Platinum ring for semiconductor manufacturing

Abstract

This utility model relates to the field of semiconductor manufacturing technology, and more particularly to a platinum ring for semiconductor manufacturing. It includes a mounting frame comprising an upper frame and a lower frame, both of which are annular circular frame structures matching the diameter of the wafer. Horizontal support plates are fixedly mounted on both sides of the top of the upper frame, and a connecting plate is detachably mounted on the top of each horizontal support plate. The connecting plate is a disc-shaped boss structure with connecting grooves on its top. The upper frame and the lower frame are fixedly connected on one side by a connecting strip made of shape memory metal, and snap-fit ​​rings that fit into the wafer edge are fixedly mounted on the inner sides of the upper and lower frames. The technical problem this utility model aims to solve is that during the electroplating process, the wafer edge area is prone to uneven plating thickness due to electric field distortion, making it difficult to ensure overall plating consistency.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor manufacturing technology, and in particular to a platinum ring for semiconductor manufacturing. Background Technology

[0002] In semiconductor manufacturing, electroplating is primarily used to deposit metal interconnect layers on wafer surfaces to ensure their electrical performance and the stability of subsequent circuit interconnects. The uniformity of the metal layer thickness directly affects the success or failure of subsequent processes such as photolithography and etching; therefore, the uniformity of the electroplated layer is of paramount importance in process design.

[0003] Under current process conditions, due to the coupling effect of multiple factors such as wafer geometry, external electric field, and hydrodynamics, electric field distortion is easily generated in the wafer edge region during electroplating. Specifically, the electric field strength at the wafer edge is significantly higher than in the center region, with current density differences reaching several times. This causes metal ions to migrate faster and deposit preferentially at the edge. This phenomenon leads to an abnormally thicker metal layer at the edge, while the plating layer in the center is relatively thin, resulting in a severely uneven overall thickness distribution. This not only affects the resolution and etching accuracy of subsequent photolithography but may also create localized stress concentrations in the chip structure, reducing device reliability and lifespan. Utility Model Content

[0004] The technical problem this invention aims to solve is that during the electroplating process, the edge area of ​​the wafer is prone to electric field distortion, resulting in uneven thickness of the electroplated layer and making it difficult to ensure the overall consistency of the plating layer.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: a platinum ring for semiconductor manufacturing, including a fitting frame, the fitting frame including an upper frame and a lower frame, both the upper frame and the lower frame being configured as annular circular frame structures matching the diameter of the wafer, horizontal support plates being fixedly provided on both sides of the top of the upper frame, a connecting plate being detachably provided on the top of the horizontal support plate, the connecting plate being configured as a disc-shaped boss structure, and a connecting spiral pattern being provided on the top, the upper frame and the lower frame being fixedly connected on one side by a connecting strip made of memory metal, and a fastening ring body that fits into the wafer bezel being fixedly provided on the inner side of the upper frame and the lower frame.

[0006] As a further improvement of this utility model, the fitting frame is made of titanium alloy, the fastening ring is fixedly installed on the top side of the fitting frame, and the fastening ring is made of platinum.

[0007] As a further improvement of this utility model, an abutment plate is fixedly provided on the inner side of the upper frame and the lower frame.

[0008] As a further improvement of this utility model, the connecting strip is made of nickel-titanium alloy and is fixedly provided with reinforcing ribs on the outside.

[0009] As a further improvement of this utility model, a vertically upward insert is fixedly connected to the top of the horizontal support plate, and insert rings that fit into the insert are fixedly provided on both sides of the connecting plate.

[0010] As a further improvement of this utility model, finger buckles are fixedly provided on the outer sides of both the upper frame and the lower frame.

[0011] The beneficial effects of this invention are as follows: This invention addresses the problem of uneven plating thickness at the wafer edge due to electric field distortion during electroplating. By incorporating a platinum interlocking ring on the inside of the interlocking frame, and combining it with a titanium alloy substrate to form a ring-shaped auxiliary cathode structure, effective equalization of current distribution is achieved. Specifically, the titanium alloy substrate possesses high strength and excellent corrosion resistance, allowing for long-term stable operation in acidic plating solutions. The interlocking ring utilizes the high conductivity and chemical stability of platinum to form a continuous equipotential ring at the wafer edge, uniformly dispersing the originally concentrated strong electric field circumferentially, significantly reducing the current density difference between the edge and center regions. Through this structural design, metal ion deposition on the wafer tends to be more uniform during electroplating, thereby significantly improving the overall consistency of the plating thickness. Attached Figure Description

[0012] Figure 1 This is an overall schematic diagram of a platinum ring for semiconductor manufacturing according to this utility model;

[0013] Figure 2 This is a disassembly diagram of a platinum ring for semiconductor manufacturing according to this utility model;

[0014] Figure 3 This is a cross-sectional view of a platinum ring for semiconductor manufacturing according to this utility model;

[0015] Figure 4 This is a partial view of a platinum ring for semiconductor manufacturing according to this utility model.

[0016] As shown in the figure: 1. Fitting frame; 101. Upper frame; 102. Lower frame; 2. Horizontal support plate; 3. Connecting plate; 4. Connecting strip; 5. Fastening ring; 6. Abutment plate; 7. Insert post; 8. Insert ring; 9. Finger buckle. Detailed Implementation

[0017] The directional terms such as up, down, left, right, front, back, front, back, top, and bottom mentioned or possibly mentioned in this specification are defined relative to their structure and are relative concepts. Therefore, they may vary depending on their location and usage; thus, these or other directional terms should not be interpreted as restrictive terms.

[0018] The singular forms “a,” “the,” and “the” used in this specification are intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes one or more of the associated listed items, any or all possible combinations thereof.

[0019] To make the technical problems to be solved, the technical solutions, and the beneficial effects of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0020] This utility model provides a platinum ring for semiconductor manufacturing, including a fitting frame 1;

[0021] As attached Figure 1 , 2 As shown in Figures 3 and 4, the mounting frame 1 includes an upper frame 101 and a lower frame 102. Both the upper frame 101 and the lower frame 102 are designed as annular circular frame structures that match the diameter of the wafer. Horizontal support plates 2 are fixedly installed on both sides of the top of the upper frame 101. A connecting plate 3 is detachably installed on the top of the horizontal support plate 2. A vertically upward insert post 7 is fixedly connected to the top of the horizontal support plate 2, and insert rings 8 that fit into the insert post 7 are fixedly installed on both sides of the connecting plate 3 to ensure convenient assembly. At the same time, the connecting plate 3 is designed as a disc-shaped boss structure with connecting grooves on the top, providing a combined connection effect. The connecting plate 3 can be connected to other pushing devices to push the wafer to the liquid surface. The upper frame 101 and the lower frame 102 are fixedly connected on one side by a connecting strip 4 made of shape memory metal. The connecting strip 4 is made of nickel-titanium metal and has reinforcing ribs fixedly installed on the outside, which can accommodate a maximum allowable elastic angle ≤18°. An abutment plate 6 is fixedly installed on the inner side of the upper frame 101 and the lower frame 102. The abutment plate 6 is made of the same material as the buckle ring 5, which is platinum, to enhance the abutment effect. Finger buckles 9 are fixedly installed on the outer side of the upper frame 101 and the lower frame 102 to facilitate the up-and-down movement and separation of the upper frame 101 and the lower frame 102.

[0022] In addition, as attached Figure 3As shown, the upper frame 101 and lower frame 102 are fixedly equipped with snap-fit ​​rings 5 ​​that fit into the wafer bezel. The frame 1 is made of Ti-6Al-4V titanium alloy with a yield strength ≥800MPa, strong corrosion resistance, and is suitable for long-term use in electroplating solutions (such as copper sulfate, nickel sulfate, etc.). The snap-fit ​​rings 5 ​​are fixedly installed on the top side of the frame and are made of platinum with a surface roughness Ra of ≤2.5μm, which is beneficial for stabilizing the electric field distribution. The difference in current density between the wafer edge and center is reduced from 2.5 to 3 times that of the traditional structure to ≤1.2 times; the uniformity of the metal layer thickness after electroplating (mean square deviation of the thickness of the entire wafer) is improved from ≥10% to ≤3%. The rings show no significant corrosion after continuous operation for ≥750 hours in typical acidic electroplating solutions (pH 0.5 to 1.5, temperature 20 to 50℃). By introducing a ring-shaped auxiliary cathode with a titanium alloy substrate and a local platinum layer, not only is the structural strength and long-term corrosion resistance guaranteed, but the electric field distribution is also effectively improved, resulting in a significant improvement in the uniformity of the wafer coating thickness and meeting the stringent requirements of advanced processes for the flatness of the metal interconnect layer.

[0023] Working Principle: In practical application, the wafer needs to be fitted into the internal space of the mounting frame 1. The upper frame 101 and the lower frame 102 form an annular frame structure and are tightly fitted to the edge of the wafer through the fastening ring 5, thereby ensuring the stability of the wafer position. The upper frame 101 and the lower frame 102 are fixed by a connecting strip 4 made of shape memory metal. When the snap ring 9 is pried open by external force, the connecting strip 4 can generate elastic deformation, allowing the upper frame 101 and the lower frame 102 to be easily separated, facilitating the quick loading and unloading of the wafer. The horizontal support plate 2 serves as an extension support of the upper frame 101. A connecting plate 3 can be installed on its top. The connecting plate 3 is reliably fitted with the insert ring 8 and the insert post 7, and is connected to the external pushing device by the connecting groove of the connecting plate 3, thereby pushing the connecting plate 3 downward and causing the wafer to contact the liquid surface. The mounting frame 1 plays the role of an auxiliary cathode in the electroplating process. The snap ring 5 is made of platinum and is placed inside the interlocking frame 1.

[0024] During electroplating, electric field concentration occurs at the wafer edges due to abrupt geometric changes. If left unchecked, the current lines contract sharply at the edges, resulting in a current density 2.5 to 3 times higher at the edges than at the center, leading to excessively rapid metal deposition at the edges. The snap-fit ​​ring 5 is made of platinum, a material with high conductivity and excellent electrochemical stability, with a conductivity of approximately 9.4 × 10⁻⁶. 6With a conductivity of S / m, much higher than the ionic conductivity of the electroplating solution itself, a low-impedance current shunt path can be formed within the ring. Specifically, when an external power source is connected to the mounting frame 1 via the connecting plate 3, the current preferentially distributes along the annular platinum fastening ring 5 before entering the electrolyte. Due to the circumferential continuity of the annular geometry, the current forms an equipotential barrier around the wafer, thereby diffusing the high electric field originally concentrated at the local edge into an electric field uniformly distributed along the wafer periphery, effectively reducing local distortion. At the same time, the titanium alloy substrate provides the necessary strength and corrosion resistance support, allowing the platinum ring to fit tightly and stably against the wafer edge, ensuring the stability and repeatability of the electric field distribution.

[0025] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A platinum ring for semiconductor manufacturing, comprising a mounting frame (1), characterized in that: The fitting frame (1) includes an upper frame (101) and a lower frame (102), and both the upper frame (101) and the lower frame (102) are set as annular circular frame structures that match the diameter of the wafer. Horizontal support plates (2) are fixedly provided on both sides of the top of the upper frame (101). A connecting plate (3) is detachably provided on the top of the horizontal support plate (2). The connecting plate (3) is set as a disc-shaped boss structure and has connecting grooves on the top. The upper frame (101) and the lower frame (102) are fixedly connected on one side by a connecting strip (4) made of memory metal. Fastening rings (5) that fit into the wafer frame are fixedly provided on the inner side of the upper frame (101) and the lower frame (102).

2. The platinum ring for semiconductor manufacturing according to claim 1, characterized in that: The fitting frame (1) is made of titanium alloy, and the fastening ring (5) is fixedly installed on the top side of the fitting frame, and the fastening ring (5) is made of platinum.

3. The platinum ring for semiconductor manufacturing according to claim 2, characterized in that: The upper frame (101) and lower frame (102) are fixedly provided with abutment plates (6).

4. The platinum ring for semiconductor manufacturing according to claim 1, characterized in that: The connecting strip (4) is made of nickel-titanium alloy and has reinforcing ribs fixed on its outer side.

5. A platinum ring for semiconductor manufacturing according to claim 1, characterized in that: The top of the horizontal support plate (2) is fixedly connected to a vertically upward insert post (7), and the two sides of the connecting plate (3) are fixedly provided with insert rings (8) that fit into the insert post (7).

6. A platinum ring for semiconductor manufacturing according to claim 1, characterized in that: Finger buckles (9) are fixedly provided on the outer sides of both the upper frame (101) and the lower frame (102).

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