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CN-115413332-B - Particle testing system, sampling bar, projection exposure apparatus and method for testing surface particle contamination

CN115413332BCN 115413332 BCN115413332 BCN 115413332BCN-115413332-B

Abstract

The invention relates to a particle testing system (1) for testing particle contamination on a surface (2), comprising a sampling belt (7) for receiving particles (5) and a sampling device (3). The sampling device (3) comprises a roller body (9), which roller body (9) is arranged to guide the sampling belt (7) on an outer surface (10) of the roller body. The sampling device (3) is designed to roll the roller body (9) together with the sampling belt (7) over the surface (2) to be tested in order to transfer the particles (5) from the surface (2) to be tested to the sampling belt (7). The sampling device (3) has a guide frame (22) in order to position the sampling device (3) on the surface (2) to be inspected or adjacent to the surface (2) to be inspected. The guide frame (22) has at least one contact interface (24, 25), by means of which at least one contact interface (24, 25) the guide frame (22) rests on the surface (2) to be inspected or on another surface. According to the invention, the sampling device (3) has a first measuring device (16) and/or a second measuring device (19). The first measuring device (16) is designed to detect any rotational movement of the roller body (9). The second measuring device (19) is designed to detect any contact pressure of the roller body (9) on the surface (2) to be inspected.

Inventors

  • M. SCHILLING
  • M. Ruth
  • M. NAGEL

Assignees

  • 卡尔蔡司SMT有限责任公司

Dates

Publication Date
20260512
Application Date
20210215
Priority Date
20200217

Claims (19)

  1. 1. Particle inspection system (1) for inspecting particle contamination of a surface (2), having a sampling strip (7) for sucking particles (5) and a sampling device (3), wherein the sampling device (3) has a roller body (9), which roller body (9) is arranged to guide a sampling strip (7) on its outer surface (10), and wherein the sampling device (3) is arranged to roll the roller body (9) together with the sampling strip (7) against the surface (2) to be inspected in order to transfer particles (5) from the surface (2) to be inspected to the sampling strip (7), wherein the sampling device (3) has a guide frame (22) for positioning the sampling device (3) on the surface (2) to be inspected or beside the surface (2) to be inspected, wherein the guide frame (22) has at least one positioning interface (24, 25), through which positioning interface (24, 25), the guide frame (22) is located on the surface (2) to be inspected or on the other surface (3), and wherein the sampling device (3) is positioned on the surface (2) to be inspected A) Having a first measuring device (16) designed to detect any rotational movement of the roller body (9), and/or B) Having a second measuring device (19) designed to detect any contact pressure of the roller body (9) on the surface (2) to be inspected, Wherein the roller body (9) is mounted in the sampling device (3) in an elastic manner relative to the surface (2) to be inspected.
  2. 2. Particle inspection system (1) according to claim 1, characterized in that the sampling strip (7) has a sampling surface (8), which sampling surface (8) is designed for adhesively sucking up the particles (5) from the surface (2) to be inspected, wherein the sampling surface (8) is remote from the outer surface (10) of the roller body (9) when the sampling strip (7) is guided along the outer surface (10) of the roller body (9).
  3. 3. Particle inspection system (1) according to claim 2, characterized in that the sampling surface (8) has a pressure sensitive adhesive (15) for adhesive suction of the particles (5) from the surface (2) to be inspected.
  4. 4. A particle inspection system (1) according to any one of claims 1 to 3, characterized in that the sampling strip (7) is formed of a translucent material.
  5. 5. A particle inspection system (1) according to any one of claims 1 to 3, characterized in that the roller body (9) is spring-mounted in the sampling device (3) with respect to the surface (2) to be inspected.
  6. 6. A particle inspection system (1) according to any one of claims 1 to 3, characterized in that the first measuring device (16) has an optical sensor (17) or a magnetic sensor in order to detect the angle of rotation of the roller body (9), the rotational speed of the roller body (9) and/or the angular speed of the roller body (9).
  7. 7. A particle inspection system (1) according to any one of claims 1 to 3, characterized in that the second measuring device (19) has a force sensor (20) in order to detect the contact pressure of the roller body (9) on the surface (2) to be inspected.
  8. 8. Particle inspection system (1) according to claim 7, characterized in that the force sensor (20) is a force sensor with a spring element, an electrodynamic force sensor or a piezoelectric force sensor.
  9. 9. A particle inspection system (1) according to any one of claims 1 to 3, characterized in that the sampling device (3) has a display (21) to show information detected by means of the first measuring device (16) and/or detected by means of the second measuring device (19) to a user of the sampling device (3).
  10. 10. Particle inspection system (1) according to claim 9, characterized in that the display (21) is an electronic display (21).
  11. 11. A particle inspection system (1) according to any one of claims 1 to 3, characterized in that the guide frame (22) is movable parallel to the surface (2) to be inspected on the surface (2) to be inspected or beside the surface (2) to be inspected in order to roll the roller body (9) together with the sampling strip (7) against the surface (2) to be inspected.
  12. 12. A particle inspection system (1) according to any one of claims 1 to 3, characterized in that the sampling device (3) has an actuator device (26) to move the roller body (9) parallel to the surface (2) to be inspected in order to roll the roller body (9) together with the sampling strip (7) against the surface (2) to be inspected in an automated manner.
  13. 13. A particle inspection system (1) according to any one of claims 1 to 3, characterized in that the particle inspection system (1) has an evaluation device (4), which evaluation device (4) is designed to evaluate the particles (5) sucked up by the sampling strip (7) in terms of particle size, particle type, particle quantity and/or particle distribution.
  14. 14. Particle inspection system (1) according to claim 13, characterized in that the evaluation device (4) comprises a microscope (29).
  15. 15. Particle inspection system (1) according to claim 14, characterized in that the microscope (29) is a transmission light microscope.
  16. 16. Projection exposure apparatus (100, 200, 400) for semiconductor lithography, wherein a particle inspection system (1) as claimed in any one of claims 1 to 15 is provided for inspecting a surface (2) of a component of the projection exposure apparatus (100, 200, 400) for particle contamination.
  17. 17. Projection exposure apparatus (100, 200, 400) according to claim 16, characterized in that the particle inspection system (1) is provided for inspecting a surface (2) of an optical element (415, 416, 418, 419, 420, 108, 201) of an optical unit (107, 403, 408) of the projection exposure apparatus (100, 200, 400).
  18. 18. Method for inspecting particle contamination of a surface (2), wherein a roller body (9) of a sampling device (3) rolls together with a sampling strip (7) guided over an outer surface (10) of the roller body (9) against the surface (2) to be inspected in order to transfer particles (5) from the surface (2) to be inspected to the sampling strip (7), wherein the sampling device (3) is positioned on or beside the surface (2) to be inspected via a guide frame (22), wherein the guide frame (22) has at least one positioning interface (24, 25), the guide frame (22) being on the surface (2) to be inspected or on the other surface by means of the at least one positioning interface (24, 25), and wherein A) The first measuring means (16) of the sampling device (3) detect any rotational movement of the roller body (9), and/or B) The second measuring device (19) of the sampling device (3) detects any contact pressure of the roller body (9) on the surface (2) to be inspected, The roller body (9) is mounted in the sampling device (3) in an elastic manner relative to the surface (2) to be inspected.
  19. 19. A computer program product having program code means for implementing the method as claimed in claim 18 when the program is executed on the control means (6) of the particle inspection system (1).

Description

Particle testing system, sampling bar, projection exposure apparatus and method for testing surface particle contamination The present application claims priority from german patent application number 10 2020 201 935.5, the contents of which are incorporated herein by reference in their entirety. Technical Field The invention relates to a particle inspection system for inspecting a surface for particle contamination, having a sampling strip for sucking up particles and a sampling device. The invention also relates to a projection exposure apparatus for semiconductor lithography. The invention also relates to a sampling strip for a particle inspection system for inspecting a surface for particle contamination. The invention also relates to a use of the sampling strip, a method of inspecting a surface for particle contamination and a computer program product having program code means for implementing the method of inspecting for particle contamination. Background Particle analysis for detecting particle contamination of surfaces can be used in a meaningful way in almost all areas of natural science and technology. Particles deposited on the surface to be inspected may be qualitatively and/or quantitatively performed throughout the particle inspection process or by sampling. The particles are typically small objects of different types, such as abraded metal, abraded plastic, dust or organic substances, depending on the specific technical application and environment. It is often necessary to inspect the surfaces for particle contamination, especially during the process of ensuring technical cleanliness of the technical components. The inspection should ensure that particle contamination of the surface (e.g., due to the manufacture, maintenance and/or operation of the technical components) is sufficiently low that the function of the technical equipment is not limited for short or long periods of time. In particular for components of projection exposure apparatuses, for example for surfaces of optical elements or mechanical components, the assurance of low particle contamination is now of great importance. As semiconductor circuits are continually miniaturized, the demands on resolution and accuracy of projection exposure apparatuses are equally increasing. There are also correspondingly high demands made on the components used there, which in particular influence the beam path in the projection exposure apparatus. In particular, the requirements imposed on the positioning of optical elements, such as mirrors of EUV (extreme ultraviolet) projection exposure apparatuses, are now also very high for resolution reasons. Particle contamination during the manufacturing, during maintenance and during operation of the projection exposure apparatus must also be taken into account due to the high precision required for the optical and mechanical components. Various methods are known in practice for inspecting surfaces for particle contamination. For example, it is known to detect particle contamination of a surface by means of a compressed air probe in combination with an optical particle counter. However, such methods do not provide a reliable sizing option for small particles, and thus reliable statements about size distribution and particle type are often not accurate enough. It is also known that a particle sample can be collected from a surface by means of a collecting bar or an adhesive pad (for example by means of a so-called particle measuring card, PMC) and then optically evaluated by means of incident or glancing light. However, this also does not lead to a meaningful enough conclusion about the size distribution and the particle type, since analytical detection by means of incident or glancing light may lead to a drastic effect on the particles and thus to a distortion of the measurement results. Furthermore, a problem is that the known processes have a high degree of user dependence, which often results in low reproducibility in sampling and evaluation, for example due to manual contact operations of the sampling strips with an uncertain contact pressure. Thus, known methods of sampling a surface to detect particle contamination are associated with high inaccuracy. In particular, there is a need to improve the known methods in order to meet the high requirements of particle inspection of components of projection exposure apparatuses. Disclosure of Invention In view of the known prior art, it is an object of the present invention to provide an improved particle inspection system, with which, in particular, a reduced tendency to errors in the inspection of particle contamination of a surface can be ensured. It is a further object of the invention to provide an improved projection exposure apparatus for semiconductor lithography with a particle inspection system in order to be able to advantageously inspect components of the projection exposure apparatus for particle contamination, in particular with reduced erro