Metal replacement device

Abstract

The utility model provides a metal replacement device which is provided with a bearing table for placing a wafer, and a spraying device for spraying a silver ion solution is arranged above the bearing table. According to the device, the use amount of a silver ion Ag < + > solution can be reduced, the silver ion solution flows in the silver replacement process, and the wafer is rotated by using the bearing table while the silver ion solution is matched, so that by-products such as copper ions Cu < + > and silver ions generated by silver replacement and a solution with relatively low silver ion concentration can be outwards rotated out, and the uniform silver ion concentration is maintained; therefore, the silver layer on the wafer is uniform.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor technology, and in particular to a metal displacement device. BACKGROUND

[0002] Copper to copper bonding is a step in manufacturing semiconductor package structure. When copper is butted against copper, copper is easily oxidized to form copper oxide which inhibits copper diffusion, resulting in increased bonding temperature (≧250℃) and holes on the bonding surface. It is known that silver displacement on copper surface can overcome the aforementioned problems. Currently, silver displacement on copper surface is performed by sequentially immersing multiple wafers in silver ion (Ag+) solution, however Ag+ in the solution will decrease with the increase of the number of immersion pieces, so that the silver layer thickness of the wafers immersed later is thinner, and the silver layer thickness between wafers is not uniform. In addition, the Ag+ solution does not flow during the immersion process, resulting in uneven Ag+ concentration and uneven silver layer on the same wafer. Although the aforementioned problems can be solved by replacing the Ag+ solution multiple times, the consumption is large and the cost is high. CONTENT OF THE UTILITY MODEL

[0003] The present application provides a metal displacement device, comprising:

[0004] a carrying table for carrying wafers;

[0005] a spraying device arranged above the carrying table, the spraying device being used for spraying solution and depositing metal ions in the solution on the wafers.

[0006] In some optional embodiments, the device further comprises:

[0007] a shell in a hollow shape and used for accommodating the carrying table and the spraying device, the shell surrounding an oxygen-free space.

[0008] In some optional embodiments, the device further comprises:

[0009] a recovery tank surrounding the carrying table, the recovery tank being used for recovering solution.

[0010] In some optional embodiments, the carrying table moves relative to the recovery tank between a preliminary position protruding from the recovery tank and a working position accommodated in the recovery tank.

[0011] In some optional embodiments, the recovery tank comprises a tank wall, an opening arranged on the tank wall, and a pipeline buried in the tank wall and connecting the opening and the outside.

[0012] In some optional embodiments, the device further comprises:

[0013] A blocking structure is arranged around the shower device and around the recovery tank.

[0014] In some embodiments, the projection area of the shower device on the wafer is larger than the area of the wafer.

[0015] In some embodiments, the carrier table is rotatable relative to the shower device.

[0016] In some embodiments, the device further comprises:

[0017] At least one solution tank is in communication with the shower device.

[0018] In some embodiments, the device further comprises:

[0019] A housing is arranged between the shower device and the solution tank, and the housing is used to contain the solution flowing from the solution tank.

[0020] In some embodiments, the device further comprises:

[0021] An ultrasonic generator is arranged in the housing to vibrate the solution.

[0022] In some embodiments, the device further comprises:

[0023] A vacuum suction device is arranged in the carrier table, and the vacuum suction device is used to suction and fix the wafer on the carrier table by vacuum.

[0024] In some embodiments, the device further comprises:

[0025] A lifting device is arranged in the carrier table, and the lifting device is used to rise above the carrier table to carry the wafer on the lifting device, and the lifting device is used to descend to carry the wafer on the carrier table.

[0026] In some embodiments, the lifting device is a pin.

[0027] In some embodiments, the device further comprises:

[0028] A gas suction device is arranged in the housing, and the gas suction device is used to suck the oxygen in the housing to provide an oxygen-free space.

[0029] The metal replacement device provided by the application is provided with a bearing table for placing a wafer, and a spraying device above the bearing table is used to spray silver ion solution. The device can reduce the amount of silver ion Ag+ solution, and make the silver ion solution flow during silver replacement, cooperate with the silver ion solution, and rotate the wafer by using the bearing table, so as to rotate the by-products such as copper ion Cu+ and silver ion generated by silver replacement and the solution with low silver ion concentration to the outside, so as to maintain uniform silver ion concentration, thereby making the silver layer on the wafer uniform. BRIEF DESCRIPTION OF DRAWINGS

[0030] Other features, objects and advantages of the application will become more apparent from the following detailed description of non-limiting embodiments made with reference to the accompanying drawings:

[0031] Figure 1 is a structural schematic diagram of a metal replacement device according to an embodiment of the application;

[0032] Figures 2 to 7B is a structural schematic diagram of a metal replacement device according to an embodiment of the application in different states.

[0033] Symbol explanation:

[0034] 1-bearin table, 2-spraying device, 3-outer shell, 31-door body, 4-recovery tank, 41-tank wall, 42-opening, 43-pipe, 5-blocking structure, 6-first solution tank, 7-second solution tank, 8-third solution tank, 9-housing, 10-ultrasonic wave generator, 11-vacuum adsorption device, 12-lifting device, 13-pumping device, 14-first shunt valve, 15-second shunt valve, 16-wafer, 17-metal layer (copper pad), 18-silver layer, 20-metal oxide, 21-second pipe, 22-dielectric layer, 23-chemical residue, 24-acid residue. DETAILED DESCRIPTION

[0035] The specific embodiments of the application are described below in conjunction with the drawings and examples, and those skilled in the art can easily understand the technical problems solved by the application and the technical effects produced by the application through the content recorded in the description. It can be understood that the specific embodiments described herein are only used to explain the related utility model, and not to limit the utility model. In addition, in order to facilitate the description, only the parts related to the utility model are shown in the drawings.

[0036] It should be noted that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for illustrative purposes to aid those skilled in the art and to facilitate understanding and reading of the contents described in the specification. They are not intended to limit the scope of this application and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives of this application, should still fall within the scope of the technical content disclosed in this application. Furthermore, terms such as "above," "first," "second," and "a" used in this specification are merely for clarity of description and are not intended to limit the scope of this application. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this application's implementation.

[0037] It should also be noted that the longitudinal section corresponding to the embodiment of this application can be the section corresponding to the front view direction, the transverse section can be the section corresponding to the right view direction, and the horizontal section can be the section corresponding to the top view direction.

[0038] It should be readily understood that the meanings of “on,” “above,” and “on top of” in this application should be interpreted in the broadest sense, such that “on” means not only “directly on something,” but also “on something” including intermediate components or layers existing between the two.

[0039] Furthermore, for ease of description, spatial relative terms such as "below," "under," "lower," "above," and "upper" may be used in this application to describe the relationship of one element or component to another element or component shown in the accompanying drawings. In addition to the orientations described in the figures, the spatial relative terms are also intended to cover different orientations of the device during use or operation. The device may be oriented in other ways (rotated 90° or otherwise), and the spatial relative descriptive terms used in this application may be interpreted accordingly.

[0040] Furthermore, where there is no conflict, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0041] like Figures 1 to 3 As shown, the metal replacement device includes a support platform 1 and a spray device 2 disposed above the support platform 1.

[0042] In this embodiment, the support stage 1 can be used to support the wafer 16. The spray device 2 can be used to spray a solution (e.g., a silver ion solution) and deposit metal ions (e.g., silver ions, Ag+) in the solution onto the wafer 16.

[0043] In one embodiment, the projection area of the spraying device 2 onto the wafer 16 can be larger than the area of the wafer 16. The projection range of the spraying device 2 can cover the wafer 16, so as to expand the spraying range of the solution. The solution can be uniformly sprayed on the surface of the wafer 16, so as to make the silver layer thickness more uniform.

[0044] In one embodiment, the device can further comprise a housing 3. The housing 3 is hollow and can be used to accommodate the supporting table 1 and the spraying device 2. The housing 3 surrounds an oxygen-free space. The oxygen-free environment can be created by using the sealed housing 3 in combination with adding inert gas, which can prevent the diffusion of chemical gas and avoid the oxidation of the metal (e.g. copper) of the wafer 16 bonding interface by contacting oxygen.

[0045] In particular, the device can further comprise an air extraction device 13 inside the housing 3. The air extraction device 13 can be used to extract oxygen in the housing 3 to provide an oxygen-free space.

[0046] In one embodiment, the housing 3 can have a door 31 for the wafer 16 to enter or exit.

[0047] In one embodiment, the device can further comprise a recovery tank 4 surrounding the supporting table 1. In particular, the recovery tank 4 can comprise a tank wall 41, an opening 42 opened on the tank wall 41, and a pipeline 43 embedded inside the tank wall 41 and connecting the opening 42 with the outside, the tank wall 41 can collect excess solution, so that the excess solution can flow into the pipeline 43 from the opening 42 of the recovery tank 4 for recycling, so as to be further recycled. Before recycling the solution, the solution can be treated, such as filtering or purifying, to remove impurities in the solution.

[0048] Further, the device can further comprise a second flow divider valve 15 connected with the recovery tank 4. The recovery tank 4 and the second flow divider valve 15 can further be provided with a second pipeline 21 for transporting the recycled solution. The second flow divider valve 15 can be used to classify and recycle the recycled solution according to the chemical type.

[0049] In one embodiment, the supporting table 1 can rotate and lift. In particular, the supporting table 1 can rotate relative to the spraying device 2. That is, the wafer 16 is rotated while spraying the solution (containing silver ions Ag+), so as to displace the byproducts such as Cu+, silver particles, and the solution with low Ag+concentration, and make the Ag+concentration on the wafer 16 uniform.

[0050] Further, the supporting table 1 can be relative to the recovery tank 4 in a standby position (see Fig. 1) protruding from the recovery tank 4, and a working position (see Fig. 2) accommodated in the recovery tank 4. Figure 2 Figure 3 Further, the supporting table 1 can be relative to the recovery tank 4 in a standby position (see Fig. 1) protruding from the recovery tank 4, and a working position (see Fig. 2) accommodated in the recovery tank 4.The carrier table 1 is moved up and down between a position protruding from the recovery tank 4 and a position in the recovery tank 4. When the wafer 16 is to be transferred to the carrier table 1, the carrier table 1 is in the position protruding from the recovery tank 4 to facilitate the transfer of the wafer 16. When the solution is being sprayed, the carrier table 1 is in the position in the recovery tank 4 to avoid splashing of the solution.

[0051] In one embodiment, the apparatus can further comprise a vacuum suction device 11 disposed in the carrier table 1. The vacuum suction device 11 can be used to suction and fix the wafer 16 to the carrier table 1 by vacuum.

[0052] In one embodiment, the apparatus can further comprise a barrier structure 5 disposed above and peripherally to the spraying device 2. Further, the barrier structure 5 can be moved up and down with the spraying device 2 and can be lowered into the recovery tank 4 together with the carrier table 1. That is, the barrier structure 5 can surround the recovery tank 4 to avoid splashing of the solution into the interior of the housing 3 to cause contamination.

[0053] In one embodiment, the apparatus can further comprise at least one solution tank respectively. Each solution tank can be connected to the spraying device 2. For example, a first shunt valve 14 disposed between the solution tank and the spraying device 2 can be used to control the connection between the at least one solution tank and the spraying device 2 to allow the corresponding solution to flow to the spraying device 2 at a predetermined step.

[0054] Here, the plurality of solution tanks can contain an acidic solution, a silver ion solution and deionized water respectively. Thus, the steps of pickling (removing copper oxide on the copper pad), silver replacement and water washing can be completed in one station in the metal replacement apparatus provided by the present application. Not only the work efficiency can be improved, but also the risk of breaking the wafer 16 due to replacement of the apparatus to move the wafer 16 can be avoided.

[0055] Specifically, the first solution tank 6 can contain an acidic solution for removing metal oxide. The second solution tank 7 can contain a silver ion solution for silver replacement. The third solution tank 8 can be used to contain deionized water for cleaning the surface of the wafer 16.

[0056] In one embodiment, the apparatus can further comprise a housing 9 disposed between the spraying device 2 and the solution tank. The housing 9 can be used to contain the solution flowing from the solution tank. Further, an ultrasonic generator 10 can be disposed in the housing 9. The ultrasonic generator 10 can be used to vibrate the solution in the housing 9.

[0057] Here, the ultrasonic generator 10 can dissolve the metal ions (silver ions Ag+) precipitated in the solution for a long time into the solution to make the concentration of the metal ions in the solution uniform.

[0058] In one embodiment, the apparatus can further comprise a lifting device 12 disposed in the carrier table 1. The lifting device 12 can be, for example, a pin.

[0059] When the wafer 16 is transferred to the carrier 1 by the robot, the lifting device 12 can be used to rise above the carrier 1 so that the wafer 16 is carried on the lifting device 12, at this time the lifting device 12 can provide space for the robot (not shown in the figure) to place so that the robot transfers the wafer 16 into the device. After the robot is removed from the device, the lifting device 12 can be used to descend so that the wafer 16 is carried on the carrier 1, thereby stably placing the wafer 16 on the carrier 1 and enabling the wafer 16 to be adsorbed and fixed on the carrier 1 by the vacuum adsorption device 11.

[0060] The metal replacement device provided by the present application is provided with the carrier 1 for placing the wafer 16, and the spraying device 2 above the carrier 1 is used to spray the silver ion solution. The device can reduce the amount of silver ion solution and make the silver ion solution flow during the silver replacement process. The wafer 16 is rotated by the carrier 1 at the same time as the silver ion solution, which can rotate the by-products such as copper ions (Cu+) and silver particles generated by the silver replacement and the solution with low silver ion concentration outward, so that the silver ion concentration on the wafer 16 can be maintained uniform, thereby making the silver layer on the wafer 16 uniform.

[0061] Figures 2 to 7B It is a structural schematic diagram of the metal replacement device according to the embodiment of the present application in different states.

[0062] As shown in Figure 2 , the door body 31 of the shell 3 is opened, and the spraying device 2 and the carrier 1 are respectively raised and lifted, and the wafer 16 is transferred to the carrier 1.

[0063] In addition, an oxygen-free environment needs to be created before or after the wafer 16 enters. Since the door body 31 will not be opened again during the process from when the wafer 16 enters to when the silver replacement operation is completed, that is, the air inside and outside the shell 3 will not be exchanged, therefore, it is better to create an oxygen-free environment after the wafer 16 enters.

[0064] As shown in Figure 3 , the door body 31 of the shell 3 is closed, and the spraying device 2 and the carrier 1 are respectively lowered.

[0065] As shown in Figure 4A and Figure 4B , the wafer 16 is simultaneously provided with the metal layer 17 (copper pad) and the dielectric layer 22. The acidic solution in the first solution tank 6 is sprayed to the surface of the metal layer 17 to remove the metal oxide 20 on the surface of the metal layer 17. The wafer 16 can be rotated with the carrier 1 to rotate the acidic solution and the metal oxide 20 outward to the recovery tank 4, and the excess acidic solution and the metal oxide 20 are recovered by the recovery tank 4.

[0066] As shown in Figure 5A andFigure 5B As shown, deionized water in the third solution tank 8 is sprayed onto the surface of the metal layer 17 to clean the acidic residue 24 on the surface of the metal layer 17, completing the water washing step. The wafer 16 can rotate with the support stage 1 to transfer the deionized water and acidic residue 24 outward to the recovery tank 4, and the recovery tank 4 is used to recover excess deionized water and acidic residue 24.

[0067] like Figure 6A and Figure 6B As shown, the silver ion solution in the second solution tank 7 is sprayed onto the surface of the metal layer 17. The wafer 16 rotates in conjunction with the support stage 1 to complete the silver replacement step, making the silver layer 18 on the surface of the wafer 16 more uniform. Excess silver ion solution is then recovered using the recovery tank 4.

[0068] like Figure 7A and Figure 7B As shown, deionized water from the third solution tank 8 is sprayed onto the surface of the metal layer 17 to clean the chemical residues 23 on the surface of the metal layer 17 (see Figure 8). Figure 6B The washing process is completed. The wafer 16 can rotate with the support stage 1 to transfer the deionized water and chemical residues 23 to the recycling tank 4, and the recycling tank 4 is used to recover excess deionized water and chemical residues 23.

[0069] Although this application has been described and illustrated with reference to specific embodiments thereof, such description and illustration are not limiting of this application. It will be readily understood by those skilled in the art that various changes can be made and equivalent elements can be substituted within embodiments without departing from the true spirit and scope of this application as defined by the appended claims. Illustrations may not be drawn to scale. Differences may exist between the technical representation in this application and actual equipment due to variables in the manufacturing process, etc. Other embodiments of this application may exist that are not specifically described. The specification and drawings should be considered illustrative rather than restrictive. Modifications can be made to adapt particular circumstances, materials, composition, methods, or processes to the objectives, spirit, and scope of this application. All such modifications fall within the scope of the appended claims. While the methods disclosed in this application have been described with reference to specific operations performed in a particular order, it should be understood that these operations can be combined, subdivided, or reordered to form equivalent methods without departing from the teachings of this application. Therefore, unless specifically indicated herein, the order and grouping of operations are not limiting of this application.

Claims

1. A metal replacement device, comprising: A support platform is used to support wafers; A spraying device is disposed above the support platform. The spraying device is used to spray a solution containing metal ions and deposit the metal ions in the solution onto the wafer. A recovery tank, surrounding the support platform, is used to recover the solution; The support platform drives the wafer to rotate, transferring the solution on the wafer into the recycling tank.

2. The metal replacement device according to claim 1, characterized in that, The device further includes: The housing and the exhaust device are hollow and used to house the support platform and the spray device. The housing defines an oxygen-free space. The exhaust device is used to extract oxygen from the housing to provide an oxygen-free space. A blunt gas is added to the housing. The solution tank is connected to the spraying device; A housing is disposed between the spraying device and the solution tank, the housing being used to contain the solution flowing out of the solution tank; An ultrasonic generator is disposed in the housing to vibrate the solution; A lifting device is located inside the support platform. The lifting device is used to rise above the support platform to support the wafer on the lifting device, and the lifting device is used to descend to support the wafer on the support platform.

3. The metal replacement device according to claim 1, characterized in that, The device further includes: The recovery tank includes a tank wall, an opening formed in the tank wall, and a pipe embedded inside the tank wall and connecting the opening to the outside. The tank wall is used to recover excess solution. The support platform moves relative to the recovery tank between a preparatory position protruding from the recovery tank and a working position accommodated in the recovery tank. The second diversion valve is connected to the recovery tank; The second pipeline is located between the recovery tank and the second diversion valve for conveying the recovery solution; Multiple solution tanks are connected to the spray device, and the multiple solution tanks respectively contain acidic solution, silver ion solution and deionized water; A first diversion valve is disposed between the solution tank and the spray device to control the communication state between at least one of the solution tanks and the spray device, thereby allowing the corresponding solution to flow to the spray device in a preset step.

4. The metal replacement device according to claim 1, characterized in that, The vertical projection area of ​​the spraying device onto the wafer is larger than the area of ​​the wafer. The spraying device is used to spray the solution from top to bottom, spraying the solution onto the entire surface of the wafer. The device further includes: A barrier structure surrounds the spraying device and the recycling tank, and the barrier structure is capable of rising and falling together with the spraying device.

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