Wafer adsorption system and wafer adsorption method

Abstract

The present application provides a wafer adsorption system and a wafer adsorption method. The wafer adsorption system includes a wafer carrying module, an adsorption module and a control module; the wafer carrying module includes a transparent carrying platform, a center detector and multiple edge detectors; the transparent carrying platform is used to carry the wafer; the center detector is used to detect the distance between the center detector and the center of the wafer; the multiple edge detectors are used to detect the warpage at the edge of the wafer; the adsorption module includes an adsorption body, a suction cup and multiple first adsorption channels; multiple suction cups are evenly distributed at the bottom of the adsorption body; the suction cup has a threaded joint and multiple evenly distributed suction holes at the bottom; multiple first adsorption channels are located inside the adsorption body, and the adsorption force is transmitted to the suction cup through the threaded joint; the control module is used to control the operation of the adsorption module. The wafer adsorption system can realize the front adsorption of wafers with different warpages, and can avoid damage to the wafer surface, thereby improving work efficiency.

Description

Technical Field

[0001] The present application relates to the field of semiconductor manufacturing technology, and in particular to a wafer adsorption system and a wafer adsorption method. Background Art

[0002] With the rapid development of semiconductor chip manufacturing technology, the size of wafers is getting larger and larger, the number of chips made on a single wafer is increasing, and the integration density of devices is also increasing, which leads to the problem of wafer warpage becoming more and more prominent. In the field of semiconductor integrated circuit manufacturing, wafer transfer is very important. At present, the transfer method of warped wafers mainly relies on adsorption and transfer of wafers from the back side of the wafer. However, in some special manufacturing processes, such as epitaxial reactions, due to technical limitations, the back side transfer method cannot be applied. In this case, the wafer must be transferred from the front side of the wafer.

[0003] When a wafer is warped, if the adsorption force from the front of the wafer is too large, it may cause damage to the wafer; if the adsorption force is too small, the wafer may not be completely adsorbed, and there is a risk of falling off during transportation. Especially when the wafer is too warped, the difficulty of adsorption will increase significantly.

[0004] In the prior art, the wafer warpage is usually obtained from the front or side of the warped wafer. Based on the obtained wafer warpage, the adsorption force is controlled from the back of the wafer to adsorb the warped wafer in a partitioned manner to reduce the wafer warpage, and then the wafer is adsorbed and moved from the front of the wafer. This method is used to obtain the wafer warpage from the side of the wafer. The side morphology of the warped wafer is complex, and the side measurement may not be able to obtain the accurate wafer warpage, and thus the accurate adsorption force cannot be obtained. Too small or too large an adsorption force will increase the possibility of wafer damage. Summary of the invention

[0005] In view of this, the present application provides a wafer adsorption system and a wafer adsorption method, aiming to solve the technical problem in the prior art that the wafer cannot be stably adsorbed from the front side of the wafer due to wafer warping, and can use a wafer adsorption system to adsorb wafers with different warping degrees. While adsorbing the wafer from the front side, it avoids damage to the wafer caused by improper control of the pressing force and pressing speed of the warped wafer or improper control of the adsorption force of the wafer, thereby ensuring the safe handling of the wafer.

[0006] The technical solutions provided by this application are as follows:

[0007] In a first aspect, the present application provides a wafer adsorption system, the wafer adsorption system comprising: a wafer carrying module, an adsorption module and a control module;

[0008] The wafer carrying module comprises: a transparent carrying platform, a center detector and a plurality of edge detectors;

[0009] The transparent carrying platform is used to carry the wafer to be adsorbed;

[0010] The central detector is located at the center of the transparent carrying platform and is used to detect the distance between the central detector and the center of the wafer to be adsorbed;

[0011] The plurality of edge detectors are evenly distributed at the edge positions inside the transparent carrying platform, and are used to detect the warping position and warping height of the edge positions of the wafer to be adsorbed;

[0012] The adsorption module comprises: an adsorption body, a suction cup and a plurality of first adsorption channels;

[0013] When the adsorption body is in use, the control module controls the adsorption body to rotate, and a plurality of suction cups are evenly distributed on the bottom of the adsorption body;

[0014] The suction cup is hollow inside and has an insertable threaded joint, and the bottom of the suction cup has a plurality of evenly distributed suction holes, and the suction cup is used to press and absorb the wafer to be absorbed;

[0015] The plurality of first adsorption channels are located inside the adsorption body and are correspondingly connected to the threaded joints, and the adsorption force is transmitted to the suction cup through the threaded joints;

[0016] The control module is used to control the operation of the adsorption module.

[0017] Furthermore, when the suction cup is in an unstretched and unextended state, the height of the threaded joint is between 1 / 2 and 2 / 3 of the entire height of the suction cup.

[0018] Further, when the suction cup is in a non-stretched and non-extruded state, the bottom end of the threaded joint is lower than the connection portion between the suction cup and the threaded joint.

[0019] Furthermore, the suction cup is a circular silicone corrugated suction cup with 1.5 folds.

[0020] Furthermore, the wafer adsorption system further comprises: an air supply and suction unit;

[0021] The air supply and suction unit includes a plurality of second adsorption channels connected to the first adsorption channels in a one-to-one correspondence. The air supply and suction unit is controlled by the control module to perform air supply or air suction operations on the plurality of first adsorption channels.

[0022] Furthermore, the air supply and suction unit simultaneously delivers gas to the plurality of suction cups through the plurality of first adsorption channels, and the temperature range of the gas is 0-180°C.

[0023] On the other hand, the present application also provides a method for wafer adsorption using the above-mentioned wafer adsorption system, and the wafer adsorption method comprises the following steps:

[0024] Step S1: the center detector and the plurality of edge detectors respectively detect the distances between the center and edge areas of the wafer to be adsorbed and the corresponding detectors, and send the detection data to the control module;

[0025] Step S2: the control module calculates the warpage position, overall warpage and edge warpage of the wafer to be adsorbed according to the received detection data, and divides adjacent wafer regions with similar edge warpage into the same region, thereby dividing the wafer to be adsorbed into multiple regions;

[0026] Step S3: the control module controls the adsorption body to rotate, and matches the multiple regions of the adsorption body with the multiple regions of the wafer to be adsorbed;

[0027] Step S4: the control module controls the adsorption module to press the wafer to be adsorbed according to the overall warpage of the wafer to be adsorbed acquired in real time;

[0028] Step S5: the control module determines in real time whether the absolute value of the overall warpage is less than or equal to a preset threshold; if so, execute step S6; if not, continue to execute step S4;

[0029] Step S6: the control module controls the adsorption module to stop pressing the wafer to be adsorbed;

[0030] Step S7: the control module obtains the regional warpage of the wafer to be adsorbed in different areas respectively, and calculates the adsorption force of each group of the suction cups according to the regional warpage;

[0031] Step S8: the control module controls the adsorption force of the suction cup by partitioning the plurality of first adsorption channels to adsorb the wafer to be adsorbed from the front.

[0032] Furthermore, the step S4 further includes:

[0033] Step S400: heating the gas, and transferring the heated gas to the suction cup through the first adsorption channel, and further transferring the heated gas to the surface of the wafer to be adsorbed.

[0034] Furthermore, before step S4, the method further includes:

[0035] Step S300: The temperature of the heating gas is set by the control module according to the initial warpage of the wafer to be adsorbed.

[0036] Furthermore, the step S4 further includes:

[0037] Step S410: the control module adjusts the pressing speed and the pressing force of the adsorption module on the wafer to be adsorbed in real time according to the overall warpage of the wafer to be adsorbed acquired in real time.

[0038] The solution provided in this application has the following beneficial effects:

[0039] 1. The wafer adsorption system provided in the present application presses the warped wafer by setting a suction cup with a threaded joint to make the warped wafer flat and then stably adsorb it from the front side of the wafer, so as to avoid increasing the warpage of the wafer and damaging the wafer when adsorbing a wafer with a large warpage.

[0040] 2. The wafer adsorption system provided in the present application is more conducive to the pressing of the warped wafer by the suction cup by setting a first adsorption channel to transfer the heated gas to the suction cup, and then by the suction cup to the surface of the warped wafer to be adsorbed; and before the adsorption module presses the wafer, the temperature of the heated gas acting on the wafer surface can be set according to the initial warpage of the wafer, which can avoid the aggravation of the wafer warpage due to excessively high temperature, or the lack of obvious wafer flattening effect due to excessively low temperature.

[0041] 3. The wafer adsorption system provided in the present application can detect the warpage of the wafer at different positions from the back of the wafer by setting a central detector and multiple edge detectors inside the transparent carrying platform, thereby improving the accuracy of detecting the warpage position and warpage height of the wafer.

[0042] 4. In the wafer adsorption method provided by the present application, the control module can control the adsorption force of the suction cup in groups according to the acquired regional warpage of different areas of the wafer, and utilize the different adsorption forces of different groups of suction cups to avoid damage to the wafer caused by excessive or insufficient adsorption force; the control module can also adjust the pressing speed and pressing force of the wafer in real time to avoid the wafer from being broken due to sudden pressing of the wafer with excessive pressing speed or pressing force when the warpage is too large.

[0043] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0045] Figure 1 A schematic diagram of a wafer adsorption system provided in an embodiment of the present application;

[0046] Figure 2 A schematic diagram of the bottom of the adsorption body provided in an embodiment of the present application;

[0047] Figure 3 A bottom schematic diagram of a corrugated suction cup with an inserted threaded joint provided in an embodiment of the present application;

[0048] Figure 4 A schematic cross-sectional view of a corrugated suction cup with an insertable threaded joint provided in an embodiment of the present application;

[0049] Figure 5 A schematic diagram of a wafer adsorption system with an air supply and suction unit provided in an embodiment of the present application;

[0050] Figure 6 A flow chart of a wafer adsorption method provided in an embodiment of the present application;

[0051] Figure 7 This is a schematic diagram of step S3 of the wafer adsorption method provided in an embodiment of the present application.

[0052] Description of reference numerals:

[0053] 100-adsorption module; 110-adsorption body; 120-suction cup; 121-threaded joint; 122-suction hole; 123-connecting part; 130-first adsorption channel; 200-wafer carrying module; 210-transparent carrying platform; 220-center detector; 230-edge detector; 300-control module; 400-wafer to be adsorbed; 500-air supply and suction unit. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0055] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0056] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0057] In the description of this application, it should be noted that the terms "inside", "outside", "upper", "lower", "vertical", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the product of the application is usually placed when in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0058] Some embodiments of the present application are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the features of the following embodiments can be combined with each other.

[0059] In view of the defects of the prior art, the technical solution of the present application is proposed. The technical solution of the present application will be described in detail below.

[0060] See also Figure 1-Figure 3 , Figure 1 A schematic diagram of a wafer adsorption system provided in an embodiment of the present application, Figure 2 This is a bottom schematic diagram of the adsorption body provided in an embodiment of the present application. Figure 3 A bottom schematic diagram of a corrugated suction cup with an inserted threaded joint provided in an embodiment of the present application.

[0061] The wafer adsorption system includes a wafer carrying module 200 , an adsorption module 100 and a control module 300 .

[0062] The wafer carrying module 200 includes a transparent carrying platform 210 , a center detector 220 and a plurality of edge detectors 230 .

[0063] The transparent carrying platform 210 is used to carry the wafer 400 to be adsorbed. The transparent carrying platform 210 is set to be transparent, and the real-time position and warpage height change of the wafer 400 to be adsorbed can be clearly observed. The specific shape of the transparent carrying platform 210 is not limited, and the transparent carrying platform 210 can be round, square or rectangular.

[0064] The center detector 220 is located at the center of the transparent carrying platform 210, and is used to detect the distance between the center detector 220 and the center of the wafer 400 to be adsorbed. After the transparent carrying platform 210 carries the wafer 400 to be adsorbed, the center detector 220 immediately detects the distance between the center of the wafer 400 to be adsorbed and the center of the wafer 400 to be adsorbed from the back side of the wafer 400 in a direction perpendicular to the plane where the transparent carrying platform 210 is located.

[0065] The multiple edge detectors 230 are evenly distributed at the edge positions inside the transparent carrying platform 210, and are used to detect the warping position and warping height of the edge positions of the wafer 400 to be adsorbed. The warping height and warping shape of different positions of the wafer 400 to be adsorbed are different, and the multiple edge detectors 230 detect the warping degree of different edge positions of the wafer 400 to be adsorbed from the back of the wafer 400 to be adsorbed.

[0066] The adsorption module 100 includes an adsorption body 110 , a suction cup 120 and a plurality of first adsorption channels 130 .

[0067] When the adsorption body 110 is in use, the control module 300 controls the rotation of the adsorption body 110, and a plurality of suction cups 120 are evenly distributed at the bottom of the adsorption body 110. The specific shape of the adsorption body 110 is not limited, and it can be circular, square or rectangular, and its specific shape matches the shape of the transparent carrying platform 210. When in use, the control module 300 controls the adsorption body 110 to move up and down in a direction perpendicular to the plane where the transparent carrying platform 210 is located, thereby driving the plurality of suction cups 120 evenly distributed at the bottom of the adsorption body 110 to move in a direction perpendicular to the plane where the transparent carrying platform 210 is located. The adsorption body 110 can also be controlled by the control module 300 to rotate, so as to complete the matching of various areas of the adsorption body 110 and various areas of the wafer 400 to be adsorbed.

[0068] The suction cup 120 is hollow inside and has an insert-type threaded joint 121, and the bottom of the suction cup 120 has a plurality of evenly distributed suction holes 122, and the suction cup 120 is used to press and adsorb the wafer 400 to be adsorbed. There are multiple suction cups 120, and their specific number is the same as the number of the multiple edge detectors 230 evenly distributed at the inner edge position of the transparent supporting platform 210. The multiple suction cups 120 are evenly distributed at the bottom edge position of the adsorption body 110, and their specific positions correspond one-to-one to the positions of the multiple edge detectors 230. When in use, the adsorption body 110 drives the suction cup 120 to move to the surface of the wafer 400 to be adsorbed, and contacts, presses and adsorbs the surface of the wafer 400 to be adsorbed.

[0069] In one embodiment, the threaded joint 121 is insertably disposed on the inner wall of the suction cup 120, and its upper end is fixedly connected to the bottom of the adsorption body 110. The interior of the threaded joint 121 is hollow, extending downward and connected to the internal space of the suction cup 120, allowing gas to flow in or out.

[0070] like Figure 3 As shown, the bottom of the suction cup 120 is evenly distributed with a plurality of suction holes 122. The specific shape of the suction holes 122 is not limited, and can be circular, square or rectangular. When the suction cup 120 adsorbs the wafer 400 to be adsorbed, the suction holes 122 can further adsorb the wafer 400 to be adsorbed in different areas according to the curvature of the warped part of the wafer 400 to be adsorbed. Preferably, the number of the suction holes 122 is an even number, so that the adsorption force generated by the suction cup 120 is more uniform and symmetrical. For example Figure 3 As shown, the number of the suction holes 122 is 16, and every 8 suction holes 122 are symmetrical with respect to the bottom of the suction cup 120, which increases the stability of the suction cup 120 in adsorbing the wafer 400 to be adsorbed. Of course, the number of the suction holes 122 is not limited to this. In addition, the number of the suction holes 122 can also be an odd number, and the odd number of suction holes can be evenly distributed on the same plane.

[0071] The plurality of first adsorption channels 130 are located inside the adsorption body 110 and are connected to the threaded joints 121 to transmit the adsorption force to the suction cup 120. Figure 2 As shown, the adsorption body 110 is circular, and the plurality of first adsorption channels 130 are arc-shaped, and their curvature matches the curvature of the adsorption body 110. The plurality of first adsorption channels 130 are evenly spaced on the inner wall of the adsorption body 110 along its circumference, and each of the first adsorption channels 130 is connected to the same number of the suction cups 120 evenly spaced.

[0072] The control module 300 is used to control the operation of the adsorption module 100. The control module 300 includes a collection module, a calculation module and a processing module. The collection module is used to receive the data detected in real time by the center detector 220 and the multiple edge detectors 230, and transmit the detection data to the calculation module. The calculation module calculates the overall warpage of the wafer 400 to be adsorbed, as well as the warpage position and warpage of the edge area of ​​the wafer 400 to be adsorbed based on the detection data, and divides the multiple adjacent areas of the wafer 400 to be adsorbed with similar edge warpage into the same area, thereby dividing the wafer 400 to be adsorbed into multiple areas. In addition, the calculation module obtains the adsorption force and adsorption speed of each of the multiple suction cups 120 according to the calculation results, and transmits the obtained results to the processing module. The processing module controls the operation of the control module 300 according to the results obtained by the calculation module.

[0073] In this embodiment, by providing a transparent carrying platform, when the wafer 400 to be adsorbed is pressed, the real-time position and warping height change of the wafer 400 to be adsorbed can be clearly observed, avoiding the detection error of the wafer warping position and warping height caused by the blind area when detecting data from the front or side of the wafer 400 to be adsorbed, and improving the detection accuracy. By providing multiple edge detectors 230, the warping degree of different warping areas of the wafer 400 to be adsorbed can be detected. In addition, by providing a corrugated suction cup with an inserted threaded joint at the bottom of the adsorption body 110, the wafer 400 to be adsorbed can be lightly pressed before adsorbing it, avoiding damage to the wafer 400 to be adsorbed due to excessive pressing; when the suction cup 120 cannot press the wafer 400 to the overall warping degree less than or equal to the preset threshold, the threaded joint 121 can be used to further press the warped wafer to make it flat, which is more conducive to the stable adsorption of the front of the wafer 400 to be adsorbed. Secondly, the control module 300 can control the pressing speed and pressing force of the suction cup 120 in real time according to the calculation results, so as to avoid damage to the surface of the wafer 400 to be adsorbed due to excessive pressing force or pressing speed; it can also divide adjacent different wafer areas with similar warping into the same area according to the calculation results, and then use a first adsorption channel 130 to control multiple suction cups 120 at the same time, thereby reducing the number of first adsorption channels 130 and saving costs; the control module 300 can also control the suction cup 120 to adsorb the wafer 400 to be adsorbed from the front with an appropriate adsorption force according to the warping of different areas of the wafer 400 to be adsorbed, so as to avoid damage to the wafer surface due to excessive adsorption force or wafer falling off due to insufficient adsorption force.

[0074] See also Figure 4 , Figure 4A cross-sectional schematic diagram of a suction cup 120 having an insert-type threaded joint 121 is provided for an embodiment of the present application.

[0075] The suction cup 120 is a circular silicone corrugated suction cup with 1.5 folds. The 1.5 folds can prevent the gaps between the folds from accumulating too much dust and dirt, thereby reducing the contamination of the surface of the wafer 400 to be adsorbed. Preferably, the bottom opening radius of the suction cup 120 is not greater than 2 mm, further avoiding contact contamination of the surface of the wafer 400 to be adsorbed.

[0076] When the suction cup 120 is in a state of not being stretched or squeezed, the height of the threaded joint 121 is between 1 / 2 and 2 / 3 of the height of the entire suction cup 120. When in use, the suction cup 120 first presses the wafer 400 to be sucked. If the suction cup 120 cannot press the wafer 400 to be sucked until the overall warpage is less than or equal to a preset threshold, the threaded joint 121 continues to press downward until the surface of the wafer 400 to be sucked tends to be flat.

[0077] When the suction cup 120 is in a non-stretched and non-compressed state, the bottom end of the threaded joint 121 is lower than the connection portion 123 between the suction cup 120 and the threaded joint 121. The bottom end being lower than the connection portion 123 can prevent the connection portion 123 from leaking or even breaking due to repeated stretching and compression when pressing the wafer 400 to be adsorbed.

[0078] In this embodiment, the suction cup 120 provided is a circular silicone corrugated suction cup 120 with a bottom opening radius of no more than 2 mm, which can reduce contact contamination on the surface of the wafer 400 to be adsorbed; the threaded joint 121 can further press the wafer 400 to be adsorbed when the suction cup 120 does not press the wafer 400 to be adsorbed to be flat, so as to make it more flat, so as to facilitate stable adsorption from the front of the wafer 400 to be adsorbed. In addition, the silicone soft suction cup 120 can avoid damage to the surface of the wafer 400 to be adsorbed during pressing and adsorption, and the silicone also has good temperature resistance and can work normally at high temperatures.

[0079] See also Figure 5 , Figure 5 Schematic diagram of a wafer adsorption system with an air supply and suction unit 500 provided in an embodiment of the present application.

[0080] The wafer adsorption system further includes: an air supply and suction unit 500; the air supply and suction unit 500 includes a plurality of second adsorption channels (not shown in the figure) connected one-to-one with the plurality of first adsorption channels 130, and the air supply and suction unit 500 is controlled by the control module 300 to supply or suction air to the plurality of first adsorption channels 130. When the adsorption module 100 presses down the wafer 400 to be adsorbed, the air supply and suction unit 500 delivers heated gas to the plurality of first adsorption channels 130 through the plurality of second adsorption channels; after the pressing is completed, the air supply and suction unit 500 extracts gas from the plurality of first adsorption channels 130 through the plurality of second adsorption channels, thereby providing adsorption force to the suction cup 120.

[0081] In one embodiment, the air supply and suction unit 500 can be split into an air supply unit, an air suction unit and a switching unit, and the air supply unit and the air suction unit are connected to the multiple first adsorption channels 130 through the switching unit. The number of the air supply unit is 1, and the heated gas can be delivered to the multiple first adsorption channels 130 at the same time. The number of the air suction unit is multiple, and the number of the air suction units matches the number of the multiple first adsorption channels 130. When the adsorption module 100 presses the wafer 400 to be adsorbed, the switching unit connects the first adsorption channel 130 and the air supply unit, and the air supply unit delivers heated gas to the first adsorption channel 130; when the adsorption module 100 stops pressing the wafer 400 to be adsorbed, the switching unit connects the multiple first adsorption channels 130 and the air suction unit, and under the action of the air suction unit, the suction cup 120 absorbs the wafer 400 to be adsorbed with different adsorption forces according to the different edge warpages of the wafer 400 to be adsorbed.

[0082] In one embodiment, the gas supply and suction unit 500 simultaneously delivers gas to the plurality of suction cups 120 through the plurality of first adsorption channels 130, and the temperature range of the gas is 0-180° C. As the temperature rises, the atomic vibration of the material of the wafer 400 to be adsorbed intensifies, and the interaction force between atoms weakens, so that the wafer 400 to be adsorbed is more likely to deform, which is more conducive to the flattening of the wafer 400 to be adsorbed.

[0083] In the present embodiment, the air supply and suction unit 500 supplies heated gas to the wafer 400 to be adsorbed while the suction cup 120 presses the wafer 400 to be adsorbed, so that the temperature of the surface of the wafer 400 to be adsorbed increases, making it easier to deform, and further making the suction cup 120 press the wafer 400 to be adsorbed more fully, which is more conducive to the flattening of its warped surface, and at the same time shortens the flattening time of the surface of the wafer 400 to be adsorbed, thereby improving work efficiency; in addition, the air supply and suction unit 500 can also extract internal gas after the suction cup 120 finishes pressing the wafer 400 to be adsorbed, thereby providing adsorption force for the suction cup 120 to adsorb the wafer 400 to be adsorbed.

[0084] The present application also provides a method for wafer adsorption using the above-mentioned wafer adsorption system, see Figure 6 , Figure 6 The flowchart of the wafer adsorption method provided in the embodiment of the present application. The wafer adsorption method comprises the following steps:

[0085] Step S1 : the center detector 220 and the plurality of edge detectors 230 respectively detect the distances between the center and edge regions of the wafer 400 to be adsorbed and the corresponding detectors, and send the detection data to the control module 300 .

[0086] Among them, if the edge area of ​​the warped wafer is higher than the central area of ​​the warped wafer, the wafer is "concave" bowl-shaped warp; when the edge area of ​​the warped wafer is lower than the central area of ​​the warped wafer, the wafer is "convex" bowl-shaped warp.

[0087] Step S2: The control module 300 calculates the warping position, overall warping and edge warping of the wafer 400 to be adsorbed according to the received detection data, and divides adjacent wafer areas with similar edge warping into the same area, thereby dividing the wafer 400 to be adsorbed into multiple areas.

[0088] Step S3: the control module 300 controls the adsorption body 110 to rotate, and matches multiple regions of the adsorption body 110 with multiple regions of the wafer 400 to be adsorbed.

[0089] In a specific embodiment, the number of regional groups of the adsorption body 110 is M, each region Mi includes a plurality of suction cups 120 arranged at the edge of the adsorption body 110, and the suction cups 120 of each region Mi share one first adsorption channel 130. The number of partitions of the wafer 400 to be adsorbed is N, , M=4, 8, 12. The control module 300 controls the rotation of the adsorption body 110 according to the warping position and warping degree of the wafer 400 to be adsorbed, matches multiple regions of the adsorption body 110 with multiple regions of the wafer 400 to be adsorbed, and then independently controls the transmission of adsorption force of different regions Mi according to the regional warping degrees of different regions of the wafer 400 to be adsorbed.

[0090] For example Figure 7 As shown, Figure 7 Schematic diagram of step S3 of the wafer adsorption method provided in an embodiment of the present application. The adsorption body 110 is divided into four areas A, B, C, and D, and each area includes a plurality of suction cups 120 arranged on the edge of the adsorption body 110. The suction cups 120 in each area share a first adsorption channel 130, and the adsorption force of each group of suction cups 120 in different areas is independently controlled according to the regional warpage of different areas of the wafer 400 to be adsorbed. According to the edge warpage of the wafer 400 to be adsorbed, the wafer 400 to be adsorbed is divided into four areas a, b, c, and d, and each area corresponds to four different regional warpages. Figure 7 As shown in a, before the adsorption body 110 rotates, the A area of ​​the adsorption body corresponds to the a area (having the first warpage) and the b area (having the second warpage) of the wafer 400 to be adsorbed, that is, the A area of ​​the adsorption body 110 corresponds to different areas of the wafers with two different warpages. It is impossible to realize the partitioned adsorption of the wafer 400 to be adsorbed according to different warpages. Figure 7 As shown in FIG. 2 , after the adsorption body 110 rotates, the region A of the adsorption body 110 corresponds to the region a of the wafer 400 to be adsorbed, so that the suction cup 120 in region A can adsorb the wafer 400 with a suitable adsorption force according to the warpage of region a of the wafer 400 to be adsorbed. Based on the same principle, the control module 300 controls the adsorption body 110 to rotate, and matches different regions of the two according to different warpages of different regions of the wafer 400 to be adsorbed.

[0091] Step S4: the control module 300 controls the adsorption module 100 to press the wafer 400 to be adsorbed according to the overall warpage of the wafer 400 to be adsorbed obtained in real time.

[0092] The overall warpage is the difference between the highest point and the lowest point of the wafer 400 to be adsorbed.

[0093] Step S5: The control module 300 determines in real time whether the absolute value of the overall warpage is less than or equal to a preset threshold; if so, execute step S6; if not, continue to execute step S4.

[0094] In a specific embodiment, the preset threshold value varies according to the size, manufacturing process, and application scenario of the wafer 400 to be adsorbed. For example, the warpage specification of an 8-inch or 12-inch wafer is that the absolute value of the overall warpage of the wafer is less than or equal to 5 mm, that is, the preset threshold value is 5 mm. When the absolute value of the overall warpage of the wafer is less than or equal to 5 mm, stop pressing the 8-inch or 12-inch warped wafer.

[0095] Step S6: the control module 300 controls the adsorption module 100 to stop pressing the wafer 400 to be adsorbed.

[0096] In a specific embodiment, for the wafer 400 to be adsorbed with a large degree of warping, the adsorption module 100 presses the wafer 400 to be adsorbed until the absolute value of its overall warping is less than or equal to the preset threshold value, and then stops pressing the wafer 400 to be adsorbed to reduce the warping degree of the wafer 400 to be adsorbed, so as to provide a wafer with a smaller degree of warping for the adsorption module 100 to adsorb, thereby avoiding the wafer being broken or falling off due to the difficulty in controlling the adsorption force when adsorbing a wafer with a large degree of warping.

[0097] Step S7: the control module 300 respectively obtains the regional warpage of the wafer 400 to be adsorbed in different regions, and calculates the adsorption force of each group of the suction cups 120 according to the regional warpage.

[0098] In one embodiment, the warpage of the wafer 400 to be adsorbed in different areas is obtained in step S7 specifically as follows: according to the center detector 220 and the multiple edge detectors 230, respectively detect the distance between the center and edge areas of the wafer 400 to be adsorbed and the corresponding detectors, calculate the edge warpage Xi of the wafer warpage area corresponding to each corrugated suction cup 120 in each group of corrugated suction cups 120, and the average value Z of the corresponding warpage of each group of corrugated suction cups 120 as the regional warpage of the area.

[0099] For example, if the edge curvatures Xi corresponding to the three suction cups 120 in a certain area A are X1, X2, and X3 respectively, the area curvature Z of area A is (X1+X2+X3) / 3. Similarly, the area curvatures of other areas are calculated in sequence.

[0100] Step S8: The control module 300 controls the adsorption force of the suction cup 120 in different zones through the plurality of first adsorption channels 130 to adsorb the wafer 400 to be adsorbed from the front.

[0101] Among them, the front side of the wafer refers to the side of the wafer that is processed into various circuit component structures, which is the key part for realizing specific electrical functions.

[0102] In a specific embodiment, for a flat wafer, that is, a wafer with an overall warpage of 0, it is adsorbed with a uniform adsorption force; for a wafer with a relatively small degree of warpage, that is, a wafer with an absolute value of the overall warpage of the wafer greater than 0 and less than or equal to the preset threshold, the edge of the wafer is divided into multiple edge areas, and the position of each edge area and the warpage of the corresponding edge area are obtained respectively, and the adsorption force required to adsorb the multiple edge areas of the wafer is calculated respectively. According to the warpage of the edge warpage area of ​​the wafer, the adsorption module 100 adsorbs the multiple edge areas of the wafer with different adsorption forces, and adsorbs and transports the wafer from the front of the wafer. The wafer is adsorbed in different areas with different adsorption forces according to the warpage of the edge area of ​​the wafer. By adsorbing the wafer in different areas, it is further avoided that the wafer breaks or falls off when it is adsorbed.

[0103] In a specific embodiment, the step S4 further includes: step S400: heating the gas, and transferring the heated gas to the suction cup 120 through the first adsorption channel 130, and then transferring it to the surface of the wafer 400 to be adsorbed. While the control module 300 controls the adsorption module 100 to press the wafer to be adsorbed, the heated gas is transferred to the suction cup 120 through the first adsorption channel 130, and the hot gas increases the surface temperature of the wafer 400 to be adsorbed, which is conducive to the suction cup 120 pressing the surface of the wafer 400 to be adsorbed.

[0104] In a specific embodiment, before step S4, the following further includes: step S300: the temperature of the heating gas is set by the control module 300 according to the initial warpage of the wafer 400 to be adsorbed. In this step, the temperature of the gas is determined by the initial warpage of the wafer 400 to be adsorbed, so as to avoid the aggravation of the warpage of the wafer 400 to be adsorbed due to too high temperature, or the insignificant flattening effect of the wafer 400 to be adsorbed due to too low temperature.

[0105] In a specific embodiment, the step S4 further includes: step S410: the control module 300 adjusts the pressing speed and pressing force of the adsorption module 100 pressing the wafer 400 to be adsorbed in real time according to the overall warpage of the wafer 400 to be adsorbed acquired in real time.

[0106] In a specific embodiment, the wafer 400 to be adsorbed is pressed by the adsorption module 100, and as the absolute value of the overall warpage of the wafer gradually decreases, the pressing force is adjusted in real time to gradually decrease. When the warpage of the wafer 400 to be adsorbed is large, a large pressing force is required to press it, thereby reducing the warpage; but as the warpage of the wafer 400 to be adsorbed decreases, the pressing force is adjusted in real time according to the absolute value of the overall warpage of the wafer, so as to avoid excessive stress caused by excessive pressing force, resulting in damage to the wafer or unnecessary deformation.

[0107] Furthermore, in the process of pressing the wafer 400 to be adsorbed, when the warping degree of the wafer 400 to be adsorbed is large, a large pressing force needs to be applied, and the corresponding pressing speed is small, so as to avoid excessive impact force on the wafer due to the pressing speed being too fast, thereby increasing the risk of wafer cracking or damage. As the absolute value of the overall warping degree of the wafer 400 to be adsorbed gradually decreases, the pressing speed also changes accordingly.

[0108] In this embodiment, the wafer adsorption method adopts corresponding wafer adsorption methods according to the different degrees of warping of different wafers by judging the degree of warping of the wafer, and realizes the use of a wafer adsorption system to adsorb wafers with different degrees of warping, which can adapt to wafers with different degrees of warping without replacing the adsorption device or adjustment mechanism, and has strong adaptability. In addition, according to the overall warping of the wafer obtained in real time, the pressing speed and pressing force of the wafer can be adjusted in time, and the warped wafer can be pressed to the preset threshold in a shorter time, which improves work efficiency and avoids the wafer cracking caused by suddenly pressing the wafer with a large pressing force or pressing speed when the warping is too large.

[0109] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0110] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A wafer adsorption system, characterized in that: The wafer adsorption system comprises: a wafer carrying module (200), an adsorption module (100) and a control module (300); The wafer carrying module (200) comprises: a transparent carrying platform (210), a center detector (220) and a plurality of edge detectors (230); The transparent carrying platform (210) is used to carry the wafer to be adsorbed (400); The central detector (220) is located at the central position inside the transparent carrying platform (210) and is used to detect the distance between the central detector (220) and the center of the wafer (400) to be adsorbed; The plurality of edge detectors (230) are evenly distributed at edge positions inside the transparent carrying platform (210) and are used to detect the warping position and warping height of the edge position of the wafer (400) to be adsorbed; The adsorption module (100) comprises: an adsorption body (110), a suction cup (120), and a plurality of first adsorption channels (130); When the adsorption body (110) is in use, the control module (300) controls the adsorption body (110) to rotate, and a plurality of suction cups (120) are evenly distributed on the bottom of the adsorption body (110); The suction cup (120) is hollow inside and has an insertable threaded joint (121), and the bottom of the suction cup (120) has a plurality of evenly distributed suction holes (122), the suction cup (120) is used to press and adsorb the wafer (400) to be adsorbed, and the threaded joint (121) is used to further press the wafer (400) to be adsorbed when the suction cup (120) cannot press the wafer (400) to a degree where the overall warpage is less than or equal to a preset threshold value; The suction cup (120) is a circular silicone corrugated suction cup with 1.5 folds, and when the suction cup (120) is in a state of not being stretched or squeezed, the height of the threaded joint (121) is between 1 / 2 and 2 / 3 of the height of the entire suction cup (120), and the bottom end of the threaded joint (121) is lower than the connection portion (123) between the suction cup (120) and the threaded joint (121); The plurality of first adsorption channels (130) are located inside the adsorption body (110) and are correspondingly connected to the threaded joint (121), and the adsorption force is transmitted to the suction cup (120) via the threaded joint (121); Wherein, the first adsorption channel (130) is used to transfer the heated gas to the suction cup (120) through the threaded joint (121); The control module (300) is used to control the operation of the adsorption module (100). The control module (300) is used to calculate the warping position, overall warping and edge warping of the wafer to be adsorbed (400) based on the data detected by the central detector (220) and the multiple edge detectors (230). The control module (300) is also used to divide adjacent wafer areas with similar edge warping into the same area, divide the wafer to be adsorbed (400) into multiple areas, and control the rotation of the adsorption body (110) to match the multiple areas of the adsorption body (110) with the multiple areas of the wafer to be adsorbed (400).

2. The wafer adsorption system according to claim 1, characterized in that: The wafer adsorption system further comprises: an air supply and suction unit (500); The air supply and suction unit (500) comprises a plurality of second adsorption channels connected to the plurality of first adsorption channels (130) in a one-to-one correspondence, and the air supply and suction unit (500) is controlled by the control module (300) to perform air supply or air suction operations on the plurality of first adsorption channels (130).

3. The wafer adsorption system according to claim 2, characterized in that: The air supply and suction unit (500) simultaneously delivers gas to the plurality of suction cups (120) through the plurality of first adsorption channels (130), and the temperature range of the gas is 0-180°C.

4. A wafer adsorption method, characterized in that: The wafer adsorption system according to any one of claims 1 to 3 is adopted, and the wafer adsorption method comprises the following steps: Step S1: the center detector (220) and the plurality of edge detectors (230) respectively detect the distances between the center and edge regions of the wafer to be adsorbed (400) and the corresponding detectors, and send the detection data to the control module (300); Step S2: the control module (300) calculates the warping position, overall warping and edge warping of the wafer to be adsorbed (400) according to the received detection data, and divides adjacent wafer regions with similar edge warping into the same region, thereby dividing the wafer to be adsorbed (400) into a plurality of regions; Step S3: the control module (300) controls the adsorption body (110) to rotate, so as to match multiple regions of the adsorption body (110) with multiple regions of the wafer (400) to be adsorbed; Step S4: the control module (300) controls the adsorption module (100) to press the wafer (400) to be adsorbed according to the overall warpage of the wafer (400) to be adsorbed acquired in real time; Step S5: the control module (300) determines in real time whether the absolute value of the overall warpage is less than or equal to a preset threshold; if so, executing step S6; if not, continuing to execute step S4; The control module (300) first controls the suction cup (120) to press the wafer (400) to be adsorbed, and when the suction cup (120) is unable to press the wafer (400) to be adsorbed until the overall warpage is less than or equal to the preset threshold, the threaded joint (121) continues to press the wafer (400) to be adsorbed until the surface of the wafer (400) to be adsorbed tends to be flat; Step S6: the control module (300) controls the adsorption module (100) to stop pressing the wafer to be adsorbed (400); Step S7: the control module (300) respectively obtains the regional warpage of the wafer (400) to be adsorbed in different regions, and calculates the adsorption force of each group of the suction cups (120) according to the regional warpage; Step S8: the control module (300) controls the adsorption force of the suction cup (120) in a partitioned manner through the plurality of first adsorption channels (130) to adsorb the wafer (400) to be adsorbed from the front.

5. The wafer adsorption method according to claim 4, characterized in that: The step S4 further comprises: Step S400: heating the gas, and transferring the heated gas to the suction cup (120) through the first adsorption channel (130), and further transferring the heated gas to the surface of the wafer (400) to be adsorbed.

6. The wafer adsorption method according to claim 5, characterized in that: Before step S4, the method further includes: Step S300: The temperature of the heating gas is set by the control module (300) according to the initial warpage of the wafer (400) to be adsorbed.

7. The wafer adsorption method according to claim 4, characterized in that: The step S4 further comprises: Step S410: the control module (300) adjusts in real time the pressing speed and pressing force of the adsorption module (100) pressing the wafer (400) to be adsorbed according to the overall warpage of the wafer (400) to be adsorbed acquired in real time.

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