Photoresist coating equipment and wafer surface hydrophobicity detection method

Abstract

The invention provides photoresist coating equipment and a wafer surface hydrophobicity detection method, and belongs to the technical field of semiconductor equipment.The photoresist coating equipment comprises a base, a first mounting piece arranged on the upper side of the base and a second mounting piece arranged on the lower side of the base, the base is used for bearing a wafer, and the first mounting piece is arranged on the upper side of the base; a photoresist spray head and a detection liquid injection head are arranged on the first mounting part, the photoresist spray head is used for spraying photoresist on the surface of a wafer, the detection liquid injection head is used for forming detection liquid drops on the surface of the wafer, and an image collector and a first driving structure are arranged on the second mounting part; the first driving structure is used for driving the image collector to move to a preset position according to the position of the detection liquid drop so as to collect an image of the detection liquid drop. When the photoresist coating equipment is used for detecting the hydrophobicity of the surface of the wafer, the wafer does not need to be taken down from the base to obtain an image of a detection liquid drop on the wafer, so that the problem that the wafer is polluted and scrapped due to exposure in air is avoided, the measurement cost is reduced, and the measurement efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor equipment, and more specifically, relates to a photoresist coating equipment and a method for detecting the hydrophobicity of a wafer surface. Background Art

[0002] The contact angle is the angle between the tangent of the gas-liquid interface and the solid-liquid junction line at the three-phase intersection of gas, liquid, and solid. It is a measure of the wetting degree of a liquid on a solid surface. The size of the contact angle reflects the spreading degree of the liquid on the solid surface and is an important parameter of wettability. The hydrophilicity and hydrophobicity of the wafer surface have an important impact on the adhesion between the photoresist and the wafer in the semiconductor lithography process. The more hydrophobic the wafer surface is, the more beneficial it is to the adhesion between the photoresist and the wafer. Currently, the contact angle is commonly used to characterize the hydrophilicity and hydrophobicity of the wafer. The larger the contact angle, the more hydrophobic the wafer surface. For example, Figure 1 It is a schematic diagram for characterizing the hydrophilicity and hydrophobicity of the wafer according to the contact angle. Among them, the contact angle θ greater than 90 degrees represents that the wafer surface is hydrophobic, and the contact angle θ less than 90 degrees represents that the wafer surface is hydrophilic.

[0003] Currently, in the semiconductor manufacturing field, the contact angle measurement is realized by using a contact angle measuring instrument. During the contact angle measurement process, by dropping a liquid droplet on the surface of the solid sample, the shape image of the liquid droplet is obtained by using a microscope lens and a camera, and then the contact angle of the liquid droplet in the image is calculated by using digital image processing and algorithms.

[0004] However, when measuring the contact angle of the wafer by using a contact angle measuring instrument in the existing semiconductor lithography process, the wafer needs to be taken out of the carrier and exposed to the air environment. Due to the requirements for the cleanliness of the wafer in the semiconductor manufacturing field, these wafers often need to be scrapped, which has the disadvantages of low measurement efficiency and high cost. Summary of the Invention

[0005] The purpose of the present invention is to provide a photoresist coating equipment and a method for detecting the hydrophobicity of a wafer surface. The photoresist coating equipment and the method for detecting the hydrophobicity of the wafer surface can ensure the cleanliness of the wafer during the detection process, avoid the scrapping of the wafer, and have high measurement efficiency.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is: In the first aspect of the present invention, a photoresist coating equipment is provided, including a base, a first mounting member disposed on the upper side of the base, and a second mounting member disposed on the lower side of the base; The base is used for carrying the wafer. A photoresist spray head and a detection liquid injection head are disposed on the first mounting member. The photoresist spray head is used for spraying photoresist on the wafer surface, and the detection liquid injection head is used for forming a detection liquid droplet on the wafer surface; An image collector and a first driving structure are provided on the second mounting member. The first driving structure is configured to drive the image collector to move to a preset position according to the position of the detected droplet to collect an image of the detected droplet.

[0007] After the detection liquid injection head of the photoresist coating equipment forms a detection liquid droplet on the wafer, the first driving structure can drive the image collector to move to a preset position according to the position of the detection liquid droplet to collect an image of the detection liquid droplet. When detecting the hydrophobicity of the wafer surface, the photoresist coating equipment does not need to remove the wafer from the base to obtain an image of the detection liquid droplet on the wafer, avoiding the problem of the wafer being exposed to the air and being contaminated and scrapped, reducing the measurement cost and improving the measurement efficiency.

[0008] Further, when the image collector moves to the preset position, the projection of the image collector on the plane where the wafer is located is located outside the wafer, and the optical axis of the lens of the image collector is parallel to the plane where the wafer is located. The image collector of the photoresist coating equipment takes pictures from a horizontal angle when collecting an image of the detection liquid droplet, and the image of the detection liquid droplet coincides with the actual situation, reducing or eliminating the error of the contact angle obtained through the image of the detection liquid droplet, improving the accuracy of contact angle measurement, and thus improving the accuracy of hydrophobicity detection.

[0009] Further, when the image collector moves to the preset position, the distance between the optical axis of the lens of the image collector and the plane where the wafer is located is greater than one-third of the height of the detection liquid droplet and less than the height of the detection liquid droplet. The photoresist coating equipment makes the image of the detection liquid droplet collected by the image collector clearer.

[0010] Further, a second driving structure is further provided on the first mounting member. The second driving structure is configured to drive the detection liquid injection head to move a preset distance toward or away from the wafer. The photoresist coating equipment drives the detection liquid injection head to move toward or away from the wafer through the second driving structure, which can prevent the detection liquid injection head from being contaminated during the glue coating process.

[0011] Further, a distance sensor is further provided on the first mounting member. The distance sensor is configured to obtain the height of the detection liquid droplet on the surface of the wafer; the distance sensor is further configured to obtain the distance between the detection liquid injection head and the wafer. The photoresist coating equipment obtains the distance between the detection liquid injection head and the wafer through the distance sensor, and can make the detection liquid injection head move the same distance toward the wafer each time during the process of controlling the detection liquid injection head to move toward the wafer, reducing the hydrophobicity measurement error of different wafers in different measurement areas.

[0012] Further, the first driving structure includes a horizontal telescopic driving structure, a vertical telescopic driving structure, and a horizontal rotation driving structure. The image collector is housed below the base in the initial state. The horizontal telescopic driving structure is used to drive the image collector to move horizontally, so that the projection of the image collector on the plane where the wafer is located is outside the wafer. The vertical telescopic driving structure is used to drive the image collector to move vertically. The horizontal rotation driving structure is used to drive the image collector to rotate to a position directly facing the detected droplet.

[0013] When the image collector of the photoresist coating equipment is housed below the base in the unused state, it prevents the contamination of the image collector during the coating process, and improves the accuracy of contact angle measurement when obtaining the contact angle from the image of the detected droplet acquired by the image collector.

[0014] Further, the image collector includes a camera and a light source. When the image collector acquires the image of the detected droplet, the camera and the light source are respectively located at both ends in the diameter direction of the wafer. The light source of the photoresist coating equipment can enhance the features of the detected droplet to be photographed, making it easier for the camera to capture a clear and well-contrasted image of the detected droplet. Further, it further includes a contact angle calculation unit, and the contact angle calculation unit is used to calculate the contact angle of the detected droplet according to the image of the detected droplet. The photoresist coating equipment can directly calculate the contact angle of the detected droplet by setting the contact angle calculation unit.

[0015] The second aspect of the present invention provides a method for detecting the hydrophobicity of the wafer surface, using the above-mentioned photoresist coating equipment. The method includes: obtaining the position of the detected droplet on the wafer to be tested; Driving the image collector to move to a preset position according to the position of the detected droplet to acquire the image of the detected droplet; Obtaining the contact angle of the detected droplet according to the image of the detected droplet, and judging the hydrophobicity of the wafer surface according to the contact angle.

[0016] Further, the obtaining the position of the detected droplet on the wafer to be tested includes: Obtaining the coordinates of the projection of the detected liquid injection head on the wafer; Obtaining the coordinates of the detected droplet according to the coordinates of the projection of the detected liquid injection head on the wafer.

[0017] Further, the driving the image collector to move to a preset position according to the coordinates of the detected droplet to acquire the image of the detected droplet includes: Drive the image collector to move a preset distance in the horizontal direction so that the projection of the image collector on the plane where the wafer is located is outside the wafer; Obtain the height of the detected droplet on the surface of the wafer; Drive the image collector to move in the vertical direction according to the distance between the image collector and the upper surface of the wafer and the height of the detected droplet on the surface of the wafer; Drive the image collector to horizontally rotate to a position directly facing the detected droplet according to the coordinates of the detected droplet.

[0018] Further, before obtaining the coordinates of the detected droplet on the wafer to be measured, it includes: Drive the detection liquid injection head to move a preset distance in the direction of the wafer; The detection liquid injection head forms a detected droplet on the wafer.

[0019] Further, the driving the image collector to move to a preset position to collect an image of the detected droplet according to the coordinates of the detected droplet includes: Collect images of the detected droplet multiple times to obtain a detected droplet image with high clarity.

[0020] Further, the driving the image collector to move to a preset position to collect an image of the detected droplet according to the coordinates of the detected droplet includes: when the image collector moves to the preset position, the distance between the optical axis of the lens of the image collector and the plane where the wafer is located is greater than one-third of the height of the detected droplet and less than the height of the detected droplet.

[0021] The method for detecting the hydrophobicity of the wafer surface provided by the present invention includes obtaining the position of the detected droplet on the wafer to be measured; driving the image collector to move to a preset position to collect an image of the detected droplet according to the position of the detected droplet; calculating the contact angle of the detected droplet according to the image of the detected droplet, and judging the hydrophobicity of the wafer surface according to the contact angle. After obtaining the position of the detected droplet on the wafer to be measured, the detection method drives the image collector to move to a preset position to collect an image of the detected droplet according to the position of the detected droplet, and then calculates the contact angle of the detected droplet according to the image of the detected droplet. When detecting the hydrophobicity of the wafer surface, the detection method does not need to remove the wafer from the base to obtain an image of the detected droplet on the wafer, avoiding the problem that the wafer is exposed to the air and contaminated and scrapped, reducing the measurement cost and improving the measurement efficiency. Description of the Drawings

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the accompanying drawings required for use in the embodiments or the description of the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0023] Figure 1 Schematic diagram for characterizing the hydrophilicity and hydrophobicity of a wafer through the contact angle provided by an embodiment of the present invention; Figure 2 Schematic comparison diagram of the water droplet image (right side) obtained by the image collector of the photoresist coating equipment provided by an embodiment of the present invention and the water droplet image (left side) obtained by the photoresist coating equipment in the prior art; Figure 3 Schematic structural diagram of the image collector of the photoresist coating equipment provided by an embodiment of the present invention in the unused state; Figure 4 Schematic structural diagram of the image collector of the photoresist coating equipment provided by an embodiment of the present invention in the used state; Figure 5 Schematic coordinate diagram of a water droplet on the wafer surface provided by an embodiment of the present invention; Figure 6 Schematic diagram of the height measurement principle of a water droplet on the wafer surface measured by a distance sensor provided by an embodiment of the present invention; and schematic diagram of the principle of the distance sensor for obtaining the distance between the detection liquid injection head and the wafer.

[0024] Figure 7 Schematic diagram of the water droplet height provided by an embodiment of the present invention; Figure 8 Schematic diagram of the optical axis of the image collector at half of the water droplet height provided by an embodiment of the present invention; Figure 9 Schematic diagram of the process of the image collector rotating to the position directly facing the water droplet provided by an embodiment of the present invention; Figure 10 Flowchart of the method for detecting the hydrophobicity of the wafer surface provided by an embodiment of the present invention; Figure 11 Flowchart of driving the image collector to move to a preset position to collect the image of the water droplet according to the position of the water droplet in the method for detecting the hydrophobicity of the wafer surface provided by an embodiment of the present invention.

[0025] Among them, the reference numerals in the figure: 1 - base; 2 - first mounting member; 3 - second mounting member; 4 - wafer; 21 - photoresist nozzle; 22 - detection liquid injection head; 23 - distance sensor; 31 - image collector; 311 - camera; 312 - light source. Detailed implementation manners

[0026] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0027] In the description of the present invention, it should be understood that 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 does not necessarily limit to those clearly listed steps or units, but may include other steps or units not clearly listed or inherent to these process, method, product or device.

[0028] It should be understood that the orientation or positional relationships indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0029] In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. It should be understood that the term "and / or" used herein is only a description of the associated relationship of the associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In the description of the present invention, unless otherwise specified, the meaning of "plural" is two or more.

[0030] Contact angle is used to evaluate properties such as the wettability and hydrophobicity of materials. Currently, in the field of semiconductor manufacturing, contact angle measurement is achieved using a contact angle measuring instrument. During the contact angle measurement process, by dropping a liquid droplet onto the surface of a solid sample, the shape image of the liquid droplet is obtained using a microscope lens and a camera, and the contact angle of the liquid droplet in the image is calculated using digital image processing and algorithms. However, when the existing contact angle measuring instrument measures the contact angle of a wafer, the wafer needs to be taken out of the carrier of the device and exposed to the air environment. For example, in semiconductor lithography processes, the wafer needs to be taken out of the carrier of the photoresist coating equipment and exposed to the air environment. Due to the requirements for wafer cleanliness in the semiconductor manufacturing field, these wafers often need to be scrapped, which has disadvantages such as low measurement efficiency and high costs. Based on the above problems, this application provides a photoresist coating equipment and a method for detecting the hydrophobicity of the wafer surface.

[0031] The following will detail the photoresist coating equipment and the method for detecting the hydrophobicity of the wafer surface provided by the present invention with reference to specific embodiments.

[0032] Figure 3 It is a schematic structural diagram of the image collector of the photoresist coating equipment provided by the embodiment of the present invention in the unused state. Figure 4 It is a schematic structural diagram of the image collector of the photoresist coating equipment provided by the embodiment of the present invention in the used state. Please refer to Figure 3 and Figure 4 In the first aspect of this embodiment, a photoresist coating equipment is provided, including a base 1, a first mounting member 2 disposed on the upper side of the base 1, and a second mounting member 3 disposed on the lower side of the base 1.

[0033] The base 1 is used to carry the wafer 4. A photoresist spray head 21 and a detection liquid injection head 22 are disposed on the first mounting member 2. The photoresist spray head 21 is used to spray photoresist on the surface of the wafer 4, and the detection liquid injection head 22 is used to form a detection liquid droplet on the surface of the wafer 4. The detection liquid droplet in the embodiment of this application can be a water droplet, a plasma water droplet, or other liquid droplets capable of realizing hydrophobicity detection. In the following embodiments, the detection liquid droplet is introduced taking a water droplet as an example.

[0034] An image collector 31 and a first driving structure are disposed on the second mounting member 3. The first driving structure is used to drive the image collector 31 to move to a preset position according to the position of the detection liquid droplet to collect an image of the detection liquid droplet.

[0035] The photoresist coating equipment of this embodiment is mainly used to coat photoresist on the surface of a silicon wafer. The photoresist coating equipment is usually used in conjunction with a lithography machine to complete processes such as photoresist coating, curing, and development of the wafer. These devices play a crucial role in semiconductor manufacturing and directly affect the formation of fine exposure patterns in the lithography process and the quality of subsequent processes. After obtaining the image of the water droplet, the photoresist coating equipment of this embodiment can monitor the change in the surface properties of the wafer 4 before photoresist coating due to the previous process and other factors, as well as the surface hydrophobicity after the coating of hexamethyldisilazane (HMDS) (HMDS is a commonly used chemical reagent mainly used for the adhesion enhancement treatment of silicon substrate wafers in the integrated circuit lithography process. HMDS reacts with the oxide layer on the substrate surface to form a hydrophobic protective layer, which can effectively prevent water molecules in the air from adsorbing on the surface and improve the adhesion and uniformity of the photoresist). For example, by detecting the hydrophobicity of the wafer 4, engineers can judge the adhesion situation between the photoresist and the wafer 4, and at the same time help to explore and solve defects in the production process, such as the collapse of photoresist lines and the problem of residual photoresist that is not developed cleanly.

[0036] The base 1 of the photoresist coating equipment of this embodiment is used to carry the wafer 4 after hydrophobic treatment. That is, after the wafer 4 that has undergone hydrophobic treatment is transferred into the photoresist coating equipment, the hydrophobicity of the wafer 4 fixed on the base 1 is first detected, and then photoresist coating is carried out on the wafer 4. The specific structure of the base 1 is not particularly limited in this embodiment.

[0037] In this embodiment, a photoresist nozzle 21 and a detection liquid injection head 22 are provided on the first mounting member 2. The photoresist nozzle 21 and the detection liquid injection head 22 are arranged above the base 1. The photoresist nozzle 21 is used to spray photoresist on the surface of the wafer 4, and the detection liquid injection head 22 can drip the detection liquid onto the wafer 4 placed on the base 1. For example, the detection liquid injection head 22 forms a water droplet on the upper surface of the wafer 4. Exemplarily, the photoresist nozzle 21 and the detection liquid injection head 22 can be the photoresist nozzle 21 and the detection liquid injection head 22 in the existing photoresist coating equipment.

[0038] In this embodiment, an image collector 31 and a first driving structure are provided on the second mounting member 3. The first driving structure is used to drive the image collector 31 to move to a preset position to collect the image of the water droplet according to the position information of the water droplet on the wafer 4. In this embodiment, the position of the water droplet on the wafer 4 is the position of the projection of the detection liquid injection head 22 on the wafer 4. Figure 5 For the schematic diagram of the coordinates of the water droplet on the wafer surface provided by the embodiment of the present invention, please refer to Figure 5, in the two-dimensional rectangular coordinate system with the center of the wafer 4 as the origin on the surface of the wafer 4, if the coordinates of the projection of the detection liquid injection head 22 on the wafer 4 are (x, y), then the coordinates of the water droplet on the wafer 4 are (x, y). For example, the image collector 31 in this embodiment includes a camera 311. The camera 311 is initially located directly below the wafer 4. When an image of the water droplet needs to be captured, the first driving structure drives the camera 311 to move to a position where the lens is directly opposite the water droplet, and the camera 311 captures an image of the water droplet facing the water droplet. For example, the optical axis of the camera 311 is parallel to the X-axis in the initial state. After the first driving structure drives the camera 311 to extend out of the side of the wafer in the horizontal direction, the camera 311 is driven to extend a certain distance in the vertical direction, and then the camera 311 is driven to rotate by an angle θ, where θ = arctan y / x. After the image of the water droplet is obtained, the contact angle of the water droplet can be obtained. Among them, obtaining the contact angle of the water droplet based on the water droplet image belongs to the prior art. Exemplarily, after the water droplet image is obtained, the method disclosed in Patent CN105571993B can be adopted to obtain the contact angle of the water droplet. Of course, this embodiment can also adopt known existing methods to obtain the contact angle of the water droplet.

[0039] The photoresist coating equipment provided by the embodiment of the present invention includes a base, a first mounting member provided on the upper side of the base, and a second mounting member provided on the lower side of the base. The base is used to carry the wafer. A photoresist spray head and a detection liquid injection head are provided on the first mounting member. The photoresist spray head is used to spray photoresist on the surface of the wafer, and the detection liquid injection head is used to form a water droplet on the surface of the wafer. An image collector and a first driving structure are provided on the second mounting member. The first driving structure is used to drive the image collector to move to a preset position according to the position of the water droplet to collect an image of the water droplet. After the detection liquid injection head of the photoresist coating equipment forms a water droplet on the wafer, the first driving structure can drive the image collector to move to a preset position according to the position of the water droplet to collect an image of the water droplet. When detecting the hydrophobicity of the wafer surface, the photoresist coating equipment does not need to remove the wafer from the base to obtain an image of the water droplet on the wafer, avoiding the problem that the wafer is exposed to the air and contaminated and scrapped, reducing the measurement cost and improving the measurement efficiency.

[0040] Further, when the image collector 31 moves to the preset position, the projection of the image collector 31 on the plane where the wafer 4 is located is located outside the wafer 4, and the optical axis of the lens of the image collector 31 is parallel to the plane where the wafer 4 is located. Figure 2 For a comparison schematic diagram of the water droplet image (right side) obtained by the image collector of the photoresist coating equipment provided by the embodiment of the present invention and the water droplet image (left side) obtained by the photoresist coating equipment in the prior art, please refer to Figure 2, when the existing photoresist coating equipment calculates the contact angle of the water droplet by obtaining the image of the water droplet, generally, a camera takes pictures obliquely above the wafer 4. Due to the influence of the inclined top-down shooting, the image of the water droplet taken by the camera is an inclined plane image, resulting in a smaller height H of the cross-section of the water droplet. The height H of the cross-section of the water droplet directly affects the size of the contact angle, that is, the contact angle error obtained through image feedback is relatively large. In this embodiment, when the image collector 31 obtains the image of the water droplet, it takes pictures from a horizontal angle. The height H of the cross-section of the water droplet in the obtained water droplet image coincides with the actual water droplet, reducing or avoiding the contact angle error and improving the accuracy of contact angle measurement, that is, improving the accuracy of wafer hydrophobicity detection.

[0041] In one embodiment, a second driving structure is further provided on the first mounting member 2. The second driving structure is used to drive the detection liquid injection head 22 to move a preset distance toward or away from the wafer 4. The second driving structure is provided on the first mounting member 2 in this embodiment. The detection liquid injection head 22 is driven to move toward or away from the wafer 4 through the second driving structure. For example, when it is necessary to inject a water droplet onto the wafer 4, the second driving structure drives the detection liquid injection head 22 to move toward the wafer 4. After the contact angle measurement is completed, the second driving structure drives the detection liquid injection head 22 to move away from the wafer 4, and the detection liquid injection head 22 is retracted and housed on the first mounting member 2, which can prevent the detection liquid injection head 22 from being contaminated during the glue coating process.

[0042] In one embodiment, a distance sensor 23 is further provided on the first mounting member 2. The distance sensor 23 is used to obtain the height of the water droplet on the surface of the wafer 4. Figure 6 It is a schematic diagram of the measurement principle of the distance sensor provided by the embodiment of the present invention for measuring the height of the water droplet on the wafer surface; and a schematic diagram of the principle of the distance sensor for obtaining the distance between the detection liquid injection head and the wafer. Figure 7 It is a schematic diagram of the water droplet height provided by the embodiment of the present invention. Please refer to Figure 6 , Figure 7, in this embodiment, a distance sensor 23 is provided on the first mounting member. When no water droplet is injected onto the wafer 4, the distance sensor 23 can measure the distance h0 between the upper surface of the wafer 4 and the distance sensor 23. After a water droplet is injected onto the wafer 4, the distance sensor 23 can measure the distance h1 between the highest point of the water droplet and the distance sensor 23. The height of the water droplet on the surface of the wafer 4 is h2 = h0 - h1. The distance sensor 23 is further configured to obtain the distance between the detection liquid injection head 22 and the wafer 4. In this embodiment, the distance d1 between the detection liquid injection head 22 and the wafer 4 is the distance h0 between the upper surface of the wafer 4 and the distance sensor 23 minus the distance d2 between the detection liquid injection head 22 and the distance sensor 23, that is, the distance d1 between the detection liquid injection head 22 and the wafer 4 is d1 = h0 - d2, where the distance d2 between the detection liquid injection head 22 and the distance sensor 23 is a known value. In this embodiment, the distance between the detection liquid injection head 22 and the wafer 4 is obtained by the distance sensor 23. During the process of controlling the movement of the detection liquid injection head 22 towards the wafer 4, the detection liquid injection head 22 can be made to move the same distance towards the wafer 4 each time. By fixing the distance between the detection liquid injection head 22 and the wafer 4 in this embodiment, when measuring the contact angle at different positions on different wafers 4, the measurement error of different measurement regions on different wafers 4 can be reduced.

[0043] A surface activator spray head 24 is further provided on the first mounting member 2 of this embodiment. For example, the surface activator spray head 24 sprays a solvent onto the wafer 4 for pre-wetting before spraying photoresist onto the wafer, which is beneficial to the coating of the photoresist.

[0044] Figure 8 It is a schematic diagram of the optical axis of the image collector provided by the embodiment of the present invention being located at half of the water droplet height. Figure 9 It is a schematic diagram of the process of the image collector provided by the embodiment of the present invention rotating to a position directly facing the water droplet; please refer to Figure 8 and Figure 9, in one embodiment, the first driving structure includes a horizontal telescopic driving structure, a vertical telescopic driving structure, and a horizontal rotation driving structure. The image collector 31 is received below the base 1 in the initial state. The horizontal telescopic driving structure and the vertical telescopic driving structure are used to drive the image collector 31 to extend out from below the base 1; the horizontal rotation driving structure is used to drive the image collector 31 to rotate to a position directly opposite to the water droplet. For example, the image collector 31 of this embodiment is installed on the telescopic arm 32. The telescopic arm 32 is provided with a horizontal telescopic driving structure, a vertical telescopic driving structure, and a horizontal rotation driving structure. In the initial state, the telescopic arm 32 is received below the base 1, and the telescopic arm 32 and the image collector 31 do not occupy extra space in the horizontal direction. When the image collector 31 is in use, the horizontal telescopic driving structure drives the telescopic arm 32 to move in the horizontal direction, so that the projection of the image collector 31 on the plane where the wafer is located is located outside the wafer 4. The vertical telescopic driving structure drives the image collector 31 to move in the vertical direction, so that the optical axis of the image collector 31 moves to a preset height. The horizontal rotation driving structure is used to drive the telescopic arm 32 to rotate in the horizontal plane, so that the optical axis of the image collector 31 rotates to a position directly opposite to the water droplet. The image collector 31 of this embodiment is received below the base 1 in the unused state, preventing the contamination of the image collector 31 by the glue application, and improving the accuracy of the contact angle measurement when obtaining the contact angle from the image of the water droplet acquired by the image collector 31.

[0045] In the above embodiment, the image collector 31 includes a camera 311 and a light source 312. When the image collector 31 collects the water droplet image, the camera 311 and the light source 312 are respectively located at both ends in the diameter direction of the wafer 4. The image collector 31 of this embodiment includes a camera 311 and a light source 312. The lens of the camera 311 is arranged opposite to the light source 312. The light source 312 of this embodiment can enhance the features of the captured water droplet, making it easier for the camera 311 to capture a clear and well-contrasted water droplet image.

[0046] In this embodiment, when the image collector 31 moves to a preset position, the distance between the optical axis of the lens of the image collector 31 and the plane where the wafer 4 is located is greater than one-third of the height of the water droplet and less than the height of the water droplet. Exemplarily, please refer to Figure 8, when the first driving structure of this embodiment drives the image collector 31 to rotate to a position directly facing the water droplet, the optical axis of the camera 311 coincides with 1 / 2 of the height h2 of the water droplet. Exemplarily, the vertical distance between the upper surface of the wafer 4 and the telescopic arm 32 in this embodiment is h3, and the vertical distance h4 between the optical axis of the camera 311 and the telescopic arm 32 is h4 = h3 + h2 / 2. h3 in this embodiment is a determined value, and the lens of the camera 311 can be adjusted according to the value of the water droplet height h2 so that the optical axis of the lens coincides with 1 / 2 of the water droplet height, which is beneficial to obtaining a clearer picture of the water droplet. Please refer to Figure 7 , the water droplet height h2 of this embodiment is obtained by the above distance sensor 23. For example, when no water droplet is injected on the wafer 4, the distance sensor 23 can measure the distance h0 between the upper surface of the wafer 4 and the distance sensor 23. After the water droplet is injected on the wafer 4, the distance sensor 23 can measure the distance h1 between the highest point of the water droplet and the distance sensor 23. The height of the water droplet on the surface of the wafer 4 is h2 = h0 - h1.

[0047] In one embodiment, it further includes a contact angle calculation unit, and the contact angle calculation unit is used to calculate the contact angle of the water droplet according to the image of the water droplet. By setting the contact angle calculation unit in this embodiment, after the image collector 31 acquires the image of the water droplet, the contact angle calculation unit calculates the contact angle of the water droplet according to the image of the water droplet. The method of calculating the contact angle of the water droplet according to the image of the water droplet belongs to the prior art, and the acquisition method thereof will not be elaborated in this embodiment.

[0048] The photoresist coating device provided by the embodiment of the present invention includes a base, a first mounting member provided on the upper side of the base, and a second mounting member provided on the lower side of the base. The base is used to carry the wafer. A photoresist nozzle and a detection liquid injection head are provided on the first mounting member. The photoresist nozzle is used to spray photoresist on the surface of the wafer, and the detection liquid injection head is used to form a water droplet on the surface of the wafer. An image collector and a first driving structure are provided on the second mounting member. The first driving structure is used to drive the image collector to move to a preset position according to the position of the water droplet to collect the image of the water droplet. After the detection liquid injection head of the photoresist coating device forms a water droplet on the wafer, the first driving structure can drive the image collector to move to a preset position according to the position of the water droplet to collect the image of the water droplet. When detecting the hydrophobicity of the wafer surface, the photoresist coating device does not need to remove the wafer from the base to obtain the image of the water droplet on the wafer, avoiding the problem of the wafer being exposed to the air and being contaminated and scrapped, reducing the measurement cost and improving the measurement efficiency.

[0049] Figure 10 is a flowchart of the method for detecting the hydrophobicity of the wafer surface provided by the embodiment of the present invention. Please refer to Figure 10 , Figures 1 - 5, the second aspect of the present invention provides a method for detecting the hydrophobicity of a wafer surface, using the photoresist coating device as described above. The method includes: S101. Obtain the position of the water droplet on the wafer to be measured; Specifically, in this embodiment, the position of the water droplet on the wafer 4 is the position of the projection of the detection liquid injection head 22 on the wafer 4. For example, in the two-dimensional rectangular coordinate system with the center of the wafer 4 as the origin on the surface of the wafer 4, if the coordinates of the projection of the detection liquid injection head 22 on the wafer 4 are (x, y), then the coordinates of the water droplet on the wafer 4 are (x, y). That is, in this embodiment, the position of the water droplet on the wafer 4 can be obtained by detecting the position of the projection of the detection liquid injection head 22 on the wafer 4.

[0050] S102. Drive the image collector to move to a preset position according to the position of the water droplet to collect an image of the water droplet; Specifically, the image collector 31 in this embodiment is located below the base 1 in the initial state. After obtaining the position of the water droplet on the wafer 4 to be measured, the first driving structure drives the image collector 31 to move to a preset position according to the position of the water droplet to collect an image of the water droplet. Exemplarily, the first driving structure includes a horizontal telescopic driving structure, a vertical telescopic driving structure, and a horizontal rotation driving structure. The image collector 31 is accommodated below the base 1 in the initial state. The horizontal telescopic driving structure and the vertical telescopic driving structure are used to drive the image collector 31 to extend from below the base 1, and the horizontal rotation driving structure is used to drive the image collector 31 to rotate to a position directly facing the water droplet.

[0051] S103. Obtain the contact angle of the water droplet according to the image of the water droplet, and judge the hydrophobicity of the wafer surface according to the contact angle.

[0052] Specifically, after obtaining the image of the water droplet, the contact angle of the water droplet can be obtained. Among them, obtaining the contact angle of the water droplet from the water droplet image belongs to the prior art. Exemplarily, after obtaining the water droplet image, the method disclosed in Patent CN105571993B can be adopted to obtain the contact angle, so as to judge the hydrophobicity of the surface of the wafer 4 according to the contact angle. For example, when the contact angle is less than 90 degrees, it is judged that the surface of the wafer 4 is hydrophilic; when the contact angle is greater than 90 degrees, it is judged that the surface of the wafer 4 is hydrophobic. Of course, in this embodiment, after obtaining the image of the water droplet, other existing known methods can also be adopted to obtain the contact angle of the water droplet.

[0053] The hydrophobicity detection method for the wafer surface provided by the embodiment of the present invention includes obtaining the position of the water droplet on the wafer to be measured; driving the image collector to move to a preset position according to the position of the water droplet to collect an image of the water droplet; obtaining the contact angle of the water droplet according to the image of the water droplet, and judging the hydrophobicity of the wafer surface according to the contact angle. After obtaining the position of the water droplet on the wafer to be measured, this detection method drives the image collector to move to a preset position to collect an image of the water droplet according to the position of the water droplet, and then obtains the contact angle of the water droplet according to the image of the water droplet. When detecting the hydrophobicity of the wafer surface, this detection method does not need to remove the wafer from the base to obtain an image of the water droplet on the wafer, avoiding the problem that the wafer is exposed to the air and contaminated and scrapped, reducing the measurement cost and improving the measurement efficiency.

[0054] In one embodiment, the obtaining the position of the water droplet on the wafer to be measured includes: Obtaining the coordinates of the projection of the detection liquid injection head on the wafer; Obtaining the coordinates of the water droplet according to the coordinates of the projection of the detection liquid injection head on the wafer.

[0055] In this embodiment, the position of the water droplet on the wafer 4 is the position of the projection of the detection liquid injection head 22 on the wafer 4. For example, in the two-dimensional rectangular coordinate system with the center of the wafer 4 as the origin on the surface of the wafer 4, if the coordinates of the projection of the detection liquid injection head 22 on the wafer 4 are (x, y), then the coordinates of the water droplet on the wafer 4 are (x, y). In this embodiment, the position of the water droplet on the wafer 4 can be obtained by the position of the projection of the detection liquid injection head 22 on the wafer 4.

[0056] Figure 11 The following is the flowchart of driving the image collector to move to a preset position to collect an image of the water droplet according to the position of the water droplet in the hydrophobicity detection method for the wafer surface provided by the embodiment of the present invention. Please refer to Figure 11 In one embodiment, the driving the image collector to move to a preset position to collect an image of the water droplet according to the position of the water droplet includes: S1031. Driving the image collector to move a preset distance in the horizontal direction so that the projection of the image collector on the plane where the wafer is located is outside the wafer; S1032. Obtaining the height of the water droplet on the surface of the wafer; S1033. Driving the image collector to move in the vertical direction according to the distance between the image collector and the upper surface of the wafer and the height of the water droplet on the surface of the wafer; S1034. Driving the image collector to horizontally rotate to a position directly facing the water droplet according to the position of the water droplet.

[0057] In this embodiment, please combine Figure 3and Figure 4 , the first driving structure includes a horizontal telescopic driving structure, a vertical telescopic driving structure and a horizontal rotation driving structure. The image collector 31 is received below the base 1 in the initial state. The horizontal telescopic driving structure and the vertical telescopic driving structure are used to drive the image collector 31 to extend out from below the base 1; the horizontal rotation driving structure is used to drive the image collector 31 to rotate to a position directly opposite to the water droplet. For example, in this embodiment, the image collector 31 is installed on the telescopic arm 32. The telescopic arm 32 is provided with a horizontal telescopic driving structure, a vertical telescopic driving structure and a horizontal rotation driving structure. In the initial state, the telescopic arm 32 is received below the base 1. The extending direction of the telescopic arm 32 in the horizontal direction is the same as the direction of the X-axis. In the initial state, the telescopic arm 32 and the image collector 31 do not occupy extra space in the horizontal direction. When the image collector 31 is in use, the horizontal telescopic driving structure drives the telescopic arm 32 to move in the horizontal direction so that the projection of the image collector 31 on the plane where the wafer 4 is located is located outside the outer contour of the wafer 4. The vertical telescopic driving structure drives the image collector 31 to move in the vertical direction so that the optical axis of the image collector 31 moves to a preset height. The horizontal rotation driving structure is used to drive the telescopic arm 32 to rotate in the horizontal plane so that the optical axis of the image collector 31 rotates to a position directly opposite to the water droplet.

[0058] In one embodiment, before obtaining the position of the water droplet on the wafer to be measured, it includes driving the detection liquid injection head to move a preset distance towards the wafer direction, and then the detection liquid injection head forms a water droplet on the wafer.

[0059] Please combine Figure 3 and Figure 6, a second driving structure is provided on the first mounting member of this embodiment. The detection liquid injection head 22 is driven by the second driving structure to move towards or away from the wafer 4. For example, when it is necessary to inject water droplets onto the wafer 4, the second driving structure drives the detection liquid injection head 22 to move towards the wafer 4. After the contact angle measurement is completed, the second driving structure drives the detection liquid injection head 22 to move away from the wafer 4, and the detection liquid injection head 22 is retracted, which can prevent the detection liquid injection head 22 from being contaminated during the glue coating process. Exemplarily, a distance sensor 23 is provided on the first mounting member of this embodiment. The distance sensor 23 is used to obtain the distance between the detection liquid injection head 22 and the wafer 4. In this embodiment, the distance between the detection liquid injection head 22 and the wafer 4 is obtained through the distance sensor 23. During the process of controlling the detection liquid injection head 22 to move towards the wafer 4, it can be ensured that the detection liquid injection head 22 moves the same distance each time towards the wafer 4. During the contact angle measurement process, the height of the detection liquid injection head 22 when dripping water has a certain influence on the height of the water droplets on the wafer 4. In this embodiment, when the detection liquid injection head 22 injects water droplets towards the wafer 4, the distance between the detection liquid injection head 22 and the wafer 4 is fixed. When measuring the contact angle at different positions on different wafers 4, the measurement error of different measurement areas on different wafers 4 can be reduced, and the accuracy of the contact angle measurement is improved.

[0060] In one embodiment, after driving the image collector to horizontally rotate to a position directly opposite to the water droplet according to the position of the water droplet, the following further includes: S1035. Collect images of the water droplet multiple times to obtain a water droplet image with high clarity.

[0061] In this embodiment, a water droplet image with high resolution is obtained by collecting images of the water droplet multiple times. The image collector 31 of this embodiment includes a camera 311. For example, by focusing and shooting with the camera 311 multiple times, the clearest water droplet image is selected from the images taken multiple times.

[0062] In one embodiment, driving the image collector 31 to move to a preset position to collect an image of the water droplet according to the coordinates of the water droplet includes: when the image collector 31 moves to the preset position, the distance between the optical axis of the lens of the image collector 31 and the wafer 4 is greater than one-third of the height of the water droplet and less than the height of the water droplet. Preferably, the optical axis of the lens of the image collector 31 coincides with 1 / 2 of the height h2 of the water droplet.

[0063] Exemplarily, please combine Figures 6 - 8, when the first driving structure of this embodiment drives the image collector 31 to rotate to a position facing the water droplet directly, the optical axis of the camera 311 coincides with 1 / 2 of the height h2 of the water droplet. In the initial state, the vertical distance between the upper surface of the wafer 4 and the telescopic arm 32 is h3, then the vertical distance between the optical axis of the camera 311 and the telescopic arm 32 is h4 = h3 + h2 / 2. h3 in this embodiment is a determined value, and the lens of the camera 311 can be adjusted according to the value of the water droplet height h2 so that the optical axis of the lens coincides with 1 / 2 of the water droplet height, which is beneficial to obtaining a clearer picture of the water droplet. The water droplet height h2 in this embodiment is obtained by the above-mentioned distance sensor 23. For example, when no water droplet is injected onto the wafer 4, the distance sensor 23 can measure the distance h0 between the upper surface of the wafer 4 and the distance sensor 23. After the water droplet is injected onto the wafer 4, the distance sensor 23 can measure the distance h1 between the highest point of the water droplet and the distance sensor 23. The height h2 of the water droplet on the surface of the wafer 4 = h0 - h1. When the camera 311 takes an image of the water droplet in this embodiment, the optical axis of the camera 311 coincides with 1 / 2 of the water droplet height h2, making the water droplet image clearer.

[0064] In the prior art, when obtaining an image of the water droplet on the wafer 4, it is generally taken from an oblique upper direction, and the obtained water droplet image is an inclined plane image, resulting in a smaller cross-sectional height of the water droplet, so that the contact angle error reflected by the water droplet image is relatively large. In this embodiment, when taking an image of the water droplet, it is taken from the horizontal angle of the water droplet. The water droplet image coincides with the actual situation, reducing or eliminating the error and improving the measurement accuracy.

[0065] In the above description, the descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0066] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A photoresist coating device, characterized in that: It comprises a base, a first mounting member arranged on the upper side of the base, and a second mounting member arranged on the lower side of the base; The base is used to carry the wafer, and the first mounting member is provided with a photoresist spray head and a detection liquid injection head, the photoresist spray head is used to spray photoresist on the surface of the wafer, and the detection liquid injection head is used to form detection liquid droplets on the surface of the wafer; The second mounting member is provided with an image collector and a first driving structure, and the first driving structure is used for driving the image collector to move to a preset position according to the position of the detection droplet to collect an image of the detection droplet.

2. The photoresist coating device according to claim 1, characterized in that: When the image collector moves to a preset position, the projection of the image collector on the plane where the wafer is located is located outside the wafer, and the optical axis of the lens of the image collector is parallel to the plane where the wafer is located.

3. The photoresist coating device according to claim 2, characterized in that: When the image collector moves to a preset position, the distance between the optical axis of the lens of the image collector and the plane where the wafer is located is greater than one third of the height of the detection droplet and less than the height of the detection droplet.

4. The photoresist coating device according to claim 2, characterized in that: A second driving structure is also provided on the first mounting member, and the second driving structure is used to drive the detection liquid injection head to move toward or away from the wafer by a preset distance.

5. The photoresist coating device according to claim 4, characterized in that: The first mounting member is also provided with a distance sensor, and the distance sensor is used to obtain the height of the detection droplet on the wafer surface; The distance sensor is also used to obtain the distance between the detection liquid injection head and the wafer.

6. The photoresist coating device according to claim 5, characterized in that: The first driving structure includes a horizontal telescopic driving structure, a vertical telescopic driving structure and a horizontal rotation driving structure. The image collector is accommodated under the base in an initial state; the horizontal telescopic driving structure is used to drive the image collector to move in a horizontal direction so that the projection of the image collector on the plane where the wafer is located is located outside the wafer, and the vertical telescopic driving structure is used to drive the image collector to move in a vertical direction; The horizontal rotation driving structure is used to drive the image collector to rotate to a position directly facing the detection droplet.

7. The photoresist coating device according to claim 2, characterized in that: The image collector comprises a camera and a light source, wherein when the image collector collects the detection droplet image, the camera and the light source are respectively located at two ends of the wafer in the diameter direction.

8. The photoresist coating device according to any one of claims 1 to 7, characterized in that: The method further comprises a contact angle calculation unit, wherein the contact angle calculation unit is used to calculate the contact angle of the detection droplet according to the image of the detection droplet.

9. A method for detecting hydrophobicity of a wafer surface, used in the photoresist coating device according to any one of claims 1 to 8, characterized in that: The method comprises: Obtaining the position of the detection droplet on the wafer to be tested; According to the position of the detection droplet, an image collector is driven to move to a preset position to collect an image of the detection droplet; The contact angle of the detection droplet is acquired according to the image of the detection droplet, and the hydrophobicity of the wafer surface is determined according to the contact angle.

10. The method for detecting hydrophobicity of a wafer surface according to claim 9, characterized in that: The step of obtaining the position of the detection droplet on the wafer to be tested comprises: Acquiring the coordinates of the projection of the detection liquid injection head on the wafer; The coordinates of the detection liquid droplet are acquired according to the coordinates of the projection of the detection liquid injection head on the wafer.

11. The method for detecting hydrophobicity of a wafer surface according to claim 10, characterized in that: The step of driving the image collector to move to a preset position according to the position of the detection droplet to collect the image of the detection droplet comprises: Driving the image collector to move a preset distance in the horizontal direction so that the projection of the image collector on the plane where the wafer is located is located outside the wafer; Acquire the height of the detection liquid droplet on the surface of the wafer; driving the image collector to move in a vertical direction according to the distance between the image collector and the upper surface of the wafer and the height of the detection droplet on the surface of the wafer; According to the position of the detection droplet, the image collector is driven to rotate horizontally to a position directly facing the detection droplet.

12. The method for detecting hydrophobicity of a wafer surface according to claim 9, characterized in that: The method of obtaining the position of the detection droplet on the wafer to be tested includes: Driving the detection liquid injection head to move a preset distance toward the wafer; The detection liquid injection head forms detection liquid droplets on the wafer.

13. The method for detecting hydrophobicity of a wafer surface according to claim 11, characterized in that: After driving the image collector to rotate horizontally to a position facing the detection droplet according to the detection droplet position, the method further comprises: The image of the detection droplet is collected multiple times to obtain a detection droplet image with high definition.

14. The method for detecting hydrophobicity of a wafer surface according to any one of claims 9 to 13, characterized in that: The method of driving the image collector to move to a preset position according to the position of the detection droplet to collect the image of the detection droplet includes: when the image collector moves to the preset position, the distance between the optical axis of the lens of the image collector and the plane where the wafer is located is greater than one third of the height of the detection droplet and less than the height of the detection droplet.

Images