Photoelectric module of photoetching machine and distance parameter adjusting method for photoelectric module

Abstract

The invention relates to the technical field of photoetching machines, in particular to a photoelectric module of a photoetching machine and a distance parameter adjusting method for the photoelectric module. The photoelectric module comprises a light source used for emitting light under a preset light intensity condition; a measured object which reflects light from the light source by a measured plane; the camera is used for receiving the light reflected by the measured plane for imaging, and an imaging image comprises an effective imaging area corresponding to the reflected light and a distance calibration area outside the effective imaging area; and the distance parameter adjusting device is used for acquiring a reference gray value of the distance calibration area based on the reference distance parameter under a preset light intensity condition, determining a real-time gray value of the distance calibration area under the preset light intensity condition, and adjusting the distance parameter of the measured object based on the reference gray value and the real-time gray value. The distance parameter of the measured object is adjusted based on the gray value of the distance calibration area outside the effective imaging area of the image of the measured object, the system complexity and cost of a photoelectric module are reduced, and the utilization rate of imaging resources is improved.

Description

Technical Field

[0001] This application relates to the technical field of lithography machines. More specifically, it relates to an optoelectronic module of a lithography machine and a method for adjusting distance parameters thereof. Background Art

[0002] A lithography machine is an important device in the semiconductor manufacturing process. Its function is to accurately transfer the circuit pattern on the photomask (also called the reticle) to the silicon wafer or other substrates according to the predetermined size and position through the exposure process.

[0003] The optoelectronic module is a core component of the lithography machine, mainly including a light source camera, a camera, a measured object (such as a photomask), etc. Among them, the calibration and adjustment of the distance parameter of the measured plane of the measured object, such as the plane of the photomask, such as (Z-axis height or vertical distance), are key steps to ensure lithography accuracy. Traditional methods usually use mechanical off-line calibration or add a ranging sensor to achieve, but these methods have certain limitations. Mechanical off-line calibration and adjustment need to be accurately adjusted during installation, are easily affected by environmental factors (such as temperature, vibration), and cannot achieve real-time calibration and adjustment; while adding a ranging sensor can provide real-time measurement, but it will increase the system complexity and cost.

[0004] Therefore, it is desirable to provide an improved optoelectronic module of a lithography machine and a method for adjusting distance parameters thereof. Summary of the Invention

[0005] Embodiments of this application provide an optoelectronic module of a lithography machine and a method for adjusting distance parameters thereof. It adjusts the distance parameter of the measured object based on the gray value of the distance calibration area outside the effective imaging area of the camera imaging the measured object, reduces the system complexity and cost of the optoelectronic module of the lithography machine, and improves the utilization rate of imaging resources.

[0006] According to one aspect of this application, an optoelectronic module of a lithography machine is provided, including: a light source for emitting light under a predetermined light intensity condition; a measured object, the measured plane of the measured object reflecting the light from the light source; a camera for receiving the reflected light of the measured plane to image, wherein the imaging image includes an effective imaging area corresponding to the reflected light and a distance calibration area outside the effective imaging area; and a distance parameter adjustment device for obtaining the reference gray value of the distance calibration area based on the reference distance parameter under the predetermined light intensity condition, determining the real-time gray value of the distance calibration area under the predetermined light intensity condition, and adjusting the distance parameter of the measured object based on the reference gray value and the real-time gray value.

[0007] In the photoelectric module of the above-mentioned lithography machine, the distance parameter adjustment device adjusts the distance parameter of the object to be measured based on the reference gray value and the real-time gray value, including: controlling the driving device of the object to be measured based on the reference gray value and the real-time gray value to adjust the distance parameter of the object to be measured.

[0008] In the photoelectric module of the above-mentioned lithography machine, the distance parameter is the height in the Z-axis direction of the plane to be measured.

[0009] In the photoelectric module of the above-mentioned lithography machine, the distance parameter adjustment device adjusts the distance parameter of the object to be measured based on the reference gray value and the real-time gray value, including: in response to the reference gray value being less than the real-time gray value, increasing the distance parameter of the object to be measured; and in response to the reference gray value being greater than the real-time gray value, decreasing the distance parameter of the object to be measured.

[0010] In the photoelectric module of the above-mentioned lithography machine, the distance parameter adjustment device adjusts the distance parameter of the object to be measured based on the reference gray value and the real-time gray value, including: calculating the gray difference between the reference gray value and the real-time gray value; determining the distance parameter difference corresponding to the gray difference based on a pre-calibrated gray-distance parameter model; and adjusting the distance parameter of the object to be measured based on the distance parameter difference.

[0011] In the photoelectric module of the above-mentioned lithography machine, the distance parameter adjustment device adjusts the distance parameter of the object to be measured based on the reference gray value and the real-time gray value, including: determining whether the gray difference between the reference gray value and the real-time gray value is greater than a predetermined threshold, and in response to the gray difference being greater than the predetermined threshold, adjusting the distance parameter of the object to be measured based on the reference gray value and the real-time gray value.

[0012] In the photoelectric module of the above-mentioned lithography machine, after the distance parameter adjustment device determines the real-time gray value of the distance calibration area under the predetermined light intensity condition, it further includes: calibrating the real-time distance parameter corresponding to the real-time gray value based on a pre-calibrated gray-distance parameter model.

[0013] In the photoelectric module of the above-mentioned lithography machine, the distance parameter adjustment device adjusts the distance parameter of the object to be measured based on the reference gray value and the real-time gray value, including: determining the gray difference of the imaging images of multiple consecutive frames of the camera, and in response to the gray differences of the imaging images of the multiple consecutive frames being greater than a predetermined threshold, adjusting the distance parameter of the object to be measured based on the reference gray value and the real-time gray value.

[0014] In the photoelectric module of the above-mentioned lithography machine, the distance parameter adjustment device is further configured to perform at least one of the following: in response to the reference gray value being less than a predetermined threshold, enhancing the light intensity of the light source under the predetermined light intensity condition; in response to the difference between the reference gray value and the saturation gray value being less than a predetermined threshold, reducing the light intensity of the light source under the predetermined light intensity condition.

[0015] In the photoelectric module of the above-mentioned lithography machine, the distance parameter adjustment device is further configured to perform at least one of the following: in response to the moving speed of the object to be measured being greater than a predetermined threshold, reducing the exposure time of the camera and increasing the light intensity of the light source under the predetermined light intensity condition; in response to the real-time gray value of a local area of the distance calibration area being lower than a predetermined threshold, increasing the exposure time of the camera, and keeping the light intensity of the light source under the predetermined light intensity condition unchanged.

[0016] According to another aspect of the present application, there is provided a method for adjusting distance parameters of a photoelectric module for a lithography machine, including: determining a reference gray value of a distance calibration area outside an effective imaging area where a camera in the photoelectric module images an object to be measured under a predetermined light intensity condition of a light source in the photoelectric module; measuring the real-time gray value of the distance calibration area in real time; and adjusting the distance parameters of the object to be measured based on the reference gray value and the real-time gray value.

[0017] The photoelectric module of the lithography machine and the method for adjusting distance parameters therefor provided by the embodiments of the present application can adjust the distance parameters of the object to be measured based on the gray value of the distance calibration area outside the effective imaging area where the camera images the object to be measured, thereby reducing the system complexity and cost of the photoelectric module of the lithography machine and improving the utilization rate of imaging resources. Description of the Drawings

[0018] By reading the detailed description of the preferred specific embodiments below, various other advantages and benefits of the present application will become clear to those of ordinary skill in the art. The drawings in the specification are only for the purpose of illustrating the preferred embodiments and are not considered to be a limitation of the present application. Obviously, the drawings described below are only some embodiments of the present application, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts. Moreover, throughout the drawings, the same reference numerals are used to represent the same components.

[0019] Figure 1 A simplified schematic diagram of a photoelectric module of a lithography machine according to an embodiment of the present application is illustrated.

[0020] Figure 2 An example of a scanned image of a camera in a photoelectric module of a lithography machine according to an embodiment of the present application is illustrated.

[0021] Figure 3 The block diagram of the optoelectronic module of a lithography machine according to an embodiment of the present application is illustrated.

[0022] Figure 4 The schematic diagram of the closed-loop feedback control mechanism of the optoelectronic module of a lithography machine according to an embodiment of the present application is illustrated.

[0023] Figure 5 The schematic flowchart of the method for adjusting the distance parameter of the optoelectronic module for a lithography machine according to an embodiment of the present application is illustrated.

[0024] Figure 6 The schematic flowchart of the application example of the method for adjusting the distance parameter of the optoelectronic module for a lithography machine according to an embodiment of the present application is illustrated. Detailed implementation manners

[0025] Next, example embodiments according to the present application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. It should be understood that the present application is not limited by the example embodiments described herein.

[0026] Figure 1 The simplified schematic diagram of the optoelectronic module of a lithography machine according to an embodiment of the present application is illustrated. As Figure 1 shown, in the embodiment of the present application, the optoelectronic module of the lithography machine includes a camera, a light source, and an object to be measured, which together constitute an optical measurement system. The light source emits light, for example, emits several light spots (for example, four light spots). The light emitted by the light source is projected onto the measured plane of the object to be measured. The camera forms an image by receiving the reflected light from the measured plane. For example, the camera is a line-scan camera and captures an image by scanning the measured plane.

[0027] Figure 2 The example of the imaging image of the camera in the optoelectronic module of a lithography machine according to an embodiment of the present application is illustrated. As Figure 2 shown, for a line-scan camera, in a row of pixels scanned by the camera, only the middle region (within the dashed box) is the effective region corresponding to the light spots emitted by the light source. Although the remaining regions are imaged, they are generally considered as invalid regions and are cut off. That is, the imaging image includes an effective imaging region corresponding to the light reflected from the measured plane of the object to be measured and an invalid imaging region outside the effective imaging region. However, in the embodiment of the present application, the pixels in these invalid imaging regions can be used for the calibration and adjustment of the distance of the object to be measured. Therefore, in the following, these pixels will be referred to as distance calibration regions. Correspondingly, in the optoelectronic module of a lithography machine according to an embodiment of the present application, the real-time calibration and adjustment of the distance parameter (such as the Z-axis height) of the object to be measured are achieved by monitoring the change in the gray value of the distance calibration region.

[0028] Specifically, in the optoelectronic module of the lithography machine according to the embodiments of the present application, first, in the off-line calibration stage, a suitable light intensity condition of the light source is determined, such that the gray value of the distance calibration area detected by the camera reaches a reference gray value, and this reference gray value corresponds to the reference distance parameter of the object to be measured, for example, a known reference height in the Z-axis direction. Then, during actual use, the camera (for example, usually a line-scan camera) can continuously image the measured plane of the object to be measured at a fixed frame rate (for example, a line frequency of 10 kHz), and determine the pixel gray value of the distance calibration area.

[0029] When the camera detects that the gray value of the distance calibration area changes, it indicates that the reflected light intensity of the measured plane has changed, and further indicates that the distance parameter of the object to be measured, such as the height in the Z-axis direction, has changed. At this time, the distance parameter adjustment device of the optoelectronic module according to the embodiments of the present application will judge whether the object to be measured is moving away from or approaching the camera according to the change direction (increase or decrease) of the gray value, and control and adjust the distance parameter of the object to be measured, such as the height in the Z-axis direction, until the gray value of the distance calibration area detected by the camera returns to the reference gray value determined during off-line calibration. For example, the distance parameter adjustment device can send an instruction to the driving device of the object to be measured, such as a driving motor, to adjust the distance parameter of the object to be measured. Through this closed-loop feedback control mechanism, the optoelectronic module of the lithography machine according to the embodiments of the present application can dynamically adjust the distance parameter of the object to be measured in real time to ensure measurement accuracy and stability.

[0030] Therefore, the optoelectronic module of the lithography machine according to the embodiments of the present application includes: a light source for emitting light under a predetermined light intensity condition; an object to be measured, the measured plane of the object to be measured reflecting the light from the light source; a camera for receiving the reflected light of the measured plane to image, wherein the imaging image includes an effective imaging area corresponding to the reflected light and a distance calibration area outside the effective imaging area; and a distance parameter adjustment device for obtaining the reference gray value of the distance calibration area based on the reference distance parameter under the predetermined light intensity condition, determining the real-time gray value of the distance calibration area under the predetermined light intensity condition, and adjusting the distance parameter of the object to be measured based on the reference gray value and the real-time gray value.

[0031] Moreover, in the optoelectronic module of the above lithography machine, the distance parameter adjustment device adjusting the distance parameter of the object to be measured based on the reference gray value and the real-time gray value includes: controlling the driving device of the object to be measured to adjust the distance parameter of the object to be measured based on the reference gray value and the real-time gray value.

[0032] In addition, in the optoelectronic module of the above lithography machine, the distance parameter is the height in the Z-axis direction of the measured plane.

[0033] Figure 3 The block diagram of the optoelectronic module of a lithography machine according to an embodiment of the present application is illustrated. As Figure 3 shown, the optoelectronic module of a lithography machine according to an embodiment of the present application includes a light source, a measured object, a camera, and a distance parameter adjustment device.

[0034] In one example, under the predetermined light intensity condition of the light source, the measured plane is fixed at a known Z-axis height, and the gray value of the distance calibration area at this time is determined as the reference gray value, for example, denoted as Gref. Then, during the distance calibration and adjustment of the measured object, the real-time average value of the gray value of the distance calibration area is calculated to obtain the real-time gray value, for example, denoted as Greal, and further, the deviation ΔG = Greal - Gref between the real-time gray value and the reference gray value can be calculated.

[0035] Then, the direction can be judged based on the deviation ΔG between the real-time gray value and the reference gray value: when ΔG>0, it indicates that the light intensity received by the calibration area increases, and the measured plane approaches the camera, resulting in enhanced reflected light. At this time, it is determined that the Z-axis height decreases; when ΔG<0, it indicates that the light intensity received by the calibration area weakens, and the measured plane moves away from the camera, resulting in weakened reflected light. At this time, it is determined that the Z-axis height increases. Further, through the pre-calibrated height-gray model, ΔG can also be converted into a specific Z-axis height deviation ΔZ = f(ΔG).

[0036] That is, based on the reference gray value and the real-time gray value, if the reference gray value is less than the real-time gray value, the distance parameter of the measured object is increased accordingly, and if the reference gray value is greater than the real-time gray value, the distance parameter of the measured object is decreased accordingly.

[0037] In this way, a closed-loop feedback control mechanism can be formed among the camera, the distance parameter adjustment device, and the driving device of the measured object, so as to dynamically adjust the distance parameter of the measured object in real time and ensure the measurement accuracy and stability. Here, Figure 4 The schematic diagram of the closed-loop feedback control mechanism of the optoelectronic module of a lithography machine according to an embodiment of the present application is illustrated.

[0038] Therefore, in the optoelectronic module of a lithography machine according to an embodiment of the present application, the distance parameter adjustment device adjusts the distance parameter of the measured object based on the reference gray value and the real-time gray value, including: in response to the reference gray value being less than the real-time gray value, increasing the distance parameter of the measured object; and in response to the reference gray value being greater than the real-time gray value, decreasing the distance parameter of the measured object.

[0039] Therefore, in the optoelectronic module of the lithography machine according to the embodiment of the present application, the distance parameter adjusting device adjusts the distance parameter of the object to be measured based on the reference gray value and the real-time gray value, including: calculating the gray difference between the reference gray value and the real-time gray value; determining the distance parameter difference corresponding to the gray difference based on a pre-calibrated gray-distance parameter model; and adjusting the distance parameter of the object to be measured based on the distance parameter difference.

[0040] Here, those skilled in the art can understand that in the embodiment of the present application, the real-time gray value can also be converted into a real-time distance parameter based on a pre-calibrated height-gray model to realize the real-time calibration of the distance parameter of the object to be measured. That is, the distance parameter adjusting device can be only used for calibrating the distance parameter of the object to be measured. Then, based on the calibrated distance parameter, the distance parameter of the object to be measured can be optionally adjusted.

[0041] Therefore, in the optoelectronic module of the lithography machine according to the embodiment of the present application, after the distance parameter adjusting device determines the real-time gray value of the distance calibration area under the predetermined light intensity condition, it further includes: calibrating the real-time distance parameter corresponding to the real-time gray value based on a pre-calibrated gray-distance parameter model.

[0042] In addition, to improve the reliability of distance parameter calibration and adjustment and avoid misjudgment caused by noise, a gray value deviation threshold δ can be set. For example, when δ = |ΔG| > δ, the direction judgment and distance parameter adjustment are triggered. At the same time, the ΔG values of multiple consecutive frames of images can be continuously monitored, and the direction is judged and the distance parameter is adjusted only when the ΔG values of consecutive n rows (such as 3 rows) all meet the judgment conditions.

[0043] Therefore, in the optoelectronic module of the lithography machine according to the embodiment of the present application, the distance parameter adjusting device adjusts the distance parameter of the object to be measured based on the reference gray value and the real-time gray value, including: determining whether the gray difference between the reference gray value and the real-time gray value is greater than a predetermined threshold, and in response to the gray difference being greater than the predetermined threshold, adjusting the distance parameter of the object to be measured based on the reference gray value and the real-time gray value.

[0044] Moreover, in the optoelectronic module of the lithography machine according to the embodiment of the present application, the distance parameter adjusting device adjusts the distance parameter of the object to be measured based on the reference gray value and the real-time gray value, including: determining the gray difference of the imaging images of multiple consecutive frames of the camera, and in response to the gray differences of the imaging images of the multiple consecutive frames being all greater than the predetermined threshold, adjusting the distance parameter of the object to be measured based on the reference gray value and the real-time gray value.

[0045] Furthermore, for the process selection of the optoelectronic module of the lithography machine, the distance parameter adjustment device may include flexible parameter adjustment options, that is, it can adjust the light intensity of the light source under the predetermined light intensity condition, and can also correspondingly adjust the exposure time of the camera to further optimize the performance and adaptability of distance parameter calibration and adjustment. For example, by adjusting the light intensity of the light source, the dynamic range of the gray value of the distance calibration area can be controlled to maintain a high signal-to-noise ratio during the detection process, thereby improving the measurement accuracy.

[0046] For example, in a low light intensity environment, the light source intensity can be appropriately increased to ensure that the gray value of the distance calibration area is within the detectable range. For instance, if the reflectivity of the silicon wafer surface is low (such as having an oxide layer), the ambient light is insufficient, or the light source is aging, resulting in the reference gray value of the distance calibration area being too low (for example, Gref < 50 at 256 gray levels), then the signal-to-noise ratio is poor. At this time, the light source can be controlled to increase the light intensity under the predetermined light intensity condition, for example, from 70 to 125, to enhance the light intensity of the reflected light spot. And correspondingly, the exposure time of the camera can be extended from 40 μs to 100 μs to increase the integration time of the camera sensor. In addition, the gray value deviation threshold δ can be adjusted from 5 to 3 because the proportion of noise decreases after the signal is enhanced. Through actual measurement, after adjusting the light intensity of the light source, the gray reference value of the calibration area is increased from Gref = 40 to Gref = 140 (the dynamic range is expanded), and the sensitivity of ΔG is improved, and the response of distance parameter adjustment is more significant.

[0047] Therefore, in the optoelectronic module of the lithography machine according to the embodiment of the present application, the distance parameter adjustment device is further configured to: in response to the reference gray value being lower than a predetermined threshold, enhance the light intensity of the light source under the predetermined light intensity condition.

[0048] And, in the optoelectronic module of the above lithography machine, the distance parameter adjustment device is further configured to: increase the exposure time of the camera.

[0049] For another example, in a high-intensity light environment, the light source intensity can be reduced to avoid gray value saturation. For instance, when the silicon wafer is a highly reflective polished silicon wafer (reflectivity > 90%), the gray value of the calibration area may be close to saturation (Gref ≈ 250), resulting in the inability to effectively distinguish height changes in ΔG. At this time, the light intensity of the light source under the predetermined light intensity condition can be reduced, for example, from 125 to 40, to reduce the light intensity. Correspondingly, the exposure time of the camera is shortened from 200 μs to 40 μs to avoid overexposure of the camera sensor. At the same time, the gray value deviation threshold δ is maintained at 5 because the ΔG response of the high-reflection surface is more sensitive. And through actual measurement, after adjusting the light intensity of the light source, the gray reference value of the calibration area is reduced from Gref = 250 to Gref = 120. The ΔG sensitivity is improved, avoiding the non-linear error caused by saturation.

[0050] Therefore, in the optoelectronic module of the lithography machine according to the embodiment of the present application, the distance parameter adjustment device is further configured to: in response to the difference between the reference gray value and the saturation gray value being less than a predetermined threshold, reduce the light intensity of the light source under the predetermined light intensity condition.

[0051] Moreover, in the optoelectronic module of the above lithography machine, the distance parameter adjustment device is further configured to: reduce the exposure time of the camera.

[0052] In addition, in the embodiment of the present application, in addition to adaptively adjusting the exposure time of the camera based on the light intensity change, the exposure time of the camera can also be adjusted based on the imaging requirements. Specifically, reducing the exposure time is applicable to high-intensity light or fast-moving scenarios to avoid image blurring or overexposure. For example, when the silicon wafer moves at a high speed during the conveying process (such as a 20% increase in the scanning speed), an exposure time of 120 μs will cause image blurring in the calibration area and an increase in gray value fluctuations. At this time, shortening the exposure time from 120 μs to 50 μs can reduce motion blurring. Synchronously, the light intensity of the light source is increased from 100 to 150 to compensate for the light quantity loss caused by the shortened exposure time. And the number of consecutive confirmation lines n of the gray value deviation threshold δ can also be reduced from 3 lines to 2 lines to accelerate the response speed. Thus, the image blurring degree after adjustment is reduced, adapting to the high-speed motion requirements.

[0053] On the other hand, increasing the exposure time can improve the light quantity receiving ability of the sensor. For example, when there are deep trench structures on the surface of the silicon wafer and the reflected light is unevenly distributed, resulting in the local gray value of the calibration area being too low (such as Gref = 30) and it being difficult to extract effective signals. At this time, the exposure time of the camera can be extended from 100 μs to 300 μs, for example, to enhance the light quantity accumulation in the weak reflection area. And the light intensity of the light source remains unchanged to avoid overexposure at the trench edge. Thus, the gray reference value of the adjusted calibration area is increased from Gref = 30 to Gref = 90, and the ΔG sensitivity in the trench area is increased by 3 times.

[0054] Therefore, in the optoelectronic module of the lithography machine according to the embodiment of the present application, the distance parameter adjusting device is further configured to: in response to the moving speed of the object to be measured being greater than a predetermined threshold, reduce the exposure time of the camera, and increase the light intensity of the light source under the predetermined light intensity condition.

[0055] Moreover, in the optoelectronic module of the lithography machine according to the embodiment of the present application, the distance parameter adjusting device is further configured to: in response to the real-time gray value of a local area of the calibration area being lower than a predetermined threshold, increase the exposure time of the camera, and keep the light intensity of the light source under the predetermined light intensity condition unchanged.

[0056] In this way, in the optoelectronic module of the lithography machine according to the embodiment of the present application, by combining the adjustment of the light intensity and the exposure time, the calibration performance of the distance parameter can be flexibly optimized according to the requirements of specific application scenarios, that is, by ensuring the stability and reliability of the gray value of the calibration area, the accuracy and efficiency of the distance parameter calibration can be improved.

[0057] Figure 5 The schematic flowchart of the distance parameter adjustment method for the optoelectronic module of the lithography machine according to the embodiment of the present application is illustrated.

[0058] As Figure 5 shown, the distance parameter adjustment method for the optoelectronic module of the lithography machine according to the embodiment of the present application includes: S110, determining the reference gray value of the distance calibration area outside the effective imaging area where the camera in the optoelectronic module images the object to be measured based on the reference distance parameter under the predetermined light intensity condition of the light source in the optoelectronic module; S120, measuring the real-time gray value of the distance calibration area in real time; and S130, adjusting the distance parameter of the object to be measured based on the reference gray value and the real-time gray value.

[0059] Here, those skilled in the art can understand that the specific details of the distance parameter adjustment method for the optoelectronic module of the lithography machine according to the embodiment of the present application have been described above in the description of the optoelectronic module of the lithography machine according to the embodiment of the present application, and will not be repeated here to avoid redundancy.

[0060] Figure 6 The schematic flowchart of the application example of the distance parameter adjustment method for the optoelectronic module of the lithography machine according to the embodiment of the present application is illustrated.

[0061] As Figure 6As shown, when applying to calibrate the Z-axis height of the measured plane of the object to be measured, first fix the measured plane at a known Z-axis height. At this time, the gray value of the calibration area is selected as the reference value Gref. Then, calculate the real-time average value Greal of the gray value of the calibration area and its deviation from the reference value ΔG = Greal - Gref.

[0062] Thus, direction judgment is carried out: when ΔG > 0, it indicates that the light intensity received by the calibration area increases, and the measured plane approaches the camera, resulting in enhanced reflected light. At this time, it is determined that the Z-axis height decreases; when ΔG < 0, it indicates that the light intensity received by the calibration area weakens, and the measured plane moves away from the camera, resulting in weakened reflected light. At this time, it is determined that the Z-axis height increases. Moreover, through the pre-calibrated height-gray model, ΔG can also be converted into the Z-axis height deviation ΔZ = f(ΔG).

[0063] Meanwhile, in order to avoid misjudgment caused by noise, set the gray value deviation threshold δ. When |ΔG| > δ, the direction judgment and height adjustment are triggered. At the same time, the ΔG values of multiple frames of images can be continuously monitored. Only when the ΔG values of consecutive n rows (such as 3 rows) all meet the judgment conditions, the direction is confirmed.

[0064] That is, the distance parameter adjustment method for the optoelectronic module of the lithography machine according to the embodiment of the present application can use the area outside the effective image during actual use of the line scan camera for distance calibration, that is, by analyzing the image information captured by the line scan camera in the non-effective imaging area, calculate the distance between the object and the camera, so as to realize the real-time calibration of the distance parameter.

[0065] In this way, the optoelectronic module of the lithography machine and the distance parameter adjustment method for it according to the embodiment of the present application can eliminate the need for additional distance sensor hardware, but make full use of the existing imaging ability of the camera, reducing the system complexity and cost. At the same time, by real-time monitoring the change of the gray value of the calibration area, the height of the measured plane can be dynamically adjusted to adapt to factors such as light intensity change and environmental interference, with strong robustness. In addition, the pixel of the invalid area that is usually cut off in the traditional method is fully utilized in the embodiment of the present application, improving the resource utilization rate of the system. Finally, the optoelectronic module of the lithography machine and the distance parameter adjustment method for it according to the embodiment of the present application can be used in multiple subsystems of the lithography machine and can be seamlessly integrated with other optical measurements, such as the alignment system, the focus and leveling system, etc.

[0066] The basic principles of the present application have been described in conjunction with specific embodiments. However, it should be noted that the advantages, benefits, effects, etc. mentioned in the present application are merely examples and not limitations. It cannot be considered that these advantages, benefits, effects, etc. are essential for each embodiment of the present application. Additionally, the specific details disclosed above are for illustrative and facilitating understanding purposes only, and not limitations. These details do not limit the present application to necessarily implement using the above specific details.

[0067] The block diagrams of the devices, apparatuses, equipment, and systems involved in the present application are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open-ended terms, meaning "including but not limited to", and can be used interchangeably with each other. The word "or" and "and" used herein refer to the word "and / or", and can be used interchangeably with each other, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to", and can be used interchangeably with each other.

[0068] It should also be noted that in the devices, equipment, and methods of the present application, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent solutions of the present application.

[0069] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

[0070] The above description has been given for purposes of illustration and description. Additionally, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions, and sub-combinations thereof.

Claims

1. An optoelectronic module of a photolithography machine, wherein: include: A light source, used to emit light under predetermined light intensity conditions; An object to be measured, wherein a measured plane of the object to be measured reflects light from the light source; A camera, used for receiving the reflected light of the measured plane to form an image, wherein the imaged image includes an effective imaging area corresponding to the reflected light and a distance calibration area outside the effective imaging area; as well as A distance parameter adjustment device is used to obtain a reference grayscale value of the distance calibration area based on a reference distance parameter under the predetermined light intensity condition, determine a real-time grayscale value of the distance calibration area under the predetermined light intensity condition, and adjust the distance parameter of the object to be measured based on the reference grayscale value and the real-time grayscale value.

2. The optoelectronic module of the lithography machine according to claim 1, wherein: The distance parameter adjustment device adjusts the distance parameter of the object to be measured based on the reference grayscale value and the real-time grayscale value, including: Based on the reference grayscale value and the real-time grayscale value, a driving device of the object to be measured is controlled to adjust a distance parameter of the object to be measured.

3. The optoelectronic module of the lithography machine according to claim 2, wherein: The distance parameter is the height of the measured plane in the Z-axis direction.

4. The optoelectronic module of the lithography machine according to claim 1, wherein: The distance parameter adjustment device adjusts the distance parameter of the object to be measured based on the reference grayscale value and the real-time grayscale value, including: In response to the reference grayscale value being less than the real-time grayscale value, increasing the distance parameter of the object to be measured; and, In response to the reference grayscale value being greater than the real-time grayscale value, the distance parameter of the object to be measured is reduced.

5. The optoelectronic module of the lithography machine according to claim 1, wherein: The distance parameter adjustment device adjusts based on the reference grayscale value and the real-time grayscale value: the distance parameter of the object to be measured includes: Calculating a grayscale difference between the reference grayscale value and the real-time grayscale value; Determining the distance parameter difference corresponding to the grayscale difference based on a pre-calibrated grayscale-distance parameter model; and The distance parameter of the object to be measured is adjusted based on the distance parameter difference.

6. The optoelectronic module of the lithography machine according to claim 1, wherein: After determining the real-time grayscale value of the distance calibration area under the predetermined light intensity condition, the distance parameter adjustment device further comprises: Based on the pre-calibrated grayscale-distance parameter model, the real-time distance parameter corresponding to the real-time grayscale value is calibrated.

7. The optoelectronic module of the lithography machine according to claim 1, wherein: The distance parameter adjustment device adjusts the distance parameter of the object to be measured based on the reference grayscale value and the real-time grayscale value, including: Determine whether a grayscale difference between the reference grayscale value and the real-time grayscale value is greater than a predetermined threshold, and in response to the grayscale difference being greater than the predetermined threshold, adjust the distance parameter of the object to be measured based on the reference grayscale value and the real-time grayscale value.

8. The optoelectronic module of the lithography machine according to claim 7, wherein: The distance parameter adjustment device adjusts the distance parameter of the object to be measured based on the reference grayscale value and the real-time grayscale value, including: The grayscale difference of the imaging images of the camera in succession is determined, and in response to the grayscale difference of the imaging images in succession being greater than a predetermined threshold, the distance parameter of the object to be measured is adjusted based on the reference grayscale value and the real-time grayscale value.

9. The optoelectronic module of the lithography machine according to claim 1, wherein: The distance parameter adjustment device is further used for at least one of the following: In response to the reference gray value being less than a predetermined threshold, increasing the light intensity of the light source under the predetermined light intensity condition; In response to the difference between the reference gray value and the saturation gray value being smaller than a predetermined threshold, the light intensity of the light source under the predetermined light intensity condition is reduced.

10. The optoelectronic module of the lithography machine according to claim 1, wherein: The distance parameter adjustment device is further used for at least one of the following: In response to the moving speed of the object being measured being greater than a predetermined threshold, reducing the exposure time of the camera and increasing the light intensity of the light source under the predetermined light intensity condition; In response to the local real-time grayscale value of the distance calibration area being lower than a predetermined threshold, the exposure time of the camera is increased, and the light intensity of the light source remains unchanged under the predetermined light intensity condition.

11. A method for adjusting distance parameters of an optoelectronic module of a photolithography machine, wherein: include: Determine a reference grayscale value of a distance calibration area outside an effective imaging area for imaging the object under a predetermined light intensity condition of the light source in the photoelectric module based on a reference distance parameter; measuring the real-time grayscale value of the distance calibration area in real time; and, The distance parameter of the object to be measured is adjusted based on the reference grayscale value and the real-time grayscale value.

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