Method and device for determining detection position of sensor of wafer detection equipment and wafer detection equipment

Abstract

The invention discloses a method and device for determining the detection position of a sensor of wafer detection equipment and the wafer detection equipment, the wafer detection equipment comprises a workbench, a wafer and a sensor, the sensor comprises an objective lens and a camera, a target graph is arranged on the wafer, the camera shoots the target graph by receiving transmission light of the objective lens, and the target graph is obtained through the camera. The method for determining the detection position of the sensor comprises the following steps: moving a workbench to a preset position, and enabling the sensor to correspond to at least one part of a target graph; based on the preset position, controlling the workbench to move for multiple times, and sequentially obtaining the position coordinate of the workbench and the gray value of the target graph in the image shot by the camera; and determining the position coordinate detected by the sensor according to the corresponding relation between the position coordinate and the gray value. According to the method for determining the detection position of the sensor provided by the invention, the coordinates of the detection position of the sensor can be calculated by combining the target graph on the wafer with a stepping photographing mode, the cost is low, the operation is simple, and the calibration efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing technology, and in particular to a sensor detection position determination method and device for wafer detection equipment, and wafer detection equipment. Background Art

[0002] With the development of advanced semiconductor processes, the number of process links continues to increase, which puts higher requirements on the level of process control. The process steps of the 28nm process node have hundreds of processes. Due to the use of multi-layer overlay technology, the process steps of 14nm and below nodes have increased to nearly a thousand processes. Only when the yield rate of each process exceeds 99.99% can the final yield rate exceed 95%. Therefore, the wafer overlay measurement link runs through the entire manufacturing process and is a key link to ensure the yield rate of chip production.

[0003] Overlay error is defined as the planar distance between the centers of two layers of graphic structures. As the number of layers of integrated circuits continues to increase, multi-patterning and multi-exposure lithography processes are widely used, and the overlay accuracy between circuit patterns formed in different steps becomes increasingly important. Misalignment caused by excessive overlay error will cause the entire circuit to fail and be scrapped. Overlay error measurement equipment is used to ensure the correct alignment and placement of circuit patterns at different levels and circuit patterns on the same layer. Overlay error measurement is usually performed after each lithography step.

[0004] Figure 1 This is a partial schematic diagram of the wafer, refer to Figure 1 At present, the machine that realizes the overlay error measurement requires the cooperation of the sensor and the moving stage to obtain the image of the object to be measured set on the moving stage. Therefore, it is necessary to confirm the position of the sensor relative to the moving stage, that is, to obtain the detection position of the sensor, and the method for obtaining the detection position of the sensor is mainly to align the sensor with the mark 100 on the object to be measured. However, for a high-power objective lens, its field of view is very small. At this time, if the sensor is in an uncalibrated position, it is very difficult to align with the mark 100 on the object to be measured. It requires experienced personnel to repeatedly fine-tune to find the mark 100, and then repeatedly fine-tune to align the mark 100. It has high requirements for personnel, and the debugging is difficult and inefficient. Therefore, how to achieve accurate detection of the sensor detection position is an urgent problem to be solved. Summary of the invention

[0005] The present invention provides a sensor detection position determination method and device for wafer detection equipment and wafer detection equipment. The position coordinates of the sensor can be calculated by stepping and photographing the target pattern in the wafer, which is not only low-cost and simple to operate, but also can improve calibration efficiency.

[0006] According to a first aspect of the present invention, a method for determining a sensor detection position of a wafer detection device is provided. The detection device includes a workbench, a wafer and a sensor. The sensor includes an objective lens and a camera. A target pattern is provided on the wafer. The camera photographs the target pattern by receiving the transmitted light of the objective lens. The method for determining the sensor detection position includes:

[0007] Moving the workbench to a preset position so that the sensor corresponds to at least a portion of the target pattern;

[0008] Based on the preset position, controlling the workbench to move multiple times, and sequentially acquiring the position coordinates of the workbench and the grayscale value of the target graphic in the image captured by the camera;

[0009] The position coordinates of the sensor are determined according to the corresponding relationship between the position coordinates and the grayscale value.

[0010] Optionally, before the workbench is moved to a preset position so that the sensor corresponds to at least a portion of the target pattern, the method further includes:

[0011] determining a target pattern in the wafer;

[0012] The preset position of the workbench is determined according to the target graphic; wherein the size of the target graphic is larger than the installation error of the sensor.

[0013] Optionally, based on the preset position, controlling the workbench to move multiple times, and sequentially recording the position coordinates of the workbench and the grayscale value of the target graphic in the image captured by the camera, comprises:

[0014] Taking the starting position as the starting point, the workbench is controlled to move x times along the first direction with a first preset step length, and the x position coordinates of the workbench and the x grayscale values ​​of the target pattern in the wafer in the image taken by the camera are recorded at the same time, and the x grayscale values ​​are recorded as G respectively. 11 ~G 1x ;

[0015] Taking the starting position as the starting point, the workbench is controlled to move y times along the second direction with a second preset step length, and the y position coordinates of the workbench and the y grayscale values ​​of the target pattern in the wafer in the image taken by the camera are recorded at the same time, and the y grayscale values ​​are recorded as G respectively. 21 ~G 2y ;

[0016] The first direction and the second direction are perpendicular to each other; x and y are both positive integers greater than 1.

[0017] Optionally, determining the position coordinates of the sensor according to the corresponding relationship between the position coordinates and the grayscale value includes:

[0018] Based on the x position coordinates and the x grayscale values, establishing a first working curve diagram of the wafer detection device;

[0019] Determining a first position coordinate of the sensor based on the first working curve graph;

[0020] Based on the y position coordinates and the y grayscale values, establishing a second working curve diagram of the wafer detection device;

[0021] A second position coordinate of the sensor is determined based on the second working curve diagram.

[0022] Optionally, determining the first position coordinates of the sensor based on the first working curve graph, and determining the second position coordinates of the sensor based on the second working curve graph includes:

[0023] Calculate a first grayscale median value of the image in the first direction based on the x grayscale values;

[0024] Determine a first position coordinate of the sensor according to the first grayscale median value;

[0025] A second grayscale median value of the image in the second direction is calculated based on the y grayscale values; and a second position coordinate of the sensor is determined according to the second grayscale median value.

[0026] Optionally, the first grayscale median is calculated by formula (1):

[0027]

[0028] Among them, G ax is the first grayscale median, G max1 is the maximum grayscale value in the image along the first direction, G min1 is the minimum grayscale value in the image along the first direction, where G max1 and G min1 G 11 ~G 1x The maximum and minimum values ​​in ;

[0029] Determine the first position coordinate D of the sensor according to the x grayscale values ​​and the first grayscale median value x ,

[0030] D x │G m -G ax │ min Timem Corresponding to the coordinates in the first direction, where |G m -G ax │ min is the minimum value of the absolute value of the difference between the x grayscale values ​​and the first grayscale median value, G m G 11 ~G 1x The value in ;

[0031] The second grayscale median is calculated by formula (II):

[0032]

[0033] Among them, G ay is the second grayscale median, G max2 is the maximum grayscale value in the image along the second direction, G min2 is the minimum grayscale value in the image along the second direction, where G max2 and G min2 G 21 ~G 2y The maximum and minimum values ​​in ;

[0034] Determine the second position coordinate D of the sensor according to the y grayscale values ​​and the second grayscale median value y ,

[0035] D y │G n -G ay │ min Time n Corresponding to the coordinates in the second direction, where |G n -G ay │ min The minimum value G of the absolute value of the difference between the y grayscale values ​​and the second grayscale median value is n G 21 ~G 2y The value in .

[0036] Optionally, after determining the first position coordinates of the sensor according to the first grayscale median value and determining the second position coordinates of the sensor according to the second grayscale median value, the method further comprises:

[0037] Get the first position coordinate D of the sensor x and the second position coordinate D of the sensor y ;

[0038] According to the first position coordinate D of the sensor x and the second position coordinate D of the sensor yDetermine the position coordinates of the sensor as (D x , D y ).

[0039] Optionally, the shape of the target graphic includes any one of a rectangle, a right triangle, an "L" shape and a "U" shape.

[0040] According to a second aspect of the present invention, a sensor detection position determination device of a wafer inspection device is provided, wherein the position determination device is used to perform the sensor detection position determination method of the wafer inspection device described in any one of the first aspects of the present invention, and the position determination device comprises:

[0041] An acquisition module, used for moving the workbench to a preset position so that the sensor corresponds to at least a portion of the target pattern;

[0042] A recording module, used for controlling the workbench to move multiple times based on the preset position, and sequentially obtaining the position coordinates of the workbench and the grayscale value of the target graphic in the image taken by the camera;

[0043] A calculation module is used to determine the position coordinates of the sensor according to the corresponding relationship between the position coordinates and the grayscale value.

[0044] According to a third aspect of the present invention, there is provided a wafer inspection device, comprising the sensor detection position determination device of the wafer inspection device described in the second aspect of the present invention.

[0045] The present invention discloses a sensor detection position determination method and device for wafer detection equipment, and wafer detection equipment. The detection equipment includes a workbench, a wafer and a sensor. The sensor includes an objective lens and a camera. A target pattern is arranged on the wafer. The camera photographs the target pattern by receiving the transmitted light of the objective lens. The method for determining the sensor detection position includes: moving the workbench to a preset position so that the sensor corresponds to at least a part of the target pattern; based on the preset position, controlling the workbench to perform multiple displacements, sequentially obtaining the position coordinates of the workbench and the grayscale value of the target pattern in the image photographed by the camera; and determining the position coordinates of the sensor according to the corresponding relationship between the position coordinates and the grayscale value. The sensor detection position determination method for wafer detection equipment provided by the present invention utilizes the target pattern in the wafer to calculate the position coordinates detected by the sensor by stepping and photographing. It is not only low in cost and simple to operate, but also can improve the calibration efficiency.

[0046] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0048] Figure 1 It is a partial schematic diagram of the wafer;

[0049] Figure 2 It is a flow chart of a method for determining a sensor detection position of a wafer inspection device provided by an embodiment of the present invention;

[0050] Figure 3 is a flow chart of another sensor detection position determination method of a wafer inspection device provided by an embodiment of the present invention;

[0051] Figure 4 It is a schematic diagram of an icon in a method for determining a sensor detection position of a wafer inspection device provided by an embodiment of the present invention;

[0052] Figure 5 is a flow chart of another sensor detection position determination method of a wafer inspection device provided by an embodiment of the present invention;

[0053] Figure 6 It is a step-by-step photographing step diagram in a sensor detection position determination method for a wafer inspection device provided by an embodiment of the present invention;

[0054] Figure 7 It is a step-by-step photographing step diagram in another sensor detection position determination method of a wafer inspection device provided by an embodiment of the present invention;

[0055] Figure 8 is a flow chart of another sensor detection position determination method of a wafer inspection device provided by an embodiment of the present invention;

[0056] Fig. 9 is a first working curve diagram of a sensor detection position determination method for a wafer inspection device provided by an embodiment of the present invention;

[0057] Fig.10 is a flow chart of another sensor detection position determination method of a wafer inspection device provided by an embodiment of the present invention;

[0058] Fig.11 is a flow chart of another sensor detection position determination method of a wafer inspection device provided by an embodiment of the present invention;

[0059] Fig.12The present invention provides a sensor detection position determination device block diagram of a wafer detection device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0060] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0061] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0062] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0063] Figure 2 is a flow chart of a sensor detection position determination method for a wafer inspection device provided by an embodiment of the present invention, with reference to Figure 2 The wafer inspection equipment includes a workbench, a wafer and a sensor. The sensor includes an objective lens and a camera. A target pattern is set on the wafer. The camera photographs the target pattern by receiving the transmitted light of the objective lens.

[0064] Specifically, the workbench refers to a device used to carry and process wafers, which can be displaced; the wafer refers to a silicon chip used to make silicon semiconductor circuits; the objective lens can be understood as a light-transmitting hole, and the camera uses the objective lens to capture the target image.

[0065] refer to Figure 1 and Figure 2 The method for determining the sensor detection position of the wafer detection equipment provided by the embodiment of the present invention includes:

[0066] S1. Move the workbench to a preset position so that the sensor corresponds to at least a portion of the target pattern.

[0067] Specifically, the workbench is controlled to move to a preset position so that the sensor corresponds to at least a portion of the target graphic 200 and ensures that the camera can capture a clear target graphic completely and accurately.

[0068] S2. Based on the preset position, the workbench is controlled to move multiple times, and the position coordinates of the workbench and the grayscale values ​​of the target graphics in the image taken by the camera are obtained in sequence.

[0069] Specifically, after the camera moves to the preset position in the above step S1, the workbench is controlled to move, and each time the workbench moves, the position coordinates of the workbench after the displacement are recorded. At the same time, the camera receives the transmitted light of the objective lens to shoot the target pattern. It can be understood that each time the workbench moves, the wafer carried on the workbench will also move accordingly, that is, the target pattern on the wafer will also move accordingly; each time the workbench moves once, the position coordinates of the workbench and the grayscale value of the image taken by the camera are recorded once, wherein the displacement coordinates of the workbench can be read out through the data of the grating ruler, and finally a set of position coordinates of the workbench and the grayscale value of the image will be obtained, and the position coordinates and the grayscale values ​​correspond one to one.

[0070] S3. Determine the position coordinates of the sensor according to the corresponding relationship between the position coordinates and the grayscale value.

[0071] Specifically, according to the correspondence between the position coordinates of the workbench and the grayscale values ​​of the image recorded in the above step S2, the position coordinates of the sensor are calculated and determined, and a plurality of position coordinates of the workbench and a plurality of grayscale values ​​of the image taken by the camera are obtained to perform a fitting curve. The position coordinates of the sensor are calculated and determined based on the fitting curve. The specific calculation steps will be described in detail below and will not be elaborated here.

[0072] The sensor detection position determination method of the wafer inspection equipment provided in the embodiment of the present invention utilizes the target pattern on the wafer to replace the small-size pattern in the prior art, and combines it with the stepping photography method to calculate the position coordinates detected by the sensor. It is not only low-cost and simple to operate, but also can reduce the difficulty of aligning the sensor with the mark and improve the calibration efficiency.

[0073] Based on the above-mentioned embodiment of the invention, the embodiment of the invention further refines the process of moving the workbench to a preset position so that the sensor corresponds to at least a part of the target pattern. Figure 3 is a flow chart of another sensor detection position determination method of a wafer inspection device provided by an embodiment of the present invention, with reference to Figure 3 The sensor detection position determination method of the wafer inspection device provided by the embodiment of the present invention includes:

[0074] S21. Determine a target pattern in the wafer.

[0075] Specifically, a pattern is selected from the wafer as a target pattern, wherein a size of the target pattern is larger than an installation error of the sensor.

[0076] In the optical detection device, the size of the target pattern is set to be larger than the installation error of the sensor, that is, the target pattern can cover the mechanical error, so that the sensor can quickly capture at least part of the target pattern, which can improve the efficiency of identifying the target pattern, simplify the operation, and thus improve the efficiency of the sensor detection position determination, thereby improving the calibration efficiency. Preferably, the two sides of the right angle in the target pattern are greater than or equal to 3mm.

[0077] Figure 4 is a schematic diagram of an icon in a sensor detection position determination method for a wafer inspection device provided by an embodiment of the present invention, with reference to Figure 4 Optionally, the shape of the target graphic includes any one of a rectangle O, a right triangle P, an "L" shape Q and a "U" shape R.

[0078] S22. Determine a preset position of the workbench according to the target graphic.

[0079] Specifically, the expected moving position P of the worktable is calculated based on the known nominal position in the target pattern on the wafer (exemplarily, the center of the left vertical boundary in the target pattern is the nominal position) 1 (X 1 _expect,Y 1 _expect) mm, obtain the installation error of the sensor, and convert the expected position P 1 The first preset position P1' (X 1 _expect-m,Y 1 _expect) mm, similarly, the expected position P 1 The second preset position P1" (X 1 _expect,Y 1 Since the size of the target pattern is larger than the installation error of the sensor, even if the preset position is obtained by subtracting the installation error of the sensor from the expected position in the target pattern, the sensor can still detect at least part of the target pattern.

[0080] S23, moving the workbench to a preset position so that the sensor corresponds to at least a portion of the target graphic.

[0081] S24. Based on the preset position, control the workbench to move multiple times, and sequentially obtain the position coordinates of the workbench and the grayscale value of the target graphic in the image taken by the camera.

[0082] S25. Determine the position coordinates of the sensor according to the corresponding relationship between the position coordinates and the grayscale value.

[0083] The sensor detection position determination method of the wafer inspection equipment provided in an embodiment of the present invention can cover the mechanical error by utilizing the "large-size graphics" (i.e., graphics with two right-angle sides greater than or equal to 3 mm) on the wafer as the target graphics, thereby making the sensor detection position coordinates finally calculated more accurate.

[0084] On the basis of the above-mentioned embodiments of the invention, the embodiments of the invention further refine the control of the workbench to move based on the preset position and sequentially obtain the position coordinates of the workbench and the grayscale value of the target graphic in the image taken by the camera. Figure 5 is a flow chart of another sensor detection position determination method of a wafer inspection device provided by an embodiment of the present invention, with reference to Figure 5 , a method for determining a sensor detection position of a wafer inspection device provided by an embodiment of the present invention includes:

[0085] S31, moving the workbench to a preset position so that the sensor corresponds to at least a portion of the target graphic.

[0086] S32, starting from the starting position, controlling the workbench to move x times along the first direction with a first preset step length, and recording x position coordinates of the workbench and x grayscale values ​​of the target pattern in the wafer in the image taken by the camera, and recording x grayscale values ​​G respectively. 11 ~G 1x .

[0087] Specifically, the workbench is at the first preset position P1' (X 1 _expect-m,Y 1 _expect)mm as the starting point, Figure 6 This is a step-by-step photographing step diagram in a sensor detection position determination method for a wafer inspection device provided by an embodiment of the present invention, combined with Figure 5 and Figure 6 , taking x=8 as an example, the control table moves 8 times along the first direction with the first preset step length, that is, Figure 6 As shown in the step-by-step photography from step A to step I, while the camera is taking step-by-step photography of the target pattern, the position coordinates of the workbench after each displacement are recorded. The position coordinates can be obtained by reading data from the grating ruler. While recording the position coordinates of the workbench after each displacement, the grayscale value of each image is also recorded. The grayscale value of each image is recorded as G 11 ~G1x The first preset step size may be set according to actual needs, and the embodiment of the present invention does not limit this.

[0088] S33, starting from the starting position, controlling the workbench to move y times along the second direction with a second preset step length, and recording y position coordinates of the workbench and y grayscale values ​​of the target pattern in the wafer in the image taken by the camera, and recording the y grayscale values ​​G respectively. 21 ~G 2y .

[0089] Specifically, the workbench is at the second preset position P1" (X 1 _expect,Y 1 _expect-m)mm is the starting point. The starting position here refers to the position where the camera can capture the clear target image completely and accurately. Figure 7 This is a step-by-step photographing step diagram in another sensor detection position determination method for a wafer inspection device provided by an embodiment of the present invention, combined with Figure 5 and Figure 7 , taking y=8 as an example, the control table moves 8 times along the second direction with the second preset step length, that is, Figure 7 As shown in the step-by-step photography from step A' to step I', while the camera is taking step-by-step photography of the target pattern, the position coordinates of the workbench after each displacement are recorded. The position coordinates can be obtained by reading data from the grating ruler. While recording the position coordinates of the workbench after each displacement, the grayscale value of each image is also recorded. The grayscale value of each image is recorded as G 21 ~G 2y The second preset step length can be set according to actual needs, the first preset step length and the second preset step length can be the same or different, and for example, the first preset step length and the second preset step length are both 5 mm, which is not limited in the embodiment of the present invention. The first direction and the second direction are perpendicular to each other, and x and y are both positive integers greater than 1.

[0090] S34. Determine the position coordinates of the sensor according to the corresponding relationship between the position coordinates and the grayscale value.

[0091] On the basis of the above-mentioned embodiments of the invention, the embodiments of the invention further refine the determination of the position coordinates of the sensor according to the corresponding relationship between the position coordinates and the grayscale value. Figure 8 is a flow chart of another sensor detection position determination method of a wafer inspection device provided by an embodiment of the present invention, with reference to Figure 8 , a method for determining a sensor detection position of a wafer inspection device provided by an embodiment of the present invention includes:

[0092] S41, moving the workbench to a preset position so that the sensor corresponds to at least a portion of the target pattern.

[0093] S42. Based on the preset position, control the workbench to move multiple times, and sequentially obtain the position coordinates of the workbench and the grayscale value of the target graphic in the image taken by the camera.

[0094] S43 . Based on the x position coordinates and the x grayscale values, establish a first working curve diagram of the wafer detection equipment.

[0095] Specifically, Fig. 9 is a first working curve diagram of a sensor detection position determination method for a wafer inspection device provided by an embodiment of the present invention, with reference to Fig. 9 , Fig. 9 The horizontal coordinate of each point shown represents the position coordinate of the workbench, and the vertical coordinate represents the grayscale value of the image. The x workbench position coordinates and x grayscale values ​​obtained in step S42 are fitted according to the corresponding relationship between the position coordinates and the grayscale values ​​to form a first working curve of the wafer inspection device, such as Fig. 9 shown.

[0096] S44. Determine a first position coordinate of the sensor based on the first working curve.

[0097] Specifically, the first position coordinates of the sensor are determined according to the first working curve fitted in the above step S43. The specific calculation method is described in detail below and will not be described here.

[0098] S45 . Based on the y position coordinates and the y grayscale values, establish a second working curve diagram of the wafer inspection equipment.

[0099] Specifically, the y workbench position coordinates and y grayscale values ​​obtained in the above step S42 are fitted according to the correspondence between the position coordinates and the grayscale values, and the fitting principle is the same as that in the above step S43, which will not be repeated here.

[0100] S46. Determine a second position coordinate of the sensor based on the second working curve.

[0101] Specifically, the second position coordinates of the sensor are determined according to the second working curve fitted in the above step S45. The specific calculation method is described in detail below and will not be described here.

[0102] On the basis of the above-mentioned embodiments of the invention, the embodiments of the invention further refine the determination of the first position coordinates of the sensor based on the first working curve diagram and the determination of the second position coordinates of the sensor based on the second working curve diagram. Fig.10 is a flow chart of another sensor detection position determination method of a wafer inspection device provided by an embodiment of the present invention, with reference to Fig.10 A method for determining a sensor detection position of a wafer inspection device provided by an embodiment of the present invention includes:

[0103] S51, moving the workbench to a preset position so that the sensor corresponds to at least a portion of the target graphic.

[0104] S52. Based on the preset position, control the workbench to move multiple times, and sequentially obtain the position coordinates of the workbench and the grayscale value of the target graphic in the image taken by the camera.

[0105] S53 . Based on the x position coordinates and the x grayscale values, establish a first working curve diagram of the wafer detection equipment.

[0106] S54 , calculating a first grayscale median of the image in the first direction based on the x grayscale values.

[0107] Specifically, among all the grayscale values ​​of the image of the target figure captured by the camera, the first grayscale median of the image is calculated, wherein the first grayscale median is calculated by formula (1):

[0108]

[0109] Among them, G ax is the first grayscale median, G max1 is the maximum gray value in the image along the first direction, G min1 is the minimum grayscale value in the image along the first direction, where G max1 and G min1 G 11 ~G 1x The maximum and minimum values ​​in .

[0110] S55. Determine a first position coordinate of the sensor according to the first grayscale median value.

[0111] Specifically, determining the first position coordinate of the sensor according to the first grayscale median value is specifically determining the first position coordinate D of the sensor according to x grayscale values ​​and the first grayscale median value. x , D x │G m -G ax │ min Time m Corresponding to the coordinates in the first direction, where │G m -G ax │ min G is the minimum value of the absolute value of the difference between x grayscale values ​​and the first grayscale median value. m G 11 ~G 1xWhen the first grayscale median is calculated, the data closest to the first grayscale median in the set of all x grayscale values ​​is the first position coordinate D of the sensor in the entire detection device. x .

[0112] S56. Calculate a second grayscale median of the image in the second direction based on the y grayscale values.

[0113] Specifically, the second grayscale median of the image in the second direction is calculated based on y grayscale values, and is calculated by formula (II):

[0114]

[0115] Among them, G ay is the second grayscale median, G max2 is the maximum grayscale value in the image along the second direction, G min2 is the minimum gray value in the image along the second direction, where G max2 and G min2 G 21 ~G 2y The maximum and minimum values ​​in .

[0116] S57. Determine a second position coordinate of the sensor according to the second grayscale median value.

[0117] Specifically, determining the second position coordinate of the sensor according to the second grayscale median value is specifically determining the second position coordinate D of the sensor according to y grayscale values ​​and the second grayscale median value. y , D y │G n -G ay │ min Time n Corresponding to the coordinates in the second direction, where │G n -G ay │ min The minimum value G of the absolute value of the difference between y gray values ​​and the second gray median value n G 21 ~G 2y When the second grayscale median is calculated, the data closest to the second grayscale median in the set of all x grayscale values ​​is the second position coordinate D of the sensor in the entire wafer detection device. y .

[0118] Based on the above-mentioned embodiment of the invention, the embodiment of the invention further refines the process of determining the first position coordinate of the sensor according to the first grayscale median value and determining the second position coordinate of the sensor according to the second grayscale median value. Fig.11is a flow chart of another sensor detection position determination method of a wafer inspection device provided by an embodiment of the present invention, with reference to Fig.11 A method for determining a sensor detection position of a wafer inspection device provided by an embodiment of the present invention includes:

[0119] S61, moving the workbench to a preset position so that the sensor corresponds to at least a portion of the target graphic.

[0120] S62. Based on the preset position, control the workbench to move multiple times, and sequentially obtain the position coordinates of the workbench and the grayscale value of the target graphic in the image taken by the camera.

[0121] S63. Determine a first position coordinate of the sensor according to the first grayscale median value.

[0122] S64. Determine a second position coordinate of the sensor according to the second grayscale median value.

[0123] S65. Obtain the first position coordinate D of the sensor x and the second position coordinate D of the sensor y .

[0124] Specifically, the first position coordinate D of the sensor obtained in the above steps S63 and S64 is obtained. x and the second position coordinate D y .

[0125] S66, according to the first position coordinate D of the sensor x and the second position coordinate D of the sensor y Determine the position coordinates of the sensor as (D x , D y ).

[0126] Specifically, the first position coordinate D of the sensor x and the second position coordinate D y After integration, the sensor position coordinates are finally determined as (D x , D y ).

[0127] According to the same inventive concept, an embodiment of the present invention provides a sensor detection position determination device for a wafer inspection device, the position determination device being used in the sensor detection position determination method for a wafer inspection device in any of the above-mentioned inventive embodiments. Fig.12 is a block diagram of a sensor detection position determination device for a wafer inspection device provided by an embodiment of the present invention, with reference to Fig.12 , the position determining device comprises:

[0128] The acquisition module 1 is used to move the workbench to a preset position so that the sensor corresponds to at least a part of the target pattern.

[0129] The recording module 2 is used to control the workbench to move multiple times based on a preset position, and sequentially obtain the position coordinates of the workbench and the grayscale value of the target graphic in the image taken by the camera.

[0130] The calculation module 3 is used to determine the position coordinates of the sensor according to the corresponding relationship between the position coordinates and the grayscale value.

[0131] A sensor detection position determination device for a wafer inspection device provided in an embodiment of the present invention can achieve the same technical effect as the sensor detection position determination method for a wafer inspection device in any of the above-mentioned invention embodiments, which will not be elaborated herein.

[0132] According to the same inventive concept, an embodiment of the present invention further provides a wafer inspection device, including the sensor detection position determination device of the wafer inspection device in the above-mentioned inventive embodiment.

[0133] A wafer inspection device provided by an embodiment of the present invention can achieve the same technical effect as the sensor detection position determination device of the wafer inspection device in the above-mentioned invention embodiment, which will not be elaborated here.

[0134] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for determining a sensor detection position of a wafer inspection device, characterized in that: The wafer inspection equipment includes a workbench, a wafer and a sensor, wherein the sensor includes an objective lens and a camera, a target pattern is arranged on the wafer, and the camera photographs the target pattern by receiving the transmitted light of the objective lens. The method for determining the detection position of the sensor includes: Moving the workbench to a preset position so that the sensor corresponds to at least a portion of the target pattern; Based on the preset position, controlling the workbench to move multiple times, and sequentially acquiring the position coordinates of the workbench and the grayscale value of the target graphic in the image captured by the camera; The position coordinates of the sensor are determined according to the corresponding relationship between the position coordinates and the grayscale value.

2. The sensor detection position determination method of the wafer inspection equipment according to claim 1, characterized in that: Before the workbench is moved to a preset position so that the sensor corresponds to at least a portion of the target pattern, the method includes: determining a target pattern in the wafer; The preset position of the workbench is determined according to the target graphic; wherein the size of the target graphic is larger than the installation error of the sensor.

3. The sensor detection position determination method of the wafer inspection equipment according to claim 1, characterized in that: Based on the preset position, controlling the workbench to move multiple times, and sequentially recording the position coordinates of the workbench and the grayscale value of the target graphic in the image captured by the camera, including: Taking the starting position as the starting point, the workbench is controlled to move x times along the first direction with a first preset step length, and the x position coordinates of the workbench and the x grayscale values ​​of the target pattern in the wafer in the image taken by the camera are recorded at the same time, and the x grayscale values ​​are recorded as G respectively. 11 ~G 1x ; Taking the starting position as the starting point, the workbench is controlled to move y times along the second direction with a second preset step length, and the y position coordinates of the workbench and the y grayscale values ​​of the target pattern in the wafer in the image taken by the camera are recorded at the same time, and the y grayscale values ​​are recorded as G respectively. 21 ~G 2y ; The first direction and the second direction are perpendicular to each other; x and y are both positive integers greater than 1.

4. The sensor detection position determination method of the wafer inspection equipment according to claim 3, characterized in that: The determining the position coordinates of the sensor according to the corresponding relationship between the position coordinates and the grayscale value includes: Based on the x position coordinates and the x grayscale values, establishing a first working curve diagram of the wafer detection device; Determining a first position coordinate of the sensor based on the first working curve graph; Based on the y position coordinates and the y grayscale values, establishing a second working curve diagram of the wafer detection device; A second position coordinate of the sensor is determined based on the second working curve diagram.

5. The sensor detection position determination method of wafer inspection equipment according to claim 4, characterized in that: The determining the first position coordinates of the sensor based on the first working curve diagram, and determining the second position coordinates of the sensor based on the second working curve diagram, comprises: Calculate a first grayscale median value of the image in the first direction based on the x grayscale values; Determine a first position coordinate of the sensor according to the first grayscale median value; Calculate a second grayscale median value of the image in the second direction based on y grayscale values; The second position coordinates of the sensor are determined according to the second grayscale median value.

6. The sensor detection position determination method of wafer inspection equipment according to claim 5, characterized in that: The first grayscale median is calculated by formula (1): Among them, G ax is the first grayscale median, G max1 is the maximum grayscale value in the image along the first direction, G min1 is the minimum grayscale value in the image along the first direction, where G max1 and G min1 G 11 ~G 1x The maximum and minimum values ​​in ; Determine the first position coordinate D of the sensor according to the x grayscale values ​​and the first grayscale median value x , D x │G m -G ax │ min Time m Corresponding to the coordinates in the first direction, where |G m -G ax │ min is the minimum value of the absolute value of the difference between the x grayscale values ​​and the first grayscale median value, G m G 11 ~G 1x The value in ; The second grayscale median is calculated by formula (II): Among them, G ay is the second grayscale median, G max2 is the maximum grayscale value in the image along the second direction, G min2 is the minimum grayscale value in the image along the second direction, where G max2 and G min2 G 21 ~G 2y The maximum and minimum values ​​in ; Determine the second position coordinate D of the sensor according to the y grayscale values ​​and the second grayscale median value y , D y │G n -G ay │ min Time n Corresponding to the coordinates in the second direction, where |G n -G ay │ min The minimum value G of the absolute value of the difference between the y grayscale values ​​and the second grayscale median value is n G 21 ~G 2y The value in .

7. The sensor detection position determination method of wafer inspection equipment according to claim 6, characterized in that: After determining the first position coordinates of the sensor according to the first grayscale median value and determining the second position coordinates of the sensor according to the second grayscale median value, the method comprises: Get the first position coordinate D of the sensor x and the second position coordinate D of the sensor y ; According to the first position coordinate D of the sensor x and the second position coordinate D of the sensor y Determine the position coordinates of the sensor as (D x , D y ).

8. The method for determining the sensor detection position of a wafer inspection device according to claim 1, characterized in that: The shape of the target figure includes any one of a rectangle, a right triangle, an "L" shape and a "U" shape.

9. A sensor detection position determination device for a wafer inspection device, the position determination device being used to execute the sensor detection position determination method for a wafer inspection device according to any one of claims 1 to 8, the position determination device comprising: An acquisition module, used for moving the workbench to a preset position so that the sensor corresponds to at least a portion of the target pattern; A recording module, used for controlling the workbench to move multiple times based on the preset position, and sequentially obtaining the position coordinates of the workbench and the grayscale value of the target graphic in the image taken by the camera; A calculation module is used to determine the position coordinates of the sensor according to the corresponding relationship between the position coordinates and the grayscale value.

10. A wafer inspection device, characterized in that: A sensor detection position determination device comprising the wafer inspection equipment as described in claim 9.

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