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JP-2026514276-A - Projection exposure apparatus and method for semiconductor lithography

JP2026514276AJP 2026514276 AJP2026514276 AJP 2026514276AJP-2026514276-A

Abstract

The present invention relates to a projection exposure apparatus (1, 101) for semiconductor lithography, comprising at least one optical element (Mx, 117), wherein at least one actuator (44) for deforming the optically effective surface (33) of the optical element is disposed on the back side (43) of the optical element (Mx, 117), the actuator (44) is configured to apply a compressive or tensile force to the optical element (Mx, 117) perpendicular to the optically effective surface (33), and at least one actuator (44) is disposed within a notch (35, 53) of the body (30, 50) of the optical element (Mx, 117). The present invention relates to a method for fixing an actuator (44) in a notch (63) of a body (60) of an optical element (Mx, 117), the method comprising the steps of: preparing the actuator (44) and at least one radial clamping element (68); inserting the actuator (44) and the radial clamping element (68) into the notch (53), wherein the radial clamping element (68) is positioned between the actuator (44) and the inner surface (69) of the notch (53); and tightening the clamping element (68) for the purpose of fixing the actuator (44).

Inventors

  • ヨアヒム ハエトイェス
  • ベッティナ ウェーローシュ
  • アンドレアス ラーバ
  • ヨハネス リッペルト
  • エリック ロープシュトラ

Assignees

  • カール・ツァイス・エスエムティー・ゲーエムベーハー

Dates

Publication Date
20260508
Application Date
20231019
Priority Date
20221024

Claims (19)

  1. A projection exposure apparatus (1, 101) for semiconductor lithography, comprising at least one optical element (Mx, 117), wherein at least one actuator (44) for deforming the optical effective surface (33) of the optical element is positioned on the back side (43) of the optical element (Mx, 117), and the actuator (44) is configured to apply a compressive or tensile force to the optical element (Mx, 117) perpendicular to the optical effective surface (33), in the projection exposure apparatus (1, 101), A projection exposure apparatus characterized in that the at least one actuator (44) is positioned within a notch (35, 53) of the body (30, 50) of the optical element (Mx, 117), and there is at least one cavity (42, 55, 71) between the body (30, 50, 61) and the optical body (32, 52, 61) for at least partially mechanically separating the optical body (32, 52, 61) from the body (30, 50, 60), and the at least one actuator (44) extends at least partially into the cavity (42, 71).
  2. In the projection exposure apparatus (1, 101) according to claim 1, The projection exposure apparatus is characterized in that the actuator (44) is connected to the main body (30, 50) by bearing contact surfaces (38, 69) located within the notches (35, 53).
  3. In the projection exposure apparatus (1, 101) according to claim 1 or 2, The projection exposure apparatus is characterized in that the optical element (Mx, 117) includes an intermediate body (31, 51) disposed between the optical body (32, 52) and the main body (30, 50).
  4. In the projection exposure apparatus (1, 101) according to any one of claims 1 to 3, A projection exposure apparatus characterized in that at least one cavity (42, 55) is positioned between the intermediate (31, 51) and the main body (30, 50, 60).
  5. In the projection exposure apparatus (1, 101) according to claim 1, A projection exposure apparatus characterized in that the at least one cavity (55) is isolated from the at least one actuator (44).
  6. In the projection exposure apparatus (1, 101) according to any one of claims 3 to 5, The projection exposure apparatus is characterized in that the intermediate (31) includes a flow path (34) for temperature control of the optical element (Mx, 117).
  7. In the projection exposure apparatus (1, 101) according to any one of claims 1 to 6, A projection exposure apparatus characterized in that a pin (40) is located at the bottom of the notch (35) and is mechanically connected to the actuator (44) via an effective contact surface (41).
  8. In the projection exposure apparatus (1, 101) according to claim 7 and any one of claims 3 to 6, The projection exposure apparatus is characterized in that the pin (40) is formed on the intermediate (31).
  9. In the projection exposure apparatus (1, 101) according to claim 7 or 8, A projection exposure apparatus characterized in that the distance between the optically effective surface (33) and the effective contact surface (41) is 5 mm to 20 mm.
  10. In the projection exposure apparatus (1, 101) according to any one of claims 2 to 9, A projection exposure apparatus characterized in that the bearing contact surface (38) is formed on the shoulder portion (37) of the notch (35).
  11. In the projection exposure apparatus (1, 101) according to claim 1, A projection exposure apparatus characterized in that the bearing contact surface (38) is connected to the actuator (44) by adhesive connection.
  12. In the projection exposure apparatus (1, 101) according to any one of claims 10 or 11, A projection exposure apparatus characterized in that the distance between the bearing contact surface (38) and the back side of the main body is 0 mm to 500 mm, preferably 0 mm to 250 mm, and particularly preferably 50 mm to 150 mm.
  13. In the projection exposure apparatus (1, 101) according to any one of claims 1 to 12, A projection exposure apparatus characterized in that at least one clamping element (68) is positioned between the actuator (44) and the inner surface (69) of the notch (53).
  14. In the projection exposure apparatus (1, 101) according to claim 13, The projection exposure apparatus is characterized in that the clamp element (68) is formed as a sleeve-shaped body.
  15. In the projection exposure apparatus (1, 101) according to claim 13 or 14, The projection exposure apparatus is characterized in that the clamp element (68) includes a shape memory alloy.
  16. A method for fixing an actuator (44) within a notch (63) of the main body (60) of an optical element (Mx, 117), The steps include preparing the actuator (44) and at least one radial clamping element (68), The step is to insert the actuator (44) and the radial clamping element (68) into the notch (53), wherein the radial clamping element (68) is positioned between the actuator (44) and the inner surface (69) of the notch (53), A method comprising the step of tightening the clamp element (68) for the purpose of fixing the actuator (44).
  17. In the method according to claim 16, A method for tightening the clamp element (68) by changing the temperature of the main body (60) or the clamp element (68).
  18. In the method according to claim 17, The clamping element (68) comprises a shape memory alloy, in a method.
  19. In the method according to any one of claims 16 to 18, A method of pushing the actuator (66) in the direction of the optically effective surface (62) with a specified contact force (F) before tightening the clamp element (68).

Description

This application claims priority to German Patent Application No. 10 2022 211 226.1, filed on 24 October 2022, the contents of which are fully incorporated herein by reference. This invention relates to a projection exposure apparatus for semiconductor lithography having an optical element equipped with an actuator, and to a method for incorporating the actuator. Projection lithography equipment for semiconductor technology is used to fabricate extremely fine structures, particularly on semiconductor components or other microstructured components. The operating principle of this equipment is based on the fabrication of extremely fine structures down to the nanometer range by using a reticle to reduce and image the structure on a mask onto a wafer, which is a structured element on which a photosensitive material is attached. The minimum dimensions of the fabricated structure directly depend on the wavelength of the light used. In addition to light sources with emission wavelengths in the so-called DUV range of 100 nm to 300 nm, which are mainly used, the use of light sources with emission wavelengths of approximately a few nanometers, for example, 1 nm to 120 nm, and especially around 13.5 nm, has been increasing in recent years. This wavelength range is also called the EUV range. The optical elements used for imaging in the above applications must be positioned with the highest precision and/or, in some cases, deformed to ensure sufficient image quality. In particular, optical elements in the form of mirrors are not only positioned with up to six degrees of freedom but are also configured to deform their optically effective surface. The optically effective surface is the surface of the optical element to which radiation used for imaging and exposure is incident during the normal operation of the associated device. In this case, the deformation is brought about by an actuator positioned on the back side of the mirror opposite the optically effective surface. The actuator used can, in principle, act on the optical element parallel to the optically effective surface, but also perpendicular to it. A corresponding configuration is disclosed in Patent Document 1. In the optical element disclosed in this document, the actuator acts on the optical element from the back side, i.e., from the opposite side of the optically effective surface, introducing a force perpendicular to the optically effective surface. According to the teachings in this document, a backplate is used as a counter bearing, and the actuator is supported on it. However, as a result of using a backplate, the actuator becomes not optimally accessible for maintenance or repair purposes. German Patent Application Publication No. 10, 2020, 210, 773 Specification A schematic diagram of the meridian cross-section of a projection exposure system for EUV projection lithography is shown.A schematic diagram of the meridian cross-section of a projection exposure system for DUV projection lithography is shown.A first embodiment of the optical element according to the present invention is shown.Another embodiment of the optical element according to the present invention is shown.Another embodiment of the optical element according to the present invention is shown. In the following text, the essential components of the microlithography projection exposure apparatus 1 will be explained illustratively, first with reference to Figure 1. The basic structure of the projection exposure apparatus 1 and its components should be understood as non-exclusive. One embodiment of the illumination system 2 of the projection exposure apparatus 1 includes, in addition to the radiation source 3, an illumination optical unit 4 that illuminates the object field of view 5 on the object surface 6. In an alternative embodiment, the light source 3 may be provided as a separate module from the rest of the illumination system. In this case, the illumination system does not include the light source 3. The reticle 7, positioned in the object field of view 5, is exposed. The reticle 7 is held by the reticle holder 8. The reticle holder 8 is displaceable, particularly in the scanning direction, by the reticle displacement drive 9. For explanation purposes, Figure 1 shows a Cartesian x-y-z coordinate system. The x-direction extends perpendicular to the plane of the figure. The y-direction extends horizontally, and the z-direction extends vertically. In Figure 1, the scanning direction extends in the y-direction. The z-direction extends perpendicular to the object plane 6. The projection exposure apparatus 1 includes a projection optical unit 10. The projection optical unit 10 functions to form an image of the object field of view 5 onto the image field of view 11 of the image plane 12. The image plane 12 extends parallel to the object surface 6. Alternatively, angles other than 0° are possible between the object surface 6 and the image plane 12. The structure on the reticle 7 is imaged onto t