Horizontal double-sided electroplating method for panel and semiconductor circuit

Abstract

The invention provides a horizontal double-sided electroplating method for a panel and a semiconductor circuit, which adopts a three-layer combined cavity structure, the upper layer and the lower layer are electroplating anode layers, and the middle layer is an electroplating cathode layer; a to-be-electroplated workpiece is fixed to the rotating clamp of the middle layer, the rotating clamp is driven by the driving structure to rotate at the adjustable rotating speed, and double-face electric conduction is achieved; electroplating liquid is conveyed through the up-and-down jet-flow device, and the flow is adjusted in a plurality of gears; dividing the upper-layer anode and the lower-layer anode into a plurality of concentric annular independent control areas, and adjusting the current on-off time ratio of each area; alternately executing the electroplating stage and the etching stage in the same cavity by adopting a double-pulse power supply; the loading and unloading liquid level and the electroplating liquid level are automatically switched through the liquid level control system; according to the invention, the problems of poor plating uniformity, inflexible flow control, non-adjustable current distribution and the like in the traditional electroplating process are solved, and high-precision and high-efficiency horizontal double-sided electroplating is realized. The invention relates to the field of TGV electroplating processes.

Description

Technical Field

[0001] The present invention relates to the field of TGV electroplating technology, and in particular to a method for horizontal double-sided electroplating of a panel and a semiconductor circuit. Background Art

[0002] In the field of panel and semiconductor manufacturing, electroplating is one of the key technologies for forming high-precision conductive lines. In particular, for high-density interconnect structures such as through-glass vias (TGVs) and advanced packaging, the uniformity and process control of double-sided electroplating are crucial. Traditional electroplating methods typically use a vertical plating tank structure, where the workpiece is vertically immersed in the plating solution, and metal deposition is achieved through the relative positioning of the anode and cathode. However, this structure has significant limitations, such as uneven distribution of the plating solution flow field, which leads to inconsistent coating thickness on the workpiece surface, especially large differences between the edge and center areas. In addition, vertical electroplating makes it difficult to achieve double-sided simultaneous plating, and bubbles generated during the plating process easily adhere to the workpiece surface, affecting the coating quality.

[0003] In order to improve the uniformity of electroplating, the existing technology has proposed a horizontal electroplating method, in which the workpiece is placed horizontally and the plating solution is supplied from the upper and lower sides simultaneously. However, the existing horizontal electroplating device still has many problems. First, the flow control of the plating solution is relatively simple, and it is difficult to dynamically adjust the balance or differential mode of the upper and lower liquid flows according to process requirements, resulting in limited ability to adjust the uniformity of the coating. Secondly, the anode usually adopts an integral structure and cannot independently control the current distribution in different areas, making it difficult to accurately control the coating thickness at the center and edge of the workpiece. In addition, traditional electroplating equipment usually adopts a fixed liquid level design, and the plating solution needs to be completely emptied when loading and unloading the workpiece, which increases the process complexity and time cost.

[0004] In terms of electroplating process control, existing technologies mostly use DC power supply or single pulse power supply, which makes it difficult to simultaneously take into account the needs of electroplating deposition and etching peak clipping, resulting in insufficient surface flatness of the coating. In addition, the circulation and replenishment system of the electroplating solution usually adopts direct mixing or mechanical stirring, which has low mixing efficiency and the risk of backflow, affecting the stability and service life of the electroplating solution.

[0005] Therefore, the inventors urgently need a method for horizontal double-sided electroplating of a panel and a semiconductor circuit to solve the above problems. Summary of the Invention

[0006] In response to the above-mentioned defects of the prior art, the present invention provides a method for horizontal double-sided electroplating of panels and semiconductor circuits, aiming to solve the problems existing in the prior art of panel and semiconductor circuit electroplating processes, such as poor coating uniformity, inflexible plating liquid flow control, non-adjustable anode current distribution, low liquid level switching efficiency, and inability to integrate electroplating and etching in the same chamber.

[0007] To achieve the above object, the technical solution adopted by the present invention is: a method for horizontal double-sided electroplating of a panel and a semiconductor circuit, comprising the following steps:

[0008] S1: Provide a three-layer combined cavity, the upper and lower layers are electroplating anode layers, and the middle layer is electroplating cathode layer;

[0009] S2: Fixing the workpiece to be electroplated on the rotating fixture of the middle layer, driving the rotating fixture to rotate at an adjustable speed through the driving structure, and conducting double-sided conductivity on the upper and lower surfaces of the workpiece through the electroplating liquid;

[0010] S3: delivering the plating solution into the three-layer combined cavity through the upper and lower jet devices, and adjusting the flow rate in several steps to achieve a balanced or differential flow mode;

[0011] S4: Divide the upper and lower anodes into several concentric ring-shaped independent control areas, adjust the current on-off time ratio of each area, and control the electroplating uniformity of the center and edge of the workpiece;

[0012] S5: electroplating and etching the workpiece using a dual-pulse power supply, and performing electroplating and etching stages alternately in the three-layer combination chamber;

[0013] S6: The liquid level control system switches the loading and unloading liquid level, electroplating liquid level and emptying liquid level. When loading and unloading, the liquid level drops to the bottom of the fixture, and when electroplating, the liquid level reaches the overflow height.

[0014] Based on the above, the beneficial effects of a method for horizontal double-sided electroplating of panels and semiconductor circuits are to solve the problems existing in the prior art of panel and semiconductor circuit electroplating processes, such as poor coating uniformity, inflexible electroplating solution flow control, non-adjustable anode current distribution, low liquid level switching efficiency, and inability to achieve integrated electroplating and etching in the same chamber. The main advantages are:

[0015] 1. The present invention drives the workpiece to rotate by the rotating fixture in step S3, and combines the independent control of the concentric annular anodes in step S4 to dynamically adjust the current distribution, effectively improving the consistency of the coating thickness at the center and edge of the workpiece, and solving the problem of poor coating uniformity caused by uneven electric field distribution in traditional electroplating.

[0016] 2. The present invention adjusts the flow rate through the multiple gears of the upper and lower spray devices in step S3, supports balanced or differential flow modes, and combines the dynamic adjustment of driving parameters and liquid circuit pressure to solve the problem of single electroplating solution flow control in the prior art and difficulty in adapting to different process requirements;

[0017] 3. The present invention divides the upper and lower anodes into several concentric ring-shaped independent control areas through step S4. By programmatically adjusting the on-off time ratio of the current in each area, refined current control is achieved, solving the problem that the traditional anode monolithic structure cannot be adjusted by different zones;

[0018] 4. The present invention uses the liquid level control system in step S6 to automatically switch the loading and unloading liquid level (lowering to the bottom of the fixture) and the electroplating liquid level (raising to the overflow height). Combined with the liquid path switching structure, this achieves rapid and stable liquid level adjustment, solving the problem of low efficiency caused by the need for complete drainage of traditional equipment;

[0019] 5. Step S5 of the present invention uses a dual-pulse power supply to alternately perform electroplating (forward pulse) and etching (reverse pulse) stages in a three-layer combination chamber, thereby achieving simultaneous completion of coating deposition and surface peak clipping, solving the problems of traditional processes requiring step-by-step processing, low efficiency, and insufficient flatness.

[0020] Furthermore, before step S1, step S0 is also included: pre-treating the three-layer combination cavity, and the pre-treating step includes cleaning the three-layer combination cavity with acid solution.

[0021] Based on the above, the beneficial effects of acid cleaning pretreatment of the three-layer combination cavity before electroplating are: effectively removing organic pollutants, oxides and particulate impurities inside the three-layer combination cavity, avoiding impurities from mixing into the plating solution during the electroplating process and causing plating defects. This pretreatment step can significantly improve the purity of the plating solution, ensure the stability of the electroplating reaction, thereby improving the density and bonding strength of the plating, and solving the problems of loose plating, pinholes or poor adhesion caused by cavity contamination in traditional electroplating processes.

[0022] Furthermore, the flow rate adjustment in several stages in step S3 is achieved by adjusting the pumping power and / or valve opening of the jet device.

[0023] Furthermore, the current adjustment step of the concentric annular independent control area in step S4 includes: independently controlling the on and off of each annular anode according to a preset program, and the preset program adjusts the on and off time ratio according to the real-time monitoring result of the electroplating thickness on the workpiece surface.

[0024] Based on the above, the beneficial effect of the concentric ring anode partition design combined with the preset program to independently control the on and off of each area is to solve the problem of different coating thicknesses caused by uneven current distribution in traditional electroplating processes; at the same time, the programmed control on-off time ratio adjustment method can be flexibly optimized according to the requirements of different workpiece shapes and sizes, which not only greatly improves the process adaptability and product yield, but also ensures a high degree of consistency between batches.

[0025] Furthermore, the rotation control of the driving structure in step S2 includes: driving the rotating fixture to rotate through a mechanical connection, and maintaining the electrical connection between the cathode power supply and the workpiece through the electroplating solution through dynamic conductive contact during the rotation process.

[0026] Based on the above, the beneficial effect of the mechanical connection driving the rotation of the rotating fixture is not only to ensure the uniformity of current distribution during the electroplating process, but also to significantly improve the reliability of the system operation. Compared with the traditional fixed cathode structure, the rotation control system significantly improves the uniformity of the plating layer while reducing energy consumption, providing reliable process guarantees for the large-scale production of high-precision panels and semiconductor circuits.

[0027] Furthermore, the liquid level control in step S6 includes: lowering the liquid level to below the fixture during the loading and unloading stage, raising the liquid level to the overflow height during the electroplating stage, and realizing the liquid level increase and decrease by switching the liquid circuits of the loading and unloading liquid level, electroplating liquid level and emptying liquid level.

[0028] Furthermore, in step S5, the electroplating stage adopts a forward pulse current, and the etching stage adopts a reverse pulse current.

[0029] Based on the above, the beneficial effect of the dual-pulse power supply alternatingly applying forward pulse current (electroplating stage) and reverse pulse current (etching stage) is to solve the problem of poor control of the surface roughness of the coating in the traditional electroplating process. The peak clipping effect of the periodic reverse current significantly improves the flatness of the coating surface. At the same time, the forward pulse electroplating ensures the efficient deposition of metal ions, thereby improving the density of the coating. This alternating pulse working mode not only simplifies the process flow and avoids the efficiency loss caused by the step-by-step treatment of electroplating and etching in the traditional process, but also improves the overall quality of the coating by dynamically balancing the deposition and dissolution processes. It is particularly suitable for the preparation requirements of high-precision circuits.

[0030] Furthermore, the electroplating solution comprises copper sulfate, sulfuric acid and water.

[0031] In order to more clearly illustrate the above features of the present invention and the objects to be achieved, the present invention will be further described below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 : is a flow chart of the method of the present invention;

[0033] Figure 2 : is a schematic diagram of the three-layer composite cavity of the present invention;

[0034] Figure 3 : Schematic diagram of the concentric annular independent control areas of the present invention.

[0035] Explanation of the accompanying numbers: 1-three-layer combined chamber, 2-electroplating anode layer, 3-electroplating cathode layer, 4-rotating fixture, 5-jet device, 6-concentric annular independent control area, 7-loading and unloading liquid level, 8-electroplating liquid level, 9-emptying liquid level. DETAILED DESCRIPTION

[0036] See also Figure 1-3 As shown,

[0037] The present invention discloses a method for horizontal double-sided electroplating of a panel and a semiconductor circuit, comprising the following steps:

[0038] S1: Provide a three-layer composite cavity 1, wherein the upper and lower layers are electroplated anode layers 2, and the middle layer is an electroplated cathode layer 3;

[0039] S2: Fix the workpiece to be electroplated on the rotating fixture 4 of the middle layer, drive the rotating fixture 4 to rotate at an adjustable speed through the driving structure, and conduct double-sided conductivity on the upper and lower surfaces of the workpiece through the electroplating liquid;

[0040] S3: delivering the plating solution into the three-layer combined cavity 1 through the upper and lower jet devices 5, and adjusting the flow rate in several steps to achieve a balanced or differential flow mode;

[0041] S4: Divide the upper and lower anodes into several concentric ring-shaped independent control areas 6, adjust the current on-off time ratio of each area, and control the electroplating uniformity of the center and edge of the workpiece;

[0042] S5: electroplating and etching the workpiece using a dual-pulse power supply, and performing electroplating and etching stages alternately in the three-layer combined chamber 1;

[0043] S6: The loading and unloading liquid level 7, the electroplating liquid level 8 and the emptying liquid level 9 are switched through the liquid level control system. When loading and unloading the wafer, the liquid level drops to the bottom of the fixture, and when electroplating, the liquid level reaches the overflow height.

[0044] In this embodiment, before step S1 , step S0 is further included: pre-treating the three-layer combined cavity 1 , wherein the pre-treating step includes cleaning the three-layer combined cavity 1 with an acid solution.

[0045] In this embodiment, the flow rate adjustment in several stages in step S3 is achieved by adjusting the pumping power and / or valve opening of the jet device 5 .

[0046] In this embodiment, the current adjustment step of the concentric annular independent control area 6 in step S4 includes: independently controlling the on and off of each annular anode according to a preset program, and the preset program adjusts the on and off time ratio according to the real-time monitoring result of the electroplating thickness of the workpiece surface.

[0047] In this embodiment, the rotation control of the driving structure in step S2 includes: driving the rotating fixture 4 to rotate through a mechanical connection, and maintaining the electrical connection between the cathode power supply and the workpiece through the electroplating solution through dynamic conductive contact during the rotation process.

[0048] In this embodiment, the liquid level control described in step S6 includes: lowering the liquid level to below the fixture during the loading and unloading stage, raising the liquid level to the overflow height during the electroplating stage, and realizing the liquid level rise and fall by switching the liquid circuits of the loading and unloading liquid level 7, the electroplating liquid level 8 and the emptying liquid level 9.

[0049] In this embodiment, the electroplating stage in step S5 uses a forward pulse current, and the etching stage uses a reverse pulse current.

[0050] In this embodiment, the electroplating solution includes copper sulfate, sulfuric acid and water.

[0051] In summary, the specific embodiments of the present invention are as follows:

[0052] First, the working principle of the present invention is based on the synergistic effect of the three-layer combined cavity 1 to achieve horizontal double-sided electroplating of the panel and semiconductor circuit. The upper and lower layers serve as the electroplating anode layer 2, and the middle layer serves as the electroplating cathode layer 3, forming a symmetrical double-sided electroplating field. The workpiece to be electroplated is horizontally fixed on the rotating fixture 4 in the middle layer. The workpiece is rotated by the driving structure, and the electroplating liquid is conductive on both the upper and lower surfaces of the workpiece. This structural design effectively avoids the problems of bubble adhesion and uneven flow field in traditional vertical electroplating, and promotes uniform distribution of the electroplating liquid through rotational motion.

[0053] Secondly, the flow rate of the plating solution is controlled by the upper and lower layer jet devices 5. Several adjustment modes are adopted, which can flexibly switch between balanced or differential flow modes according to process requirements. The jet device 5 dynamically adjusts the liquid flow area by controlling the driving parameters and the liquid circuit pressure, thereby accurately controlling the flow rate. The circulation and replenishment of the plating solution utilize the low-pressure area generated by the high-speed flow of the jet device 5 to absorb the return liquid and replenishment liquid, mix them, and then deliver them to the plating solution supply path. This design not only improves mixing efficiency but also avoids the risk of backflow.

[0054] Thirdly, both anodes are designed with several concentric ring-shaped independent control areas 6. The current in each area is independently controlled by a preset program, and the on-off time ratio is adjustable within the range of 0.1:1 to 10:1. This partitioned control method can accurately adjust the current distribution at the center and edge of the workpiece, effectively improving the uniformity of the coating. At the same time, a dual-pulse power supply is used to alternately perform the electroplating stage and the etching stage in the three-layer combination chamber 1. The forward pulse current realizes metal deposition, and the reverse pulse current performs surface peak clipping, thereby simultaneously completing the coating formation and surface leveling in a single process.

[0055] Finally, the liquid level control system realizes the automatic switching of the loading and unloading liquid level 7, the electroplating liquid level 8 and the emptying liquid level 9. When loading and unloading the wafer, the liquid level drops to the bottom of the fixture for easy operation. During electroplating, the liquid level rises to the overflow height to ensure process stability. This design simplifies the operating process and improves production efficiency. In addition, the three-layer combination cavity 1 and the liquid path system are pre-treated with acid before electroplating to effectively remove pollutants and ensure the purity of the electroplating solution and process stability. The entire system realizes high-precision and high-efficiency horizontal double-sided electroplating through the synergistic effect of mechanical rotation, fluid control and electrochemical regulation.

[0056] The above description is only the optimal solution embodiment of the present invention and is not intended to limit the present invention. Various modifications or substitutions made by those skilled in the art without departing from the essence and protection scope of the present invention should also be within the protection scope of the present invention.

Claims

1. A method for horizontal double-sided electroplating of a panel and a semiconductor circuit, characterized in that: The following steps are involved: S1: providing a three-layer combined cavity (1), wherein the upper and lower layers are electroplated anode layers (2), and the middle layer is an electroplated cathode layer (3); S2: Fixing the workpiece to be electroplated on the rotating fixture (4) of the middle layer, driving the rotating fixture (4) to rotate at an adjustable speed through the driving structure, and performing double-sided conductive treatment on the upper and lower surfaces of the workpiece through the electroplating liquid; S3: delivering the electroplating solution into the three-layer combined cavity (1) through the upper and lower jet devices (5), and adjusting the flow rate in several steps to achieve a balanced or differential flow mode; S4: Divide the upper and lower anodes into several concentric ring-shaped independent control areas (6), adjust the current on-off time ratio of each area, and control the electroplating uniformity of the center and edge of the workpiece; S5: electroplating and etching peak cutting are performed on the workpiece using a dual-pulse power supply, and the electroplating stage and the etching stage are alternately performed in the three-layer combined cavity (1); S6: The loading and unloading liquid level (7), electroplating liquid level (8) and emptying liquid level (9) are switched through the liquid level control system. When loading and unloading the tablets, the liquid level drops to the bottom of the fixture, and when electroplating, the liquid level reaches the overflow height.

2. The method for horizontal double-sided electroplating of a panel and a semiconductor circuit according to claim 1, characterized in that: Before step S1, step S0 is also included: pre-treating the three-layer combined cavity (1), and the pre-treating step includes cleaning the three-layer combined cavity (1) with acid solution.

3. The method for horizontal double-sided electroplating of a panel and a semiconductor circuit according to claim 1, characterized in that: The flow rate adjustment in several stages in step S3 is achieved by adjusting the pumping power and / or valve opening of the jet device (5).

4. The method for horizontal double-sided electroplating of a panel and a semiconductor circuit according to claim 1, characterized in that: The current adjustment step of the concentric annular independent control area (6) in step S4 includes: independently controlling the on and off of each annular anode according to a preset program, and the preset program adjusts the on and off time ratio according to the real-time monitoring result of the electroplating thickness of the workpiece surface.

5. The method for horizontal double-sided electroplating of a panel and a semiconductor circuit according to claim 1, characterized in that: The rotation control of the driving structure in step S2 includes: driving the rotating fixture (4) to rotate through a mechanical connection, and maintaining the electrical connection between the cathode power supply and the workpiece through the electroplating solution through dynamic conductive contact during the rotation process.

6. The method for horizontal double-sided electroplating of a panel and a semiconductor circuit according to claim 1, characterized in that: The liquid level control in step S6 includes: lowering the liquid level to below the fixture during the loading and unloading stage, raising the liquid level to the overflow height during the electroplating stage, and achieving liquid level rise and fall by switching on and off the liquid circuits of the loading and unloading liquid level (7), the electroplating liquid level (8) and the emptying liquid level (9).

7. The method for horizontal double-sided electroplating of a panel and a semiconductor circuit according to claim 1, characterized in that: In step S5 , the electroplating stage uses a forward pulse current, and the etching stage uses a reverse pulse current.

8. The method for horizontal double-sided electroplating of a panel and a semiconductor circuit according to claim 1, characterized in that: The electroplating solution comprises copper sulfate, sulfuric acid and water.

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