Wafer vertical cleaning method and device and wafer cleaning equipment

Abstract

The invention provides a wafer vertical cleaning method and device and wafer cleaning equipment. The method comprises the steps that S1, a front face spraying rod and a back face spraying rod are arranged; s2, driving the wafer to rotate, enabling a rolling brush to brush and wash the wafer, and enabling a front spraying rod and a back spraying rod to spray cleaning liquid to the wafer; s3, after brushing is finished, the two spraying rods are kept working so as to flush pollutants released from the annular groove; the step S1 comprises the steps that S11, h1-h2 is set to be larger than or equal to 0 and smaller than or equal to a height threshold value, h1 is the height of the front face drop point, and h2 is the height of the back face drop point; and S12, setting the positions of the front drop point and the back drop point from the edge of the wafer based on the difference between the h1 and the h2. According to the technical scheme, the pollution defect of the front face of the wafer can be effectively prevented, the cleanliness of the wafer is improved, and the quality and yield of the chip are improved.

Description

Technical Field

[0001] This application relates to the field of semiconductor wafer processing technology, specifically to a wafer vertical cleaning method, apparatus, and wafer cleaning equipment. Background Technology

[0002] After chemical mechanical polishing (CMP) of wafers, cleaning is usually required, including vertical cleaning and horizontal cleaning. During vertical cleaning, the wafer rotates at a certain speed, and roller brushes on both sides of the wafer scrub the surface while spray bars on both sides rinse the wafer. In the final stage of the vertical cleaning process, the roller brushes usually stop working before the spray bars. At this point, contaminants may splash back from the back of the wafer (the side where electronic circuitry forms) with the cleaning solution. Since there is no scrubbing function at this time, it is very easy to cause contamination of the front side of the wafer, affecting the yield of subsequent chip manufacturing. Summary of the Invention

[0003] In view of the above, this application provides a wafer vertical cleaning method, apparatus and wafer cleaning equipment, thereby solving or at least alleviating one or more of the above-mentioned problems and other problems existing in the prior art.

[0004] According to one aspect of this application, a wafer vertical cleaning method is provided, comprising:

[0005] S1: Set the positions of the front and rear spray booms;

[0006] S2: Activate the support wheel to drive the wafer to rotate, while the roller brush washes the wafer and the front spray bar and back spray bar spray cleaning fluid onto the wafer;

[0007] S3: After brushing, keep both spray bars running to flush out contaminants released into the wafer from the annular grooves around the support wheel;

[0008] The nozzles at both ends of the front spray bar form two front landing points, and the nozzles at both ends of the rear spray bar form two rear landing points. Step S1 includes:

[0009] S11: Set the front landing point and back landing point to 0≤h1-h2≤height threshold, where h1 is the height of the front landing point and h2 is the height of the back landing point;

[0010] S12: Set the position of the front and back landing points from the wafer edge based on the difference between h1 and h2;

[0011] When 0≤h1-h2<height threshold / 2, the distance from the front landing point to the wafer center - the distance from the back landing point to the wafer center is greater than or equal to the edge distance threshold, so that the front water flow intensity is stronger than the back water flow intensity to prevent the back water flow from pushing contaminants from the back of the wafer to the front.

[0012] When height threshold / 2 ≤ h1-h2 ≤ height threshold, the distance between the two front landing points is greater than or equal to the distance between the two back landing points, so that the spray area of ​​the front nozzle covers the adhesion area of ​​the contaminants pushed from the back of the wafer to the front.

[0013] Optionally, the threshold for setting the distance from the front landing point to the wafer center minus the distance from the back landing point to the wafer center ≥ edge margin is:

[0014]

[0015] Where r is the wafer radius, d1 is the horizontal distance from the front landing point to the wafer edge, and d2 is the horizontal distance from the back landing point to the wafer edge.

[0016] Optionally, the distance between two front-facing landing points is greater than or equal to the distance between two back-facing landing points, and is set as follows:

[0017]

[0018] Where r is the wafer radius, d1 is the horizontal distance from the front landing point to the wafer edge, and d2 is the horizontal distance from the back landing point to the wafer edge.

[0019] Optionally, within a preset time before the end of the washing process, the support wheel accelerates to fling out contaminants in the annular groove with the cleaning fluid, and the roller brush is used to wash away the contaminants flung to the wafer, thereby reducing the accumulation of contaminants in the annular groove.

[0020] Optionally, after the brushing is completed, the support wheel decelerates to a stop, and the absolute value of the deceleration is less than the acceleration before the brushing is completed, so as to reduce the difference in tangential velocity between the cleaning fluid in the annular groove and the support wheel when the support wheel decelerates, thereby reducing the amount of contaminants in the annular groove that are thrown out to the wafer with the cleaning fluid.

[0021] Optionally, after the washing is completed, the support wheel is decelerated to a stop, and the absolute value of the deceleration is less than a, so as to reduce the difference in tangential velocity between the cleaning fluid in the annular groove and the support wheel when the support wheel decelerates, and reduce the amount of contaminants in the annular groove being thrown out to the wafer with the cleaning fluid.

[0022] Where a=v / t, v is the speed of the support wheel at the end of the brushing, t is the deceleration time of the support wheel, and t is the shortest time obtained from the experiment to ensure that no contaminants are detected on the edge of the wafer after vertical cleaning.

[0023] Optionally, the absolute value of the deceleration is greater than a0, where a0 = v / t0, and t0 is a preset value greater than t, to prevent the support wheel from decelerating for too long and thus reducing the cleaning efficiency.

[0024] Optionally, step S1 further includes: ensuring that the cleaning fluid sprayed by the front spray bar and the rear spray bar at least partially covers the annular groove of the support wheel.

[0025] Optionally, step S1 further includes: the cleaning fluid coverage area formed by the front landing point and the cleaning fluid coverage area formed by the back landing point both extend beyond the edge of the wafer.

[0026] According to another aspect of this application, a wafer vertical cleaning apparatus is provided for performing the wafer vertical cleaning method described above, comprising:

[0027] A support wheel is located below the wafer, and an annular groove is formed on the outer periphery of the support wheel to allow the wafer to stand upright in it;

[0028] Two roller brushes are respectively located on both sides of the wafer;

[0029] Front spray bar and back spray bar respectively located on both sides of the wafer;

[0030] The controller is used to control the operation of the support wheels, two roller brushes, and two spray bars.

[0031] According to another aspect of this application, a wafer cleaning apparatus is provided, comprising:

[0032] The wafer vertical cleaning apparatus as described above;

[0033] A wafer inspection device used to detect the distribution of contaminants on the surface of a wafer after vertical cleaning;

[0034] A wafer transport device is used to transport vertically cleaned wafers to a wafer inspection device.

[0035] According to another aspect of this application, a computer storage medium is provided, on which a computer program is stored, which, when executed by a processor, implements the wafer vertical cleaning method as described in the foregoing aspects.

[0036] According to the wafer vertical cleaning method, apparatus, and equipment of this application, by discovering and deeply analyzing the wafer edge contamination problem that may be caused by the front and back rinsing in the final stage of wafer vertical cleaning, and combining the mutual interference mechanism of front and back rinsing, the positions of the front and back landing points are reasonably set. This can effectively prevent the cleaning fluid sprayed by the back spray bar from pushing contaminants on the back of the wafer to the front of the wafer, or even if contaminants are pushed to the front of the wafer, they can be cleaned by the front spray bar in time. This effectively prevents contamination defects near the wafer edge, especially near the edge of the front of the wafer, improves the cleanliness of the wafer, provides a good foundation for the subsequent formation of electronic device areas on the front of the wafer, and improves the quality and yield of the formed chips.

[0037] Furthermore, by accelerating the support roller before the brush stops, the inertia generated by the acceleration causes the cleaning fluid containing contaminants accumulated in the annular groove to be flung out of the groove. The brush, which is still operating at this time, then washes away the contaminants flung onto the wafer surface, thereby reducing the accumulation of contaminants in the annular groove and fundamentally reducing the amount of contaminants that may adhere to the wafer edge after the brush stops. Further, this application also reasonably limits the deceleration of the support roller after brushing. The cleaning fluid containing contaminants in the annular groove and the support roller itself do not have a significant difference in tangential velocity. The adsorption force of the annular groove wall keeps the contaminants in a relatively stable state within the groove, preventing contaminants from being flung out of the annular groove and released onto the wafer edge due to a sudden stop of the support roller. This effectively reduces the amount of contaminants released from the support roller to the wafer edge, improving the wafer cleaning effect and ensuring the quality and yield of the chips formed in subsequent processes. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0039] Figure 1 This is a perspective view of a wafer vertical cleaning apparatus according to one embodiment of this application;

[0040] Figure 2 for Figure 1 A side sectional view of the wafer vertical cleaning device in the image;

[0041] Figure 3 A schematic diagram of a contaminant-removing wafer in a support wheel;

[0042] Figure 4 This is a schematic diagram of the front spray bar and the rear spray bar, as well as their front and rear impact points, where the front impact point is lower than the rear impact point.

[0043] Figure 5 for Figure 4 A side view diagram showing contaminants on the back of the wafer being pushed to the front of the wafer under the drop point setting.

[0044] Figure 6 for Figure 4 A schematic diagram showing contaminants on the back side of a wafer being pushed to the front side under the specified landing point settings, with the back side of the wafer shown.

[0045] Figure 7 for Figure 4 A schematic diagram showing contaminants on the back side of a wafer being pushed to the front side under the specified landing point settings, with the back side of the wafer shown.

[0046] Figure 8 for Figure 7 A schematic diagram showing contaminants in the wafer rotating to the front-side rinsing blind area and flowing into the interior of the wafer;

[0047] Figure 9 This is a flowchart of a wafer vertical cleaning method according to one embodiment of this application;

[0048] Figure 10 for Figure 9 A schematic diagram showing the geometric relationship between the front and back landing points;

[0049] Figure 11 This diagram illustrates the ejection of contaminants from the support wheel along with the cleaning fluid when the absolute value of the acceleration or deceleration of the support wheel is large.

[0050] Reference numerals: Wafer W; Support wheel 10; Roller brush 20; Front spray bar 31; Back spray bar 32; Contaminant 100; Front landing point 310; Back landing point 320. Detailed Implementation

[0051] To enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art should fall within the protection scope of the present invention.

[0052] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0053] In addition, in the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0054] Figure 1The vertical cleaning unit of the post-cleaning unit of a wafer chemical mechanical polishing (CMP) apparatus is shown, with part of the cabinet wall hidden for easy observation. Figure 2 It shows Figure 1 This is a cross-sectional view of the vertical cleaning device from the left. The wafer W stands on three support rollers 10. During cleaning, the support rollers 10 rotate to rotate the wafer W at a certain speed. Roller brushes 20 on both sides of the wafer W clean its surface. The two roller brushes 20 can move horizontally towards the wafer W to "clamp" it for cleaning, and can move horizontally away from the wafer W after cleaning to "release" it. A front spray bar 31 and a back spray bar 32 spray cleaning fluid onto the front and back of the wafer, respectively. Typically, at the end of the vertical cleaning process, the roller brushes 20 stop cleaning and release the wafer W. The two spray bars continue to spray cleaning fluid onto the front and back of the wafer, respectively, to further rinse away suspended contaminants (such as particles and chemicals washed off the wafer) from the liquid film on the wafer surface. Ensuring good cleanliness on the front of the wafer is particularly crucial for chip yield.

[0055] The outer periphery of the support wheel 10 is provided with an annular groove, and the edge of the wafer W is inserted into the annular groove to be stably supported by the support wheel 10. For example... Figure 3 As shown, the contaminants 100 brushed off on the wafer W (represented by an exploded graphic) will enter the annular groove of the support wheel 10 with the cleaning fluid and be randomly released as the support wheel 10 rotates. The contaminants 100 released by the support wheel 10 may re-adhere to the edge of the wafer W. Therefore, the two spray bars need to rinse off the re-adheded contaminants 100 again when the roller brush 20 releases the wafer W (at which time there is no brushing ability) to ensure that the wafer cleanliness meets the process requirements.

[0056] The nozzles at both ends of the front spray bar 31 form two frontal impact points 310, and the nozzles at both ends of the rear spray bar 32 form two rear impact points 320. These impact points are indicated by × in this text. Figure 10 To facilitate differentiation, different colors are used for the front landing point 310 and the back landing point 320. Additionally, it should be understood that... Figure 1 As shown, the front spray bar 31 and the back spray bar 32 are provided with multiple evenly distributed nozzles, and there are multiple intermediate landing points between the two front landing points 310 and between the two back landing points 320, but the intermediate landing points will not be described in detail in this article.

[0057] like Figure 4As shown, if the relative positions of the front landing point 310 and the back landing point 320 corresponding to the front spray bar 31 and the back spray bar 32 are not suitable, for example, if the height of the back landing point 320 is basically the same as the height of the front landing point 310, or if the back landing point 320 is higher than the front landing point 310, during the final stage of the vertical cleaning process when the roller brush 20 is released and the two spray bars rinse the wafer W, the cleaning fluid sprayed by the nozzles at both ends of the back spray bar 32 will release the contaminants 100 that have adhered to the back edge of the wafer from the support wheel 10, push them across the wafer side, and onto the front of the wafer. The above anti-contamination process is as follows: Figure 5 and Figure 6 As shown, Figure 5 The irregular shadows in the image represent the liquid flow formed by the cleaning fluid sprayed from the nozzle at the end of the back spray bar, which contains contaminant 100. The curved arrow across the edge of the wafer W indicates the direction of movement of contaminant 100. Figure 6 The image shows the back side of the wafer. Curved arrows indicate the rotation direction of the wafer or support wheel 10, and curved arrows at the edge of the wafer W indicate the movement direction of the contaminant 100. The × mark in the image represents the back side landing point 320. The arrows around the × mark and the dashed ellipse they point to represent the strong liquid flow zone formed by the nozzle at the end of the back side spray bar 32, which pushes the contaminant to the front side of the wafer. Figure 7 As shown, contaminant 100 may bypass the spray range (represented by multiple overlapping large ellipses) that can be covered by the nozzle at the end of the front spray bar 31, resulting in contamination of the front edge of wafer W, and as... Figure 8 As shown, since there is no longer any scrubbing ability at this time, the contaminant 100 may also rotate with the wafer W to the front rinsing blind zone above the spray range of the front spray bar 31, and flow into the interior of the front surface of the wafer W under the action of gravity, which will eventually lead to contamination of the interior area of ​​the wafer W.

[0058] In view of this problem, this application provides a wafer vertical cleaning method, such as... Figure 9 A flowchart illustrating one implementation of the method includes:

[0059] S1: Set the front spray bar 31 and the rear spray bar 32;

[0060] S2: Start the support wheel 10 to drive the wafer W to rotate, while the roller brush 20 brushes the wafer W and the front spray bar 31 and the back spray bar 32 spray cleaning fluid onto the wafer W.

[0061] S3: After the brushing is finished, keep both spray bars working to flush out contaminants 100 released from the annular groove around the outer periphery of the support wheel 10 into the wafer W;

[0062] Specifically, step S1 may include:

[0063] S11: Set the front landing point 310 and the back landing point 320 to a height threshold of 0 ≤ h1 - h2 ≤, where h1 is the height of the front landing point 310 and h2 is the height of the back landing point 320. For example, the front landing point 310 can be set to be 5~70mm higher than the wafer center WO, i.e., 5mm ≤ h1 ≤ 70mm, and the height threshold can be set to any value between 15 and 30mm. In this way, the back landing point 320 is lower than the front landing point 310. Even if the contaminant 100 is pushed from the edge of the back side of the wafer to the front side by the cleaning fluid sprayed from the nozzles at both ends of the back spray bar 32, the contaminant 100 can be quickly washed away from the wafer because it is located in the strong liquid flow area of ​​the nozzles at both ends of the front spray bar 31, thereby reducing the impact of the contaminant 100 on the wafer.

[0064] S12: Based on the difference between h1 and h2, set the positions of the front landing point 310 and the back landing point 320 from the wafer edge. Specifically:

[0065] When 0 ≤ h1 - h2 < height threshold / 2, meaning the back-side landing point 320 is slightly lower than the front-side landing point 310, and the height difference between them is small, the distance from the front-side landing point 310 to the wafer center WO - the distance from the back-side landing point 320 to the wafer center WO is greater than or equal to the edge distance threshold. In other words, the front-side landing point 310 is closer to the wafer edge than the back-side landing point 320. This ensures that when the front water flow from the front spray bar 31 and the back water flow from the back spray bar 32 counteract each other at the wafer edge, the front water flow intensity is stronger than the back water flow intensity, thus preventing the back water flow from pushing contaminants 100 from the back of the wafer to the front. "Water flow" refers to the liquid flow of the cleaning fluid.

[0066] When height threshold / 2≤h1-h2≤height threshold, the back landing point 320 is significantly lower than the front landing point 310. The front water flow of the front spray bar 31 and the back water flow of the back spray bar 32 will not compete at the wafer edge. The front contaminant 100 can be pushed to the back, and the back contaminant 100 can also be pushed to the front. However, the position of the front landing point 310 is significantly higher, and the cleaning fluid sprayed by the front spray bar 31 can wash away the contaminant 100 pushed from the back to the front. In this case, the constraints on the front landing point 310 and the back landing point 320 can be appropriately relaxed so that the distance between the two front landing points 310 is greater than or equal to the distance between the two back landing points 320. This allows the spray area of ​​the front nozzle to cover the attachment area of ​​the contaminant 100 pushed from the back of the wafer to the front, thereby effectively rinsing the contaminant 100 pushed from the back of the wafer to the front of the wafer. It also prevents the back landing point 320 from being closer to the wafer edge than the front landing point 310, which would result in a larger amount of cleaning fluid being pushed to the front and a larger load on the front spray bar 31 when rinsing the wafer edge.

[0067] like Figure 10The diagram illustrates the geometric relationship of the landing points. Red × dots represent two front landing points 310, and blue × dots represent two back landing points 320. d1 is the horizontal distance of the front landing point 310 from the wafer edge, d2 is the horizontal distance of the back landing point 320 from the wafer edge, h1 is the vertical distance of the front landing point 310 from the wafer center WO, h2 is the vertical distance of the back landing point 320 from the wafer center WO, and r is the wafer radius. When 0 ≤ h1 - h2 < height threshold / 2, the distance from the front landing point 310 to the wafer center WO - the distance from the back landing point 320 to the wafer center WO ≥ the edge margin threshold, i.e., the length of the blue solid line - the length of the blue dashed line ≥ the edge margin threshold. This can be set as follows:

[0068]

[0069] Where d1 ≤ d2, d1 can generally be set to 1~20mm, preferably 3~15mm, and d2 can be set to 10~35mm, preferably 15~30mm. The specific values ​​or ranges of the two are determined based on the above formula. The margin threshold can be set to 10~15mm.

[0070] When height threshold / 2 ≤ h1 - h2 ≤ height threshold, the distance between the two frontal landing points 310 is greater than or equal to the distance between the two backal landing points 320, that is... Figure 10 The length of the solid red line in the image must be greater than or equal to the length of the dashed red line. This can be set as follows:

[0071]

[0072] According to the technical solution of this application, by discovering and deeply analyzing the wafer edge contamination problem that may be caused by the front and back rinsing in the final stage of vertical wafer cleaning, and combining the mutual interference mechanism of front and back rinsing, the positions of the front landing point 310 and the back landing point 320 are reasonably set. This can effectively prevent the cleaning fluid sprayed by the back spray bar 32 from pushing the contaminant 100 on the back of the wafer to the front of the wafer, or even if the contaminant 100 is pushed to the front of the wafer, it can be cleaned by the front spray bar 31 in time. This effectively prevents contamination defects near the wafer edge, especially near the edge of the front of the wafer, improves the cleanliness of the wafer, provides a good foundation for the subsequent formation of electronic device areas on the front of the wafer, and improves the quality and yield of the formed chips.

[0073] like Figure 11The diagram illustrates the ejection of contaminants 100 from the support wheel 10 with the cleaning fluid when the absolute value of the acceleration or deceleration of the support wheel 10 is large. Due to the rapid acceleration or deceleration of the support wheel 10, the cleaning fluid accumulated in the annular groove of the support wheel is ejected due to inertia and maintains tangential motion. Therefore, in a preferred embodiment, the wafer vertical cleaning method of this application may further include: within a preset time before the end of brushing, the support wheel 10 accelerates to eject the contaminants 100 in the annular groove with the cleaning fluid, and the roller brush 20 is used to brush away the contaminants 100 ejected to the wafer, thereby reducing the accumulation of contaminants 100 in the annular groove. Thus, by utilizing the inertia generated by acceleration, the cleaning fluid containing contaminants 100 accumulated in the annular groove is ejected from the annular groove, and the roller brush 20, which has not yet stopped brushing, brushes away the contaminants 100 ejected to the wafer surface, thereby reducing the accumulation of contaminants 100 in the annular groove and fundamentally reducing the contaminants 100 that may adhere to the edge of the wafer surface from the annular groove after the roller brush 20 stops working.

[0074] Furthermore, the wafer vertical cleaning method of this application may also include: after the brushing is completed, the support wheel 10 decelerates to a stop, and the absolute value of the deceleration is less than the acceleration before the brushing is completed, so as to reduce the tangential velocity difference between the cleaning fluid in the annular groove and the support wheel 10 when the support wheel 10 decelerates, thereby reducing the amount of contaminants 100 in the annular groove that are thrown out to the wafer with the cleaning fluid.

[0075] Alternatively, more preferably, after the washing process, the support wheel 10 decelerates to a stop, with the absolute value of the deceleration being less than 'a'. This reduces the tangential velocity difference between the cleaning fluid in the annular groove and the support wheel 10 during deceleration, thus reducing the amount of contaminants 100 in the annular groove being ejected from the wafer by the cleaning fluid. Here, 'a' = 'v' / ', where 'v' is the velocity of the support wheel 10 at the end of the washing process, and 't' is the deceleration time of the support wheel 10. The distribution of contaminants 100 on the wafer surface after vertical cleaning can be detected using a wafer inspection device. Multiple experiments can be conducted with different deceleration times for the support wheel 10. 't' represents the shortest time during which no contaminants 100 are detectable at the wafer edge after vertical cleaning, i.e., the critical time for the presence or absence of contaminants 100 at the wafer edge. Experiments show that 't' is approximately 1 second. In addition, in order to avoid reducing WPH (Wafer Per Hour), the absolute value of the deceleration can be set to be greater than a0, where a0 = v / t0, and t0 is a preset value greater than t, such as 2.5~3s, to prevent the support wheel 10 from decelerating for too long and thus reducing the cleaning efficiency.

[0076] Therefore, by reasonably limiting the deceleration of the support wheel 10 after the washing process, there is no significant difference in tangential velocity between the cleaning fluid containing contaminants 100 in the annular groove of the support wheel 10 and the support wheel 10 itself. The wall adsorption force of the annular groove keeps the contaminants 100 in a relatively stable state in the annular groove, which can prevent the contaminants 100 from being thrown out of the annular groove and released to the wafer edge due to the sudden stop of the support wheel 10. This effectively reduces the amount of contaminants 100 released from the support wheel 10 to the wafer edge from the source, improves the wafer cleaning effect, and ensures the quality and yield of the chips formed in subsequent processes.

[0077] In specific implementation methods, such as Figure 7 and Figure 8 As shown, step S1 further includes: ensuring that the cleaning fluid sprayed by the front spray bar 31 and the back spray bar 32 at least partially covers the annular groove of the support wheel 10. This allows the front spray bar 31 and the back spray bar 32 to reach the annular groove of the support wheel 10 during wafer surface rinsing, thereby flushing away the contaminants 100 accumulated in the annular groove to a certain extent. More specifically, step S1 further includes: the cleaning fluid coverage area formed by the front landing point 310 and the cleaning fluid coverage area formed by the back landing point 320 both extend beyond the edge of the wafer, thereby ensuring that the entire surface of the wafer can be rinsed.

[0078] This application also provides a wafer vertical cleaning apparatus for performing the aforementioned wafer vertical cleaning method, including:

[0079] A support wheel 10 is located below the wafer, and an annular groove is formed on the outer periphery of the support wheel 10 to allow the wafer to be upright in it;

[0080] Two roller brushes 20 are respectively located on both sides of the wafer;

[0081] Front spray bar 31 and back spray bar 32 are respectively located on both sides of the wafer;

[0082] The controller is used to control the operation of the support wheel 10, the two roller brushes 20, and the two spray bars.

[0083] The support wheels 10 can be three or other suitable numbers. One or two of the support wheels 10 can be driving wheels, and the others are driven wheels. The front spray bar 31 and the back spray bar 32 can be configured to rotate around their respective axes to adjust the height of their respective landing points. The nozzles on the front spray bar 31 and the back spray bar 32 can move along the spray bar axis to adjust the spacing between multiple nozzles and the horizontal position of the front landing point 310 and the back landing point 320. Alternatively, the nozzles can be fixed. In this case, after determining the positions of the front spray bar 31 and the back spray bar 32, front spray bars 31 and the back spray bar 32 with corresponding nozzle mounting positions need to be selected or machined.

[0084] This application also provides a wafer cleaning apparatus, which can be used in the post-cleaning process of wafer CMP processing, the wafer cleaning apparatus comprising:

[0085] The aforementioned wafer vertical cleaning device;

[0086] A wafer inspection device used to detect the distribution of contaminants on the surface of a wafer after vertical cleaning;

[0087] A wafer transport device is used to transport vertically cleaned wafers to a wafer inspection device.

[0088] In addition, this application also provides a computer storage medium storing a computer program that, when executed by a processor, implements the aforementioned wafer vertical cleaning method.

[0089] The above embodiments are only used to illustrate the embodiments of this application, and are not intended to limit the embodiments of this application. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of this application. Therefore, all equivalent technical solutions also fall within the scope of the embodiments of this application, and the patent protection scope of the embodiments of this application should be defined by the claims.

Claims

1. A method for vertically cleaning wafers, characterized in that, include: S1: Set the front spray bar and the rear spray bar; S2: Activate the support wheel to drive the wafer to rotate, while the roller brush washes the wafer and the front spray bar and back spray bar spray cleaning fluid onto the wafer; S3: After brushing, keep both spray bars running to flush out contaminants released into the wafer from the annular grooves around the support wheel; The nozzles at both ends of the front spray bar form two front landing points, and the nozzles at both ends of the rear spray bar form two rear landing points. Step S1 includes: S11: Set the front landing point and back landing point to 0≤h1-h2≤height threshold, where h1 is the height of the front landing point and h2 is the height of the back landing point; S12: Set the position of the front and back landing points from the wafer edge based on the difference between h1 and h2; When 0≤h1-h2<height threshold / 2, the distance from the front landing point to the wafer center - the distance from the back landing point to the wafer center is greater than or equal to the edge distance threshold, so that the front water flow intensity is stronger than the back water flow intensity to prevent the back water flow from pushing contaminants from the back of the wafer to the front. When height threshold / 2 ≤ h1-h2 ≤ height threshold, the distance between the two front landing points is greater than or equal to the distance between the two back landing points, so that the spray area of ​​the front nozzle covers the adhesion area of ​​the contaminants pushed from the back of the wafer to the front.

2. The wafer vertical cleaning method as described in claim 1, characterized in that, The distance from the front landing point to the wafer center minus the distance from the back landing point to the wafer center, ≥ edge margin threshold, is set as follows: Where r is the wafer radius, d1 is the horizontal distance from the front landing point to the wafer edge, and d2 is the horizontal distance from the back landing point to the wafer edge.

3. The wafer vertical cleaning method as described in claim 1, characterized in that, The distance between two frontal landing points is greater than or equal to the distance between two backal landing points. Where r is the wafer radius, d1 is the horizontal distance from the front landing point to the wafer edge, and d2 is the horizontal distance from the back landing point to the wafer edge.

4. The wafer vertical cleaning method as described in claim 1, characterized in that, Within a preset time before the end of the washing process, the support wheel accelerates to fling out contaminants in the annular groove with the cleaning fluid, and the roller brush is used to wash away the contaminants flung to the wafer, thereby reducing the accumulation of contaminants in the annular groove.

5. The wafer vertical cleaning method as described in claim 1 or 4, characterized in that, After the brushing is finished, the support wheel decelerates to a stop, and the absolute value of the deceleration is less than the acceleration before the brushing is finished, so as to reduce the difference in tangential velocity between the cleaning fluid in the annular groove and the support wheel when the support wheel decelerates, and reduce the amount of contaminants in the annular groove that are thrown out to the wafer with the cleaning fluid.

6. The wafer vertical cleaning method as described in claim 1 or 4, characterized in that, After the washing is finished, the support wheel decelerates to a stop, and the absolute value of the deceleration is less than a, so as to reduce the difference in tangential velocity between the cleaning fluid in the annular groove and the support wheel when the support wheel decelerates, and reduce the amount of contaminants in the annular groove thrown out to the wafer with the cleaning fluid. Where a=v / t, v is the speed of the support wheel at the end of the brushing, t is the deceleration time of the support wheel, and t is the shortest time obtained from the experiment to ensure that no contaminants are detected on the edge of the wafer after vertical cleaning.

7. The wafer vertical cleaning method as described in claim 6, characterized in that, The absolute value of the deceleration is greater than a0, where a0 = v / t0, and t0 is a preset value greater than t, to prevent the support wheel from decelerating for too long and thus reducing cleaning efficiency.

8. The wafer vertical cleaning method as described in claim 1, characterized in that, Step S1 further includes: ensuring that the cleaning fluid sprayed by the front spray bar and the rear spray bar at least partially covers the annular groove of the support wheel.

9. The wafer vertical cleaning method as described in claim 1, characterized in that, Step S1 also includes: the cleaning fluid coverage area formed by the front landing point and the cleaning fluid coverage area formed by the back landing point both extend beyond the edge of the wafer.

10. A wafer vertical cleaning apparatus for performing the wafer vertical cleaning method as described in any one of claims 1-9, characterized in that, include: A support wheel is located below the wafer, and an annular groove is formed on the outer periphery of the support wheel to allow the wafer to stand upright in it; Two roller brushes are respectively located on both sides of the wafer; Front spray bar and back spray bar respectively located on both sides of the wafer; The controller is used to control the operation of the support wheels, two roller brushes, and two spray bars.

11. A wafer cleaning device, characterized in that, include: The wafer vertical cleaning apparatus as described in claim 10; A wafer inspection device used to detect the distribution of contaminants on the surface of a wafer after vertical cleaning; A wafer transport device is used to transport vertically cleaned wafers to a wafer inspection device.

12. A computer storage medium, characterized in that, The computer storage medium stores a computer program that, when executed by a processor, implements the wafer vertical cleaning method as described in any one of claims 1-9.

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