Sensorless substrate image collection method, recording medium therefor, method and apparatus for inspecting substrate defect

Abstract

A sensorless substrate image collection method according to an embodiment is a method for collecting substrate images by photographing a substrate being transported by a transport robot with a line scan camera, comprising: a step of collecting a plurality of test line images by test photographing the substrate at a preset line rate using the line scan camera during the process of transporting the substrate by the transport robot; a step of estimating the movement speed of the substrate for each movement section by analyzing the plurality of test line images; a step of calculating a trigger interval for each movement section of the substrate using the movement speed of the substrate for each movement section, and generating a trigger profile by accumulating a plurality of the calculated trigger intervals; and a step of collecting substrate images by controlling the line scan camera using the trigger profile during the process of transporting a substrate to be inspected by the transport robot.

Description

Technology Field

[0001] The present invention relates to a sensorless image collection method capable of collecting high-resolution images from a moving substrate without using a sensor, a recording medium for the same, and a substrate defect inspection method and apparatus utilizing the sensorless image collection method. Background Technology

[0002] Semiconductor devices are manufactured by repeatedly performing a series of processing steps, such as a deposition process to form a thin film on a substrate and an etching process to form a pattern on a substrate.

[0003] During the semiconductor manufacturing process described above, contaminants may adhere to the substrate, or various defects such as cracks, chipping, and broken parts may occur due to the manufacturing process. Accordingly, conventionally, after performing the semiconductor manufacturing process, a separate inspection device is used to conduct defect inspections to check for the occurrence of defects on the substrate.

[0004] Recently, a substrate inspection device has been developed and is being utilized that photographs a portion of a substrate using a line scan camera during the process of transporting a substrate to a substrate processing device using a transport robot, collects a substrate image by aligning the captured portions, and inspects for defects on the substrate using the collected substrate image.

[0005] The above-described substrate inspection device utilizes a method of generating a trigger signal at regular time intervals to photograph a substrate moving in a straight line; however, this method has a problem in that precise substrate inspection is difficult because distortion phenomena, such as compression or stretching of some line scan areas in the collected substrate images, frequently occur. The problem to be solved

[0006] According to one embodiment, the invention provides technical content regarding a sensorless image acquisition method and a recording medium that enables precise shooting of a moving substrate and enables the acquisition of high-resolution images by first collecting a test line image through test shooting before collecting a substrate image, calculating the movement speed of each moving section of the substrate, calculating the trigger interval between pulses based on the calculated movement speed of each section, and creating a trigger profile by accumulating the calculated trigger interval data for each moving section to control the line rate of a line scan camera.

[0007] According to one embodiment, the invention aims to provide technical content regarding a sensorless image acquisition method and a recording medium that can collect high-resolution images even when the movement speed of a substrate changes, by eliminating the need for a separate speed sensor and by identifying constant speed sections, deceleration sections, and acceleration sections during the movement of the substrate to generate a trigger profile including trigger intervals of irregular time lengths to control a line scan camera.

[0008] According to one embodiment, the invention aims to provide technical content regarding a sensorless image acquisition method and a recording medium capable of calculating the pulse interval of a trigger signal for each moving section of a substrate, and arranging the calculated pulse interval of the trigger signal for each moving section of the substrate to enable trigger pulse scheduling.

[0009] According to one embodiment, a trigger signal pulse is generated according to an accumulated time array in microsecond units, and the scanning timing of the TDI camera can be synchronized according to the number of accumulated stages (number of shots) by reflecting the shooting characteristics of a time difference delay method. In particular, the trigger interval increases during the deceleration section, and the maximum pulse time of the trigger signal can be limited through the duty cycle, thereby providing technical content regarding a sensorless image acquisition method and a recording medium specialized for TDI cameras. means of solving the problem

[0010] A sensorless substrate image collection method according to an embodiment is an image collection method for collecting substrate images by photographing a substrate being transported by a transport robot with a line scan camera, comprising: a step of collecting a plurality of test line images by test photographing the substrate at a preset line rate using the line scan camera during the process of transporting the substrate by the transport robot; a step of estimating the movement speed of the substrate for each movement section by analyzing the plurality of test line images; a step of calculating a trigger interval for each movement section of the substrate using the movement speed of the substrate for each movement section, and generating a trigger profile by accumulating a plurality of the calculated trigger intervals; and a step of collecting substrate images by controlling the line scan camera using the trigger profile during the process of transporting a substrate to be inspected by the transport robot.

[0011] According to one embodiment, the transfer robot may have a structure comprising a main rotation axis, a plurality of robot arms connected to the main rotation axis in a bidirectional rotational structure, an end effector connected to one end of the robot arm, and a plurality of sub-rotation axes for driving the plurality of robot arms and the end effector in bidirectional rotation, respectively.

[0012] According to one embodiment, the transfer robot can transfer the substrate with a speed profile including constant velocity motion, acceleration motion, and deceleration motion with respect to the direction of movement of the substrate.

[0013] According to one embodiment, the step of collecting the test line image may be performed by using a defect-free substrate in which no defects occur on the surface or a substrate having a square grid pattern formed on its surface.

[0014] According to one embodiment, the step of estimating the movement speed of the substrate for each movement section comprises: detecting the intersection point of a pattern displayed on the test line image; measuring the length of the pattern in the Y-axis direction and calculating the distortion ratio of the test line image by comparing it with a reference line image; and calculating the movement speed of the substrate in the section where the test line image was captured using the distortion ratio of the test line image.

[0015] According to one embodiment, the step of estimating the movement speed of the substrate for each movement section may involve estimating the movement speed of the substrate for each movement section, then identifying a constant speed section, an acceleration section, and a deceleration section among the movement sections of the substrate, calculating a trigger interval for adjusting the line rate of the line scan camera based on the movement speed data of the identified acceleration section and deceleration section, and generating the trigger profile by accumulating the calculated trigger interval for the movement sections of the substrate.

[0016] According to one embodiment, the trigger profile may include at least one parameter among the total number of pulses of a trigger signal for adjusting the line rate of the line scan camera, the interval between each pulse of the trigger signal, and the peak holding time of the pulse of the trigger signal.

[0017] According to one embodiment, the step of generating the trigger profile involves, when a deceleration section is identified among the moving sections of the substrate, evaluating the trigger HIGH holding time of the identified deceleration section, and if the trigger HIGH holding time of the identified deceleration section exceeds a preset reference time, shortening the trigger HIGH holding time to the same time as the preset time, or dividing the trigger HIGH holding time into a plurality of unit times to sub-pulse it.

[0018] Meanwhile, the substrate defect inspection method according to the embodiment is a substrate defect inspection method for inspecting whether there is a defect on the surface of a substrate by photographing a substrate being transported by a transport robot with a line scan camera, and may include: a step of collecting a plurality of test line images by test photographing the substrate at a preset line rate using the line scan camera during the process of transporting the substrate by the transport robot; a step of estimating the movement speed of the substrate for each movement section by analyzing the plurality of test line images; a step of calculating a trigger interval for each movement section of the substrate using the movement speed of the substrate for each movement section, and generating a trigger profile by accumulating a plurality of the calculated trigger intervals; a step of collecting a substrate image by controlling the line scan camera using the trigger profile during the process of transporting the substrate to be inspected by the transport robot; and a step of inspecting whether a defect has occurred on the substrate to be inspected by comparing the substrate image with a reference image.

[0019] A substrate defect inspection device according to an embodiment may include: a shooting module that collects substrate images including a line scan camera that photographs the substrate during the process of transporting the substrate; a transport module that includes a transport robot that transports the substrate; a calculation module that collects a plurality of test line images by test-photographing the substrate at a preset line rate using the line scan camera, analyzes the plurality of test line images to estimate the movement speed of the substrate for each movement section, calculates a trigger interval for each movement section of the substrate using the movement speed of the substrate for each movement section, and generates a trigger profile by accumulating a plurality of the calculated trigger intervals; a control module that receives the trigger profile generated by the calculation module and controls the line scan camera to collect substrate images using the trigger profile during the process of transporting the substrate to be inspected to the transport robot; and an inspection module that checks whether a defect has occurred on the substrate to be inspected by comparing the substrate image with a reference image.

[0020] The recording medium according to the embodiment may have a computer-readable structure on which a program for performing the substrate image collection method described above is recorded. Effects of the invention

[0021] A sensorless substrate image acquisition method according to an embodiment first acquires a test line image through test shooting before acquiring a substrate image to calculate the movement speed of the substrate for each movement section, calculates the trigger interval between pulses based on the calculated movement speed for each section, and generates a trigger profile by accumulating the calculated trigger interval data for each movement section, and controls the line rate of a line scan camera using the trigger profile when shooting a substrate to be inspected, thereby enabling precise shooting of a moving substrate and enabling the acquisition of high-resolution images.

[0022] The sensorless substrate image acquisition method according to the embodiment does not require a separate speed sensor and can control a line scan camera by identifying constant speed sections, deceleration sections, and acceleration sections during the movement of the substrate and generating a trigger profile that includes trigger intervals of irregular time lengths, thereby enabling the acquisition of high-resolution images even when the movement speed of the substrate changes.

[0023] The sensorless substrate image acquisition method according to the embodiment enables the calculation of pulse intervals of trigger signals for each moving section of the substrate, and enables trigger pulse scheduling by arranging the calculated pulse intervals of trigger signals for each moving section of the substrate in an accumulated time sequence.

[0024] The sensorless substrate image acquisition method according to the embodiment generates trigger signal pulses according to an accumulated time array in microsecond units and can synchronize the scanning timing of the TDI camera with the number of accumulated stages (number of shots) by reflecting the shooting characteristics of the time difference delay method, and in particular, the trigger interval increases during the deceleration section, and the maximum time of the trigger signal pulse can be limited through the duty cycle, so that substrate images can be acquired specialized for the TDI camera. Brief explanation of the drawing

[0025] FIG. 1 is a state diagram showing (a) the state before transferring the substrate with a transfer robot and (b) the state of transferring the substrate with a transfer robot to explain a line scan substrate image collection method according to an embodiment. Figure 2 is a process diagram illustrating a line scan substrate image collection method according to an embodiment. FIG. 3 is a conceptual diagram illustrating the process of collecting a test image through a line scan substrate image collection method according to an embodiment. FIG. 4 is a conceptual diagram illustrating a line scan substrate image acquisition method according to an embodiment, showing (a) a trigger profile having a regular trigger interval, (b) a trigger profile having an irregular trigger interval, and (c) a trigger profile having an irregular trigger interval, wherein the trigger HIGH holding time in the deceleration section is divided into a plurality of unit times to form sub-pulses. FIG. 5 is a conceptual diagram showing (a) a normal test line image, (b) a test line image with increased length in the direction of substrate movement, and (c) a test line image with reduced length in the direction of substrate movement, collected by a line scan substrate image collection method according to an embodiment. Figure 6 is a process diagram showing a substrate defect inspection method according to an embodiment. FIG. 7 is a configuration diagram showing a substrate defect inspection device according to an embodiment. Specific details for implementing the invention

[0026] FIG. 1 is a state diagram showing (a) the state before transferring the substrate with a transfer robot and (b) the state of transferring the substrate with a transfer robot to explain a line scan substrate image collection method according to an embodiment.

[0027] The line scan-based image collection method according to the embodiment relates to a method for collecting a substrate image by taking a picture of a substrate (S) being transferred to a transfer robot (130) with a line scan camera, i.e., a shooting module (110), as shown in FIG. 1(a), while the substrate is loaded on a transfer robot (130) as shown in FIG. 1(b).

[0028] At this time, the transfer robot (130) rotates a plurality of robot arms while the substrate (S) is loaded on the end effector to transfer the substrate (S) from the substrate storage unit (11) to the target area (15).

[0029] The above transfer robot (130) may have a structure comprising a main rotation axis for loading and transferring a substrate (S), a plurality of robot arms connected to the main rotation axis in a bidirectional rotational structure, an end effector connected to one end of the robot arm and having a substrate (S) loaded on its upper surface, and a plurality of sub-rotation axes for driving the plurality of robot arms and the end effector in bidirectional rotational directions, respectively.

[0030] A transfer robot (130) having the above-described structure has a structure in which a plurality of robot arms rotate by means of a sub-rotation axis to transfer a substrate (S) in one direction. As a result, the transfer robot (130) forms a structure in which the substrate (S) is transferred with a speed profile of constant speed, acceleration, and deceleration with respect to the direction of movement of the substrate (S). That is, the transfer robot (130) does not transfer the substrate (S) in the direction of movement only with constant speed, but forms a structure in which a plurality of robot arms rotate to transfer the substrate (S) in one direction, thereby forming a structure in which the movement speed of the substrate changes according to the transfer section during the process of transferring the substrate (S).

[0031] As described above, when a substrate (S) is transferred by a transfer robot (130) that does not move at a constant speed and the substrate (S) is line-scanned at a constant line rate, a region in which the line image is compressed into a short length or a region in which it is stretched out is formed in the section where the moving speed of the substrate accelerates or decelerates, and there is a problem that it is difficult to accurately inspect for substrate defects from the generated substrate image when the substrate image is created by aligning such distorted line images.

[0032] The sensorless substrate image acquisition method according to the embodiment relates to a control technology that enables the control of a trigger signal based on the movement speed of the substrate (S) in order to minimize image distortion caused by changes in the movement speed of the substrate (S) and to capture the substrate (S) precisely.

[0033] Hereinafter, a method for collecting images of a sensorless substrate according to an embodiment will be described in detail.

[0034] FIG. 2 is a process diagram illustrating a line scan substrate image collection method according to an embodiment. FIG. 3 is a conceptual diagram illustrating the process of collecting a test image through a line scan substrate image collection method according to an embodiment.

[0035] Referring to FIGS. 2 and 3, a substrate image collection method according to an embodiment may include the step of collecting a test line image (S110), the step of estimating the movement speed of a substrate (S) for each movement section (S120), the step of generating a trigger profile (S130), and the step of collecting a substrate image (S140).

[0036] First, in step S110, during the process of transferring the substrate (S) to the transfer robot (130), the substrate (S) is test-photographed using the line scan camera to collect a test line image.

[0037] Referring to FIG. 3, the line scan camera scans test line images one line at a time in the direction in which the substrate (S) moves (Y-axis direction).

[0038] Specifically, the line scan camera can generate a single test line image by scanning a line area for a single substrate movement section in a direction perpendicular to the movement direction of the substrate (S) (X-axis direction), and can generate a two-dimensional planar substrate image by aligning the generated multiple test line images (S1 to S11).

[0039] In particular, the line scan camera can utilize a TDI camera. The TDI camera can repeatedly capture a single shooting area on a substrate (S) multiple times and superimpose multiple captured image data to generate a single superimposed image for a single shooting area, and can align multiple superimposed images to generate a single two-dimensional substrate image.

[0040] In this step, to increase the accuracy of the estimation of the movement speed for each movement section of the substrate (10), a defect-free substrate that does not have defects on its surface or a substrate with a square grid pattern formed on its surface is used to collect test line images.

[0041] In the above step S120, the test line image is analyzed to estimate the movement speed of the substrate for each movement section.

[0042] Specifically, in step S110, a substrate (S) is transported using a transport robot (130) having the structure described above, and a test line image is collected by test-photographing the substrate (S) during the process of transporting the substrate (S) in order to generate a trigger profile. At this time, the line scan camera is controlled by a preset line rate, and the line rate generates a trigger signal at regular, that is, at regular time intervals to control the line scan camera. Then, the transport robot (130) transports the substrate (S) with a speed profile that includes constant velocity motion, acceleration motion, and deceleration motion with respect to the transport direction in which the substrate (S) is transported. Accordingly, the collected test line image is in a state where image distortion occurs, including compressed areas and stretched areas.

[0043] In this step, compressed and stretched regions are identified in the collected test line images, and features of the identified regions are extracted to estimate the movement speed of the substrate (S) for each movement section.

[0044] Specifically, in this step, the intersection points of the pattern appearing in the collected test line image are detected, the distance or length of the pattern in the Y-axis direction (or the direction of movement of the substrate) is measured, the distortion ratio of the collected test line image relative to the reference line image is calculated, and the movement speed of the substrate in the area where the collected test line image was captured can be calculated using the calculated distortion ratio. The test line image may capture a grid pattern in which a plurality of grids are formed.

[0045] FIG. 4 is a conceptual diagram illustrating a line scan substrate image acquisition method according to an embodiment, showing (a) a trigger profile having a regular trigger interval, (b) a trigger profile having an irregular trigger interval, and (c) a trigger profile having an irregular trigger interval, wherein the trigger HIGH holding time in the deceleration section is subpulsed by dividing it into a plurality of unit times. FIG. 5 is a conceptual diagram showing (a) a normal test line image, (b) a test line image with an extended length in the substrate movement direction, and (c) a test line image with a shortened length in the substrate movement direction, collected by the line scan substrate image acquisition method according to an embodiment.

[0046] Referring to FIG. 4(a), in step S110, a plurality of test line images (S1 to S11) are collected while the substrate (S) moves at a preset line rate. At this time, the line rate is controlled by a trigger profile in which the trigger signal is turned on and off at regular intervals, and the trigger interval (G) is all the same.

[0047] In addition, to explain using the 11th test line image captured during the 11th movement section (S11) as an example, as shown in FIG. 4(a), when the substrate is captured at a line rate suitable for the movement speed of the substrate, a test line image having a length (d1) corresponding to the movement section can be collected.

[0048] On the other hand, as shown in FIG. 4(b), when the moving speed of the substrate is faster than the line rate, a test line image is generated that includes an area with a length (d2) increased in the Y-axis direction. And, as shown in FIG. 4(c), when the moving speed of the substrate is slower than the line rate, a test line image is generated that includes an area with a length (d3) decreased in the Y-axis direction.

[0049] In this step, in order to collect high-resolution line images when photographing the substrate, the test line images are analyzed to estimate the movement speed of the substrate for each movement section.

[0050] In this step, the intersection points of the grid pattern appearing in the collected test line image are detected. If a bare wafer is photographed, the edge region of the substrate is detected in the collected test line image, and the moving speed of the substrate is calculated by evaluating the edge region.

[0051] Then, the distance in the Y-axis direction of the pattern displayed on the test line image is measured to identify whether the test line image is in a compressed or stretched state. If, as a result of identification, distortion occurs where the pattern on the test line image is compressed or stretched, the distortion ratio of the test line image is calculated, and the movement speed of the substrate in the area where the test line image was captured can be calculated using the calculated distortion ratio.

[0052] At this time, in the case of an acceleration section where the movement speed is faster than the moving speed of the substrate applied to calculate the preset line rate, the image is stretched, and in the opposite case, as a deceleration section, the length of the image is reduced by compression. Also, if the deviation of the moving speed increases, the distortion ratio increases.

[0053] The movement speed and line rate of the above substrate (S) can be calculated using the following Equation 1.

[0054] [Equation 1]

[0055]

[0056] In the above Equation 1, the reference real interval refers to the length in the Y-axis direction of the pattern appearing in the test line image determined to be normal, the corresponding image interval refers to the length in the Y-axis direction of the pattern appearing in the test line image, and the line rate refers to the number of test line images that the line scan camera can collect in one second. In addition, the line rate refers to the Y-axis interval of a single test line image, that is, a test line image that the line scan camera can collect in one second.

[0057] If the scan interval of the reference line scan camera and the preset line rate (lines / second) are known, the movement speed of the substrate can be inversely calculated using Equation 1 below.

[0058] In this step, a reference feature is extracted from one of the collected multiple test line images, and the Y-axis interval of the reference feature extracted from one test line image is calculated. The Y-axis interval exhibits the characteristic that it increases as the image length increases in the case of an acceleration section where the moving speed of the substrate (S) is fast relative to the line rate, and decreases as the image length becomes shorter in the case of a deceleration section where the moving speed of the substrate (S) is relatively slow.

[0059] In this step, using the characteristics described above, the movement speed can be estimated and calculated for each movement section of the substrate, such as acceleration sections, deceleration sections, and constant speed sections, and the acceleration sections and deceleration sections can be specified.

[0060] In step S130 above, a trigger profile including a segment-specific trigger signal calculated using the movement speed of each movement segment of the substrate (S) is generated.

[0061] In this step, a trigger profile including an irregularly shaped trigger interval for controlling the line rate can be generated using the moving speed of the substrate in the acceleration and deceleration sections of the moving section of the substrate (S).

[0062] Specifically, referring to FIG. 4(b), a trigger profile is generated such that a trigger signal is generated at a corresponding trigger interval according to the constant speed section, the acceleration section, and the deceleration section. At this time, the line rate is such that the trigger signal is turned on and off at irregular intervals, and the trigger intervals (G1~G8) are controlled by an irregular trigger profile corresponding to the movement speed of the substrate.

[0063] And, since the deviation from the constant velocity section's movement speed may differ for each of the acceleration and deceleration sections, a trigger interval is calculated from a single test line image based on the movement speed data of the acceleration and deceleration sections, and these are accumulated to form a trigger profile ( triggerCumulative It can generate ), and the trigger profile and trigger interval ( TriggerInterval ) can be calculated using the following Equations 2 and 3.

[0064] [Equation 2]

[0065]

[0066] [Equation 3]

[0067]

[0068] In the above Equation 2 triggerCumulative [i] represents a trigger profile that accumulates the trigger interval of a single test line image.

[0069] Then, the trigger intervals (G1~G8) are calculated according to the movement speed of the substrate (S) estimated in each movement interval and accumulated, and consequently, the trigger profile includes information on when, i.e., after how many μs, a trigger signal must be generated for each movement interval to minimize image distortion. That is, in the image acquisition method according to the embodiment, instead of generating a regular type of trigger profile that generates a trigger signal at a constant interval, a trigger profile can be generated in which a trigger array of trigger signals at irregular intervals is accumulated so that precise image acquisition is possible even for intervals where the movement speed of the substrate changes.

[0070] Accordingly, the trigger profile includes pulse time information at irregular intervals optimized for the movement speed of each movement segment rather than at regular intervals for the trigger signal, and enables control of the line rate of the line scan camera. The trigger profile is composed of an array of relative time information for which the trigger signal should be generated, and the time array can be utilized by a control unit for controlling the line scan camera.

[0071] The above trigger profile may include various parameters such as the total number of trigger signal pulses, the trigger signal pulse interval, and the maximum peak (high) holding time of the trigger signal pulse.

[0072] A trigger profile having an irregular trigger interval array as described above can be configured to control light generation and irradiation by synchronizing not only a line scan camera but also a light source unit that generates and irradiates light, thereby enabling the acquisition of a stable substrate image without distortion even when the substrate is moving at high speed.

[0073] In summary, the sensorless substrate image acquisition method according to the embodiment can estimate the movement speed of the actual substrate for each movement section from a test line image without a speed sensor. Then, based on the estimated movement speed of the substrate, an irregular trigger interval is calculated, an accumulated time array is constructed using the calculated trigger interval, and a line scan camera and a light source are synchronously controlled according to the array to acquire substrate images based on a line scan method.

[0074] The above irregular trigger interval means that the interval (G1~G8) at which a trigger signal instructing shooting is generated may be irregular when a line scan camera or TDI camera repeatedly shoots a moving substrate multiple times based on the calculated trigger timing, after calculating the optimal trigger signal generation timing for each movement section of the substrate (S).

[0075] The image acquisition method according to the embodiment is applicable to both line scan cameras and TDI cameras, and is a technology specifically specialized for TDI cameras.

[0076] Specifically, a time delay integration camera (TDI camera) collects test line images by repeatedly capturing the same area on a moving substrate (S) multiple times, and enables the collection of high-sensitivity images by accumulating multiple test line images captured for a single area. Due to the structural characteristics of the TDI camera that allow for the accumulation of multiple images as described above, if the movement speed of the substrate (S) changes differently depending on the movement section, the accumulation timing may not be uniform, which may result in problems such as distortion, accumulation failure, and increased noise in the substrate image.

[0077] However, the line scan-based image acquisition method according to the embodiment can be reconfigured so that the trigger interval for each moving section is irregular, that is, not a fixed period, but an optimized trigger signal interval (G1~G8) for each moving section to respond to changes in the moving speed of the substrate (S), and the trigger profile is configured in the form of an accumulated time array in microseconds (μs), thereby enabling the operation of the TDI camera in a form synchronized with the actual moving speed of the substrate (S) and providing stable accumulated timing.

[0078] In addition, the image acquisition method according to the embodiment can reflect the shooting characteristics of a time difference delay method by limiting the maximum pulse time (t) of the trigger signal.

[0079] Specifically, in the deceleration section, the maximum peak holding time of the trigger signal pulse may become excessively long due to the characteristic that the pulse interval of the trigger signal, i.e., the trigger interval, becomes longer; however, in the image acquisition method according to the embodiment, an additional function can be provided to control the trigger signal pulse to decrease when the maximum peak holding time of the trigger signal pulse in the deceleration section exceeds a preset reference holding time.

[0080] In the deceleration section where the moving speed of the substrate decreases, the trigger interval increases, and the High peak holding time increases. As shown in FIG. 5(b), in the deceleration section, the High peak holding time, i.e., the pulse maximum time (t), exceeds the set standard (MAX_HIGH_US).

[0081] In the substrate image acquisition method according to the embodiment, as shown in FIG. 5(c), when the maximum pulse time in the deceleration section exceeds a set standard, the maximum pulse time (t) is divided into multiple parts (t1, t2) to form sub-pulses.

[0082] At this time, the maximum peak holding time of the trigger signal pulse can be configured to be selectively controlled as needed, but methods such as adjusting the duty cycle to 50:50 or controlling the maximum peak to be maintained only for a preset time can be utilized. That is, if the maximum peak holding time of the trigger pulse exceeds a preset time, the peak of the trigger pulse can be reduced during the subsequent time, or the trigger pulse can be divided so that what was originally a single pulse is divided into multiple pulses, thereby preventing overexposure and signal collision and enabling the collection of high-resolution line images.

[0083] In addition, the sensorless substrate image acquisition method according to the embodiment is implemented as a pulse scheduler that generates trigger signal pulses according to an accumulated time array in microsecond units, thereby enabling the realization of a resolution in micrometer units (less than 10 μm, particularly 3 μm) of the TDI camera.

[0084] Next, in step S140, the trigger profile is applied during the process of transporting the substrate (S) to be inspected by the transport robot (130) to control the line scan camera and light source to collect an image of the substrate.

[0085] In this step, the line scan camera and the light source are synchronized based on the trigger signal data stored in the trigger profile so that the optimal test line image can be collected for each moving section of the substrate (S), and the line rate of the camera can be adjusted so that the high-resolution substrate image can be collected.

[0086] The sensorless substrate image acquisition method according to the embodiment described above first collects a test line image through test shooting before collecting a substrate image to calculate the movement speed of the substrate for each movement section, calculates the trigger interval between pulses based on the calculated movement speed for each section, and generates a trigger profile by accumulating the calculated trigger interval data for each movement section, and controls the line rate of the line scan camera using the trigger profile when shooting the substrate to be inspected, thereby enabling precise shooting of the moving substrate and enabling the collection of high-resolution images.

[0087] The sensorless substrate image acquisition method according to the embodiment does not require a separate speed sensor and can control a line scan camera by identifying constant speed sections, deceleration sections, and acceleration sections during the movement of the substrate and generating a trigger profile that includes trigger intervals of irregular time lengths, thereby enabling the acquisition of high-resolution images even when the movement speed of the substrate changes.

[0088] The sensorless substrate image acquisition method according to the embodiment enables the calculation of pulse intervals of trigger signals for each moving section of the substrate, and enables trigger pulse scheduling by arranging the calculated pulse intervals of trigger signals for each moving section of the substrate in an accumulated time sequence.

[0089] The sensorless substrate image acquisition method according to the embodiment generates trigger signal pulses according to an accumulated time array in microsecond units and can synchronize the scanning timing of the TDI camera with the number of accumulated stages (number of shots) by reflecting the shooting characteristics of the time difference delay method, and in particular, the trigger interval increases during the deceleration section, and the maximum time of the trigger signal pulse can be limited through the duty cycle, so that substrate images can be acquired specialized for the TDI camera.

[0090] Furthermore, it can be implemented using only an external trigger board without modifying the structure of existing equipment, and since it is implemented with a pulse scheduler based on an accumulated time array, it can generate trigger profiles suitable for various equipment, allowing for universal application even when different manufacturers use transfer robots.

[0091] Meanwhile, FIG. 5 is a process diagram showing a substrate defect inspection method according to an embodiment.

[0092] Referring to FIG. 5, a substrate defect inspection method according to an embodiment may include the steps of collecting a test line image (S210), estimating the movement speed of a substrate for each movement section (S220), generating a trigger profile (S230), collecting a substrate image (S240), and evaluating whether a defect has occurred on the surface of the inspection target by comparing the substrate image with a reference image (S250).

[0093] In the substrate defect inspection method according to the embodiment, a substrate image of the substrate (S) to be inspected is generated using the image generation method described above, and a detailed description thereof is omitted.

[0094] And, in step S250, the occurrence of defects on the surface of the substrate (S) to be inspected is evaluated by comparing the substrate image and the reference image. The reference image may be collected from the substrate (S) to be inspected having the same shape and structure as determined to be free of defects.

[0095] Meanwhile, FIG. 6 is a configuration diagram showing a substrate defect inspection device according to an embodiment.

[0096] Referring to FIG. 6, a substrate defect inspection device according to an embodiment may have a structure including a shooting module (110), a transfer module (130), a calculation module (150), a control module (170), and an inspection module (190).

[0097] The above-described shooting module (110) serves to collect a test line image and a substrate image of the substrate (S) to be analyzed, respectively. The above-described shooting module (110) may include a shooting unit (111), a lighting unit (113), and an emission change unit (115).

[0098] The above-described imaging unit (111) can collect reflected light reflected from the substrate (S) to be analyzed. The reflected light may refer to light reflected after irradiating light onto the substrate (S) to be analyzed by the illumination unit (113) to be described later.

[0099] The above-mentioned shooting unit (111) can be implemented using a shooting means having various conventional forms that are utilized to photograph a substrate (S) and generate a substrate image.

[0100] Specifically, the above-mentioned shooting unit (111) can be a TDI scan camera (Time delay integration scan camera) or a line scan camera as representative examples. In particular, the above-mentioned shooting unit (111) can use a TDI scan camera.

[0101] The above TDI scan camera can continuously take photos of the substrate (S) to be analyzed from the first shooting point to the last shooting point, and can generate a substrate image that displays the entire substrate (S) to be analyzed by overlapping multiple captured line scan images.

[0102] The above-mentioned imaging unit (111) may be positioned at a certain distance from the substrate (S) to be analyzed. The imaging unit (111) may collect line scan images having a certain length in the X-axis direction, parallel to the transport direction of the substrate (S) to be analyzed.

[0103] The lighting unit (113) can irradiate light onto the substrate (S) to enable the surface of the substrate (S) to be photographed. The lighting unit (113) may include at least one light source to irradiate light onto the substrate (S). The lighting unit (111) may have a structure that irradiates light onto the substrate (S) at the same angle of incidence or at different angles of incidence.

[0104] The above-mentioned emission change unit (115) may be positioned between the above-mentioned shooting unit (111) and the above-mentioned substrate (S). The above-mentioned emission change unit (115) can change the path of reflected light reflected from the substrate (S). The above-mentioned emission change unit (115) can concentrate reflected light from various directions reflected from the substrate (S) into a single direction and transmit it to the above-mentioned shooting unit (111). The above-mentioned emission change unit (115) can be implemented using a prism that is utilized to change the path of light.

[0105] The above transfer module (130) performs the role of transferring a substrate (S) by including a transfer robot (130) that transfers the substrate to a target point. The above transfer module (130) can be implemented using a transfer robot comprising a main rotation axis, a plurality of robot arms connected to the main rotation axis in a bidirectional rotational structure, an end effector connected to one end of the robot arm, and a plurality of sub-rotation axes for driving the plurality of robot arms and the end effector in bidirectional rotation, respectively.

[0106] The above computation module (150) analyzes a plurality of test line images collected by test-taking the substrate (S) and estimates the movement speed of the substrate (S) for each movement section.

[0107] The control module (170) receives the trigger profile generated by the computation module (150) and controls the line scan camera of the camera module (110) to collect a substrate image using the trigger profile during the process of transferring the substrate (S) to the transfer robot (130).

[0108] Specifically, the control module (170) generates a trigger profile including a segment-specific trigger signal calculated using the movement speed of the transfer robot (130) for each movement segment, and generates the segment-specific trigger signal included in the generated trigger profile and transmits it to the shooting module (110) so that the line rate of the shooting unit (111) can be adjusted for each movement segment of the substrate. The shooting module controls the line rate according to the trigger profile provided by the computation module (150) to collect a plurality of line images and align them to generate a substrate image.

[0109] The above control module (170) may be configured to include an information storage unit to store the trigger profile and various data.

[0110] The above inspection module (190) compares the collected substrate image with a reference image to evaluate whether a defect has occurred in the substrate to be inspected.

[0111] The inspection module (190) can extract information such as pixel value, defect size, luminance, brightness, and color from the substrate image and detect the type of defect occurring on the substrate (S) to be analyzed by comparing the extracted information with a reference image. The defect may have a form including at least one of contamination, impurity, scratch, crack, chipping, and broken.

[0112] The above inspection module (190) may include a display unit (not shown) to output and display inspection results externally. The inspection results may be displayed (output) via a UI (User Interface) or GUI (Graphic User Interface), etc.

[0113] In the substrate defect inspection device according to the embodiment, the computation module (150) and the inspection module (190) can each be implemented in the form of a computer-readable recording medium on which a program is recorded to perform the substrate image collection and substrate defect inspection methods described above.

[0114] Specifically, the line scan substrate image collection method and substrate defect inspection method according to the embodiment can be implemented in the form of a computer-readable recording medium on which a program is recorded to perform the same, and can function as a pulse scheduler of a shooting module in a substrate inspection device.

[0115] More specifically, the line scan-based image acquisition method and the substrate defect inspection method may be implemented as an application or in the form of program instructions that can be executed through various computer components and recorded on a computer-readable recording medium. The computer-readable recording medium may include program instructions, data files, data structures, etc., either individually or in combination.

[0116] The program instructions recorded on the computer-readable recording medium may be those specifically designed and configured to implement the embodiment, or may be those known and available to those skilled in the art of computer software. Examples of the computer-readable recording medium may include magnetic media such as hard disks, floppy disks, and magnetic tapes; optical recording media such as CD-ROMs and DVDs; magneto-optical media such as floptical disks; and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, and flash memory.

[0117] Examples of the above program instructions may include not only machine code, such as that generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter, etc. The above hardware device may be configured to operate as one or more software modules to perform the cleaning process end detection method according to the embodiment, and vice versa.

[0118] The above recording medium may be implemented in the form of an external trigger board to perform the image acquisition method and the substrate defect inspection method, and the external trigger board may generate a trigger profile to control the line rate of a line scan camera and provide a trigger signal. In particular, the external trigger board can generate a trigger profile by universally applying it to a substrate processing device equipped with various transfer robots of different manufacturers, and can use this to acquire high-resolution substrate images.

[0119] The substrate defect inspection device according to the embodiment described above can collect a substrate image during the process of transporting the substrate (S) to be analyzed and evaluate whether a defect has occurred on the substrate (S) to be analyzed.

[0120] Referring again to FIG. 6, the substrate defect inspection device according to the embodiment can be installed on a semiconductor processing system and utilized to evaluate whether a defect has occurred on a substrate (S) to be analyzed. The semiconductor processing system may include a plurality of separate partitioned spaces, each including a substrate loading area (1), a substrate transfer area (3), and a substrate processing area (5).

[0121] The semiconductor processing system may include a substrate storage unit (11), such as a front opening unified pod (FOUP), in which a plurality of substrates are loaded and stored. The substrate storage unit (11) may be placed on the substrate loading area (1).

[0122] Additionally, the semiconductor processing system may include a transfer robot (130) for loading an analysis target substrate (S) from the substrate storage unit (11) and transferring it to the substrate processing unit (15) to be described later. The transfer robot (130) may be placed on the substrate transfer area (3). The transfer robot (130) may also perform the role of transferring the analysis target substrate (S) processed in the substrate processing unit (15) to the substrate storage unit (11). In particular, the transfer robot (130) may form a structure for transferring the analysis target substrate (S) processed in the substrate processing unit (15) to a location other than the substrate storage unit (11).

[0123] Additionally, the semiconductor processing system may include a substrate processing unit (15) for processing an analysis target substrate (S) transferred from the transfer robot (130). The substrate processing unit (15) may have the structure of various types of conventional substrate processing devices used to manufacture semiconductor devices, etc.

[0124] In the above semiconductor processing system, the substrate loading area (1), substrate transfer area (3), and substrate processing area (5) may each form a space partitioned by a partition wall. The partition wall may have a structure in which a gate (not shown) capable of opening and closing is formed to move the substrate (S) to be analyzed in each area.

[0125] The above regions (1, 3, 5) are shielded from the outside to protect the substrate (S) from foreign substances such as dust, and in particular, the substrate processing region (5) where the processing process is performed can be formed as a sealed vacuum space capable of gas injection and plasma formation.

[0126] The above-mentioned transfer robot (130) is equipped with at least one robot arm and transfers the substrate (S) to be analyzed by vacuum suction using an end effector installed at the end of the robot arm. The above-mentioned transfer robot (130) can transfer the substrate (S) to be analyzed from the substrate storage unit (11) to the substrate processing unit (15) of the substrate processing area (3), or load the substrate (S) to be analyzed, after the processing process is completed at the substrate processing unit (15), back into the substrate storage unit (11) for storage.

[0127] The above-mentioned imaging module (110) is installed on the substrate transfer area (3) and can collect original substrate images of a substrate subject to analysis before processing that is transferred from the substrate storage unit (11) to the substrate processing unit (15). Additionally, the above-mentioned imaging module (110) can collect original substrate images of a substrate subject to analysis after processing that is transferred from the substrate processing unit (15) to the substrate storage unit (11).

[0128] At this time, the light emission change unit (115) provided in the shooting module (110) refracts the reflected light reflected from the substrate (S) to be analyzed horizontally and then directs it to the shooting unit (111), thereby allowing the shooting unit (111) to be installed horizontally relative to the direction of incidence of the reflected light. This makes it easier to install the shooting module (110) inside the substrate transfer area (3), which is a narrow space, by reducing the installation area compared to when the shooting unit (111) is installed vertically downward.

[0129] Accordingly, the substrate defect inspection device (100) according to the embodiment is installed on a transfer space where the substrate (S) to be analyzed is transferred as described above, and can be utilized to generate a substrate image to evaluate whether a defect has occurred in the pre-processing substrate (S) transferred from the substrate storage unit (11) to the substrate processing unit (15) and the post-processing substrate (S) transferred from the substrate processing unit (15) to the substrate storage unit (11).

[0130] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will understand that other specific forms can be easily modified without altering the technical spirit or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0131] The scope of the present invention is defined by the claims set forth below, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts thereof should be interpreted as being included within the scope of the present invention. Explanation of the symbols

[0132] 1: Substrate loading area 3: Substrate transfer area 5: Substrate processing area 11: Substrate storage unit 15: Substrate processing unit 110: Shooting module 111: Filming Unit 113: Lighting Unit 115: Launch Change Unit 130: Transfer Robot 150: Computation Module 170: Inspection Module S: Substrate to be analyzed

Claims

Claim 1 A sensorless substrate image collection method comprising: a step of collecting substrate images by photographing a substrate being transported by a transport robot using a line scan camera, wherein, during the process of transporting the substrate by the transport robot, the substrate is test-photographed at a preset line rate using the line scan camera to collect a plurality of test line images; a step of analyzing the plurality of test line images to estimate the movement speed of the substrate for each movement section; a step of calculating a trigger interval for each movement section of the substrate using the movement speed of the substrate for each movement section, and generating a trigger profile by accumulating a plurality of the calculated trigger intervals; and a step of controlling the line scan camera using the trigger profile to collect substrate images during the process of transporting a substrate to be inspected by the transport robot. Claim 2 A sensorless substrate image acquisition method according to claim 1, wherein the transfer robot comprises a main rotation axis, a plurality of robot arms connected to the main rotation axis in a bidirectional rotational structure, an end effector connected to one end of the robot arms, and a plurality of sub-rotation axes for rotating the plurality of robot arms and the end effector in each bidirectional manner. Claim 3 A sensorless substrate image acquisition method according to claim 2, wherein the transfer robot transfers the substrate with a speed profile including constant velocity motion, acceleration motion, and deceleration motion with respect to the direction of movement of the substrate. Claim 4 A sensorless substrate image collection method according to claim 1, wherein the step of collecting the test line image is characterized by collecting the test line image using a defect-free substrate in which no defects occur on the surface or a substrate having a square grid pattern formed on the surface. Claim 5 A sensorless substrate image collection method according to claim 1, wherein the step of estimating the movement speed of the substrate for each movement section comprises: a step of detecting an intersection point of a pattern displayed on the test line image; a step of measuring the length in the Y-axis direction of the pattern and calculating the distortion ratio of the test line image by comparing it with a reference line image; and a step of calculating the movement speed of the substrate in the section where the test line image was captured using the distortion ratio of the test line image. Claim 6 A sensorless substrate image acquisition method according to claim 5, wherein the step of estimating the movement speed for each movement section of the substrate comprises estimating the movement speed for each movement section of the substrate, then identifying a constant speed section, an acceleration section, and a deceleration section among the movement sections of the substrate, calculating a trigger interval for adjusting the line rate of the line scan camera based on the movement speed data of the identified acceleration section and deceleration section, and generating the trigger profile by accumulating the calculated trigger interval for the movement sections of the substrate. Claim 7 A sensorless substrate image acquisition method according to claim 6, wherein the trigger profile comprises at least one parameter among the total number of pulses of a trigger signal for adjusting the line rate of the line scan camera, the interval between each pulse of the trigger signal, and the peak holding time of the pulse of the trigger signal. Claim 8 A sensorless substrate image acquisition method according to claim 6, wherein the step of generating the trigger profile is characterized by, when a deceleration section among the movement sections of the substrate is identified, evaluating the trigger HIGH holding time of the identified deceleration section, and if the trigger HIGH holding time of the identified deceleration section exceeds a preset reference time, shortening the trigger HIGH holding time to the same time as the preset time or dividing the trigger HIGH holding time into a plurality of unit times to sub-pulse. Claim 9 A substrate defect inspection method for inspecting the surface of a substrate by photographing the substrate being transported by a transport robot using a line scan camera, comprising: a step of collecting a plurality of test line images by test photographing the substrate at a preset line rate using the line scan camera during the process of transporting the substrate by the transport robot; a step of estimating the movement speed of the substrate for each movement section by analyzing the plurality of test line images; a step of calculating a trigger interval for each movement section of the substrate using the movement speed of the substrate for each movement section, and generating a trigger profile by accumulating a plurality of the calculated trigger intervals; a step of collecting a substrate image by controlling the line scan camera using the trigger profile during the process of transporting the substrate to be inspected by the transport robot; and a step of inspecting whether a defect has occurred on the substrate to be inspected by comparing the substrate image with a reference image. Claim 10 A substrate defect inspection device comprising: a shooting module for collecting substrate images including a line scan camera that photographs the substrate during the process of transporting the substrate; a transport module including a transport robot for transporting the substrate; a computation module for collecting a plurality of test line images by test-photographing the substrate at a preset line rate using the line scan camera, estimating the movement speed of the substrate for each movement section by analyzing the plurality of test line images, calculating a trigger interval for each movement section of the substrate using the movement speed of the substrate for each movement section, and generating a trigger profile by accumulating a plurality of the calculated trigger intervals; a control module for receiving the trigger profile generated by the computation module and controlling the line scan camera to collect substrate images using the trigger profile during the process of transporting the substrate to be inspected by the transport robot; and an inspection module for inspecting whether a defect has occurred on the substrate to be inspected by comparing the substrate image with a reference image. Claim 11 A computer-readable recording medium having a program recorded thereon for performing a substrate image collection method described in any one of claims 1 to 8.

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