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KR-20260064320-A - WAFER INSPECTION APPARATUS AND INSPECTION METHOD THEROF

KR20260064320AKR 20260064320 AKR20260064320 AKR 20260064320AKR-20260064320-A

Abstract

A substrate inspection device according to one or more embodiments of the present disclosure may include the steps of: placing a substrate on a stage; obtaining a 2D image by irradiating an inspection area of the substrate in a direction perpendicular to the stage; identifying horizontal coordinates of a suspected defect area based on the 2D image; obtaining a 2.5D image by irradiating an inspection area with an angle inclined with respect to the vertical direction with respect to the vertical direction; identifying vertical coordinates of the suspected defect area based on the 2.5D image; obtaining a plurality of rotated images by irradiating an inspection area with respect to the horizontal and vertical coordinates of the suspected defect area with respect to the horizontal coordinates and vertical coordinates of the suspected defect area; and obtaining a 3D reconstructed image of the suspected defect area based on the plurality of rotated images.

Inventors

  • 홍석범
  • 권태진
  • 문정호
  • 이승렬
  • 최가람
  • 안명기
  • 이수영
  • 이형철

Assignees

  • 삼성전자주식회사

Dates

Publication Date
20260507
Application Date
20241031

Claims (10)

  1. Step of placing a substrate on a stage; A step of acquiring a 2D image by irradiating an inspection area of the substrate with respect to the above stage with respect to X-rays; A step of identifying the horizontal coordinates of a suspected defect area based on the above 2D image; A step of acquiring a 2.5D image by irradiating the inspection area with X-rays at an angle inclined with respect to the vertical direction; A step of identifying the vertical coordinates of the suspected defect area based on the above 2.5D image; Based on the horizontal and vertical coordinates of the suspected defect area, a step of obtaining a plurality of rotated images by irradiating the suspected defect area with X-rays; and A substrate inspection method comprising the step of acquiring a 3D reconstruction image of the suspected defect area based on the plurality of rotational images.
  2. In paragraph 1, The step of identifying the vertical coordinates of the suspected defect area is, A step of identifying 2.5D defective pixels among a plurality of pixels based on the brightness value of each of the plurality of pixels included in the 2.5D image; and A substrate inspection method comprising the step of identifying the vertical coordinates of a suspected defect area based on the 2.5D defect pixel and the horizontal coordinates of the suspected defect area.
  3. In paragraph 2, The step of identifying the above 2.5D defect pixels is, The method includes the step of identifying 2.5D defective pixels by comparing the brightness value of each of a plurality of pixels included in the 2.5D image with the brightness value of each of a plurality of pixels included in the 2.5D reference image; A substrate inspection method in which the above 2.5D reference image is a 2.5D image obtained by irradiating the inspection area with X-rays at an angle inclined with respect to the vertical direction when no defects exist in the inspection area.
  4. In paragraph 2, The step of identifying the vertical coordinates of the suspected defect area is, A step of identifying an inclined optical path of X-rays corresponding to the 2.5D defect pixel based on the pixel coordinates of the 2.5D defect pixel and the angle inclined with respect to the vertical direction; and A substrate inspection method comprising the step of identifying the vertical coordinates of the suspected defect area based on the inclined optical path and the horizontal coordinates of the suspected defect area.
  5. In paragraph 1, The step of acquiring the above plurality of rotated images is, The method comprises the step of placing an X-ray detector positioned at the lower part of the stage at each of a plurality of detection points and acquiring each of a plurality of rotational images corresponding to each of the plurality of detection points; Each of the above plurality of detection points is a plurality of points existing on the circumference of a circle centered on a reference point, and A substrate inspection method in which the reference point has the same horizontal coordinates as an X-ray light source positioned at the top of the stage and is a point located at the bottom of the stage.
  6. In paragraph 1, The step of acquiring the above 2D image is, A step of arranging an X-ray light source positioned at the upper part of the stage and an X-ray detector positioned at the lower part of the stage so as to face each other; and A substrate inspection method comprising the step of irradiating an inspection area of the substrate with X-rays in a direction perpendicular to the stage.
  7. In paragraph 1, The step of identifying the horizontal coordinates of the suspected defect area is, A step of identifying 2D defective pixels among a plurality of pixels based on the brightness value of each of the plurality of pixels included in the 2D image; A step of identifying a vertical optical path of an X-ray corresponding to a defect pixel based on the pixel coordinates of the 2D defect pixel; and A substrate inspection method comprising the step of identifying the horizontal coordinates of the suspected defect area based on the vertical optical path of the X-ray.
  8. In paragraph 1, A substrate inspection method in which the angle of inclination with respect to the above vertical direction is 30 to 70 degrees.
  9. In paragraph 1, A substrate inspection method comprising a plurality of semiconductor chips stacked in the vertical direction, wherein the substrate.
  10. In paragraph 1, A substrate inspection method comprising a plurality of semiconductor element layers stacked in the vertical direction, wherein the substrate comprises the above-mentioned substrate.

Description

Wafer Inspection Apparatus and Inspection Method Thereof The present invention relates to a substrate inspection device, and more specifically, to a substrate inspection device comprising an X-ray light source and an X-ray detector. X-ray inspection is a method that utilizes differences in image brightness based on transmission thickness and can be applied to the non-destructive inspection of various industrial products. For example, X-ray inspection can be performed to inspect micro-defects present on a substrate. To detect micro-defects present on a substrate, it is necessary to acquire 3D X-ray images. However, acquiring 3D X-ray images of the entire substrate has the disadvantage of very low throughput. Therefore, there is a growing need for a technology that can quickly identify suspected defect areas within the entire substrate. FIG. 1 is a cross-sectional view schematically showing a substrate inspection device according to one embodiment of the present disclosure. FIG. 2 is a flowchart illustrating a substrate inspection method of a substrate inspection device according to one embodiment of the present disclosure. FIG. 3 is a cross-sectional view for illustrating a substrate according to one embodiment of the present disclosure. FIG. 4 is a cross-sectional view illustrating a method for acquiring a 2D image of a substrate inspection device according to one embodiment of the present disclosure. FIG. 5 is a cross-sectional view illustrating a method for identifying the horizontal coordinates of a suspected defect area of a substrate inspection device according to one embodiment of the present disclosure. FIG. 6 is a cross-sectional view illustrating a method for acquiring a 2.5D image of a substrate inspection device according to one embodiment of the present disclosure. FIG. 7 is a cross-sectional view illustrating a method for identifying the vertical coordinates of a suspected defect area of a substrate inspection device according to one embodiment of the present disclosure. FIG. 8 is a cross-sectional view illustrating a method for obtaining a 3D reconstructed image of a substrate inspection device according to one embodiment of the present disclosure. Embodiments of the present invention will be described in detail below with reference to the attached drawings. Identical components in the drawings are denoted by the same reference numerals, and redundant descriptions thereof are omitted. In this specification, the horizontal direction may include a first horizontal direction (Y direction) and a second horizontal direction (X direction) that intersect each other. The direction intersecting the first horizontal direction (Y direction) and the second horizontal direction (X direction) may be referred to as the vertical direction (Z direction). In this specification, the vertical level may be referred to as a height level according to the vertical direction (Z direction) of any configuration. FIG. 1 is a cross-sectional view schematically showing a substrate inspection device (10) according to one embodiment of the present disclosure. Referring to FIG. 1, the substrate inspection device (10) may include an X-ray light source (110), a light source driving unit (111), an X-ray detector (120), a detector driving unit (121), a stage (130), and a control unit (200). An X-ray light source (110) may be positioned on the upper part of the stage (130). The X-ray light source (110) may emit X-rays toward the substrate (W). Here, the X-ray light source (110) may include an electron optical system and a target. For example, the electron optical system is a Schottky electron gun, and the target can be composed of a tungsten thin film and a diamond thin film. High-energy electrons emitted from the electron optical system can collide with the target, and X-rays can be emitted due to the collision between the high-energy electrons and the target. The X-ray light source (110) may be replaced by various terms referring to a device that emits X-rays, such as "X-ray tube" or "X-ray emitter." However, in this disclosure, it will be referred to by the name "X-ray light source (110)." The light source driving unit (111) is connected to the X-ray light source (110) and can move the X-ray light source (110). Specifically, the light source driving unit (111) can move the X-ray light source (110) in a horizontal direction and/or a vertical direction. Additionally, the light source driving unit (111) can rotate the X-ray light source so that the X-ray light source (110) is positioned in a tilted state with respect to the vertical direction. According to one embodiment, the light source driving unit (111) may move the X-ray light source (110) in a horizontal direction toward a position corresponding to the next inspection area whenever the inspection area (IA) is changed. Additionally, the light source driving unit (111) may rotate the X-ray light source (110) in a vertical direction by an angle corresponding to the changed X-ra