Wafer processing method, edge glue uniformizing method and edge glue uniformizing device

Abstract

The invention relates to a wafer processing method, an edge glue uniformizing method and an edge glue uniformizing device, and belongs to the technical field of semiconductor manufacturing and micro-nano machining. The wafer edge glue uniformizing device comprises a carrying table and a glue spraying nozzle, and the glue spraying nozzle is positioned at a preset height above the carrying table during working; the carrying table carries a wafer, the wafer is a wafer with the degummed edge, and the wafer with the degummed edge comprises an edge exposed area; the edge exposed area is coated with glue through a glue spraying glue nozzle; the wafer rotates at a first rotating speed S1, the glue spraying nozzle coats glue on the edge exposed area to cover the edge exposed area, and the wafer rotates at a second rotating speed S2 to form an edge glue film layer covering the edge exposed area. According to the wafer edge glue uniformizing device and method, automatic operation of wafer edge glue uniformizing can be achieved, the wafer edge glue uniformizing process is stable and controllable, and the wafer edge glue uniformizing efficiency and uniformity are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor manufacturing and micro-nano processing, and in particular to a wafer processing method, an edge glue uniformizing method and an edge glue uniformizing device. BACKGROUND

[0002] In the process of manufacturing semiconductor chips, the preparation of chips usually involves multiple key processes such as photolithography, thin film deposition, etching, diffusion, etc., among which the photolithography process as a core technology directly determines the performance and manufacturing quality of the chips. In the photolithography process, the wafer is subjected to glue uniformizing treatment in a full-automatic glue uniformizing machine, so that a uniform glue film layer is formed on the wafer surface, thereby providing a basic guarantee for subsequent exposure and pattern transfer. The treatment of the glue on the edge of the wafer has a significant impact on the process quality and yield of semiconductor chip manufacturing.

[0003] In the traditional semiconductor chip manufacturing process, if the glue on the edge of the wafer is not effectively treated, it will cause multiple problems: first, the glue on the edge may flow to the back of the wafer due to the action of heat flow or gravity in the subsequent baking and cooling process. If the residual glue is not removed by using processes such as edge bead removal (EBR) or wafer edge exposure (WEE), the glue remaining on the back will contaminate the hot plate and cold plate in the glue uniformizing machine, resulting in a decrease in equipment performance and a reduction in service life; second, when the wafer enters the photolithography machine for exposure, backside contamination will cause particles to be generated, which will contaminate the clamping table of the photolithography machine and cause the wafer to be out of level, thereby causing exposure defects and seriously affecting the accuracy and consistency of pattern transfer; third, due to the natural action of surface tension, glue accumulation will inevitably occur on the edge of the wafer, and if this area as an invalid area is not removed, it will significantly reduce the overall effect of the photolithography process. Therefore, removing the glue on the edge of the wafer (for example, using EBR technology or WEE technology) has become a necessary step for optimizing the semiconductor chip manufacturing process. However, simply removing the glue on the edge of the wafer cannot completely solve the related problems. In the subsequent dry etching process, some etching equipment lacks effective protection function for the edge area. In the edge area without glue protection, ion bombardment will directly act on the wafer surface, causing edge damage and generating tiny wafer fragments. Although these fragment particles are extremely small, they can cause serious particle contamination to the semiconductor chip production, causing process abnormalities, chip yield reduction, and even possibly causing the entire batch of products to be scrapped, i.e., the EBR / WEE glue removal process exposes a new technical problem. SUMMARY

[0004] The application aims to provide a wafer processing method, an edge glue uniformizing method and an edge glue uniformizing device to solve the negative effects of removing edge glue by EBR / WEE glue removing process on subsequent processes, reduce damage caused by ion bombardment, reduce or avoid the generation of fine wafer fragments, and eliminate serious particle pollution. In a first aspect, an edge glue uniformizing device for a wafer includes: a carrier, and a glue nozzle, wherein the glue nozzle is positioned above the carrier at a preset height when working; the carrier carries a wafer, the wafer is an edge glue removed wafer, and the edge glue removed wafer includes an edge exposed area; and the glue nozzle applies glue to the edge exposed area; the wafer rotates at a first rotating speed S1, the glue nozzle applies glue to the edge exposed area, the wafer rotates at a second rotating speed S2, and an edge glue film layer covering the edge exposed area is formed.

[0005] Optionally, the glue nozzle and the wafer form an angle α, 30°≤α≤60°; and / or, a projection line of the glue nozzle in the wafer plane is tangent to a circular ring formed by a line connecting a contact point of the glue and the wafer and a center of the wafer, and the glue injection direction follows the rotating direction of the wafer.

[0006] Optionally, the edge glue uniformizing device further includes a base and a second mechanical arm, the second mechanical arm is installed on the base, and the second mechanical arm grabs and centers the wafer.

[0007] Optionally, α=35°; and / or, the rotating speed range of the first rotating speed S1 is 300rpm≤S1≤1000rpm; and / or, the rotating speed range of the second rotating speed S2 is 1000rpm≤S2≤6000rpm; and / or, the edge glue uniformizing device further includes a first mechanical arm, the first mechanical arm moves to drive the glue nozzle to move to the edge exposed area of the wafer, the glue injection end of the glue nozzle is located above the edge exposed area of the wafer, the height of the glue injection end of the glue nozzle from the wafer surface is H, and 1mm≤H≤3mm is satisfied.

[0008] In a second aspect, an edge glue uniformizing method for a wafer includes: Step S200: the wafer is an edge glue removed wafer, the wafer rotates at a first rotating speed S1, a glue nozzle applies glue to the edge exposed area to cover the edge exposed area, the wafer rotates at a second rotating speed S2, and an edge glue film layer covering the edge exposed area is formed.

[0009] Optionally, step S200 includes: Step S201: the carrier rotates to drive the wafer to rotate, and the wafer rotates at the first rotating speed S1; Step S202: The first mechanical arm moves the glue nozzle to the edge exposed area of the wafer, the glue nozzle forms an angle α with the plane of the wafer, 30°≤α≤60°, and the glue nozzle coats the edge exposed area to cover the edge exposed area. Step S203: The stage rotates to rotate the wafer, and the wafer rotates at a second rotating speed S2, and the glue solution solvent volatilizes to form an edge glue film layer covering the edge exposed area.

[0010] Optionally, before step S200, the method further comprises: step S100: centering the wafer and conveying the centered wafer to the stage so that the center of the wafer coincides with the center of the stage, the wafer being an edge-deglued wafer; and / or, in step S202, the first mechanical arm moves the glue nozzle to the edge exposed area of the wafer, the glue nozzle is located above the edge exposed area of the wafer, the height of the glue nozzle from the surface of the wafer is H, and 1mm≤H≤3mm is satisfied.

[0011] Optionally, after step S200, the method further comprises: step 300: stopping the rotation of the wafer, and baking the wafer to obtain a baked wafer, and cooling the baked wafer.

[0012] Optionally, after step S300, the final thickness of the edge glue film layer ranges from 1um to 20um, and the width ranges from 1mm to 10mm.

[0013] In a third aspect, a wafer processing method is provided, which adopts the wafer edge glue uniformizing device of any one of the first aspect or the wafer edge glue uniformizing method of any one of the second aspect, and the wafer processing method comprises: Step S10: uniformly coating photoresist on the wafer; Step S20: edge-degluing the wafer to form an edge exposed area; Step S30: exposing the wafer processed in step S20; Step S40: adopting the wafer edge glue uniformizing device of any one of the first aspect to perform wafer edge glue uniformizing on the wafer exposed in step S30 to form an edge glue film layer; or, adopting the wafer edge glue uniformizing method of any one of the second aspect to perform wafer edge glue uniformizing on the wafer exposed in step S30 to form an edge glue film layer, to obtain a wafer after edge glue uniformizing; Step S50: performing wafer processing on the wafer after edge glue uniformizing in step S40, the wafer processing including but not limited to wafer etching process or wafer bonding process; Step S60: edge-degluing the wafer in step S50 to remove the edge glue film layer of the wafer and the photoresist formed in step S10, to obtain a processed wafer.

[0014] In summary, compared with the prior art, the present application has the following beneficial technical effects: (1) In the present application, firstly, through the cooperation between the first mechanical arm, the carrier and the glue nozzle, the automatic operation of the wafer edge glue uniformization is realized, so that the wafer edge glue uniformization process is stable and controllable, not only the efficiency and precision of the edge glue uniformization are improved, but also the quality and consistency of the wafer edge glue uniformization product are improved; in addition, by optimizing the included angle α between the glue nozzle and the wafer plane to 30° to 60° (preferably 35°), the inclined angle design improves the flow state of the photoresist liquid falling on the wafer surface, reduces the glue marks and sawteeth generated when the glue contacts the wafer, and the glue liquid forms an edge glue film layer with substantially uniform thickness in the edge exposed area P2, improving the uniformity of wafer edge glue coating, meeting the high-quality wafer edge protection requirements in semiconductor manufacturing process.

[0015] (2) In the present application, firstly, in steps S201 and S202, the carrier rotates to drive the wafer to rotate at a first rotation speed S1, and in step S202, the glue nozzle coats the edge exposed area P2 with an included angle α (30°≤α≤60°), which ensures that the glue liquid uniformly covers the entire edge exposed area, improves the flow state of the glue liquid, avoids missing coating or excessive accumulation, reduces the sawtooth defects on the inner side of the glue surface, improves the flatness and uniformity of the coating edge, enhances the process stability, and in step S203, the wafer rotates at a second rotation speed S2, which promotes the rapid evaporation of the photoresist glue liquid solvent, forms a dense edge glue film layer, reduces or avoids the generation of bubbles, reduces or avoids the risk of wafer edge protection failure, effectively resists damage caused by ion bombardment, reduces or avoids the generation of fine wafer fragments, eliminates serious particle pollution, and controls the second rotation speed to adjust the thickness of the edge glue film layer, meeting the thickness requirements of different processes; in addition, through the step-by-step control of wafer bearing and rotation in step S201, precise glue coating in step S202, and film formation in step S203, the complete process flow from wafer edge glue coating to glue film layer formation is realized, reducing the need for manual intervention and subsequent wafer edge glue uniformization trimming, improving the quality, production efficiency and consistency of wafer edge glue uniformization, and the controllable adjustment range of the first rotation speed S1 and the second rotation speed S2 and the included angle α can be optimized according to different wafer sizes, glue liquid characteristics and process requirements, enhancing the applicability of the wafer edge glue uniformization method in semiconductor manufacturing, and providing a good process basis for subsequent wafer etching process. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a working principle schematic diagram of the wafer edge glue uniformization device of the present application; Figure 2 is a structure schematic diagram of the wafer edge glue uniformization device of the present application; Figure 3 is a flow schematic diagram of the wafer edge glue uniformization method of the present application; Figure 4The annular Map of wafer edge uniformity thickness is an embodiment of the present application. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0018] In the description of the present application, it should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0019] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, "a plurality of" means one or two or more than two, unless otherwise explicitly specified and limited.

[0020] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or one-piece molding, or integration; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0021] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0022] A wafer edge spin coating device As Figures 1 to 2 shown in the first aspect, the application provides a wafer edge uniform coating device, comprising: a carrier R and a glue nozzle S, the glue nozzle S is positioned above the carrier R at a predetermined height when working; In some embodiments, the carrier R is made of an anti-static material, and the surface of the carrier is provided with a vacuum groove and a vacuum suction port. The carrier can carry the wafer by vacuum suction, and firmly fix the wafer on the carrier by vacuum suction to prevent the wafer from shifting during rotation or coating. The bottom of the carrier is connected to a rotary motor, which is the source of rotary power. The rotary motor can drive the carrier to rotate, and the rotation of the carrier can drive the wafer to rotate. Wafer rotation is one of the keys to achieving uniform edge coating of wafers.

[0023] In some embodiments, the wafer edge uniform coating device can include a first mechanical arm M1, and the glue nozzle S is installed on the first mechanical arm M1. The first mechanical arm M1 can be configured to move, such as rotating around a fixed rotation axis relative to the plane parallel to the carrier R. In the working state, the first mechanical arm positions the glue nozzle S at a predetermined position above the carrier. The predetermined position is determined according to the position of the edge of the wafer after it is positioned on the carrier.

[0024] The carrier R carries the wafer W, which is an edge-debonded wafer. The edge-debonded wafer includes an edge-exposed area P2. The glue nozzle S coats the edge-exposed area P2 with glue; In some embodiments, the edge-debonded wafer includes a glue-attached area P1 and an edge-exposed area P2. The area forming the lithography pattern is defined by the application as the effective area P3, which is located within the glue-attached area P1 and is generally a subset of the glue-attached area P1. The effective area P3 can be a functional structure or circuit area of the wafer, and its shape is determined by the design of the lithography mask. It is not necessarily circular, but generally the area formed by the largest circumscribed circle of the effective area P3 is within the glue-attached area P1. The glue-attached area P1 is circular, and the edge-exposed area P2 is annular. The edge-exposed area P2 is located at the edge of the wafer and is located at the periphery of the glue-attached area P1. It is an exposed area exposed by the edge-debonding process (such as using EBR technology or WEE technology), which is used for the glue nozzle to coat glue.

[0025] As Figure 1The embodiment shown gives a setting mode of the glue nozzle in working state, the contact point of the glue liquid and the wafer, and the line connecting the wafer center and the contact point form a ring circle with a radius, and the projection line of the glue nozzle in the wafer plane is preferably tangent to the ring circle. Exemplarily, the center of the contact point of the glue liquid and the wafer or the line connecting the inner side edge of the contact point close to the wafer center to the wafer center can be taken as the radius; the profile line obtained by the projection of the glue nozzle in the wafer plane is taken as the projection line, or the center line (for example, the center axis, Figure 1 the dashed line shown in the figure) of the projection of the glue nozzle in the wafer plane is taken as the projection line, the projection line can be tangent to the ring circle, and in general, the direction of the glue injection should follow the rotation direction of the wafer to facilitate ensuring the uniformity of the glue uniformity in the process of the rotation glue uniformity. Moreover, based on this requirement, the preset position of the glue nozzle in working state can be determined, which is generally positioned around the edge bare area P2 to ensure that the injected glue liquid falls into the edge bare area P2.

[0026] In some embodiments, the first mechanical arm M1 is responsible for accurately positioning the glue nozzle S above the edge bare area P2 of the wafer, and the first mechanical arm M1 ensures that the glue liquid injected by the glue nozzle S is only coated on the predetermined edge bare area P2. After the actual glue nozzle is coated with photoresist, it is often difficult to cover the edge bare area P2 exactly, so in order to ensure the process stability, the edge of the glue area P1 can be appropriately covered to ensure full coverage of the edge bare area P2. The first mechanical arm M1 ensures that the injected glue liquid is only coated on the edge bare area P2 and the circumferential edge of the glue area P1, and both should be avoided to affect the functional structure or circuit area of the edge delamination wafer, at this time the coated glue liquid can enter the glue area P1, but only remains at the edge of the glue area P1, which strictly does not enter the effective area P3 in the glue area P1. Further, the shape of the effective area P3 is generally irregular, so the glue liquid should not enter the range defined by the maximum circumscribed circle of the effective area P3 in the process of spin coating. In other words, a glue area with an appropriate width can be reserved outside the effective area P3 in the edge delamination step such as EBR or WEE to provide a space for glue coating in the edge glue uniformity process, and accordingly a gap is formed between the glue area P1 and the effective area P3. Exemplarily, the gap can be understood or meant as a radial gap along the radial direction of the wafer, and the minimum gap is greater than or equal to 1 mm to ensure the stability of the process, so that the edge bare area P2 can be effectively covered, and the process can be stably ensured to prevent the glue from spilling into the effective area P3. The maximum value of the minimum gap is not specified, but from the utilization point of view, it is generally desirable that the width of the glue area P1 is as small as possible to expand the effective area P3 and improve the device yield of a single wafer.

[0027] In the present application, the main function of the glue solution is to protect the edge exposed area from the subsequent process after the treatment, such as ensuring that the wafer material of the edge exposed area will not be bombarded by etching ions in the subsequent etching process, thereby avoiding the generation of edge fragments and the environmental pollution caused by the fragments. In other words, the main characteristic of the glue solution is the inertness to the plasma in etching, thereby playing a function of protecting the inner layer material. Most of the glue used in semiconductors is available, and obviously, the photoresist can be used as the glue solution for forming the protective layer here. In fact, the same type of photoresist as the photoresist layer formed in the glue-attached area can be used to ensure the compatibility of the glue layer between the glue-attached area and the edge exposed area, thereby ensuring good contact between the glue layers during the wafer is placed in the hot plate or the cold plate or other processes such as etching, avoiding the peeling between the glue layers to generate fragments of the glue layer and other problems. In the process, the photoresist of the same type as the glue-attached area can be directly selected as the glue solution for the edge exposed area. Not only is this considered above, but also the wafer edge glue uniformizing device can be used for the whole surface glue uniformizing of the wafer when other components are added, that is, the glue uniformizing and the edge glue uniformizing can share the same cavity, and under this design, it is obvious that using the same photoresist is advantageous, which can avoid cross contamination between the glue materials and can simplify the cleaning work of the cavity.

[0028] The wafer works at a first rotation speed S1, and the glue nozzle sprays glue to the edge exposed area to cover the edge exposed area. The wafer works at a second rotation speed S2, and the edge glue film layer covering the edge exposed area is formed.

[0029] In the present application, the first rotation speed S1 is in the range of 300 rpm≤S1≤1000 rpm, and preferably S1 is 400 rpm. In the range of 300 rpm to 1000 rpm, the first rotation speed S1 affects the centrifugal force distribution of the glue solution at the edge of the wafer, and preferably the first rotation speed S1 is 400 rpm, the centrifugal force is moderate, the glue solution can be uniformly spread to the edge exposed area P2, and the accumulation of the glue solution caused by too low first rotation speed S1 or the sputtering caused by too high rotation speed is reduced or avoided; at the same time, the control of the first rotation speed S1 determines the balance between the deposition thickness and the surface tension of the glue solution. 400 rpm provides stable centrifugal force, so that the glue solution forms a smooth initial coating along the edge of the wafer, further reducing the inside sawtooth or glue marks caused by unstable flow state.

[0030] In the present application, the wafer rotates at a second rotation speed S2, the solvent of the glue solution volatilizes to form an edge glue film layer, and the edge glue film layer covers the edge bare area. The second rotation speed S2 is in the range of 1000 rpm≤S2≤6000 rpm, and preferably the second rotation speed S2 is 1500 rpm. Within the range of 1000 rpm to 6000 rpm, a higher second rotation speed enhances centrifugal force and air convection, promotes rapid volatilization of the solvent in the glue solution, reduces the generation of bubbles and defects, and forms a dense edge glue film layer after the solvent volatilizes, ensuring the flatness and stability of the edge glue film layer. When the second rotation speed S2 is 1500 rpm, the volatilization rate matches the viscosity of the glue solution, so that the glue solution spreads in the edge bare area, and the excess glue solution can be thrown out. Therefore, under the condition that the viscosity of the glue solution is determined (50 cp), the rotation speed of 1500 rpm determines the thickness of the final edge bare area. As shown in FIG. 8, the edge glue film layer thickness of the edge bare area is controlled at about 2 μm; at the same time, the second rotation speed S2 directly affects the strength of the centrifugal force, and 1500 rpm provides moderate centrifugal force, so that the glue solution can form a uniform edge glue film layer, reduces or avoids the risk of wafer edge protection failure, effectively resists damage caused by ion bombardment, reduces or avoids the generation of fine wafer fragments, eliminates serious particle contamination, and controls the second rotation speed to adjust the thickness of the edge glue film layer, which can adapt to the thickness requirements of the edge glue film layer in different processes. Figure 4

[0031] In the present application, in the subsequent wafer bonding process, the bonding substrate only contacts the edge glue film layer for bonding, thereby avoiding contact between the effective area P3 and the bonding substrate, avoiding damage to the chip due to high temperature and high pressure in the bonding and debonding process, improving the yield of the chip, and the thickness of the edge glue film layer can meet the requirements of different wafer bonding conditions. Different thicknesses of the edge glue film layer can be used for wafer bonding process, which expands the window range of the wafer bonding process. The uniform edge glue film layer indicates that the overall thickness fluctuation is small, the edge glue film layer can maintain good flatness during the wafer bonding process, improves the precision of the wafer bonding process, and reduces the difficulty of subsequent wafer processing process.

[0032] Optionally, the glue nozzle S and the wafer W form an angle a, 30°≤a≤60°, and preferably a=35°.

[0033] ​Firstly, the glue nozzle is a dispensing component of the glue solution, which can coat the glue solution to the edge exposed area P2 of the wafer. The glue solution is a viscous liquid, and its flow state in the coating process is affected by the relative angle between the glue nozzle and the wafer surface. When 30°≤α≤60°, the glue solution is sprayed at a proper angle, which can form a stable flow state under the joint action of gravity and surface tension. When α=35°, the initial impact force and diffusion speed of the glue solution reach a proper balance, avoiding excessive splashing or too slow deposition, which can guide the glue solution to spread along the edge of the wafer, combined with the rotation of the wafer, to form uniform deposition of the ring-shaped coating, making the edge glue film layer more uniform. In addition, under the traditional vertical injection (α≈90°) or too small angle, the glue solution may form an inside sawtooth defect due to local accumulation or uneven diffusion. By tilting the angle, the glue solution contacts the wafer surface at an inclined path, flows more smoothly in the edge direction, and reduces local accumulation, thereby effectively smoothing the inside profile and improving the edge glue quality of the wafer. The first rotation speed S1 (such as 400 rpm) and the glue nozzle angle α (preferably 35°) work together to enhance the uniform distribution of the glue solution during rotation, effectively improving the sawtooth edge of the glue surface inside. The first rotation speed S1, the second rotation speed S2, and the glue nozzle angle α (preferably 35°) work together to form the core of the wafer edge glue uniformizing device, which can optimize the glue surface state before and after coating, respectively, and enhance the uniformity of the glue distribution in the edge exposed area P2 and the consistency of the edge glue film layer during rotation. In addition, the wafer W with edge de-glued is placed on the stage R and firmly fixed by vacuum adsorption to ensure that the wafer remains stable during subsequent rotation and glue coating. The first mechanical arm M1 moves the glue nozzle S above the edge exposed area P2 of the wafer, and the glue nozzle forms an angle α (30°≤α≤60°, preferably 35°) with the wafer plane. The rotation motor starts to drive the stage R to rotate, and then drives the wafer W to rotate around the central axis. While the wafer is rotating, the glue nozzle S starts to distribute the glue solution to the edge exposed area P2. The rotation of the wafer ensures that the glue solution is evenly distributed along the entire edge, and finally the glue solution is evenly deposited and coated on the surface of the wafer with edge de-glued.

[0034] In the present application, firstly, through the cooperation between the first mechanical arm, the carrier and the glue nozzle, the automatic operation of the wafer edge glue uniformization is realized, so that the wafer edge glue uniformization process is stable and controllable, not only the efficiency and precision of the edge glue uniformization are improved, but also the quality and consistency of the wafer edge glue uniformization product are improved. In addition, by optimizing the angle α between the glue nozzle and the wafer plane to 30° to 60° (preferably 35°), the inclined angle design improves the flow state of the photoresist liquid falling on the wafer surface, reduces the glue marks and serrations generated when the glue contacts the wafer, and the glue liquid forms an edge glue film layer with substantially uniform thickness in the edge exposed area P2, which improves the uniformity of the wafer edge glue coating and meets the high-quality wafer edge protection requirements in the semiconductor manufacturing process.

[0035] Optionally, the wafer edge glue uniformization device further comprises a first mechanical arm, the first mechanical arm moves to drive the glue nozzle to move to the edge exposed area of the wafer, and the glue outlet end of the glue nozzle is located above the edge exposed area of the wafer, and the height of the glue outlet end of the glue nozzle from the wafer surface is H, which satisfies: 1mm≤H≤3mm.

[0036] In some embodiments, the first mechanical arm moves to drive the glue nozzle to move to the edge exposed area of the wafer, and the glue outlet end of the glue nozzle is located above the edge exposed area of the wafer, and the height of the glue outlet end of the glue nozzle from the wafer surface is H. It should be understood that the glue outlet end of the glue nozzle is kept at a certain height H from the wafer surface, which can ensure that the glue liquid is sprayed to the edge exposed area P2 in a stable flow state, avoid accumulation of glue liquid due to too close distance or splashing caused by too far distance, improve the precision of glue coating, and appropriate height H cooperates with the first rotation speed S1 and the angle α, so that the glue liquid forms a uniform initial coating on the wafer surface, reduces the thickness inconsistency and inside serration defects.

[0037] Optionally, the wafer edge glue uniformization device further comprises a base and a second mechanical arm, the second mechanical arm is installed on the base, and the second mechanical arm grabs and centers the wafer.

[0038] In the present application, the first mechanical arm and the second mechanical arm can be installed on the base, the second mechanical arm can be used to grab the wafer from the wafer rack and center the wafer. For example, the wafer can be centered by optical centering or mechanical centering, the center of the wafer can coincide with the center of the fingers of the second mechanical arm, so that the subsequent rotation is not eccentric, which can improve the uniformity of the glue coating in the edge area of the wafer, so as to obtain a larger process window, ensure the smooth progress of the subsequent process steps, and improve the quality and stability of the subsequent wafer product.

[0039] A wafer edge spin coating method As Figure 3As shown in the second aspect, the application provides a wafer edge glue uniformizing method, which uses or does not use the wafer edge glue uniformizing device of any one of the above aspects, and includes the following steps: It should be noted that the wafer edge glue uniformizing method of the application uses or does not use the wafer edge glue uniformizing device of any one of the first aspect, and when the wafer edge glue uniformizing device of any one of the first aspect is used, the corresponding technical problems, technical solutions and technical effects of any one of the wafer edge glue uniformizing device in the first aspect are also included, and the application will not be repeated here.

[0040] Step S200: the wafer is an edge-deglued wafer, the wafer rotates at a first rotation speed S1, the glue nozzle sprays glue on the edge exposed area to cover the edge exposed area, the wafer rotates at a second rotation speed S2, and an edge glue film layer covering the edge exposed area is formed; Specifically, step S200 includes: Step S201: the carrier rotates to drive the wafer to rotate, and the wafer rotates at a first rotation speed S1; In some embodiments, in step S201, all the technical problems, technical solutions and technical effects of the wafer rotating at the first rotation speed S1 can be the same as those described in the first aspect, and specific reference can be made to the technical problems, technical solutions and technical effects of the wafer rotating at the first rotation speed S1 described in the first aspect, and the application will not be repeated here.

[0041] Step S202: the first mechanical arm moves to drive the glue nozzle to move to the edge exposed area of the wafer, the glue nozzle forms an angle α with the plane where the wafer is located, 30°≤α≤60°, and the glue nozzle sprays glue on the edge exposed area to cover the edge exposed area; In some embodiments, in step S202, the glue nozzle forms an angle α with the plane where the wafer is located, 30°≤α≤60°, and the glue nozzle sprays glue on the edge exposed area to cover the edge exposed area, all the technical problems, technical solutions and technical effects can be the same as those described in the first aspect, and specific reference can be made to the technical problems, technical solutions and technical effects of the glue nozzle forming an angle α with the plane where the wafer is located, 30°≤α≤60°, and the glue nozzle spraying glue on the edge exposed area to cover the edge exposed area described in the first aspect, and the application will not be repeated here.

[0042] Step S203: the carrier rotates to drive the wafer to rotate, the wafer rotates at a second rotation speed S2, and the glue solution solvent volatilizes to form an edge glue film layer covering the edge exposed area; In some embodiments, in step S203, the wafer rotates at the second rotation speed S2, and all the technical problems, technical solutions and technical effects of the wafer rotating at the second rotation speed S2 and the glue solution volatilizing to form the edge glue film layer covering the edge exposed area are the same as those described in the first aspect, and details can be referred to the technical problems, technical solutions and technical effects of the wafer rotating at the second rotation speed S2 and the glue solution volatilizing to form the edge glue film layer covering the edge exposed area, which will not be repeated in the present application.

[0043] In the wafer edge glue uniformizing method of the present application, firstly, in steps S201 and S202, the stage rotates to drive the wafer to rotate at the first rotation speed S1, and in step S202, the glue spraying nozzle sprays glue to the edge exposed area P2 at an angle α (30°≤α≤60°), so as to ensure that the glue solution uniformly covers the entire edge exposed area, improve the flow state of the glue solution, avoid undercoating or excessive accumulation, reduce the jagged defects on the inner side of the glue surface, improve the flatness and uniformity of the coating edge, and enhance the process stability. In step S203, the wafer rotates at the second rotation speed S2, which promotes the rapid volatilization of the glue solution, forms a dense edge glue film layer, reduces or avoids the generation of air bubbles, reduces or avoids the risk of wafer edge protection failure, effectively resists damage caused by ion bombardment, reduces or avoids the generation of fine wafer fragments, eliminates serious particle pollution, and controls the second rotation speed to adjust the thickness of the edge glue film layer to meet the requirements of different processes on the thickness. In addition, through the step-by-step control of the wafer bearing and rotation in step S201, the precise glue coating in step S202, and the film formation in step S203, the complete process flow from wafer edge glue coating to glue film formation is realized, the manual intervention and subsequent wafer edge glue uniformizing trimming requirements are reduced, the quality, production efficiency and consistency of wafer edge glue uniformizing are improved, and the controllable adjustment range of the first rotation speed S1, the second rotation speed S2 and the angle α can be optimized according to different wafer sizes, glue solution characteristics and process requirements, thereby enhancing the applicability of the wafer edge glue uniformizing method in semiconductor manufacturing and providing a good process basis for subsequent wafer etching processes.

[0044] Optionally, before step S200, the following steps are included: Step S100: centering the wafer and conveying the centered wafer to the stage so that the center of the wafer coincides with the center of the stage, wherein the wafer is an edge-deglued wafer. In some embodiments, the wafer W is an edge-deglued wafer.

[0045] In some embodiments, the centering and aligning the wafer includes: using the second robot arm to pick up the wafer from the wafer rack and center the wafer. For example, the wafer can be centered and aligned by using optical centering or mechanical centering, so that the center of the wafer can coincide with the center of the fingers of the second robot arm, so as to avoid eccentric rotation in the subsequent rotation, so as to improve the precision of the edge area of the wafer, so as to obtain a larger process window, so as to ensure the smooth progress of the subsequent process steps, so as to improve the quality and stability of the subsequent wafer products.

[0046] In some embodiments, the transferring the wafer W to the center of the stage R includes: using the second robot arm to transfer the centered wafer to the stage, so that the center of the wafer W coincides with the center of the stage R, so as to avoid the eccentric rotation of the wafer.

[0047] Optionally, after step S200, the following steps are included: Step 300: The wafer stops rotating, the wafer is picked up for baking to obtain a baked wafer, and the baked wafer is cooled.

[0048] In some embodiments, the wafer stops rotating, the wafer is picked up for baking to obtain a baked wafer, and the baked wafer is cooled. The wafer stops rotating, and the wafer formed with the edge film layer can be picked up from the stage by using the third robot arm and placed in a hot plate unit for baking at 110°C for 60s. By placing the spin-coated wafer in the hot plate unit for baking, the solvent of the glue solution is further volatilized, so that the glue surface is more firm and the wafer is more closely combined.

[0049] In some embodiments, the wafer stops rotating, the wafer is picked up for baking to obtain a baked wafer, and the baked wafer is cooled. The wafer stops rotating, and the wafer formed with the edge film layer can be picked up from the stage by using the third robot arm and placed in a hot plate unit for baking at 110°C for 60s. By placing the spin-coated wafer in the hot plate unit for baking, the solvent of the glue solution is further volatilized, so that the glue surface is more firm and the wafer is more closely combined.

[0050] Optionally, in step S202, the first robot arm moves the glue spraying nozzle to the edge exposed area of the wafer, and the glue spraying nozzle glue outlet is located above the edge exposed area of the wafer, and the height H of the glue spraying nozzle glue outlet from the surface of the wafer satisfies: 1mm≤H≤3mm.

[0051] In some embodiments, in step S202, the height H of the glue spraying nozzle glue outlet from the surface of the wafer can be the same as all the technical problems, technical solutions and technical effects of the height H of the glue spraying nozzle glue outlet from the surface of the wafer in the first aspect. For details, please refer to all the technical problems, technical solutions and technical effects of the height H of the glue spraying nozzle glue outlet from the surface of the wafer in the first aspect.

[0052] Optionally, after step S300, the thickness of the edge film layer ranges from 1 um to 20 um, and the width ranges from 1 mm to 10 mm.

[0053] In the present application, by adjusting the second rotating speed S2 (1000 rpm to 6000 rpm, preferably 1500 rpm), the thickness of the edge film layer can be controlled in the range of 1 um to 20 um, meeting the diversified requirements of different photolithography processes for thin thickness, ensuring the functionality of the edge protection layer, and the width range can be coordinated with the thickness range, which can adapt to the width requirements of different wafer sizes and edge de-gluing areas, enhancing the flexibility of the wafer edge uniform coating process, and providing a good process basis for subsequent wafer etching process.

[0054] A wafer processing method Third invention, the present application also provides a wafer processing method, comprising: Step S10: uniform coating of the wafer, so that the wafer surface is covered with photoresist; Specifically, in step S10, generally obtained by using spin coating method on the uniform coating machine.

[0055] Step S20: edge de-gluing of the wafer to form an edge exposure area P2; Specifically, in step S20, the photoresist edge after step S10 can be de-glued by edge wet cleaning WEE (Wafer Edge Exposure, WEE) or edge cleaning EBR (Edge Bead Removal, EBR) process, and then the edge exposure area P2 can be obtained. Edge wet cleaning WEE process and edge cleaning EBR process belong to the prior art, and the present application will not be repeated here.

[0056] Step S30: exposing the wafer processed in step S20; Specifically, in step S30, the effective area P3 of the wafer can be exposed by using a mask with a pre-designed pattern in a photolithography equipment.

[0057] Step S40: using the wafer edge uniform coating device of any one of the first aspect to perform edge uniform coating on the wafer after exposure processing in step S30 to form an edge film layer; or using the wafer edge uniform coating method of any one of the second aspect to perform edge uniform coating on the wafer after exposure processing in step S30 to form an edge film layer, to obtain a wafer after edge uniform coating; Step S50: processing the wafer after edge uniform coating in step S40, the wafer processing includes but is not limited to wafer etching process or wafer bonding process; Specifically, based on the photoresist with the pattern exposed in step S30, after the wafer is obtained after the edge spin coating in step S40, the wafer can be further processed, and other wafer processing processes corresponding to the photolithography are performed, such as wafer etching process, wafer bonding process, etc. The wafer etching process can be a dry etching process or a wet etching process.

[0058] Step S60: The wafer is stripped in step S50, and the edge adhesive film layer of the wafer and the photoresist formed in step S10 are removed to obtain a processed wafer.

[0059] In the present application, the wafer edge spin coating device or wafer edge spin coating device method is applied in the processing process to solve the related problems caused by the edge exposure in the wafer etching process, etc. The steps S10, S20, S30, S40, S50, and S60 are completed in sequence, but it does not exclude inserting an experience processing step not mentioned in the present application between two adjacent steps, such as wafer solidification, wafer heating, wafer cleaning, and other wafer processing steps.

[0060] In the present application, the wafer edge spin coating process in step S40 is designed after the exposure process in step S30, which aims to avoid interference with the exposure process. To be precise, when the wafer is coated with photoresist on the front surface in the wafer spin coating step in step S10, the edge exists overflow to the back surface of the wafer; the back surface of the wafer also needs to be cleaned to ensure the flatness of the back surface of the wafer in the edge stripping process in step S20 or other wafer cleaning steps, so as to ensure the precise positioning of the wafer during photolithography and ensure the photolithography precision. If the wafer edge spin coating process in step S40 is placed before the exposure process in step S30, it means that the wafer back cleaning scheme needs to be repeatedly designed for the experience edge spin coating process, which makes the overall wafer processing process flow more complex. By designing the wafer edge spin coating process in step S40 after the exposure process in step S30, the influence of the back adhesive on the exposure step does not need to be considered, and the adhesive on the back surface in step S40 is not sensitive to the subsequent wafer etching process. Even if the back adhesive affects the mounting precision of the wafer, it almost has no effect on the wafer etching effect.

[0061] Examples and edge spin coating detection A wafer edge spin coating method, comprising: Step S1: obtaining and centering the wafer, and conveying the centered wafer to the stage so that the center of the wafer coincides with the center of the stage, wherein the wafer is an edge-stripped wafer. Specifically, a second mechanical arm is used to grab the wafer from a wafer rack and center the wafer.

[0062] Step S2: the wafer works at a first rotating speed of 400 rpm, the first mechanical arm moves the glue nozzle to the edge bare area of the wafer, the glue nozzle forms an angle α with the plane of the wafer, α = 35°, the glue outlet of the glue nozzle is above the edge bare area of the wafer, the height H of the glue outlet of the glue nozzle from the wafer surface is 2 mm, the glue nozzle coats the edge bare area to cover the edge bare area; the wafer works at a second rotating speed of 1500 rpm to form an edge glue film layer covering the edge bare area; Step S3: the stage stops rotating and the wafer stops rotating, the third mechanical arm picks up the wafer with the edge glue film layer from the stage, puts it into the hot plate unit to bake at 110°C for 60 s, picks up the wafer from the hot plate unit and puts it into the cold plate unit to cool at 23°C for 30 s, and the wafer can be sent back to the wafer rack after cooling.

[0063] Wafer edge glueing detection: (1) film surface state detection: through visual inspection and microscope examination, it is judged whether there are glue marks, drag marks, pinholes, bubbles, particles and other abnormalities on the glue surface; (2) edge glueing width: the width is measured by a microscope, and if it exceeds the measurement range of the microscope, it is measured by a vernier caliper; (3) thickness and uniformity of the edge glue film layer after wafer edge glueing: the thickness is measured by a thickness gauge, a ring measurement mode is selected, the center part without glue is removed to display a real ring map of the edge glue film layer, and finally the thickness and uniformity of the edge glue film layer are obtained by using the above data, and the thickness data of the final edge glue film layer includes: 2.107, 2.022, 2.018, 2.145, 2.122, 1.990, 1.991, 2.010, 1.971, 1.937, 1.962, 2.012, 1.992, 2.020, 1.943, 2.018, 2.068, 2.009, 1.897, wherein the maximum value is 2.145 um, the minimum value is 1.897, and the average value is 2.012 um.

[0064] Wafer edge glueing detection result: the final thickness of the edge glue film layer is 2 um, the uniformity is about 6.2% (single side, calculation method: (2.145-1.897) / (2.012) / 2*100%), the width is 2 mm, the surface film state is good, there are no glue marks, no serrations, no bubbles and particles, and the requirements of wafer process are met.

[0065] The technical features of the above embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above embodiments are described, but as long as the combinations of the technical features do not exist, they should be considered as the scope of the present disclosure; Those skilled in the art can understand that various operations, methods, steps, measures and schemes discussed in the present application can be alternated, changed, combined or deleted; further, other steps, measures and schemes of various operations, methods and processes discussed in the present application can also be alternated, changed, rearranged, decomposed, combined or deleted; further, steps, measures and schemes of various operations, methods and processes in the prior art can also be alternated, changed, rearranged, decomposed, combined or deleted without departing from the concept of the present application. The above-described embodiments only express several implementation manners of the present disclosure, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the present disclosure; it should be pointed out that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present disclosure, which all belong to the protection scope of the present disclosure; therefore, the protection scope of the present disclosure should be subject to the appended claims.

Claims

1. A wafer edge spin coater, comprising: The wafer edge glue uniformizing device comprises a carrier, a glue nozzle, and a carrier. The carrier carries the wafer, and the wafer is an edge-debonded wafer, which comprises an edge-exposed area. The wafer rotates at a first rotating speed S1, the glue nozzle applies glue to the edge-exposed area, and the wafer rotates at a second rotating speed S2 to form an edge glue film layer covering the edge-exposed area. The glue nozzle forms an angle α with the plane of the wafer, and 30°≤α≤60°; and / or, the projection line of the glue nozzle in the wafer plane is tangent to the annular circle formed by the radius of the line connecting the contact point of the glue and the wafer and the center of the wafer, and the glue direction follows the rotating direction of the wafer.

2. The wafer edge uniformity device of claim 1, wherein, The wafer edge glue uniformizing device further comprises a base and a second mechanical arm, and the second mechanical arm is installed on the base and grasps and centers the wafer.

3. The wafer edge uniformity device of claim 2, wherein, α=35°; and / or, the rotating speed range of the first rotating speed S1 is 300rpm≤S1≤1000rpm; and / or, the rotating speed range of the second rotating speed S2 is 1000rpm≤S2≤6000rpm; and / or, the wafer edge glue uniformizing device further comprises a first mechanical arm, and the first mechanical arm moves to drive the glue nozzle to move to the edge-exposed area of the wafer, and the glue outlet end of the glue nozzle is located above the edge-exposed area of the wafer, and the height of the glue outlet end of the glue nozzle from the surface of the wafer is H, which satisfies 1mm≤H≤3mm.

4. The wafer edge uniformity device of claim 2, wherein, The wafer edge glue uniformizing device comprises a carrier, a glue nozzle, and a carrier.

5. A method for edge bead removal of a wafer, the method comprising: Step S200: the wafer is an edge-debonded wafer, the wafer rotates at a first rotating speed S1, the glue nozzle applies glue to the edge-exposed area to cover the edge-exposed area, and the wafer rotates at a second rotating speed S2 to form an edge glue film layer covering the edge-exposed area.

6. The wafer edge glue uniformizing method of claim 5, wherein Step S200 comprises: Step S201: the carrier rotates to drive the wafer to rotate, and the wafer rotates at a first rotating speed S1; Step S202: the first mechanical arm moves to drive the glue nozzle to move to the edge-exposed area of the wafer, the glue nozzle forms an angle α with the plane of the wafer, 30°≤α≤60°, and the glue nozzle applies glue to the edge-exposed area to cover the edge-exposed area; Step S203: the carrier rotates to drive the wafer to rotate, the wafer rotates at a second rotating speed S2, and the glue solvent volatilizes to form an edge glue film layer covering the edge-exposed area. Before step S200, step S100 is performed: a wafer is obtained and centered, and the centered wafer is conveyed to the carrier, so that the center of the wafer coincides with the center of the carrier, and the wafer is an edge-debonded wafer; and / or, in step S202, the first mechanical arm moves to drive the glue nozzle to move to the edge-exposed area of the wafer, the glue outlet end of the glue nozzle is located above the edge-exposed area of the wafer, and the height of the glue outlet end of the glue nozzle from the surface of the wafer is H, which satisfies 1mm≤H≤3mm.

7. The method of claim 6, wherein the edge of the wafer is coated with the photoresist by a spin coating method. After step S200, step 300 is performed: the wafer stops rotating, the wafer is grasped and baked to obtain a baked wafer, and the baked wafer is cooled.

8. The method of claim 7, wherein the edge of the wafer is coated with the photoresist by a spin coating method. After step S300, the final thickness of the edge glue film layer ranges from 1um to 20um, and the width ranges from 1mm to 10mm.

9. The method of claim 8, wherein the edge of the wafer is coated with the photoresist by a spin coating method. The wafer edge glue uniformizing device comprises a carrier, a glue nozzle, and a carrier.

10. A wafer processing method, characterized by, ​ Step S10: coating photoresist on the wafer surface to cover the wafer surface; Step S20: removing photoresist from the wafer edge to form an edge exposure area; Step S30: exposing the wafer processed in step S20; Step S40: forming an edge photoresist film layer on the wafer edge processed in step S30 by using the wafer edge coating device according to any one of claims 1-4 or by using the wafer edge coating method according to any one of claims 5-9, to obtain a wafer after edge coating; Step S50: processing the wafer after edge coating in step S40, wherein the wafer processing includes but is not limited to wafer etching process or wafer bonding process; Step S60: removing photoresist from the wafer in step S50 to remove the edge photoresist film layer of the wafer and the photoresist formed in step S10, to obtain a processed wafer.

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