Electrodeposition wafer plating apparatus and plating control method

Abstract

This invention relates to the field of wafer manufacturing technology, and in particular to an electrodeposition wafer plating equipment and a plating control method. Regarding the electrodeposition wafer plating equipment, the plating chamber is equipped with an auxiliary current-limiting component and a perforated plate, which work together to form an electroplating solution guiding area. A skirt-shaped flexible current-guiding component surrounds the wafer clamping device and has both a natural and a contracted state. When the skirt-shaped flexible current-guiding component is in its natural state, it forms a separable surface contact with the auxiliary current-limiting component. Through the application of external force, the skirt-shaped flexible current-guiding component undergoes directional deformation between its natural and contracted states, thereby flexibly switching between sealed and reset states. Simultaneously, the auxiliary current-limiting component and the skirt-shaped flexible current-guiding component constitute a flow field constraint and synergistic system. Their combined action constrains the path of the electroplating solution and guides its return flow, effectively avoiding flow field turbulence and ensuring uniform electroplating solution concentration and flow rate on the wafer surface to be plated, thereby ensuring the quality of the wafer plating.

Description

Technical Field

[0001] This invention relates to the field of wafer manufacturing technology, and in particular to an electrodeposition wafer electroplating equipment and electroplating control method. Background Technology

[0002] In the semiconductor manufacturing field, electrodeposition and electroplating technology is one of the core processes in wafer metallization. It is widely used in key links such as copper interconnect, wafer-level packaging (WLP), and through-silicon via (TSV). Its core requirement is to ensure that the electroplating solution forms a stable and uniform flow field on the wafer surface to be plated.

[0003] In existing wafer electroplating equipment, a certain clearance needs to be reserved between the wafer clamping device and the electroplating chamber to meet the requirements of wafer clamping, rotation and equipment assembly tolerances. In order to solve the problem of electroplating solution leakage in this clearance, relevant technologies have been specifically designed.

[0004] For example, the patent with authorization announcement number CN111819674B discloses a flow-assisted dynamic seal. By conforming the upward slope of the flexible sealing component with the embedded component, the sealing effect is enhanced by the pressure of the electroplating liquid. At the same time, it can adapt to the requirements of wafer rotation. However, the sealing reliability is highly dependent on the flow pressure of the electroplating liquid. Under low flow rate electroplating conditions, the sealing strength is easily insufficient. Moreover, the deformation of the sealing component depends entirely on the guidance of the slope structure and lacks an active control mechanism, making it difficult to adapt to the flexible adjustment requirements of different equipment gap sizes.

[0005] For example, the patent with authorization announcement number CN107419312B discloses a technical solution that uses a compressible sealing component to seal the leakage gap and optimizes the flow field by dynamically adjusting the height of the crossflow manifold. Although it can take into account both sealing and rotation requirements by switching the sealing state, the sealing component is prone to compression creep after long-term use, which leads to a decrease in sealing performance. In addition, the fitting accuracy requirements between the sealing component and the flow limiting element are high, and assembly errors can easily cause local leakage. At the same time, its flow field optimization mainly relies on the manifold height adjustment. The sealing structure itself does not have the function of flow field constraint and backflow guidance, making it difficult to achieve synergistic optimization of sealing and flow field stability. It also cannot flexibly adapt to the gap changes during wafer clamping and lifting processes by switching its own state.

[0006] Therefore, it is urgent for technical personnel to solve the above problems. Summary of the Invention

[0007] The purpose of this invention is to provide an electrodeposition wafer electroplating device that aims to solve the problems of existing designs where the sealing structure depends on specific operating conditions, lacks an active control mechanism, has poor adaptability, and cannot achieve synergy between sealing and flow field optimization.

[0008] This invention relates to an electrodeposition wafer plating apparatus, comprising a wafer clamping device and an electroplating chamber; the electroplating chamber includes an auxiliary current limiting device and a perforated plate; the auxiliary current limiting device and the perforated plate cooperate to form an electroplating solution guiding operation area; the wafer clamping device is used to clamp the wafer and drive it to perform circumferential rotational motion. Furthermore, the electrodeposition wafer plating apparatus also includes a skirt-shaped flexible flow guide device; A skirt-shaped flexible flow guide is arranged around the outer periphery of the wafer clamping device and rotates synchronously with it. Its outer edge is in a free-suspended state and can switch between a natural state and a contracted state. In its natural state, the skirt-shaped flexible flow guide forms a surface contact with the auxiliary flow restrictor to create an overflow and return channel for the electroplating solution.

[0009] As a further improvement to the technical solution disclosed in this invention, the skirt-shaped flexible guide can be detachably installed on the wafer clamping device.

[0010] As a further improvement to the technical solution disclosed in this invention, the inner diameter of the upper edge of the skirt-shaped flexible guide is smaller than the inner diameter of the lower edge, and the thickness of the skirt gradually increases from top to bottom.

[0011] As a further improvement to the technical solution disclosed in this invention, the lower edge of the skirt-shaped flexible guide and the mating side of the auxiliary flow restrictor are both provided with an acid-resistant or wear-resistant coating.

[0012] As a further improvement to the technical solution disclosed in this invention, the mating surfaces of the skirt-shaped flexible guide and the auxiliary flow restrictor are conformal surfaces.

[0013] As a further improvement to the technical solution disclosed in this invention, a radial restraint member is provided on the outside of the wafer clamping device to force the skirt-shaped flexible guide member to switch between the natural state and the contracted state.

[0014] As a further improvement to the technical solution disclosed in this invention, the radial restraint member forces the skirt-shaped flexible guide member to undergo radial deformation through mechanical extrusion.

[0015] As a further improvement to the technical solution disclosed in this invention, the radial restraint member performs a lifting motion along the axial direction; As the radial restraint descends, it compresses the skirt-shaped flexible guide, causing it to contract. When the radial restraint moves upward, it releases the pressure on the skirt-shaped flexible guide, which then returns to its natural state due to its own elasticity.

[0016] Furthermore, this invention also discloses a method for controlling electrodeposition wafer plating, adapted to the aforementioned electrodeposition wafer plating equipment, comprising the following steps: S1. After wafer clamping is completed, the skirt-shaped flexible guide is constrained to a contracted state by radial clamping components; S2. Control the wafer clamping device to descend to the preset electroplating position, release the constraint of the radial restraint, and allow the skirt-shaped flexible guide to return to its natural state by its own elasticity. S3. Control the wafer clamping device to continue descending to the preset bonding position, so that the natural skirt-shaped flexible guide and the auxiliary current limiting device form a conformal surface seal, and construct a diversion and anti-overflow channel; S4. Start the electroplating operation. The wafer clamping device drives the wafer and the skirt-shaped flexible guide to rotate synchronously to maintain the sealed guide state. S5. After the electroplating operation is completed, the skirt-shaped flexible guide is constrained by the radial clamping component to shrink and release the seal. Then, the wafer clamping device is controlled to rise and reset.

[0017] Regarding the topic of electrodeposition wafer electroplating equipment, its practical applications can achieve at least the following beneficial technical effects, specifically: 1) An external force is actively applied to the skirt-shaped flexible guide, causing it to undergo directional deformation between its natural and contracted states. In its natural state, the skirt-shaped flexible guide, relying on its own flexibility, forms a separable surface contact with the auxiliary flow restrictor. This physical contact seals the gap between the wafer clamping device and the electroplating chamber. The sealing process relies on the flexibility of the skirt-shaped flexible guide itself, without the need for external operating conditions, thus ensuring sealing stability under different operating conditions and completely eliminating the risk of electroplating solution leakage. 2) When the electroplating solution flows between the porous plate and the surface of the wafer to be plated, it is subject to the lateral obstruction of the skirt-shaped flexible flow guide and the guiding effect of the auxiliary flow restrictor. The path of the flow is strictly constrained to avoid flow field turbulence or local flow velocity abnormality. At the same time, the skirt-shaped flexible flow guide guides the electroplating solution backflow, further optimizing the flow field distribution and ensuring that the concentration and flow rate of the electroplating solution on the surface of the wafer to be plated are uniform and consistent, providing a stable flow field environment for high-quality plating.

[0018] Regarding the topic of efficient electrodeposition wafer plating control method, S1 completes wafer clamping and constrains the skirt-shaped flexible guide to a contracted state, ensuring the initial state of the wafer, skirt-shaped flexible guide, and wafer clamping device are orderly; S2 controls the wafer clamping device to descend to the preset plating position and releases the constraint, allowing the skirt-shaped flexible guide to return to its natural state through its own elasticity, preparing for sealing and bonding; S3 controls the wafer clamping device to continue descending to the preset bonding position, so that the skirt-shaped flexible guide and the auxiliary flow limiting device form a conformal surface seal and construct a flow diversion and anti-overflow channel, forming a stepped control logic with S2. The two work together to ensure a stable and reliable sealing state; S4 During the plating operation, the wafer clamping device drives the wafer and skirt-shaped flexible guide to rotate synchronously and maintain the sealed flow state. With the help of the flow diversion and anti-overflow channel, the flow trajectory of the plating solution is effectively constrained, ensuring a stable and orderly flow field of the plating solution and avoiding adverse effects on the wafer plating effect caused by local anomalies in the flow field. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a three-dimensional schematic diagram of the electrodeposition wafer electroplating equipment disclosed in this invention.

[0021] Figure 2 This is a three-dimensional schematic diagram of the electroplating chamber in the electrodeposition wafer electroplating equipment disclosed in this invention.

[0022] Figure 3 This is a longitudinal sectional view (in non-operating state) of the electrodeposition wafer electroplating equipment disclosed in this invention.

[0023] Figure 4 This is a longitudinal sectional view (in the working state) of the electrodeposition wafer electroplating equipment disclosed in this invention.

[0024] Figure 5 yes Figure 4 A magnified view of part of I.

[0025] Figure 6 This is a three-dimensional schematic diagram of the skirt-shaped flexible flow guide in the electrodeposition wafer electroplating equipment disclosed in this invention.

[0026] Figure 7 This is a process flow diagram of the high-efficiency electrodeposition wafer electroplating control method disclosed in this invention.

[0027] 1-Wafer clamping device; 2-Electroplating chamber; 21-Auxiliary current limiting component; 211-Auxiliary current limiting component; 22-Perforated plate; 3-Skirt-shaped flexible current guide; 4-Radial confinement component. Detailed Implementation

[0028] The technical solution of the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings. Figure 1 A three-dimensional schematic diagram of the electrodeposition wafer plating equipment disclosed in this invention is shown. It can be seen that it mainly consists of a wafer clamping device 1, an electroplating chamber 2, and a skirt-shaped flexible flow guide 3. The electroplating chamber 2 is the core cavity structure for the electroplating operation, and it includes an auxiliary flow restrictor 21 and a perforated plate 22. The auxiliary flow restrictor 21 and the perforated plate 22 cooperate to form an electroplating solution flow guiding area, such as... Figure 2 As shown. Figure 3 , Figure 4As shown, the auxiliary flow restrictor 21 and the skirt-shaped flexible flow guide 3 form a surface contact fit, and the two work together to constrain the path of the electroplating solution.

[0029] The wafer clamping device 1 is used to clamp the wafer and drive the wafer to rotate within the electroplating chamber 2.

[0030] Skirt-shaped flexible guide 3 (e.g.) Figure 6 The wafer clamping device 1 (as described in the text) is arranged around the outer periphery of the wafer clamping device 1 and rotates synchronously with it. It also forms a separable mating structure with the electroplating chamber 2 to form an electroplating solution overflow and return channel.

[0031] It is particularly important to point out here that the skirt-shaped flexible guide element 3 is the core actuator for achieving equipment sealing and flow field constraint. For example... Figures 3-5 As shown, the skirt-shaped flexible guide 3 is detachably assembled to the wafer clamping device 1 and can be flexibly replaced according to the actual operating conditions of the equipment and its own wear and tear. The skirt-shaped flexible guide 3 has two working modes: a natural state and a contracted state, and its outer edge remains in a free and suspended state, reserving sufficient space for its own deformation.

[0032] To achieve active deformation control of the skirt-shaped flexible guide 3, such as Figures 3-5 As shown, a radial clamping member 4 is provided on the outer side of the wafer clamping device 1. The radial clamping member 4 is a deformation driving component of the skirt-shaped flexible guide member 3, which performs lifting and lowering movements along the axial direction, and applies a directional force to the skirt-shaped flexible guide member 3 through mechanical extrusion, forcing the skirt-shaped flexible guide member 3 to stably switch between the natural state and the contracted state, thereby realizing the active control of the sealing action.

[0033] Specifically, when the radial clamping member 4 moves downward, it applies radial compressive force to the skirt-shaped flexible guide member 3, causing the skirt-shaped flexible guide member 3 to contract inward and remain in a contracted state. When the radial clamping member 4 moves upward, it releases the compressive force on the skirt-shaped flexible guide member 3, and the skirt-shaped flexible guide member 3 returns to its natural state due to its own elasticity. Furthermore, the lifting and lowering movements of the radial clamping member 4 and the wafer clamping device 1 work in synergy, providing a control basis for the stepped deformation and smooth fit of the skirt-shaped flexible guide member 3, and effectively avoiding structural interference and assembly deviations.

[0034] As a parallel technical solution of the present invention, the radial clamping member 4 is composed of multiple pusher units that are evenly distributed circumferentially along the wafer clamping device 1 and can independently extend and retract radially. When each pusher unit extends synchronously, it applies a uniform radial compressive force to the skirt-shaped flexible guide member 3, keeping the skirt-shaped flexible guide member 3 in a contracted state; when each pusher unit retracts synchronously, the radial compressive force is completely released, and the skirt-shaped flexible guide member 3 smoothly returns to its natural state by its own elasticity, thus achieving active deformation control.

[0035] As another parallel technical solution of the present invention, an airbag inflation structure can be used to achieve confinement control. That is, an annular airbag is provided on the outer side of the skirt-shaped flexible guide 3. When the annular airbag inflates, it forms a uniform compressive force on the skirt-shaped flexible guide 3, keeping the skirt-shaped flexible guide 3 in a contracted state; when the annular airbag deflates and contracts, the confinement effect is released, and the skirt-shaped flexible guide 3 relies on its own elasticity to reset, ensuring uniform circumferential force and improving deformation stability.

[0036] Furthermore, the skirt-shaped flexible guide 3 preferably adopts a structure in which the inner diameter of the upper edge is smaller than that of the lower edge, and the thickness of the skirt gradually increases from top to bottom, so that the lower edge has higher structural strength and fit stability.

[0037] Furthermore, the lower edge of the skirt-shaped flexible guide 3 and the mating sides of the auxiliary flow restrictor 21 are coated with acid-resistant or wear-resistant coatings, which can improve the corrosion resistance and wear resistance of the mating surfaces and extend the service life of the components. The mating surfaces of the skirt-shaped flexible guide 3 and the auxiliary flow restrictor 21 are conformal surfaces. When the skirt-shaped flexible guide 3 is in its natural state, it can form a tight fit with the auxiliary flow restrictor 21 in all directions to ensure reliable sealing.

[0038] When the equipment is not in operation, the radial restraint 4 descends and squeezes the skirt-shaped flexible guide 3, keeping the skirt-shaped flexible guide 3 in a contracted state and separating it from the auxiliary current limiting component 21. This provides clearance space for the lifting and lowering of the wafer clamping device 1 and the wafer clamping, such as... Figure 3 As shown. When the equipment is in operation, the radial restraint 4 moves upward to release the compression, and the skirt-shaped flexible guide 3 returns to its natural state due to its own elasticity, forming a conformal sealing fit with the auxiliary flow restrictor 21, thus enclosing and forming a stable drainage and overflow prevention channel, as shown. Figure 4 , Figure 5 As shown.

[0039] The naturally shaped flexible flow guide 3 and the auxiliary flow restrictor 21 work together. On the one hand, they physically seal the gap between the wafer clamping device 1 and the electroplating chamber 2 to prevent the overflow of electroplating solution. On the other hand, they form a lateral obstruction to the electroplating solution and, together with the guiding effect of the auxiliary flow restrictor 21, constrain the path of the electroplating solution. At the same time, they guide the electroplating solution to flow back stably, optimize the flow field distribution, and make the concentration and flow rate of the electroplating solution on the wafer surface to be plated uniform, thus providing a stable flow field environment for high-quality wafer plating.

[0040] This invention also discloses a high-efficiency electrodeposition wafer plating control method, adapted to the aforementioned electrodeposition wafer plating equipment, such as... Figure 7 As shown, the specific steps include: I. Wafer clamping and shrinkage constraint After the wafer clamping is completed, the radial restraint 4 is controlled to descend, and the skirt-shaped flexible guide 3 is constrained to a contracted state by mechanical extrusion, so that the skirt-shaped flexible guide 3 retracts inward, providing structural conditions for the subsequent descent and avoidance of the wafer clamping device 1. II. Descending to Position and Elastic Reset The wafer clamping device 1 is controlled to descend to the preset electroplating position, releasing the constraint of the radial restraint 4, allowing the skirt-shaped flexible guide 3 to return to its natural state by its own elasticity, thus completing the state switch. III. Continued descent and sealing construction The wafer clamping device 1 is controlled to continue descending to the preset bonding position, so that the skirt-shaped flexible guide 3 in its natural state and the auxiliary current limiting device 21 form a conformal surface sealing fit to build a flow diversion and anti-overflow channel to complete the construction of the sealing structure; IV. Dynamic Electroplating and Sealing Maintenance When the electroplating operation is started, the wafer clamping device 1 drives the wafer and the skirt-shaped flexible flow guide 3 to rotate synchronously, continuously maintaining a sealed flow guide state. The electroplating solution flows stably between the porous plate 22 and the wafer surface to be plated, maintaining a stable and orderly flow field under the synergistic constraint of the skirt-shaped flexible flow guide 3 and the auxiliary flow restrictor 21, providing a uniform working environment for wafer plating. V. Constrained Contraction and Rise Reset After the electroplating operation is completed, the skirt-shaped flexible guide 3 is constrained by the radial clamping member 4 to shrink and release the seal. Then, the wafer clamping device 1 is controlled to rise and reset, ending the single electroplating process.

[0041] Based on the above electroplating control process, in order to further improve sealing reliability, electroplating uniformity and equipment operating stability, this method also optimizes the settings of each process stage as follows: In step one, the radial restraint 4 adopts a graded pressing mode. It first moves to the predetermined position close to the skirt-shaped flexible guide 3 at a relatively fast rate, and then completes the final extrusion constraint at a low speed and small stroke. This avoids excessive instantaneous extrusion force causing local plastic deformation of the skirt-shaped flexible guide 3, and ensures that the force is uniform in each circumferential position and the shrinkage shape is regular.

[0042] In step two, the upward reset action of the radial clamping member 4 and the downward action of the wafer clamping device 1 are set to a delayed coordination relationship. After the skirt-shaped flexible guide member 3 completes elastic reset and stabilizes in its natural state, the downward action of the wafer clamping device 1 is started to prevent interference of component movement from causing damage to the sealing surface and to ensure subsequent bonding accuracy.

[0043] In step three, after the wafer clamping device 1 descends to the preset bonding position, a short-term pressure holding process is set to ensure that the conformal surfaces of the skirt-shaped flexible guide 3 and the auxiliary current limiting device 21 are fully bonded to avoid micro-leakage during the electroplating process; and the pressure holding pressure is adaptively set according to the material stiffness of the skirt-shaped flexible guide 3.

[0044] In step five, the radial restraint 4 first moves upward slightly to release the constraint. After the skirt-shaped flexible guide 3 is fully reset and separated from the auxiliary flow restrictor 21, the wafer clamping device 1 moves upward to reset, preventing the components from sticking and pulling, which could damage the sealing surface. At the same time, during the upward movement of the wafer clamping device 1, the outer edge structure of the skirt-shaped flexible guide 3 is used to scrape off and return the adhered electroplating solution, reducing the loss of electroplating solution and equipment contamination.

[0045] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An electrodeposition wafer electroplating apparatus, comprising a wafer clamping device and an electroplating chamber; the electroplating chamber comprising an auxiliary current limiting device and a perforated plate; the auxiliary current limiting device and the perforated plate cooperating to form an electroplating solution guiding operation area; the wafer clamping device being used to clamp the wafer and drive it to perform circumferential rotational motion, characterized in that, It also includes skirt-shaped flexible guides; The skirt-shaped flexible flow guide is arranged around the outer periphery of the wafer clamping device and rotates synchronously with it. Its outer edge is in a free-suspended state and can switch between a natural state and a contracted state. In its natural state, the skirt-shaped flexible guide element forms a surface contact with the auxiliary flow restrictor to create an overflow and return channel for the electroplating solution.

2. The electrodeposition wafer electroplating equipment according to claim 1, characterized in that, The skirt-shaped flexible guide can be detachably installed on the wafer clamping device.

3. The electrodeposition wafer electroplating equipment according to claim 1, characterized in that, The inner diameter of the upper edge of the skirt-shaped flexible guide is smaller than that of the lower edge, and the thickness of the skirt gradually increases from top to bottom.

4. The electrodeposition wafer electroplating equipment according to claim 1, characterized in that, The lower edge of the skirt-shaped flexible flow guide and the mating side of the auxiliary flow restrictor are both provided with an acid-resistant or wear-resistant coating.

5. The electrodeposition wafer electroplating equipment according to claim 1, characterized in that, The mating surfaces of the skirt-shaped flexible flow guide and the auxiliary flow restrictor are conformal surfaces.

6. The electrodeposition wafer electroplating equipment according to any one of claims 1-5, characterized in that, The wafer clamping device is provided with a radial restraint member on the outside, which is used to force the skirt-shaped flexible guide to switch between the natural state and the contracted state.

7. The electrodeposition wafer electroplating equipment according to claim 6, characterized in that, The radial restraint component forces the skirt-shaped flexible guide component to undergo radial deformation through mechanical compression.

8. The electrodeposition wafer electroplating equipment according to claim 7, characterized in that, The radial clamping component performs a lifting and lowering motion along the axial direction; As the radial restraint member descends, it compresses the skirt-shaped flexible guide member, causing it to contract. When the radial restraint moves upward, it releases the pressure on the skirt-shaped flexible guide, which then returns to its natural state due to its own elasticity.

9. A method for controlling electrodeposition wafer plating, adapted to the electrodeposition wafer plating equipment according to any one of claims 6-8, characterized in that, Includes the following steps: S1. After the wafer clamping is completed, the skirt-shaped flexible guide is constrained to a contracted state by the radial clamping member; S2. Control the wafer clamping device to descend to the preset electroplating position, release the constraint of the radial restraint member, and allow the skirt-shaped flexible guide member to return to its natural state by its own elasticity. S3. Control the wafer clamping device to continue descending to the preset contact position, so that the skirt-shaped flexible guide and the auxiliary current limiting device form a conformal surface seal, and construct a diversion and anti-overflow channel; S4. Start the electroplating operation. The wafer clamping device drives the wafer and the skirt-shaped flexible guide to rotate synchronously to maintain the sealed guide state. S5. After the electroplating operation is completed, the skirt-shaped flexible guide is constrained by the radial clamping member to shrink and release the seal. Then, the wafer clamping device is controlled to rise and reset.

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