Search

DE-102025126398-A1 - Projection lens with optical measuring arrangement and vibration damper

DE102025126398A1DE 102025126398 A1DE102025126398 A1DE 102025126398A1DE-102025126398-A1

Abstract

Projection lens (100) with a plurality of optical elements (101) and with at least one optical measuring arrangement (102) for distance and/or position detection of one of the optical elements (101) relative to a component (103), wherein the optical measuring arrangement (102) comprises as objects (104) at least one sensor head (105) and a measuring target (106), and one of the sensor head (105) and measuring target (106) is arranged or can be arranged on the optical element (101), and the other of the sensor head (105) and measuring target (106) is arranged or can be arranged on the component (103), characterized in that at least one vibration damper (105) is arranged or can be arranged on at least one of the objects (104).

Inventors

  • Jonas Metz
  • Luca Mettenleiter
  • Rudolf Neumann
  • Andreas Raba
  • David Schoenen

Assignees

  • CARL ZEISS SMT GMBH

Dates

Publication Date
20260513
Application Date
20250707

Claims (15)

  1. Projection lens (100) with a plurality of optical elements (101) and with at least one optical measuring arrangement (102) for distance and/or position detection of one of the optical elements (101) relative to a component (103), wherein the optical measuring arrangement (102) comprises as objects (104) at least one sensor head (105) and a measuring target (106), and one of the sensor head (105) and measuring target (106) is arranged or can be arranged on the optical element (101), and the other of the sensor head (105) and measuring target (106) is arranged or can be arranged on the component (103), characterized in that at least one vibration damper (105) is arranged or can be arranged on at least one of the objects (104).
  2. Projection lens (100) according to Claim 1 , characterized in that the optical measuring arrangement (102) additionally has as object (104) a first connection point (108) at which one of sensor head (105) and measuring target (106) is connected or connectable to the optical element (101) and/or that the optical measuring arrangement (102) additionally has as object (104) a second connection point (109) at which the other of sensor head (105) and measuring target (106) is connected or connectable to the component (103).
  3. Projection lens (100) according to Claim 2 , characterized in that at least one vibration damper (107) is attached or can be attached at the first connection point (108) and/or that at least one vibration damper (107) is attached or can be attached at the second connection point (109).
  4. Projection lens (100) according to Claim 2 or 3 , characterized in that at least one of the attachment points (108, 109) is formed as a projection (110).
  5. Projection lens (100) according to one of the Claims 1 until 4 , characterized in that the at least one vibration damper (107) is or can be arranged away from an optically active surface or away from an optically active area on the object (104).
  6. Projection lens (100) according to one of the Claims 1 until 5 , characterized in that the at least one optical measuring arrangement (102) is or can be arranged away from an optically active surface or an optically active area (116) of the optical element (101) or component (103).
  7. Projection lens (100) according to one of the Claims 1 until 6 , characterized in that the component (103) is formed as a further optical element (101), and that the optical measuring arrangement (102) is set up to detect a change in distance and/or position between two optical elements (101).
  8. Projection lens (100) according to one of the Claims 2 until 7 , characterized in that at least one of the connection points (108,109) is designed such that the orientation of the object (104) connected to the connection point (108,109) can be adjusted in at least two degrees of freedom.
  9. Projection lens (100) according to one of the Claims 2 until 8 , characterized in that at least one of the connection points (108, 109) forms a sphere-cone connection with the object (104).
  10. Projection lens (100) according to one of the Claims 1 until 9 , characterized in that a frequency of the vibration damper (107) is adapted to a vibration mode of the object (104) to which the vibration damper (107) is attached or can be attached.
  11. Projection lens (100) according to one of the Claims 1 until 10 , characterized in that the at least one vibration damper (107) comprises a housing (111), a vibration mass (112) and a damper (113).
  12. Projection lens (100) according to Claim 11 , characterized in that the vibrating mass (112) is connected or connectable to the housing (111) by means of the damper (113).
  13. Projection lens (100) according to Claim 11 , characterized in that the material of the vibrating mass (112) is additionally damping.
  14. Projection exposure system (600,700) with a lighting system and with a projection lens (100) according to one of the Claims 1 until 13 .
  15. Lithographic apparatus with a light source and an illumination system, which is configured to direct a light beam emitted by the light source onto a reticle and to project it with a projection lens (100) according to one of the Claims 1 until 13 , which is set up to project the light beam from the reticulum onto a wafer.

Description

The invention relates to a projection lens, in particular for a microlithographic projection exposure system, comprising a plurality of optical elements and at least one optical measuring arrangement for distance and/or position detection of one of the optical elements relative to a component, wherein the optical measuring arrangement comprises at least one sensor head and one measuring target, and one sensor head and measuring target is arranged or can be arranged on the optical element, and the other sensor head and measuring target is arranged or can be arranged on the component. The invention further relates to a projection exposure system and a lithography system. Projection exposure systems are used to create extremely fine structures, particularly on semiconductor devices or other microstructured components. The operating principle of these systems is based on the creation of ultra-fine structures down to the nanometer range by means of a generally reduced-size image of structures on a mask, a so-called reticle, onto a wafer, which is coated with photosensitive material. The minimum dimensions of the generated structures depend directly on the wavelength of the light used. This light is shaped in an illumination optic to optimally illuminate the reticle. Recently, light sources with emission wavelengths in the nanometer range, for example between 1 nm and 120 nm, particularly in the 13.5 nm range, have been increasingly used. This wavelength range is also known as the EUV range. The microstructured components are manufactured not only using EUV systems but also with established DUV systems operating at wavelengths between 100 nm and 400 nm, particularly 193 nm. With the increasing demand for ever smaller structures, the requirements for optical correction in these systems have also risen. To improve efficiency, each new generation of projection exposure systems in the EUV or DUV range increases throughput. In the operation of microlithographic projection exposure systems, where the mask and wafer are typically moved relative to each other in a scanning process, the positions of the optical elements, especially mirrors, which are partially movable in all six degrees of freedom, must be set with high accuracy relative to each other, and this position/alignment must be maintained in order to avoid or at least reduce aberrations and associated impairments of the image result or image shifts. Various approaches are known in the prior art for measuring the position of individual mirrors, as well as the wafer or wafer stage and the reticles or reticle stage. Besides interferometric or encoder-based measurement setups, frequency-based position and/or distance measurement using an optical resonator is also known. In the DE 10 2012 212 663 A1 A measurement setup for frequency-based distance measurement is described. This setup discloses an optical resonator with two resonator mirrors. A first resonator mirror is attached to a reference element in the form of a measuring frame rigidly connected to the housing of the projection lens of the projection exposure system, and a second resonator mirror (as a "measuring target") is attached to a mirror whose position is to be measured. The actual distance measuring device comprises a radiation source whose optical frequency can be tuned. This source generates a coupling radiation that passes through a beam splitter and is coupled into the optical resonator. The radiation source is controlled by a coupling device such that its optical frequency is tuned to a resonance frequency of the optical resonator and thus coupled to this resonance frequency. The coupling radiation extracted via a beam splitter is analyzed by an optical frequency measuring device, which may, for example, include a frequency comb generator for highly accurate determination of the absolute frequency. If the position of the EUV mirror changes in the direction of measurement, the resonance frequency of the optical resonator also changes with the distance between the resonator mirrors, and thus – as a result of the coupling of the frequency of the tunable radiation source to the resonance frequency of the resonator – the optical frequency of the coupling radiation also changes, which in turn is directly registered by the frequency measuring device. Alternatively, instead of a tunable radiation source and a frequency comb, a frequency-based position and/or distance measurement can also include a highly stable radiation source whose frequency is tracked and stabilized or locked to the resonance frequency of the optical resonator using a frequency shifter (for example, an IQ modulator) and Pound Drive Hall technique. will be. This is the case, for example, in the DE 10 2021 203 126A1 revealed. The German patent application DE 10 2023 208 513 A1 Disclosing a measuring arrangement for frequency-based distance and/or position detection with an optical resonator, which additionally has a convolution mirror con