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US-20260124648-A1 - DEBRIS REMOVAL FROM HIGH ASPECT STRUCTURES

US20260124648A1US 20260124648 A1US20260124648 A1US 20260124648A1US-20260124648-A1

Abstract

A debris collection and metrology system for collecting and analyzing debris from a tip used in nanomachining processes, the system including an irradiation source, an irradiation detector, an actuator, and a controller. The irradiation source is operable to direct incident irradiation onto the tip, and the irradiation detector is operable to receive a sample irradiation from the tip, the sample irradiation being generated as a result of the direct incident irradiation being applied onto the tip. The controller is operatively coupled to an actuator system and the irradiation detector, and the controller is operable to receive a first signal based on a first response of the irradiation detector to the sample irradiation, and the controller is operable to effect relative motion between the tip and at least one of the irradiation source and the irradiation detector based on the first signal.

Inventors

  • Tod Evan Robinson
  • Bernabe Arruza
  • Kenneth Gilbert Roessler
  • David Brinkley
  • Jeffrey E. Leclaire

Assignees

  • Bruker Nano, Inc.

Dates

Publication Date
20260507
Application Date
20251230

Claims (18)

  1. 1 . A method for determining a composition of a particle using a debris collection and metrology apparatus comprising a substrate support assembly and a tip support assembly, each being supported by a base, the substrate support assembly comprising a fixture configured to support an extreme ultraviolet lithography (EUV) photomask, the tip support assembly comprising a scanning probe microscopy (SPM) tip that is coupled to a tip stage assembly via a tip cantilever, the method comprising: transferring the particle from the EUV photomask supported by the fixture to the SPM tip; selectively directing a beam of a first incident irradiation from an irradiation source to a first surface of the SPM tip while the SPM tip is coupled to the tip stage assembly, wherein the particle on the SPM tip is irradiated with the first incident irradiation from the irradiation source; detecting a first sample irradiation from the particle caused by the first incident irradiation with an irradiation detector, the irradiation detector comprising a light detector, in particular an x-ray detector, and/or an electron beam detector; receiving, by a controller, a first signal from the irradiation detector in response to the first sample irradiation, analyzing, by the controller, the first signal, identifying, by the controller one or more material attributes of the particle on the SPM tip; and effecting relative motion between the SPM tip and at least one of the irradiation source and the irradiation detector via one or more actuators of an actuator system based on the first signal from the irradiation detector in response to the first sample irradiation so that the beam of the first incident irradiation from the irradiation source is selectively directed to a second surface of the SPM tip that is different from the first surface of the SPM tip, wherein the one or more actuators effecting the relative motion are provided in the tip stage assembly.
  2. 2 . The method of claim 1 , wherein the first incident irradiation from the irradiation source is at least one of an x-ray, visible light, infrared light, ultraviolet light, an electron beam, and a laser.
  3. 3 . The method of claim 1 , further comprising: generating a first frequency domain spectrum of the first sample irradiation based on the first signal, and generating a second frequency domain spectrum by subtracting a background frequency domain spectrum from the first frequency domain spectrum; and effecting relative motion between the SPM tip and at least one of the irradiation source and the irradiation detector based on the second frequency domain spectrum.
  4. 4 . The method of claim 2 , further comprising generating the background frequency domain spectrum based on a response of the irradiation detector to irradiation of the SPM tip when the SPM tip is substantially free from contamination.
  5. 5 . The method of claim 1 , further comprising: irradiating the SPM tip with a second incident irradiation from the irradiation source; detecting a second sample irradiation caused by the second incident irradiation with the irradiation detector; and effecting relative motion between the SPM tip and at least one of the irradiation source and the irradiation detector based on a second signal from the irradiation detector in response to the second sample irradiation.
  6. 6 . The method of claim 5 , further comprising effecting said relative motion between the SPM tip and at least one of the irradiation source and the irradiation detector in response to a difference between the second signal and the first signal.
  7. 7 . The method of claim 5 , wherein the second incident irradiation from the irradiation source is at least one of an x-ray, visible light, infrared light, ultraviolet light, an electron beam, and laser.
  8. 8 . The method of claim 7 , wherein the second incident irradiation is a different type of irradiation than the first incident irradiation.
  9. 9 . The method of claim 1 , further comprising adjusting an intensity or frequency of the first incident irradiation from the irradiation source.
  10. 10 . The method of claim 5 , further comprising adjusting an intensity or frequency of the second incident irradiation from the irradiation source.
  11. 11 . The method of claim 1 , wherein the first irradiation source comprises an electron beam source and the first irradiation detector comprises an x-ray detector.
  12. 12 . The method of claim 5 , wherein the second irradiation source comprises an electron beam source and the second irradiation detector comprises an x-ray detector.
  13. 13 . The method of claim 1 , wherein transferring the particle from the EUV photomask further comprises contacting the particle with the SPM tip.
  14. 14 . A debris collection and metrology apparatus for determining a composition of a particle comprising: a substrate support assembly comprising a fixture configured to support a substrate that is an extreme ultraviolet lithography photomask; a tip support assembly comprising a scanning probe microscopy SPM tip that coupled to a tip stage assembly via a tip cantilever, wherein the substrate support assembly and the tip support assembly are supported by a base; means for transferring the particle from the substrate supported by the fixture to the SPM tip; an irradiation source configured to selectively direct a beam of a first incident irradiation to a first surface of the SPM tip while the SPM tip is coupled to the tip stage assembly, wherein the particle on the SPM tip is irradiated with the first incident irradiation from the irradiation source; an irradiation detector configured to detect a first sample irradiation from the particle caused by the first incident irradiation; and a controller configured to receive a first signal from the irradiation detector in response to the first sample irradiation, to analyze the first signal, to identify one or more material attributes of the particle on the SPM tip and to effect relative motion between the SPM tip and at least one of the irradiation source and the irradiation detector via one or more actuators of an actuator system based on the first signal from the irradiation detector in response to the first sample irradiation so that the beam of the first incident irradiation from the irradiation source is selectively directed to a second surface of the SPM tip that is different from the first surface of the SPM tip.
  15. 15 . The debris collection and metrology apparatus of claim 14 , wherein the first incident irradiation from the irradiation source is at least one of an x-ray, visible light, infrared light, ultraviolet light, an electron beam, and a laser.
  16. 16 . The debris collection and metrology apparatus of claim 14 , wherein the irradiation detector comprises a light detector and/or an electron beam detector.
  17. 17 . The debris collection and metrology apparatus of claim 16 , the irradiation detector comprises an x-ray detector.
  18. 18 . The debris collection and metrology apparatus of claim 14 , wherein the one or more actuators effecting the relative motion are provided in the tip stage assembly.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This patent application is a continuation of U.S. patent application Ser. No. 18/642,130 filed Apr. 22, 2024, which is continuation of U.S. patent application Ser. No. 18/093,968 filed Jan. 6, 2023 (issued as U.S. Pat. No. 11,964,310), which is a continuation of U.S. patent application Ser. No. 17/348,217 filed Jun. 15, 2021 (issued as U.S. Pat. No. 11,577,286), which is a continuation of U.S. patent application Ser. No. 16/516,842 filed Jul. 19, 2019 (issued as U.S. Pat. No. 11,040,379), which is a divisional of U.S. patent application Ser. No. 15/160,263 filed May 20, 2016 (issued as U.S. Pat. No. 10,384,238), which is a continuation-in-part of U.S. patent application Ser. No. 15/011,411 filed on Jan. 29, 2016 (issued as U.S. Pat. No. 10,618,080), all of which are incorporated herein by reference in their entirety. TECHNICAL FIELD The present disclosure relates generally to nanomachining processes. More particularly, the present disclosure relates to debris removal during and/or after to nanomachining processes. In addition, the debris removal processes of the present disclosure can be applied to removal of anything foreign to a substrate. BACKGROUND Nanomachining, by definition, involves mechanically removing nanometer-scaled volumes of material from, for example, a photolithography mask, a semiconductor substrate/wafer, or any surface on which scanning probe microscopy (SPM) can be performed. For the purposes of this discussion, “substrate” will refer to any object upon which nanomachining may be performed. Examples of photolithography masks include: standard photomasks (193 nm wavelength, with or without immersion), next generation lithography mask (imprint, directed self-assembly, etc.), extreme ultraviolet lithography photomasks (EUV or EUVL), and any other viable or useful mask technology. Examples of other surfaces which are considered substrates are membranes, pellicle films, micro-electronic/nano-electronic mechanical systems MEMS/NEMS. Use of the terms, “mask”, or “substrate” in the present disclosure include the above examples, although it will be appreciated by one skilled in the art that other photomasks or surfaces may also be applicable. Nanomachining in the related art may be performed by applying forces to a surface of a substrate with a tip (e.g., a diamond cutting bit) that is positioned on a cantilever arm of an atomic force microscope (AFM). More specifically, the tip may first be inserted into the surface of the substrate, and then the tip may be dragged through the substrate in a plane that is parallel to the surface (i.e., the xy-plane). This results in displacement and/or removal of material from the substrate as the tip is dragged along. As a result of this nanomachining, debris (which includes anything foreign to the substrate surface) is generated on the substrate. More specifically, small particles may form during the nanomachining process as material is removed from the substrate. These particles, in some instances, remain on the substrate once the nanomachining process is complete. Such particles are often found, for example, in trenches and/or cavities present on the substrate. In order to remove debris, particles or anything foreign to the substrate, particularly in high-aspect photolithography mask structures and electronic circuitry; wet cleaning techniques have been used. More specifically, the use of chemicals in a liquid state and/or agitation of the overall mask or circuitry may be employed. However, both chemical methods and agitation methods such as, for example, megasonic agitation, can adversely alter or destroy both high-aspect ratio structures and mask optical proximity correction features (i.e., features that are generally so small that these features do not image, but rather form diffraction patterns that are used beneficially by mask designers to form patterns). In order to better understand why high-aspect shapes and structures are particularly susceptible to being destroyed by chemicals and agitation; one has to recall that such shapes and structures, by definition, include large amounts of surface area and are therefore very thermodynamically unstable. As such, these shapes and structures are highly susceptible to delamination and/or other forms of destruction when chemical and/or mechanical energy is applied. It is important to note that in imprint lithography and EUV (or EUVL) that use of a pellicle to keep particles off the lithographic surface being copied is currently not feasible. Technologies that cannot use pellicles are generally more susceptible to failure by particle contamination which blocks the ability to transfer the pattern to the wafer. Pellicles are in development for EUV masks, but as prior experience with DUV pellicle masks indicates, the use of a pellicle only mitigates (but does not entirely prevent) critical particle and other contaminates from falling on the surface and any subsequent exposur