Wafer edge cleaning method and system
By dividing the wafer surface into multiple blocks and precisely cleaning the photoresist on invalid wafer particles, the problem of damage to valid wafer particles caused by traditional edge washing processes is solved, thereby improving wafer particle yield and quality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHANGXIN MEMORY TECH INC
- Filing Date
- 2022-08-03
- Publication Date
- 2026-07-21
AI Technical Summary
Traditional wafer edge washing processes can damage the effective wafer particles at the wafer edge, leading to a decrease in wafer particle yield.
An adjustable wafer edge cleaning method is adopted, which divides the wafer surface into multiple blocks and moves the cleaning device or edge blocks in sequence to accurately clean the photoresist on invalid wafer particles and avoid damage to valid wafer particles.
This improved the yield and quality of wafer chips and reduced production costs.
Smart Images
Figure CN115274406B_ABST
Abstract
Description
Technical Field
[0001] This disclosure pertains to the field of semiconductor manufacturing technology, and particularly relates to a wafer edge washing method and system. Background Technology
[0002] In semiconductor manufacturing, multiple photolithography processes are required, and the quality of these processes has a crucial impact on the yield of wafer particles. The photolithography process mainly includes wafer cleaning, photoresist coating, soft baking, exposure, post-baking, development, hard baking, etching, and inspection. During the photoresist coating process, residual photoresist remains at the wafer edges. To remove this accumulated photoresist, an edge washing process is typically added after the photoresist coating process.
[0003] Traditional edge-washing processes can affect the usable wafer particles or devices located at the wafer edge, thereby reducing their yield. Existing edge-washing processes can only adjust the size of the washing area, but they inevitably remove some photoresist from the usable wafer particles at the edge, causing damage to these particles during subsequent manufacturing processes. Therefore, there is an urgent need to develop a new wafer edge-washing method and system to solve at least one of the aforementioned problems. Summary of the Invention
[0004] To address the above problems, this disclosure provides a wafer edge washing method, including the following steps:
[0005] The wafer is fixed to the stage, and the surface of the wafer and the surface of the stage not covered by the wafer are divided into multiple blocks; wherein, the multiple blocks that are crossed by the outer contour line of the wafer are edge blocks;
[0006] The cleaning device is moved sequentially above multiple edge blocks to clean each edge block; or, multiple edge blocks are moved sequentially below the cleaning device to clean each edge block.
[0007] For example, each of the partitioned blocks is a rectangle, and the size of each rectangular block is the same as the size of a single wafer particle.
[0008] For example, the sequential movement of the cleaning device over multiple edge blocks includes: moving the nozzle of the cleaning device to the center of each edge block, moving the nozzle within the range of each edge block, and spraying solvent to clean the corresponding edge block.
[0009] For example, the step of sequentially moving multiple edge blocks below the cleaning device and cleaning each edge block includes: moving the nozzle of the cleaning device to the center of the first edge block of the wafer and spraying solvent to rinse the first edge block of the wafer; rotating the wafer to a first position by a first angle and moving the nozzle to the center of the second edge block of the wafer and spraying solvent to rinse the second edge block of the wafer; repeating the above process, continuously rotating the wafer and sequentially spraying solvent to rinse the edge blocks of the wafer until all edge blocks are rinsed.
[0010] For example, spraying solvent to rinse the edge blocks of a wafer includes: moving the nozzle in the X and Y directions based on the center point of the edge blocks, according to the rotation angle of the wafer and the size of the edge blocks, and spraying solvent within each edge block area to clean the edge blocks.
[0011] For example, the number of edge blocks is N, where N is a positive integer. The wafer rotation angles corresponding to the 2nd, 3rd, ..., Nth edge blocks are θ1, θ2, ..., θn-1, respectively, and the sum of the angles θ1, θ2, ..., θn-1 is less than 360°.
[0012] For example, at least some of the angles θ1, θ2, ..., θn-1 are the same.
[0013] For example, rotating the wafer includes: transporting the wafer to a stage, evacuating the stage, adsorbing the wafer onto the surface of the stage, and rotating the wafer using the stage.
[0014] For example, the nozzle has an adjustment range of 0-15mm in the X direction and an adjustment range of 0-15mm in the Y direction.
[0015] A wafer edge washing system, comprising:
[0016] A stage is used to hold and rotate the wafer.
[0017] A robotic arm for transporting the wafer to a stage;
[0018] A stepper motor is used to drive the nozzle to move to the edge of the wafer.
[0019] Nozzles are used to spray solvents to clean the edge areas of wafers.
[0020] The control unit is electrically connected to the stage, the robotic arm, the stepper motor, and the nozzle.
[0021] For example, the control unit is further configured to: divide the surface of the wafer and the surface of the stage not covered by the wafer into multiple blocks; wherein the multiple blocks traversed by the outer contour line of the wafer are edge blocks.
[0022] For example, each of the blocks divided by the control unit is a rectangle, and the size of each rectangular block is the same as the size of a single wafer particle.
[0023] For example, the system further includes a connecting mechanism comprising a first connecting rod and a second connecting rod, one end of the first connecting rod being connected to the stepper motor, the other end of the first connecting rod being connected to the second connecting rod, and the nozzle being disposed at the end of the second connecting rod away from the first connecting rod.
[0024] For example, the system further includes a cleaning solvent delivery line, which is fixedly mounted on the connecting mechanism, and the outlet of the delivery line is connected to the nozzle.
[0025] For example, the stepper motor drives the connecting mechanism to move, and the connecting mechanism drives the nozzle to adjust its length in the X direction within a range of 0-15mm and its width in the Y direction within a range of 0-15mm.
[0026] The embodiments of this disclosure have at least the following advantages: the wafer edge washing is designed to be adjustable, which can adjust the edge washing action according to the size of the edge washing area, effectively avoiding the solvent washing away the photoresist on the effective wafer particles at the wafer edge, maximizing the retention of the effective wafer particles at the edge, thereby effectively improving the yield and quality of the wafer particles.
[0027] Other features and advantages of this disclosure will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the disclosure. The objectives and other advantages of this disclosure may be realized and obtained by means of the structures pointed out in the description and the accompanying drawings. Attached Figure Description
[0028] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0029] Figure 1 A schematic diagram of a traditional edge-washing device is shown.
[0030] Figure 2 A schematic diagram of the wafer to be cleaned is shown;
[0031] Figure 3 This diagram shows a traditional wafer edge-washing method after edge washing.
[0032] Figure 4 A flowchart of a wafer edge washing method according to an embodiment of the present disclosure is shown;
[0033] Figure 5 A schematic diagram of block division according to an embodiment of the present disclosure is shown;
[0034] Figure 6 A schematic diagram showing the nozzle movement range according to an embodiment of the present disclosure is provided;
[0035] Figure 7 A schematic diagram of a cleaning method according to an embodiment of the present disclosure is shown;
[0036] Figure 8 A schematic diagram of another cleaning method according to an embodiment of the present disclosure is shown;
[0037] Figure 9 A schematic diagram of a wafer after edge washing according to an embodiment of the present disclosure is shown;
[0038] Figure 10 A partial structural schematic diagram of a process optimization system according to an embodiment of the present disclosure is shown. Detailed Implementation
[0039] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.
[0040] Figure 1 A schematic diagram of a traditional edge-washing device is shown. Current photolithography processes perform edge-washing on wafers coated with photoresist to address edge defects. For example... Figure 1As shown, traditional edge-washing equipment mainly includes a stage, nozzles, a rotary motor, a robotic arm, and a control unit. In traditional edge-washing methods, the robotic arm transfers the wafer to be washed onto the stage. The stage is then evacuated to hold the wafer in place, preventing it from being flung off during rotation. The control unit directs the nozzles to oscillate towards the wafer edge, spraying solvent to clean the photoresist buildup. After the photoresist is removed, the nozzles return to their original position. The washing direction is fixed and can only perform concentric edge washing; it cannot be adjusted. This process can damage the effective wafer particles at the wafer edge. It should be noted that a wafer particle can be a single grain or a combination of multiple grains. During the photolithography process, the wafer is exposed sequentially according to a pre-set exposure sequence. Each exposure operation can expose one or multiple grains (wafer particles).
[0041] Figure 2 A schematic diagram of the wafer to be edge-washed is shown. (See diagram below.) Figure 2 As shown, the wafer to be cleaned includes multiple wafer particles, and the surface of the wafer is coated with photoresist. Complete rectangular areas represent valid wafer particles, while rectangular areas with incomplete edges represent invalid wafer particles. It should be noted that each rectangular area can represent one or more wafer particles. For example, the wafer diameter is 300mm, designed with a 13x11 wafer particle layout, of which there are a total of 87 valid wafer particles, and the rest are invalid edge wafer particles. In some embodiments, with a wafer diameter of 300mm, the wafer can be designed with different wafer particle layouts such as 15x13, 20x20, or 30x30. Other wafer particle layouts can also be designed according to actual production conditions, as long as they meet the manufacturing process requirements. It's important to note that the denser the chip layout on a wafer of the same size—that is, the more rows and columns of chips—the larger the proportion of effective chips in the central area and the lower the proportion of ineffective chips at the wafer edges. Therefore, designing and producing smaller chips on a wafer of the same size results in higher chip throughput and lower production costs. The chip layout on a wafer can be designed according to specific needs. Different sized wafers and different chip layouts can be used for different chip products, as long as they meet the manufacturing process requirements. Given sufficient manufacturing processes and equipment, prioritizing larger wafers not only increases throughput but also reduces chip product costs.
[0042] Figure 3 A schematic diagram of a traditional wafer edge-washing method is shown. Figure 3As shown, in the research, the inventors of this application discovered that traditional edge washing equipment and methods have at least the following problems: the nozzles in traditional edge washing equipment can only be oriented to the edge of the wafer to be washed, the washing direction is fixed, and it can only perform concentric circle edge washing, which can only clean the annular area of the wafer edge. Figure 3 The black circular area in the middle (circle width 1mm) can remove the photoresist from the wafer edge during the edge washing process. However, it is unavoidable to wash away the photoresist on the effective wafer particles at the wafer edge (such as...). Figure 3 The presence of a cross mark (in the wafer edge area) means that the effective wafer particles at the edge lack photoresist protection during subsequent processing and manufacturing. This damages the effective wafer particles, potentially leading to their scrapping, thus reducing wafer quality and yield, and increasing production costs and time. Therefore, there is an urgent need to develop a wafer edge washing method to improve washing quality, reduce the loss of effective wafer particles, and thereby improve wafer yield.
[0043] Figure 4 A flowchart of a wafer edge-washing method according to an embodiment of the present disclosure is shown. Figure 4 As shown, according to some embodiments, the first aspect of this disclosure provides a wafer edge washing method, including the following steps:
[0044] Step 1): As Figure 5 As shown, a wafer is fixed to a stage, and the surface of the wafer and the surface of the stage not covered by the wafer are divided into multiple blocks; wherein, the multiple blocks traversed by the outer contour line of the wafer are edge blocks; the wafer surface is coated with photoresist, and the photoresist at the edge of the wafer is thicker than the photoresist in the middle area; circular areas represent wafers, areas filled with diagonal lines are valid wafer particles, and grid-filled blocks are invalid wafer particles or blocks divided by the stage surface;
[0045] Step 2): Move the cleaning device sequentially above the multiple edge blocks to clean each edge block; or move the multiple edge blocks sequentially below the cleaning device to clean each edge block.
[0046] The wafer edge washing method provided in this disclosure mainly involves designing the wafer edge washing as adjustable, which can adjust the washing action according to the size of the washing area, thereby accurately washing away the photoresist on the invalid wafer particles at the wafer edge, avoiding washing away the photoresist on the valid wafer particles at the wafer edge, maximizing the retention of the valid wafer particles at the edge, thereby effectively improving the yield of wafer particles and reducing production costs.
[0047] To make the content of this disclosure clearer and easier to understand, the following description, in conjunction with the accompanying drawings, further illustrates the content of this disclosure. Of course, this disclosure is not limited to this specific embodiment, and common substitutions well-known to those skilled in the art are also covered within the scope of protection of this disclosure.
[0048] In some embodiments, rotating the wafer includes the following steps:
[0049] The robotic arm transports the wafer to be cleaned onto the stage. The stage is then vacuumed, firmly adhering the wafer to its surface. Under control commands, the stage rotates the wafer precisely and rapidly. This vacuum method effectively prevents the wafer from being flung away during the cleaning process, minimizing the risk of wafer breakage.
[0050] In some embodiments, the robotic arm transports each wafer to be edge-washed onto the stage. When the wafer to be edge-washed is adsorbed onto the surface of the stage, there is no displacement between the two. The position of the wafer to be edge-washed on the stage is fixed, so this position is defined as the initial position of the wafer.
[0051] Figure 5 A schematic diagram illustrating the partitioning of blocks according to an embodiment of the present disclosure is shown. For example... Figure 5 As shown, in some embodiments, each of the partitioned blocks is rectangular, and the size of each rectangular block is the same as the size of a single effective wafer particle.
[0052] Figure 6 A schematic diagram showing the nozzle movement range according to an embodiment of the present disclosure is provided. Figure 6 As shown, the nozzle's adjustment range in the X direction is 0-15mm, and its adjustment range in the Y direction is 0-15mm.
[0053] In some embodiments, although the size of the rectangular block is the same as the size of a single effective wafer particle, since the size of the invalid wafer particles at the edge of the wafer is different, the size of the nozzle cleaning area can be designed to be the same as or different from the size of the rectangular block. It can be designed according to the actual size of the wafer, such as the length of the nozzle cleaning area being the same as the length of the rectangular block, but the width of the nozzle cleaning area being smaller than the rectangular block, or the length of the nozzle cleaning area being smaller than the length of the rectangular block, but the width of the nozzle cleaning area being the same as the width of the rectangular block.
[0054] Specifically, in one embodiment, the nozzle cleaning area is the same size as the edge block, with a length of 15mm and a width of 15mm. In this case, the nozzle moves 15mm in the X direction and 15mm in the Y direction. In another embodiment, the nozzle cleaning area has the same length as the rectangular block, but a smaller width. The length of the invalid wafer particles at the first edge block is the same as the rectangular block length, but a smaller width. The edge block has a length of 15mm and a width of 15mm, with the nozzle moving 15mm in the X direction and 13mm in the Y direction. In yet another embodiment, the nozzle cleaning area has a length less than the rectangular block length and the same width as the rectangular block width. The length of the invalid wafer particles at the second edge block is less than the rectangular block length, but a larger width. The edge block has a length of 15mm and a width of 15mm, with the nozzle moving 14mm in the X direction and 15mm in the Y direction.
[0055] like Figure 5 As shown, in some embodiments, the edge region of the wafer to be cleaned is divided into N edge blocks. Here, N is a natural number greater than or equal to 1. For example, the edge region of the wafer to be cleaned is divided into 32 cleaning regions, with the cleaning direction counter-clockwise. The stage rotates, causing the wafer to rotate a certain angle each time, and the nozzles, driven by a stepper motor, precisely clean each edge block sequentially.
[0056] In some embodiments, the wafer washing direction is clockwise or counterclockwise. The specific washing direction can be set according to the actual situation, as long as it meets the washing process requirements and improves production efficiency.
[0057] Although the foregoing example uses 32 edge blocks, this disclosure is not limited to this. It can be designed with multiple edge blocks, such as 26, 40, or 50, as long as the beneficial effects of this disclosure are achieved, they are all within the scope of protection of this disclosure. Those skilled in the art can comprehensively consider the principles of this disclosure and practical applications, as long as the principles of this disclosure are implemented.
[0058] There are two cleaning methods for wafer edge cleaning: the first method involves moving the nozzle without rotating the wafer, and the second method involves rotating the wafer while the nozzle moves within a small range.
[0059] Figure 7 A schematic diagram of a cleaning method according to an embodiment of the present disclosure is shown. In some embodiments, such as Figure 7 As shown, the specific steps of the first cleaning method are as follows:
[0060] Establish a Cartesian coordinate system with the wafer center O located at the initial position;
[0061] Based on the established Cartesian coordinate system, the coordinates of the center points of multiple edge blocks of the wafer are determined;
[0062] The control unit controls the nozzles of the cleaning device to move to the center point coordinates of each edge block, and moves the nozzles within the range of each edge block to spray solvent to clean the corresponding edge block.
[0063] For example, the center point coordinates of the first edge block are O1(x1, y1), the center point coordinates of the second edge block are O2(x2, y2), and the center point coordinates of the Nth edge block are On(xn, yn). When cleaning begins, the nozzle moves from its initial position to the center point coordinates O1(x1, y1) of the first edge block, and then sprays solvent within the edge block for cleaning. After cleaning the first edge block, the nozzle moves to the center point coordinates O2(x2, y2) of the second edge block, and then sprays solvent within the edge block for cleaning, completing the cleaning of the second edge block. The above steps are repeated until multiple edge blocks of the wafer have been cleaned, at which point the nozzle returns to its initial position.
[0064] In some embodiments, the center point coordinates of the first edge block are O1(x1, y1), the center point coordinates of the Nth edge block are On(xn, yn), and the center point coordinates of the (N-1)th edge block are On-1(xn-1, yn-1). When cleaning begins, the nozzle moves from its initial position to the center point coordinates O1(x1, y1) of the first edge block, and then sprays solvent within the edge block area for cleaning. After cleaning the first edge block, the nozzle moves to the center point coordinates On(xn, yn) of the Nth edge block, and then sprays solvent within the edge block area for cleaning. After cleaning the Nth edge block, the nozzle moves to the center point coordinates On-1(xn-1, yn-1) of the (N-1)th edge block, and then sprays solvent within the edge block area for cleaning, completing the cleaning operation for the (N-1)th edge block. The above steps are repeated until multiple edge blocks of the wafer have been cleaned, at which point the nozzle returns to its initial position.
[0065] Figure 8 A schematic diagram of another cleaning method according to an embodiment of the present disclosure is shown. Figure 8 As shown, in some embodiments, a second cleaning method is disclosed, in which multiple edge blocks are sequentially moved under the cleaning device, and cleaning each edge block includes the following steps:
[0066] Establish a Cartesian coordinate system with the wafer center O located at the initial position;
[0067] Based on the established Cartesian coordinate system, multiple edge blocks are sequentially defined as N1, N2, ..., Nn, and the center point coordinates O1, O2, ..., On of multiple edge blocks of the wafer are determined; n is a positive integer.
[0068] The nozzle of the cleaning device is moved to the center O1(x1, y1) of the first edge block N1 of the wafer, and solvent is sprayed to rinse the first edge block N1 of the wafer. The wafer is rotated by a first angle θ1 to a first position, and the new coordinates O2'(x2', y2') of the center of the second edge block N2 after the rotation angle θ1 are calculated. The nozzle is moved to the center O2'(x2', y2') of the second edge block of the wafer, and solvent is sprayed to rinse the second edge block N2 of the wafer. The above cleaning process is repeated, and the wafer is rotated continuously at multiple angles θ2, θ3, ..., θn-1. The new coordinates O3'(x3', y3') of the center of the third edge block N3 after the rotation angle θ2, ..., and the new coordinates On'(xn', yn') of the center of the Nth edge block Nn after the rotation angle θn-1 are calculated respectively. The nozzle is moved to the new coordinates O2', ..., On' respectively, until the cleaning of all the edge blocks is completed.
[0069] The specific steps for rinsing the edge areas of the wafer by spraying solvent are as follows:
[0070] Based on the wafer rotation angle and the size of the edge block, and based on the center point of the edge block, the nozzle is moved in the X and Y directions to spray solvent within each edge block area to clean the edge block.
[0071] The number of edge blocks is N, where N is a positive integer. The wafer rotation angles corresponding to the 2nd, 3rd, ..., Nth edge blocks are θ1, θ2, ..., θn-1, respectively, and the sum of the angles θ1, θ2, ..., θn-1 is less than 360°.
[0072] Because the wafer is divided into symmetrical blocks, at least some of the rotation angles θ1, θ2, ..., θn-1 of the wafer are the same.
[0073] In some embodiments, the center point O1 of the first edge block N1 is located on the Y-axis.
[0074] In some embodiments, θ1 is the angle between the line connecting the origin O of the coordinate system and the center point O1 of the first edge block N1, and the line connecting the origin O of the coordinate system and the center point O2 of the second edge block N2; the θ line is the angle between the line connecting the origin O of the coordinate system and the center point O2 of the second edge block N2, and the line connecting the origin O of the coordinate system and the center point O3 of the third edge block N3; the θ line is the angle between the line connecting the origin O of the coordinate system and the center point On-1 of the (N-1)th edge block Nn-1, and the line connecting the origin O of the coordinate system and the center point On of the Nth edge block Nn. Specifically, when the center point O1 of the first edge block N1 is located on the Y-axis, after the wafer rotates from its initial position by a first angle θ1 to a first position, the center point O2' of the second edge block N2 is located on the Y-axis. After the wafer rotates from the first position by a second angle θ2 to a second position, the center point O3' of the third edge block N3 is located on the Y-axis. After the wafer is rotated sequentially by θ3, ..., θn-1, the center point of the corresponding edge block is located on the Y-axis.
[0075] The fixed-direction nozzle has been improved to a movable type, and in conjunction with the software, it can precisely clean the wafer based on the invalid wafer particle area of the product, maximizing the retention of valid wafer particles.
[0076] An embodiment of this disclosure also discloses the software process and parameters for implementing the second cleaning method described above, as shown in Table 1.
[0077] Table 1. Software Flow and Parameters for Wafer Edge Cleaning
[0078]
[0079] Among them, the software parameters are defined as follows:
[0080] θ: The angle of the edge washing angle corresponds to the wafer exposure shot (the edge washing area corresponds to the unexposed invalid wafer particles);
[0081] X: Corresponds to the size of the X direction of the edge washing, and the size of the nozzle X when it is turned on;
[0082] Y: Corresponds to the size of the Y direction of the edge washing, and the size of the nozzle in the Y direction.
[0083] In some embodiments, for multiple edge blocks in the same column or row, the multiple edge blocks can be designed as a combined edge block, and the nozzle can clean the combined edge block in the same column or row at the same time, which can effectively improve the efficiency of cleaning the photoresist at the wafer edge, thereby improving the production capacity and yield.
[0084] The above description is merely illustrative and should not be construed as limiting the implementation process of the embodiments of this disclosure. Those skilled in the art can adjust the washing direction and the size of the washing area according to actual production processes / requirements, as long as the principles of this disclosure are achieved. It should be noted that...Figure 5 , Figure 7 , Figure 8 The edge washing diagram shown is merely an illustrative representation of the edge washing process and does not involve the specific size of the edge washing area or the edge washing direction. It is only for illustrative purposes and should not constitute any limitation on the implementation process of the embodiments of this disclosure.
[0085] Figure 9 A schematic diagram of a wafer after edge washing according to an embodiment of the present disclosure is shown. Figure 9 As shown in the figure, the rectangular area filled with black diagonal lines represents the effective wafer particles, and the black area at the edge represents the area where the photoresist has been cleaned by the nozzle spraying solvent. It can be seen from the figure that the wafer edge cleaning method disclosed herein can accurately clean the photoresist on the wafer edge blocks without damaging the photoresist on the effective wafer particles at the wafer edge.
[0086] Figure 10 A partial structural schematic diagram of a process optimization system according to an embodiment of the present disclosure is shown. Figure 10 As shown, according to some embodiments, a second aspect of this disclosure provides a wafer edge washing system, comprising:
[0087] A stage is used to hold and rotate the wafer.
[0088] A robotic arm for transporting the wafer to a stage;
[0089] A stepper motor is used to drive the nozzle to move to the edge of the wafer.
[0090] Nozzles are used to spray solvents to clean the edge areas of wafers.
[0091] The control unit is electrically connected to the stage, the robotic arm, the stepper motor, and the nozzle.
[0092] In an optional embodiment, the control unit is further configured to: divide the surface of the wafer and the surface of the stage not covered by the wafer into a plurality of blocks; wherein the plurality of blocks traversed by the outer contour line of the wafer are edge blocks.
[0093] In an optional embodiment, the control unit includes an X-direction control module and a Y-direction control module;
[0094] The X-direction control module is used to precisely control the movement of the nozzle in the X direction according to the software program, and the Y-direction control module is used to precisely control the movement of the nozzle in the Y direction according to the software program.
[0095] In an optional embodiment, each of the blocks divided by the control unit is a rectangle, and the size of each rectangular block is the same as the size of a single wafer particle.
[0096] In an optional embodiment, the system further includes a connecting mechanism comprising a first connecting rod and a second connecting rod, one end of the first connecting rod being connected to the stepper motor, the other end of the first connecting rod being connected to the second connecting rod, and the nozzle being disposed at the end of the second connecting rod away from the first connecting rod.
[0097] In an optional embodiment, the system further includes a cleaning solvent delivery line, which is fixedly mounted on the connecting mechanism, and the outlet of the delivery line is connected to the nozzle.
[0098] In an optional embodiment, the stepper motor drives the connecting mechanism to move, and the connecting mechanism drives the nozzle to adjust its length in the X direction within a range of 0-15mm and its width in the Y direction within a range of 0-15mm.
[0099] In an optional embodiment, in order to ensure that the nozzle can accurately clean the photoresist on the invalid wafer particles at the edge of the wafer, a camera can also be added to the wafer edge cleaning system. The camera is mounted on a bracket between the stepper motor and the nozzle. The area to be cleaned can be clearly determined through the camera, and then the image is transmitted to the control unit. The control unit sends a command to the stepper motor based on the image, and controls the stepper motor to drive the nozzle to perform precise cleaning.
[0100] It should be understood that the terms "one embodiment," "optional embodiment," or "some embodiments" used throughout the specification mean that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of this disclosure. Therefore, "in one embodiment" or "in some embodiments" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this disclosure, the sequence numbers of the above-described processes do not imply a sequential order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this disclosure. The sequence numbers of the above-described embodiments are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.
[0101] It is understood that the terms "first," "second," etc., used in this disclosure may be used to describe various edge-washing areas, but these edge-washing areas are not limited by these terms. These terms are only used to distinguish one edge-washing area from another edge-washing area.
[0102] Although the present disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure.
Claims
1. A wafer edge washing method, characterized in that, Includes the following steps: The wafer is fixed to the stage, and the surface of the wafer and the surface of the stage not covered by the wafer are divided into multiple blocks; wherein, the multiple blocks that are crossed by the outer contour line of the wafer are edge blocks; The cleaning device is moved sequentially and continuously above multiple edge blocks to clean each edge block; or, multiple edge blocks are moved sequentially and continuously below the cleaning device to clean each edge block. The sequential and continuous movement of the cleaning device above the multiple edge blocks includes: moving the nozzle of the cleaning device to the center of each edge block, moving the nozzle within the range of each edge block, and spraying solvent to clean the corresponding edge block; The process of rinsing the edge blocks of a wafer by spraying solvent includes: moving the nozzle in the X and Y directions based on the center point of the edge blocks, according to the rotation angle of the wafer and the size of the edge blocks, and spraying solvent within each edge block area to clean the edge blocks.
2. The wafer edge washing method according to claim 1, characterized in that, Each of the divisions is a rectangle, and the size of each rectangular block is the same as the size of a single wafer particle.
3. The wafer edge washing method according to claim 1, characterized in that, The step of sequentially and continuously moving multiple edge blocks under the cleaning device to clean each edge block includes: moving the nozzle of the cleaning device to the center of the first edge block of the wafer and spraying solvent to rinse the first edge block of the wafer; rotating the wafer to a first angle and a first position, moving the nozzle to the center of the second edge block of the wafer and spraying solvent to rinse the second edge block of the wafer; repeating the above process, continuously rotating the wafer, and sequentially spraying solvent to rinse the edge blocks of the wafer until all edge blocks are rinsed.
4. The wafer edge washing method according to claim 1, characterized in that, The number of edge blocks is N, where N is a positive integer. The wafer rotation angles corresponding to the 2nd, 3rd, ..., Nth edge blocks are θ1, θ2, ..., θn-1, respectively, and the sum of the angles θ1, θ2, ..., θn-1 is less than 360°.
5. The wafer edge washing method according to claim 4, characterized in that, Among the angles θ1, θ2, ..., θn-1, at least some of them are the same.
6. The wafer edge washing method according to claim 5, characterized in that, Rotating the wafer includes: transporting the wafer to a stage, evacuating the stage, adsorbing the wafer onto the surface of the stage, and rotating the wafer using the stage.
7. The wafer edge washing method according to claim 6, characterized in that, The nozzle has an adjustment range of 0-15mm in the X direction and 0-15mm in the Y direction.
8. A wafer edge washing system, said wafer edge washing system being used to perform the wafer edge washing method as described in any one of claims 1-7, characterized in that, include: A stage is used to hold and rotate the wafer. A robotic arm for transporting the wafer to a stage; A stepper motor is used to drive the nozzle to move to the edge of the wafer. Nozzles are used to spray solvents to clean the edge areas of wafers. The control unit is electrically connected to the stage, the robotic arm, the stepper motor, and the nozzle.
9. The wafer edge cleaning system according to claim 8, characterized in that, The control unit is further configured to: divide the surface of the wafer and the surface of the stage not covered by the wafer into multiple blocks; wherein the multiple blocks traversed by the outer contour line of the wafer are edge blocks.
10. The wafer edge washing system according to claim 9, characterized in that, Each of the blocks divided by the control unit is a rectangle, and the size of each rectangular block is the same as the size of a single wafer particle.
11. The wafer edge cleaning system according to claim 10, characterized in that, The system further includes a connecting mechanism, which includes a first connecting rod and a second connecting rod. One end of the first connecting rod is connected to the stepper motor, and the other end of the first connecting rod is connected to the second connecting rod. The nozzle is located at the end of the second connecting rod away from the first connecting rod.
12. The wafer edge washing system according to claim 11, characterized in that, The system also includes a cleaning solvent delivery line, which is fixedly installed on the connecting mechanism, and the outlet of the delivery line is connected to the nozzle.
13. The wafer edge washing system according to claim 11, characterized in that, The stepper motor drives the connecting mechanism to move, and the connecting mechanism drives the nozzle to adjust its length in the X direction within a range of 0-15mm and its width in the Y direction within a range of 0-15mm.