KR-20260066861-A - Device and method for wafer vision inspection with high-speed image processing function

KR20260066861AKR 20260066861 AKR20260066861 AKR 20260066861AKR-20260066861-A

Abstract

A wafer vision inspection device according to one embodiment of the present invention comprises: a camera; an alignment moving unit that moves a wafer so that the wafer is aligned based on a source image; and a control unit that determines a notch position regarding a notch of the wafer from the acquired source image, first controls the alignment moving unit so that the wafer is pre-aligned based on the notch position, and secondly controls the alignment moving unit so that the pre-aligned wafer is finely aligned, wherein, when the alignment moving unit is secondarily controlled, the control unit sets a limit on the control value for secondarily controlling the alignment moving unit so that the amount of computation is reduced.

Inventors

소재혁
황태민
이동현
강혜원

Assignees

한국전자기술연구원

Dates

Publication Date: 20260512
Application Date: 20241105

Claims (12)

One or more cameras for acquiring source images of the wafer surface; An alignment moving unit that moves the wafer so that the wafer is aligned based on the acquired source image; and It includes a control unit that determines a notch position regarding a notch of the wafer from an acquired source image, primarily controls an alignment moving unit so that the wafer is pre-aligned based on the notch position, and secondarily controls an alignment moving unit so that the pre-aligned wafer is finely aligned after the wafer is pre-aligned. The control unit is, A wafer vision inspection device having a high-speed image processing function, characterized by setting a limit on the control value for secondary control of the alignment movement unit so as to reduce the amount of computation when secondary control of the alignment movement unit.
In claim 1, The control unit is, When performing secondary control of the alignment movement unit, the marker position regarding the marker of the pre-aligned wafer is determined from the pre-alignment source image of the pre-aligned wafer, and A wafer vision inspection device having a high-speed image processing function, characterized by comparing the marker position of the pre-aligned source image with a pre-stored target image regarding the marker, and then applying an affine transform to the target image to secondarily control the alignment movement unit so that the pre-aligned wafer is finely aligned.
In claim 2, The alignment movement part is, A rotating part for rotating the wafer; including The control unit is, Control the rotating part so that the pre-aligned wafer is finely aligned within a fine alignment rotation angle range having an absolute value smaller than the absolute value of the pre-alignment rotation angle range rotated when the wafer is pre-aligned, A wafer vision inspection device having a high-speed image processing function, characterized by controlling the rotating part to rotate the wafer by a set angle step within a fine alignment rotation angle range.
In claim 3, The control unit is, When controlling a rotation unit so that a pre-aligned wafer is finely aligned within a fine alignment rotation angle range, multiple layers are formed in which the angle steps are set differently from each other, and A wafer vision inspection device having a high-speed image processing function, characterized by, when multiple layers are formed, considering the wafer marker size and the accuracy of the alignment mark used in the actual field, sequentially applying the set angle step value to the control value of the rotation part from the layer with the largest value to the layer with the smallest value among the formed multiple layers.
In claim 2, The above alignment moving part A linear moving part that linearly moves the wafer; is included, The control unit is, Control the linear movement unit so that the pre-aligned wafer is finely aligned within a fine alignment linear movement distance range smaller than the pre-alignment linear movement distance range that is linearly moved when the wafer is pre-aligned, A wafer vision inspection device having a high-speed image processing function, characterized by controlling a linear movement unit so that the wafer moves linearly by a set movement unit value within a fine alignment linear movement distance range.
In claim 5, The control unit is, When controlling a linear movement unit so that a pre-aligned wafer is finely aligned within a range of the fine alignment linear movement distance, multiple layers are formed in which the movement unit values are set differently, and A wafer vision inspection device having a high-speed image processing function, characterized by, when multiple layers are formed, considering the wafer marker size and the accuracy of the alignment mark used in the actual field, sequentially applying the set movement unit value among the formed multiple layers from the layer with the largest value to the layer with the smallest value as the control value of the linear movement unit.
In claim 1, The control unit is, Programmable Logic (PL) of a Field-Programmable Gate Array (FPGA) that calculates control values for linearly moving a wafer; and A wafer vision inspection device having a high-speed image processing function, characterized by including a Processing System (PS) that calculates a control value for rotating the wafer.
In claim 7, Programmable Logic (PL) is, A wafer vision inspection device having a high-speed image processing function, characterized by the ability to process each pixel sequentially or process consecutive pixels in parallel when comparing a pre-aligned source image and a stored target image.
In claim 7, The control value for rotating the wafer is, A wafer vision inspection device having a high-speed image processing function characterized by having a relatively larger amount of computation than the amount of computation of control values that linearly move the wafer.
A wafer vision inspection method using a wafer vision inspection device comprising one or more cameras, an alignment moving unit, and a control unit, wherein A step of acquiring a source image of the wafer surface using one or more cameras; A step of determining a notch position regarding a notch of the wafer from the source image using a control unit, and first controlling an alignment movement unit so that the wafer is pre-aligned based on the notch position; and The method includes the step of secondarily controlling an alignment moving unit using a control unit so that the pre-aligned wafer is finely aligned; The second control step is, A wafer vision inspection method having a high-speed image processing function, characterized by setting a limit on the control value that secondarily controls the alignment movement unit so as to reduce the amount of computation of the control unit.
One or more cameras for acquiring source images of the wafer surface; An alignment moving unit that moves the wafer so that the wafer is aligned based on the acquired source image; and It includes a control unit that determines a notch position regarding a notch of the wafer from an acquired source image, primarily controls an alignment moving unit so that the wafer is pre-aligned based on the notch position, and secondarily controls an alignment moving unit so that the pre-aligned wafer is finely aligned after the wafer is pre-aligned. The alignment movement part is, A rotating part for rotating the wafer; and A linear moving part that linearly moves the wafer; is included, The control unit is, A wafer vision inspection device having a high-speed image processing function, characterized by setting a limit on at least one control value among the control value of the rotating part and the control value of the linear moving part so as to reduce the amount of computation when a pre-aligned wafer is finely aligned.
A wafer vision inspection method using a wafer vision inspection device comprising one or more cameras, an alignment moving unit, and a control unit, wherein A step of acquiring a source image of the wafer surface using one or more cameras; A step of determining a notch position regarding a notch of the wafer from the source image using a control unit, and first controlling an alignment movement unit so that the wafer is pre-aligned based on the notch position; and The method includes the step of secondarily controlling an alignment moving unit using a control unit so that the pre-aligned wafer is finely aligned; The alignment movement part is, A rotating part for rotating the wafer; and A linear moving part that linearly moves the wafer; is included, The second control step is, A wafer vision inspection method having a high-speed image processing function, characterized by setting a limit on at least one control value among the control value of the rotation part and the control value of the linear movement part so as to reduce the computational amount of the control part.

Description

Device and method for wafer vision inspection with high-speed image processing function The present invention relates to a wafer vision inspection device and method, and more specifically, to a wafer vision inspection device and method having a high-speed image processing function. Generally, the semiconductor manufacturing process includes a vision inspection (appearance inspection) process for a wafer with a circuit pattern formed on its surface. In conventional technologies, the control unit performing various operations is implemented using a general PC processor. However, as semiconductor processes become miniaturized, wafer vision inspection of high-resolution images is required; yet, there is a problem in that such general PC processors have limitations in performing high-speed data processing for high-resolution images at low cost. In addition, conventional wafer vision inspection devices align wafers using a general-purpose template matching algorithm that can cover all 360° coordinates, so there is a problem in that there are limitations in performing high-precision alignment work with a small amount of computation. FIG. 1 is a drawing provided in the description of the configuration of a wafer vision inspection device having a high-speed image processing function according to an embodiment of the present invention. FIG. 2 is a drawing provided for a more detailed configuration description of the alignment moving part illustrated in FIG. 1. FIG. 3 is a drawing provided for a more detailed configuration description of the control unit illustrated in FIG. 1. FIG. 4 is a drawing showing the appearance of a wafer to show an example of pre-alignment performed through a wafer vision inspection device according to an embodiment of the present invention. FIG. 5 is a drawing showing the appearance of a wafer to show an example of fine alignment performed through a wafer vision inspection device according to an embodiment of the present invention. FIG. 6 is a drawing provided for explaining a method for limiting a control value for the rotation of a wafer in a micro-alignment process performed through a wafer vision inspection device according to one embodiment of the present invention, and, FIG. 7 is a flowchart provided for the description of a wafer vision inspection method having a high-speed image processing function according to one embodiment of the present invention. The present invention will be described in more detail below with reference to the drawings. To clearly explain the invention, parts unrelated to the description have been omitted from the drawings, and in the drawings, the width, length, thickness, etc., of the components may be exaggerated for convenience. FIG. 1 is a drawing provided in the configuration description of a wafer vision inspection device having a high-speed image processing function according to one embodiment of the present invention. A wafer vision inspection device having a high-speed image processing function according to the present embodiment (hereinafter collectively referred to as a 'wafer vision inspection device') may include one or more cameras (100), an alignment moving unit (200), a control unit (300), and a storage unit (400), as shown in FIG. 1. A camera (100) is provided to acquire a source image of the surface of the wafer. For example, when multiple markers are formed on a wafer, the camera (100) is provided in multiple numbers and can acquire source images for each marker. The alignment moving unit (200) can move the wafer so that the wafer is aligned based on the acquired source image. The storage unit (400) is a storage medium for storing programs and data necessary for the operation of the control unit (300). The control unit (300) is provided to handle all matters for aligning the wafer based on the source image. For example, the control unit (300) can determine the notch position regarding the notch of the wafer from the source image, and first control the alignment moving unit (200) so that the wafer is pre-aligned based on the notch position, and secondly control the alignment moving unit (200) so that the pre-aligned wafer is finely aligned after the wafer is pre-aligned. Specifically, the control unit (300) can control the alignment movement unit (200) so that the wafer is pre-aligned by comparing the notch position determined from the source image with a pre-stored image regarding the notch. Here, the notch may be formed at the edge of the wafer. And when the control unit (300) controls the alignment moving unit (200) in a second manner, by setting a limit on the control value that controls the alignment moving unit (200) in a second manner, the amount of computation required for wafer fine alignment can be reduced. FIG. 2 is a drawing provided for a more detailed configuration description of the alignment moving unit (200) shown in FIG. 1, FIG. 3 is a drawing provided for a more detailed configuration description of the control unit (300) s