Horizontal wafer electroplating device

Abstract

The utility model provides a horizontal wafer electroplating device which comprises a wafer placed on a fixed bearing part, and the to-be-electroplated surface of the wafer is horizontally upward; the anode piece is movably arranged above the wafer and is correspondingly arranged in parallel with the to-be-plated surface of the wafer at an interval; the infiltration cover is movably arranged above the wafer and is assembled with the bearing part in a sealing manner; the infiltration cover and the anode piece are respectively switched and oppositely arranged with the wafer in an infiltration mode and an electroplating mode, when in the infiltration mode, the infiltration cover and the bearing piece are assembled to form a sealed infiltration cavity for accommodating the wafer, and when in the electroplating mode, the anode piece and a to-be-plated surface of the wafer are horizontally and correspondingly arranged to form a counter electrode. In the embodiment of the invention, the to-be-plated surface of the wafer is fixedly upward in the infiltration and electroplating modes, and the infiltration liquid realizes a better infiltration effect on the electroplating hole; and after infiltration, the wafer does not horizontally move or turn over, so that the infiltration liquid in the hole can be prevented from being separated or falling off under the action of external force, and the electroplating hole filling yield is improved.

Description

Technical field

[0001] The present application relates to the field of wafer electroplating; specifically, to a horizontal wafer electroplating device. [Background Technology]

[0002] Electronic electroplating is a technical method for chip manufacturing that enables nanoscale electronic logic interconnection. Unlike conventional electroplating, its application areas mainly include chip Damascus interconnection, printed circuit board (PCB) plating, lead frame plating, connector plating, microwave device manufacturing, and other electronic component manufacturing. From chip copper interconnection technology, electrode bump plating technology in packaging, lead frame electroplating surface treatment, to various functional plating of printed circuit boards and connectors, electronic electroplating technology runs through the entire process of high-end electronic manufacturing, becoming a fundamental, universal, and irreplaceable technology in the production of high-end electronic products such as chip manufacturing, three-dimensional integration and device packaging, micro-nano device manufacturing, micro-electromechanical systems (MEMS), sensors, military electronic equipment and components.

[0003] Electronic electroplating technology is used to produce electronic wires for logical interconnection between transistors, forming the "neural network" of the chip. Interconnection channels (grooves or holes) are set on the substrate of the chip or wafer, and conductive materials such as copper, tungsten, cobalt, new metal alloys (copper-aluminum alloys, nickel alloys, etc.), and advanced carbon materials are filled into the interconnection channels through electronic electroplating technology. Conductive circuits are created between chips and between wafers, providing shorter electrical connection lines and more signal channels to improve device performance.

[0004] Wafers usually need to be pre-wetted before electroplating. Pre-wetting allows liquid to enter the holes to drive out the air in the holes and form a liquid film, which is beneficial to the next electroplating process. If the pre-wetting is insufficient, serious void defects will be generated inside after electroplating, especially for structures similar to deep holes. The liquid cannot completely reach the deep holes, forming pinch-off, resulting in failure of deep hole electroplating. In the prior art, wafer pre-wetting and electroplating are usually carried out in two device systems, that is, after the wafer pre-wetting is completed, it needs to be transferred to the electroplating device. During the transfer process, the wetting liquid in the hole will fall or detach under the action of external force, especially when it is necessary to turn the wafer surface to be plated downward, which destroys the evenly wetted wafer surface to be plated, making it difficult to achieve an ideal wetting effect and electroplating yield. [Utility Model Content]

[0005] In view of this, embodiments of the present invention provide a horizontal wafer electroplating apparatus and a method for electroplating a metal layer on a wafer substrate. By maintaining the wafer surface facing upward in an apparatus that integrates components for the wetting and electroplating processes, good pre-wetting of deep-hole electroplating is ensured before electroplating, improving deep-hole electroplating yield and uniformity, and eliminating or reducing deep-hole electroplating failures or void defects caused by insufficient wetting.

[0006] A horizontal wafer electroplating device includes a wafer placed on a fixed carrier, with the surface to be plated of the wafer facing horizontally upward; an anode member movably arranged above the wafer and configured to be parallel and spaced opposite to the surface to be plated of the wafer; an immersion hood movably arranged above the wafer and configured to be sealed and assembled with the carrier; the immersion hood and the anode member are switched and opposed to the wafer in immersion mode and electroplating mode respectively. When in the immersion mode, the immersion hood and the carrier are assembled to form a sealed immersion chamber for accommodating the wafer. When in the electroplating mode, the anode member is placed horizontally opposite to the surface to be plated of the wafer to form a counter electrode.

[0007] Furthermore, the immersion cover and the anode piece are respectively connected to the robotic arm, and program switching movement is achieved according to the switching requirements of the immersion mode and the electroplating mode.

[0008] Furthermore, the infiltration cover includes a first liquid flow port and an air hole; the air hole is connected to an external air pump and is used to adjust the air pressure in the sealed infiltration cavity, and the first liquid flow port is used to inject and release the infiltration liquid into the sealed infiltration cavity.

[0009] Furthermore, it includes a DC power supply, a plating solution, and a plating tank; the wafer and the anode are respectively connected to the negative pole and the positive pole of the DC power supply; in the plating mode, the plating solution immerses the wafer and the anode in the plating tank.

[0010] Furthermore, it includes a liquid storage tank, which is connected to the electroplating tank through a first liquid regulating hole, a connecting pipe, and a second liquid regulating hole respectively provided. A liquid level adjusting member is provided on the connecting pipe for adjusting the height of the electroplating liquid in the electroplating tank.

[0011] Furthermore, the anode component is connected to a first driver, which drives the anode component to rotate horizontally above the surface of the wafer to be plated.

[0012] Furthermore, the carrier is connected to the second driver to drive the wafer to perform rotational circumferential motion in the horizontal direction.

[0013] Furthermore, the bottom of the carrier is movably connected to the telescopic component, and the telescopic movement of the telescopic component can achieve height adjustment of the wafer in the vertical direction.

[0014] Furthermore, an elastic sealing ring is provided on the bottom surface of the side wall of the immersion cover.

[0015] Optionally, the immersion hood and the anode part are integrated into one piece through a sliding connection shaft; the anode part is located on the side of the immersion hood facing the wafer; the immersion hood moves up and down relative to the anode part under the drive of the sliding connection shaft. In the immersion mode, the immersion hood moves downward relative to the anode part, and in the electroplating mode, the immersion hood moves upward relative to the anode part.

[0016] Furthermore, the immersion cover includes a top wall and side walls that are sealed and enclosed to form a cavity with an opening facing downward, the top wall includes an opening, and the sliding connection shaft passes through the opening and is slidably connected to the inner wall of the opening, and is used to drive the immersion cover to move up and down when the mode is switched;

[0017] The anode member is located below the top wall on a side close to the wafer, and the orthographic projection of the anode member on the plane where the top wall is located is located inside the top wall; the wafer electroplating device also includes an anode support member for supporting and fixing the anode member, and the anode support member includes a support connection portion, which passes through the opening and is slidably connected to the sliding connection shaft.

[0018] Furthermore, the center of the anode member, the center of the top wall, and the center of the wafer are located on the same center line.

[0019] The horizontal wafer electroplating device provided by the present application integrates structural components that can realize pre-wetting and electroplating reactions. By keeping the wafer's to-be-plated surface facing upward during pre-wetting, electroplating, and switching to electroplating after pre-wetting, it is not only easy for the immersion liquid to reach the deep hole position of the wafer and displace the air in the deep hole to achieve an ideal wetting effect; but also, in the process of switching from pre-wetting to electroplating, the wafer's to-be-plated surface is kept fixed upward without horizontal movement or flipping, which can ensure that the immersion liquid in the deep hole position of the wafer after pre-wetting does not fall off or peel off, which is beneficial to the next electroplating process, improves the yield and uniformity of deep hole electroplating, and eliminates or reduces deep hole electroplating failure or void defects.

Brief Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0021] Figure 1 A schematic structural diagram of a horizontal wafer electroplating device provided in this application;

[0022] Figure 2 A schematic structural diagram of an infiltration hood provided in this application;

[0023] Figure 3 This is a structural schematic diagram of an anode component fixing device provided in this application;

[0024] Figure 4 This is a schematic structural diagram of a wafer fixing device provided in this application;

[0025] Figure 5 for Figure 1 A schematic diagram of a structure of a wafer electroplating device in an immersion mode is shown;

[0026] Figure 6 for Figure 1 A structural schematic diagram of a wafer electroplating device in an electroplating mode is shown;

[0027] Figure 7 for Figure 1 Another structural schematic diagram of the wafer electroplating device in the electroplating mode is shown;

[0028] Figure 8 A schematic structural diagram of another horizontal wafer electroplating device provided in this application;

[0029] Figure 9 for Figure 8 A schematic diagram of a structure of a wafer electroplating device in an immersion mode is shown;

[0030] Figure 10 for Figure 8 The figure shows a structural schematic diagram of a wafer electroplating device in electroplating mode. [Specific implementation method]

[0031] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0032] It should be clear that the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0033] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a," "an," and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0034] It should be understood that the term "and / or" as used herein is merely a description of the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0035] In the description of this specification, it is necessary to understand that the words "substantially", "approximately", "approximately", "about", "roughly", "generally" and the like described in the claims and embodiments of this application refer to what can be generally recognized within a reasonable process operation range or tolerance range, rather than an exact value.

[0036] Figure 1 A simplified structural diagram of a horizontal wafer electroplating device provided in this application; Figure 2 A schematic structural diagram of an infiltration hood provided in this application; Figure 3 This is a structural schematic diagram of an anode component fixing device provided in this application; Figure 4 This is a schematic structural diagram of a wafer fixing device provided in this application; Figure 5 A schematic diagram of the structure of the electroplating device provided in this application in the immersion mode; Figure 6 for Figure 1 A structural schematic diagram of a wafer electroplating device in electroplating mode is shown; Figures 1 to 6 As shown, the horizontal wafer electroplating device 100 includes a wafer 31 placed on a horizontal fixed carrier 32. "Fixed" here means that the carrier does not move horizontally or flip, but does not limit whether it can be positioned, rotated or lifted in the fixed position. The surface 311 of the wafer 31 to be plated faces horizontally upward; the anode member 20 is movably arranged above the wafer 31 and is configured to be placed parallel to and spaced from the surface 311 of the wafer 31 to be plated; the immersion hood 1 is movably arranged above the wafer 31 and is configured to be sealed and assembled with the carrier 32; the immersion hood 1 and the anode member 20 are switched to face the wafer 31 in immersion mode A and electroplating mode B respectively. When in immersion mode A, the immersion hood 1 and the carrier 32 are assembled to form a sealed immersion chamber 110 containing the wafer 31. When in electroplating mode B, the anode member 20 and the surface 311 of the wafer 31 to be plated are placed horizontally and correspondingly to form a counter electrode 302.

[0037] For details, please refer to Figure 1 、 Figure 4 and Figure 5The wafer electroplating device 100 includes a carrier 32 that is positioned and fixedly installed to carry the wafer 31, that is, the carrier 32 does not move or flip relative to the horizontal position. The carrier 32 is made of an insulating material, which can be selected from titanium alloy, polyetheretherketone (PEEK), polymethyl methacrylate (PMMA), polyphenylene sulfide (PPS), polyetherketoneketone (PEKK), etc. The upper surface of the carrier 32 is a platform structure, which provides support and fixation for the wafer 31; the wafer 31 includes a surface to be plated 311 and an insulating surface (not shown). When the wafer 31 is fixed on the carrier 32, the insulating surface is in direct surface contact with the carrier 32, and the surface to be plated 311 of the wafer 31 is facing away from the carrier 32, that is, the surface to be plated 311 of the wafer 31 is horizontally facing upward. The surface 311 of the wafer 31 to be plated contains one or more recessed through holes or grooves. During electroplating, a soluble copper plate or an insoluble metal plate is usually used as the anode 20 to act as the anode; the wafer 31 is usually composed of a semiconductor wafer with a conductive material layer, which is electrically connected to the conductive material layer and acts as a cathode. During the electroplating process, an external electric field is applied. The wafer 31 is brought into contact with the electroplating solution 81 containing a metal salt (such as copper sulfate, alkyl copper sulfonate or a mixture of salts). The Cu in the electroplating solution 81 is reduced on the cathode seed layer. 2+ The through holes or trenches of the entire wafer 31 are filled with Cu.

[0038] Many factors affect the filling effect of the through-holes in wafer 31, such as the seed layer, pre-treatment before electroplating, blind hole etching quality, and the applied electric field. Pre-wetting treatment before electroplating is primarily intended to expel gases such as air from the through-holes, grooves, or surfaces of wafer 31. The non-conductive gas resistance carried or retained in these structures can hinder the free passage of current and interfere with the electroplating process, leading to incomplete electroplated metal filling. Pre-wetting the wafer 31 substrate by vacuum pre-treatment can also appropriately avoid voids or faults within the holes. Promoting plating solution circulation through methods such as ultrasound, air bubbling, bottom jet circulation, and side jet circulation is also one way to improve hole filling quality.

[0039] Please continue reading Figure 1 In the embodiment of the present application, the wafer 31 is located at the bottom, with the surface 311 of the wafer 31 to be plated facing in parallel; the anode member 20 is located directly above the wafer 31, and is spaced apart from and parallel to the surface 311 of the wafer 31 to be plated; the size of the anode member 20 is equivalent to or slightly larger than the size of the surface 311 of the wafer 31 to be plated. The anode member 20 can be moved by the driving device (robotic arm) 6. The distance between the anode member 20 and the surface 311 of the wafer 31 to be plated is adjusted according to actual needs, and the anode member 20 is moved away during the pre-wetting process. The "moving away" here can refer to the immersion hood being raised to a certain distance height, or it can refer to moving horizontally away from the top of the wafer 31. Please continue to refer to Figure 1and Figure 5 ,like Figure 1 As shown, the immersion hood 1 is moved and arranged directly above the wafer 31 under the action of the driving device 7 and the robotic arm 6. The outermost dimension of the immersion hood 1 is larger than the dimension of the wafer 31 and can completely cover the wafer 31. The body of the immersion hood 1 can be made of hard plastic material or rigid metal material, which is not easily deformed under the action of external force. When the wafer 31 is in the pre-infiltration mode A, the robotic arm 6 driven by the driving device 7 seals and locks the immersion hood 1 and the carrier 32 into the locking structure 402\104 to form a sealed infiltration chamber 110. The infiltration liquid 111 is injected into the infiltration chamber 110 to perform a pre-infiltration operation on the wafer 31. After pre-wetting is complete, pre-wetting liquid 111 is drained. Simultaneously, robotic arm 6 removes immersion hood 1, holds wafer 31 stationary, and moves anode 20 directly above wafer 31, initiating electroplating mode B. Specifically, robotic arm 6 switches immersion hood 1 and anode 20 relative to wafer 31 in immersion mode A and electroplating mode B, respectively. Furthermore, robotic arm 6 is connected to program control system 7, enabling it to automatically switch modes based on the process. In this way, the pre-wetting and electroplating components are integrated. By keeping the surface 311 of the wafer 31 to be plated facing upward during the pre-wetting, electroplating, and switching to electroplating after pre-wetting, it is not only easy for the immersion liquid 111 to reach the deep hole position of the wafer 31, replacing the air in the deep hole to achieve the ideal wetting effect; but also in the process of switching from pre-wetting to electroplating, the surface 311 of the wafer 31 to be plated is kept fixed upward without horizontal movement or flipping operation, which can ensure that the immersion liquid 111 at the deep hole position of the wafer 31 after pre-wetting does not fall off or peel off, which is beneficial to the next electroplating process, improves the yield and uniformity of deep hole electroplating, and eliminates or reduces deep hole electroplating failure or void defects.

[0040] Please continue reading Figure 1 、 Figure 2 and Figure 5 As shown, the infiltration cover 1 also includes a first liquid flow port 101 and an air hole 102; the air hole 102 is connected to the external air pump 16 and is used to adjust the air pressure in the sealed infiltration chamber 110, and the first liquid flow port 101 is used to inject and / or release the infiltration liquid 111 into the sealed infiltration chamber 110.

[0041] Specifically, if Figure 2 and Figure 5As shown, the first liquid flow port 101 on the immersion cover 1 is connected to the immersion liquid 111 supply unit 13 through a liquid pipe, and a two-way control valve 131 is provided on the liquid pipe, and is connected to the liquid pump 132. Under the drive of the liquid pump 132, the injection and backflow of the immersion liquid 111 can be achieved through the control of the two-way control valve 131; the vacuum air hole 102 is connected to the external vacuum pump 16 through a vacuum pipe; when the immersion cover 1 and the carrier 32 are sealed and assembled to form a sealed immersion chamber 110, the liquid pump 132 and the two-way control valve 131 for supplying and backflowing the immersion liquid are closed, and the vacuum pipe control valve 151 is opened to vacuum the immersion chamber 110. Vacuuming can remove air from the surface of the wafer 31 and the deep hole channel or groove, ensuring that the subsequent immersion liquid 111 can completely fill the deep hole, avoiding the air in the deep hole (mainly all non-condensable gases (for example, nitrogen and oxygen) remaining and affecting the subsequent electroplating process. , the air pressure intensity in the infiltration chamber 110 can be controlled by the air pressure detector 15; the specific vacuum operation can adopt any public means in the prior art, which will not be repeated here. Usually, the wafer electroplating device 100 also includes an infiltration liquid 111 storage and reflux tank 13, a liquid level controller and a sensor (not shown in the figure). After the vacuum treatment is completed, the vacuum pump 16 is turned off to maintain a certain intensity of negative pressure in the infiltration chamber 110, the two-way control valve 131 on the infiltration liquid transmission pipeline is opened, and an appropriate amount of infiltration liquid 111 is injected into the infiltration chamber 110 to maintain the depth of the infiltration liquid 111 at least enough to immerse the surface 311 of the wafer 31 to be plated. This state is maintained for a period of time. The length of the infiltration time is affected by the hole depth and pore diameter of the wafer 31, which is generally proportional to the hole depth and inversely proportional to the diameter width of the hole. That is, the larger the hole depth, the longer the infiltration time, and the smaller the diameter width, the longer the infiltration time.

[0042] Furthermore, in other embodiments, the immersion liquid 111 is degassed before being injected into the immersion chamber 110, that is, the air dissolved in the immersion liquid 111 is expelled, thereby further improving the filling effect of the immersion liquid 111 on the pores. Alternatively, in other embodiments, during the immersion process, a certain negative pressure is maintained in the immersion chamber 110 by a vacuum pump 16, that is, the immersion liquid 111 is degassed simultaneously during the immersion process, which can also prevent the gas entrained in the immersion liquid 111 from entering the deep holes of the wafer 31.

[0043] For further information, please refer to Figure 5 On the bottom side of the side wall 10 of the opening of the infiltration cover 1, an elastic sealing ring 19 is provided along the opening ring. The sealing ring 19 can further enhance the sealing effect of the infiltration cover 1 and the carrier 32, improve the vacuum degassing effect and prevent the undesirable defect of leakage of the infiltration liquid 111.

[0044] After the pre-infiltration is completed, the infiltration liquid 111 in the infiltration chamber 110 is recovered by the liquid pump 132. During this process, the infiltration chamber 110 is kept at normal pressure by the pressure relief port 103 provided on the infiltration cover 1, and the pressure relief port 103 is connected to the inert gas supply device through a pipeline and a control valve; then the infiltration cover 1 is separated from the carrier 32 by the robotic arm 6, and the infiltration cover 1 is moved to a certain height or away from directly above the carrier 32; then the anode part 20 is moved to directly above the wafer 31 by the robotic arm 6, and the distance between the lower surface of the anode part 20 and the surface to be plated 311 of the wafer 31 is adjusted to a preset distance through the program control device 7.

[0045] In another alternative embodiment, the pressure relief port 103 and the vacuum vent 102 can be combined into one, connected to a main gas pipeline through the same opening 102. Branch pipes are then provided to connect to the main gas pipeline. Each branch pipe is connected to a separate control valve and connected to a vacuum pump and inert gas supply device. This can improve the integration of the pipelines and make the device simpler.

[0046] Please continue reading Figure 4 and Figure 6 As shown in the figure, the wafer electroplating device 100 includes a DC power supply 5, a plating solution 81, and an electroplating tank 8; the wafer 31 and the anode 20 are respectively connected to the negative pole and the positive pole of the DC power supply 5; in the electroplating mode B, the plating solution 81 immerses the wafer 31 and the anode 20 placed in the electroplating tank 8.

[0047] For details, please refer to Figure 4 As shown, the lower connecting portion 35 of the carrier 32 passes through the bottom wall of the electroplating tank 8 and extends into the inner cavity of the electroplating tank 8. The electroplating tank 8 is a structure with an open top. The wafer 31 is placed on the platform on the upper surface of the carrier 32. The carrier 32 is provided with a locking structure 323, which can fix the wafer 31 so that it does not move. At the same time, a conductive ring 33 is also provided on the carrier 32. One end of the conductive ring 33 is electrically connected to the conductive portion on the surface 311 to be plated of the wafer 31, and the other end of the conductive ring 33 is electrically connected to the negative pole of the external DC power supply 5; the anode member 20 is electrically connected to the positive pole of the external DC power supply 5 through a conductive connecting line. After entering electroplating mode B, the plating liquid 81 is first injected into the electroplating tank 8. The height of the plating liquid 81 in the electroplating tank 8 can at least immerse the wafer 31 and the anode member 20. Then, driven by the energy of the external power supply 5, the surface 311 to be plated of the wafer 31 is plated. During the electroplating mode B, the state of the above-mentioned immersion mode A is maintained to keep the wafer 31 from relative movement and flipping.

[0048] Alternatively, please refer to Figure 4The plating tank 8 and the liquid storage tank 9 are connected through the first liquid regulating hole 89, the connecting pipe, and the second liquid regulating hole 98 respectively provided. The connecting pipe is provided with a liquid level adjustment member 93 for adjusting the height of the electroplating liquid 81 in the plating tank 8.

[0049] Specifically, if Figure 4 As shown, a first liquid regulating hole 89 is provided on the wall of the electroplating tank 8 near the bottom thereof, for injecting the electroplating solution 81 from the liquid reservoir 9 into the electroplating tank 8 before the electroplating mode, or for returning the electroplating solution 81 to the liquid reservoir 9 for storage in the immersion mode. A second liquid regulating hole 98 is provided on the wall of the liquid reservoir 9, and the first liquid regulating hole 89 and the second liquid regulating hole 98 are connected by a connecting pipe. The connecting pipe is provided with a two-way control valve 92, a liquid pump 91, and a liquid level adjusting member 93. Under the action of the two-way control valve 92 and the two-way liquid pump 91, the electroplating solution 81 in the electroplating tank 8 can be pumped back to the liquid reservoir 9 for storage, or the level of the electroplating solution 81 in the electroplating tank 8 can be adjusted. For example, the plating liquid 81 in the plating tank 8 can be completely released after the electroplating is completed. Alternatively, the plating liquid 81 in the plating tank 8 can be adjusted to a certain height through the liquid level adjustment component 93 during the start-up phase of the electroplating process. Alternatively, in the immersion mode A, all or part of the plating liquid 81 can be discharged to leak out of the upper surface of the carrier to facilitate the start-up of the immersion mode A.

[0050] Optionally, see Figure 6 The anode member 20 is connected to the first driver 24 and driven to rotate horizontally above the surface 311 of the wafer 31 to be plated.

[0051] For details, please refer to Figure 6 As shown, the anode member 20 is suspended directly above the wafer 31 in electroplating mode B. The fixing device 21 of the anode member 20 is electrically connected to the first driver 24. The first driver 24 can drive the fixing device 21 to rotate in a fixed direction, thereby driving the anode member 20 to perform a fixed circumferential rotation. During the electroplating process, the circumferential rotation of the anode member 20 can stir the electroplating solution 81 to a certain extent. The electroplating solution 81 circulates circumferentially between the wafer 31 and the anode member 20 in the direction of rotation of the anode member 20, so that the composition content of the electroplating solution 81 flowing through various positions on the surface 311 to be plated of the wafer 31 during the electroplating process is kept as balanced as possible. At the same time, this treatment method can also improve the uniformity of the electric field at various locations on the anode member 20 and the surface 311 to be plated of the wafer 31, further improving the uniformity of metal deposition in the hole or on the surface. Meanwhile, in the electroplating device for the wafer 31 , the anode hanger that usually carries the anode member 20 is much simpler in structure than the carrier 32 that carries the wafer 31 , so the operation of driving the anode member 20 to rotate is also more stable and simple.

[0052] It should be noted that in some other variable embodiments, the supporting member 32 is also movably connected to the telescopic member 37 through a coupling 36. The telescopic member 37 can adjust the height of the wafer 31 by driving the supporting member 32 to move up and down. On the one hand, it is convenient for replacing the wafer 31. On the other hand, it can also be used to fine-tune the distance between the anode member 20 and the wafer 31 to adapt to the adaptability of the electroplating device under different sizes and static current conditions.

[0053] Further optionally, Figure 7 This is another structural schematic diagram of the horizontal wafer electroplating device provided in the present application in the electroplating mode; Figure 7 As shown, the carrier 32 is connected to the second driver 38, driving the wafer 31 to perform a positioning rotational circumferential motion in the horizontal direction. As described above, the circumferential rotation of the wafer 31 further optimizes the stirring effect on the electroplating solution 81. The electroplating solution 81 circumferentially circulates between the wafer 31 and the anode member 20 along the rotation direction of the wafer 31, further improving the consistency of the concentration components of the electroplating solution 81 near the electroplating surface of the wafer 31, so that the component content of the electroplating solution 81 flowing through various locations on the surface 311 to be plated of the wafer 31 during the electroplating process is kept as balanced as possible. At the same time, this processing method can further improve the uniformity of the electric field at various locations on the anode member 20 and the surface 311 to be plated of the wafer 31, further improving the uniformity of metal deposition in the hole or on the surface.

[0054] It should be noted that the positioning rotation directions of the anode member 20 and the wafer 31 can be consistent, and the rotation speeds of the two can be set differently or the same, which is not limited in this application.

[0055] Figure 8 A schematic structural diagram of another horizontal wafer electroplating device provided in this application; Figure 9 for Figure 8 A schematic diagram of a structure of a wafer electroplating device in an immersion mode is shown; Figure 10 for Figure 8 The schematic diagram of a wafer electroplating device in electroplating mode is shown. Figures 8-10 As shown, in the wafer electroplating device 100 provided in this embodiment, the immersion hood 1 and the anode part 2 are integrated into one piece by a sliding connection shaft 11; the anode part 2 is located on the side of the immersion hood 1 facing the wafer 31; the immersion hood 1 moves up and down relative to the anode part 2 under the drive of the sliding connection shaft 11. In the immersion mode A, the immersion hood 1 moves downward relative to the anode part 2, and in the electroplating mode B, the immersion hood 1 moves upward relative to the anode part 2.

[0056] Specifically, if Figure 8As shown, directly above the wafer 1, the immersion hood 1 and the anode member 2 are stacked up and down in a non-contact arrangement; the anode member 2 is located below the immersion hood 1 on the side close to the wafer 31. The immersion hood 1 and the anode member 2 are nested together through a sliding connection shaft 11. The sliding connection shaft 11 can be any device in existing designs and products that can realize the relative movement of the two parts connected thereto. This is not limited in this application, such as a slip ring. In immersion mode A, the sliding connection shaft 11 is adjusted so that the immersion hood 1 moves downward and is assembled with the carrier 32 of the wafer 31 to form an immersion chamber 110 and then start the immersion process. During this period, due to the downward movement of the immersion hood 1, the distance between the top of the anode member 2 and the top wall 12 of the immersion hood 1 is shortened, that is, the immersion hood 1 undergoes a process of downward relative movement relative to the anode member 2; when the immersion is completed and enters the electroplating mode B, as shown Figure 9 As shown, the immersion chamber 110 needs to be moved away to provide reaction space for electroplating mode B. During this period, the immersion hood 1 needs to be moved upward and as far away from the wafer as possible, increasing the distance between the top of the anode element 2 and the top wall 12 of the immersion hood 1. In other words, the immersion hood 1 moves downward relative to the anode element 2. By adjusting the sliding connecting shaft 11, the distance between the immersion hood 1 and the wafer 31 below can be flexibly adjusted, achieving efficient and cost-effective switching between immersion mode A and electroplating mode B, thereby improving the integration of the device.

[0057] Optionally, the immersion hood 1 includes a top wall 12 and a side wall 10 that are sealed and enclosed to form a cavity with an opening facing downward, the top wall 12 includes an opening 120, and the outer wall of the sliding connection shaft 11 is movably connected to the top wall 12 through the opening 120, and is used to drive the immersion hood 1 to move up and down; the anode part 2 is located below the top wall 12, and the positive projection of the anode part 2 on the plane where the top wall 12 is located is located within the top wall 12; the wafer electroplating device 100 also includes an anode support part 21 for supporting and fixing the anode part 2, the anode support part 21 includes a support connection part 22, and the support connection part 22 passes through the opening 120 and is movably connected to the inner wall of the sliding connection shaft 11.

[0058] Specifically, if Figure 8As shown, directly above the wafer 31, the immersion hood 1 and the anode component 2 are overlapped and integrated. The immersion hood 1 includes an open cavity enclosed by a top wall 12 and a side wall 10. The anode component 2 is located below the immersion hood 1 on the side close to the cathode wafer; the top wall 12 of the immersion hood 1 includes an opening 120, and the anode support 21 for supporting and fixing the anode component 2 includes a supporting connection portion 22, which passes through the opening 120 on the top wall 12. A sliding connection shaft 11 is provided in the opening 120, and one side wall of the sliding connection shaft 11 is in sliding contact with the supporting connection portion 22, and the other side wall is in sliding contact with the wall of the opening 120. In a more specific embodiment, the sliding connection shaft 11 is a slip ring, the support connection portion 22 passes through the slip ring and is in sealed sliding contact with the inner wall of the slip ring; the outer wall of the slip ring is in sealed contact with the inner wall of the opening 120; that is, the sliding connection shaft 11 sleeves the anode support 21 and the immersion cover 1 together to form an integrated device; and passes through the top wall 12 of the immersion cover 1 to be slidably connected.

[0059] When entering the immersion mode A, the immersion hood 1 is driven by the sliding connection shaft 11 to move downward along the supporting connection part 22 relative to the anode part 2, and the immersion hood 1 and the carrier 32 are assembled to form a sealed immersion chamber 110 containing the wafer 31. After the immersion is completed, the sliding connection shaft 11 is controlled to drive the immersion hood 1 to move upward in the opposite direction, so that the immersion hood 1 is separated from the carrier 32. The height of the upward movement of the immersion hood 1 at least does not affect the electroplating system composed of the anode part 2 and the wafer 31 and the progress of the electroplating reaction; under the condition that the structural space can be implemented, the immersion hood 1 should be kept as far away from the carrier 32 as possible. When in the electroplating mode B, the anode part 2 and the surface 311 to be plated of the wafer 31 are placed horizontally corresponding to each other to form the counter electrode 302. Figure 8 The horizontal wafer electroplating device 100 shown is composed of an anode support 21 and an immersion cover 1 as one body, which makes the device more integrated and the anode 2 does not need to move back and forth in the horizontal direction, saving the process and time of alignment with the wafer 31 each time, and improving efficiency and stability.

[0060] It should be noted that Figures 8-10 The auxiliary structure of the infiltration cover 1, including the first liquid flow hole 101, the liquid storage tank 13, the air hole 102 and the external air pressure regulating device 16 / 17 and its connecting pipes, and the relationship between the control valve 131 / 151 can still be adopted as follows Figure 2 、 Figure 5 The same structure as shown in ; Of course, in order to further improve the integration of the device; the vacuum hole 102 and the pressure relief port 103 can be the same opening 120, by setting a vacuum branch pipeline, a vacuum regulating valve; a pressure relief pipeline, and an air pressure balance valve on the main pipeline, the vacuum branch pipeline is connected to the air pump, and the pressure relief pipeline can be connected to a dry and clean inert gas tank. Unless otherwise specified, Figures 8-10 The auxiliary structure and connection relationship of the anode 2 can still be as follows Figure 3 、 Figure 6 The same structure as shown in ; Figures 8-10 The connection relationship and operation mode of the electroplating tank 8 on the cathode side, the carrier 32 of the wafer 31 and the internal and external parts can still be adopted as follows Figure 4 、 Figure 5 and Figure 6 The same structure as shown in .

[0061] Optionally, the surface 311 to be plated of the wafer 31 can also be electrically connected to the external conductive carbon rod 322 through the conductive connector 321 built into the carrier 32, and connected to the external electroplating workstation (not shown in the drawings), so as to achieve more precise control and monitoring and adjustment of the electroplating process.

[0062] Optionally, the center of the anode member 2 , the center of the top wall 12 , and the center of the wafer 31 are located on the same center line.

[0063] Specifically, the opening 120 on the top wall 12 of the immersion hood 1 is located at the center of the top wall 12, and the central axis of the anode connecting portion 21 also passes through the center of the anode component 2. In other words, the axial centerlines of the immersion hood 1 and the anode component 2 coincide and pass through the center point of the underlying wafer 31. This arrangement makes the entire wafer electroplating apparatus 100 a centrally symmetrical structure, which is beneficial to the balance and stability of the apparatus, especially when the anode component 2 and other components rotate circumferentially to avoid the occurrence of unstable center of gravity, which affects the electroplating effect.

[0064] During electroplating, the conductive material layer on the surface 311 of the wafer 31 to be plated is electrically connected to an external power source 5. When the surface 311 of the wafer 31 to be plated comes into contact with an electroplating solution 81 containing a metal salt (e.g., copper sulfate, copper alkyl sulfonate, or a mixture of salts), metal ions (e.g., copper ions) in the electroplating solution 81 are reduced and deposited on the surface 311 of the wafer 31 to be plated. In many embodiments, the surface 311 of the wafer 31 to be plated contains one or more recessed features (e.g., through-holes and / or trenches) that need to be filled by an electroplating process. In addition to the metal salt, the electroplating solution 81 may also contain an acid and typically contains one or more additives, such as halides (e.g., chlorides, bromides, etc.), accelerators, balancers, and inhibitors, to adjust the electrodeposition rate on various surfaces of the substrate.

[0065] The horizontal wafer electroplating device provided by the present application integrates structural components that can realize pre-wetting and electroplating reactions. By keeping the wafer's to-be-plated surface facing upward during pre-wetting, electroplating, and switching to electroplating after pre-wetting, it is not only easy for the immersion liquid to reach the deep hole position of the wafer and displace the air in the deep hole to achieve an ideal wetting effect; but also, in the process of switching from pre-wetting to electroplating, the wafer's to-be-plated surface is kept fixed upward without horizontal movement or flipping, which can ensure that the immersion liquid in the deep hole position of the wafer after pre-wetting does not fall off or peel off, which is beneficial to the next electroplating process, improves the yield and uniformity of deep hole electroplating, and eliminates or reduces deep hole electroplating failure or void defects.

Claims

1. A horizontal wafer electroplating device, characterized in that: The invention comprises a wafer placed on a horizontal fixed carrier, with the surface of the wafer to be plated facing upward; an anode member movably disposed above the wafer and arranged to be parallel and spaced from the surface of the wafer to be plated; and an immersion cover movably disposed above the wafer and arranged to be sealed and assembled with the carrier; The immersion hood and the anode component are respectively switched to face the wafer in the immersion mode and the electroplating mode. When in the immersion mode, the immersion hood and the carrier component are assembled to form a sealed immersion chamber for accommodating the wafer. When in the electroplating mode, the anode component is horizontally opposed to the surface to be plated of the wafer to form a counter electrode.

2. The wafer electroplating device according to claim 1, characterized in that: The immersion cover and the anode member are respectively connected to a robot arm, and program switching movement is achieved according to the switching requirements of the immersion mode and the electroplating mode.

3. The wafer electroplating device according to claim 1, characterized in that: The infiltration cover comprises a first liquid flow port and an air hole; the air hole is connected to an external air pump and is used to adjust the air pressure in the sealed infiltration cavity, and the first liquid flow port is used to inject and / or release the infiltration liquid into the sealed infiltration cavity.

4. The wafer electroplating device according to claim 1, characterized in that: It includes a direct current power supply, a plating solution, and a plating tank; the wafer and the anode are respectively connected to the negative pole and the positive pole of the direct current power supply; in the plating mode, the plating solution immerses the wafer and the anode in the plating tank.

5. The wafer electroplating device according to claim 4, characterized in that: It includes a liquid storage tank, which is connected to the electroplating tank through a first liquid regulating hole, a connecting pipe, and a second liquid regulating hole respectively arranged. The connecting pipe is provided with a liquid level adjusting member for adjusting the height of the electroplating liquid in the electroplating tank.

6. The wafer electroplating device according to claim 1, characterized in that: The anode component is connected to a first driver to drive it to perform positioning circumferential rotation just above the surface of the wafer to be plated; and / or, the carrier component is connected to a second driver to drive the wafer to perform positioning rotational circumferential motion.

7. The wafer electroplating device according to claim 4, characterized in that: The bottom of the carrier is movably connected to the telescopic component, and the telescopic movement of the telescopic component can achieve height adjustment of the wafer in the vertical direction.

8. The wafer electroplating device according to claim 3, characterized in that: An elastic sealing ring is arranged on the bottom side of the side wall of the infiltration cover.

9. The wafer electroplating device according to claim 1, characterized in that: The wetting hood and the anode component are integrally formed up and down by a sliding connection shaft; the anode component is located on the side of the wetting hood facing the wafer; the wetting hood moves up and down relative to the anode component under the drive of the sliding connection shaft, and in the wetting mode, the wetting hood moves downward relative to the anode component, and in the electroplating mode, the wetting hood moves upward relative to the anode component.

10. The wafer electroplating device according to claim 9, characterized in that: The immersion cover includes a top wall and a side wall which are sealed and enclosed to form a cavity with an opening facing downwards, the top wall includes an opening, the sliding connection shaft passes through the opening and is slidably connected to the inner wall of the opening, and is used to drive the immersion cover to move up and down when the mode is switched; The anode component is located below the top wall on one side close to the wafer, and the orthographic projection of the anode component on the plane where the top wall is located is located within the top wall; the wafer electroplating device also includes an anode support component for supporting and fixing the anode component, and the anode support component includes a supporting connection portion, which passes through the opening and is slidably connected to the sliding connection shaft.

11. The wafer electroplating device according to claim 10, characterized in that: The center of the anode member, the center of the top wall, and the center of the wafer are located on the same center line.

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