H2 · CPC title

• G01N29/022

  Fluid sensors based on microsensors, e.g. quartz crystal-microbalance [QCM], surface acoustic wave [SAW] devices, tuning forks, cantilevers, flexural plate wave [FPW] devices (microdevices per se B81B) · CPC title

• G01N21/211

  Ellipsometry (optical thickness measurement G01B11/06) · CPC title

• G03F7/70925

  Cleaning, i.e. actively freeing apparatus from pollutants, e.g. using plasma cleaning · CPC title