CN-122003729-A - System and method for distortion correction of charged particle beam imaging

Abstract

A system and method for thermal drift correction using feed forward control to reduce SEM image distortion is disclosed. The system may include a charged particle beam apparatus including a charged particle source configured to emit charged particles, a plurality of charged particle beam deflectors configured to affect a path of a primary charged particle beam formed by the emitted charged particles, and one or more processors configured to execute a set of instructions to cause the charged particle beam apparatus to perform operations including obtaining information associated with a thermal drift of a sample stage, determining a thermal drift of the sample stage at an image acquisition location of a sample based on the obtained information, and applying a control signal to at least one of the plurality of charged particle beam deflectors to compensate for the determined thermal drift of the sample stage.

Inventors

• HUANG ZHUANGXIONG
• REN YAN
• Yu Dongchi

Assignees

• ASML荷兰有限公司

Dates

Publication Date

20260508

Application Date

20240913

Priority Date

20231012

Claims (15)

1. 1. A charged particle beam apparatus comprising: A charged particle source configured to emit charged particles; A plurality of charged particle beam deflectors configured to influence a path of a primary charged particle beam formed by the emitted charged particles, the primary charged particle beam to be incident on a surface of a sample, and One or more processors configured to execute a set of instructions to cause the charged particle beam device to perform operations comprising: Obtaining information associated with a thermal drift of the sample stage; determining a thermal drift of the sample stage at an image acquisition location of the sample based on the obtained information, and Applying a control signal to at least one charged particle beam deflector of the plurality of charged particle beam deflectors to compensate for the determined thermal drift of the sample stage.
2. 2. The charged particle beam apparatus of claim 1, wherein the information associated with the thermal drift of the sample stage is obtained based on previous alignment measurements of the sample.
3. 3. The charged particle beam apparatus of claim 1, wherein the information associated with the thermal drift of the sample stage comprises a thermal drift history with respect to sample position and time.
4. 4. The charged particle beam apparatus of claim 3 in which the operations further comprise deriving the thermal drift history based on the previous alignment measurements.
5. 5. The charged particle beam apparatus of claim 1 in which the operations further comprise determining the thermal drift of the sample stage at the image acquisition location by extrapolation techniques.
6. 6. The charged particle beam apparatus of claim 1 in which the operations further comprise determining the thermal drift of the sample stage at the image acquisition location using a feed forward algorithm.
7. 7. The charged particle beam apparatus of claim 1 wherein the operations further comprise applying the control signal to at least one of the plurality of charged particle beam deflectors while an image is acquired.
8. 8. The charged particle beam apparatus of claim 1 in which the operations further comprise adjusting the applied control signal based on the determined thermal drift of the sample stage.
9. 9. Charged particle beam apparatus according to claim 1, wherein the information associated with the thermal drift of the sample stage is obtained using a numerical model.
10. 10. Charged particle beam apparatus according to claim 9, wherein the numerical model comprises a finite element method FEM model.
11. 11. Charged particle beam apparatus according to claim 9, wherein the numerical model is configured to predict the thermal drift of the sample stage based on a thermal load of the stage.
12. 12. Charged particle beam apparatus according to claim 9, wherein the numerical model is configured to predict the thermal drift of the sample stage based on characteristics of a build material of the sample stage.
13. 13. Charged particle beam apparatus according to claim 9, wherein the numerical model is configured to predict the thermal drift of the sample stage based on a movement pattern of the sample stage.
14. 14. The charged particle beam apparatus of claim 9, wherein the numerical model is configured to predict the thermal drift of the sample stage based on inputs including a thermal load of the sample stage, a build material of the sample stage, and a movement pattern of the sample stage.
15. 15. A non-transitory computer-readable medium storing a set of instructions executable by one or more processors of a charged particle beam apparatus to cause the charged particle beam apparatus to perform a method of distortion correcting a charged particle beam image, the method comprising: Obtaining information associated with a thermal drift of the sample stage; Determining a thermal drift of the sample stage at an image acquisition location of the sample based on the obtained information; Applying a control signal to at least one charged particle beam deflector of the plurality of charged particle beam deflectors to compensate for the determined thermal drift of the sample stage at the image acquisition position.

Description

System and method for distortion correction of charged particle beam imaging Cross Reference to Related Applications The present application claims priority from U.S. patent application 63/543,882, filed 10/12 at 2023, and which is incorporated herein by reference in its entirety. Technical Field The description herein relates to the field of charged particle beam systems, and more particularly to systems and methods for distortion correction of measured large field-of-view imaging by applying feedforward control of thermal drift. Background In the fabrication of Integrated Circuits (ICs), unfinished or finished circuit components need to be inspected to ensure that they are fabricated according to a design and are substantially defect free. Inspection systems using optical microscopy typically have a resolution of a few hundred nanometers, with resolution limited by the wavelength of the light. As the physical dimensions of IC components continue to shrink to sub-100 nm and even sub-10 nm, inspection systems with higher resolution than optical microscopy are required. Charged particle (e.g., electron) beam microscopes, such as Scanning Electron Microscopes (SEMs) or Transmission Electron Microscopes (TEMs), with resolution of less than a nanometer, are used as a practical tool for inspecting IC components and performing metrology on wafers with sub-100 nanometer feature sizes. For electron beam metrology of advanced technology nodes, a large field of view (FOV) may be better suited to observe more randomly induced defects in a single image. However, thermal drift associated with excessive acquisition times of large FOV SEM images may inhibit image resolution and image quality at desired locations of metrology cases in advanced device architectures. Disclosure of Invention Embodiments of the present disclosure provide apparatus, systems, and methods for thermal drift correction using feed forward control to reduce SEM image distortion. One aspect of the present disclosure relates to a charged particle beam apparatus comprising a charged particle source for emitting charged particles, the charged particle source configured to emit charged particles, a plurality of charged particle beam deflectors configured to affect a path of a primary charged particle beam formed by the emitted charged particles, and one or more processors configured to execute a set of instructions to cause the charged particle beam apparatus to perform operations comprising obtaining information associated with a thermal drift of a sample stage, determining a thermal drift of the sample stage at an image acquisition location of a sample based on the obtained information, and applying a control signal to at least one of the plurality of charged particle beam deflectors to compensate for the determined thermal drift of the sample stage. Another aspect of the present disclosure relates to a method of distortion correction in a charged particle beam image. The method includes obtaining information associated with a thermal drift of the sample stage, determining a thermal drift of the sample stage at an image acquisition location of the sample based on the obtained information, and applying a control signal to at least one charged particle beam deflector of the plurality of charged particle beam deflectors to compensate for the determined thermal drift of the sample stage at the image acquisition location. Another aspect of the disclosure relates to a non-transitory computer readable medium storing a set of instructions executable by one or more processors of a charged particle beam apparatus to cause the charged particle beam apparatus to perform a method of distortion correcting a charged particle beam image. The method includes obtaining information associated with a thermal drift of the sample stage, determining a thermal drift of the sample stage at an image acquisition location of the sample based on the obtained information, and applying a control signal to at least one charged particle beam deflector of the plurality of charged particle beam deflectors to compensate for the determined thermal drift of the sample stage at the image acquisition location. Other advantages of embodiments of the present disclosure will become apparent from the following description, taken in conjunction with the accompanying drawings, wherein certain embodiments of the present disclosure are set forth by way of illustration and example. Drawings Fig. 1 is a schematic diagram of an exemplary Electron Beam Inspection (EBI) system consistent with an embodiment of the present disclosure. Fig. 2 is a schematic diagram illustrating an exemplary multi-beam system that is part of the exemplary charged particle beam inspection system of fig. 1 consistent with embodiments of the present disclosure. FIG. 3 is a schematic diagram illustrating an example image offset from a given location caused by thermal drift. Fig. 4 is a schematic diagram illustrating the cause of