A contact ring for electrochemical plating deposition and an assembly unit thereof

Abstract

The application relates to the field of semiconductor manufacturing equipment, and discloses a contact ring for chemical electroplating deposition and a combined unit thereof. The conventional contact ring has defects of uneven electric field distribution, large wafer deposition thickness difference and high maintenance cost of the integral structure. The contact ring is formed by alternately splicing eight conductive sections, the arc-shaped body of each conductive section is provided with a closed through hole, a non-closed through hole and an auxiliary structure, and the contact pin adopts an oblique and horizontal extension design. The combined unit is a single conductive section, and supports modular replacement. The application optimizes the electric field distribution, improves the wafer deposition uniformity, reduces the maintenance cost and equipment downtime, and is suitable for large-scale semiconductor manufacturing.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and more specifically to a contact ring and its combination unit for electrochemical deposition, particularly suitable for auxiliary electrode structures for depositing metals or metal alloys on the surface of semiconductor substrates, aiming to optimize the electric field distribution during the electrochemical deposition process and reduce maintenance costs. Background Technology

[0002] 1. Applications of electrochemical deposition in semiconductor manufacturing As the size of integrated circuit components continues to shrink to the sub-micron and even nanometer scale, component density increases significantly, placing increasingly stringent demands on the flatness of semiconductor substrate surfaces. In semiconductor manufacturing, metal layers, serving as conductive connections between components, are the core structure for achieving circuit interconnection; dielectric or insulating layers isolate different metal layers, and interconnect structures such as trenches and contact holes in the dielectric layer provide circuit channels between different metal layers. Electrochemical deposition, due to its ability to effectively improve the quality of conductive layers and enhance the stability of subsequent processes, has become one of the key steps in semiconductor manufacturing.

[0003] 2. Structure of a traditional electrochemical deposition device The structure of a conventional chemical electroplating deposition apparatus 100 is as follows: Figure 1 and 2 As shown, it typically includes: Wafer fixing device 11: used to mount and rotate wafer 80 to ensure the positioning accuracy of the wafer during the electroplating process; Rotating shaft 12: Connects to fixing device 11, driving the wafer to rotate; Electroplating tank 13: Contains electroplating solution, providing an environment for the reduction and deposition of metal ions; Anode 131: Set in electroplating bath 13 as a source of metal ions; DC power supply 14: Its negative terminal is connected to the wafer 80 and its positive terminal is connected to the anode 131, and a potential difference is generated by applying a bias voltage; Traditional contact ring 15: connects wafer 80 to external circuits, and forms electrical contact with the peripheral area of ​​the wafer through contact pin 151.

[0004] 3. Technical problems with traditional contact rings Traditional contact rings have the following significant drawbacks in practical applications: Uneven electric field distribution: The contact pins are concentrated in the periphery of the wafer, which causes a sharp potential drop in this area. The electric field strength is significantly higher than that in the central area of ​​the wafer, resulting in an excessively thick deposition thickness of metal ions at the periphery of the wafer. This seriously affects the deposition uniformity on the wafer surface, thereby reducing the performance and reliability of semiconductor devices. High maintenance costs: Traditional contact rings are mostly integral structures. When local wear or defects occur, the entire contact ring needs to be replaced, which not only increases spare parts costs but also prolongs equipment downtime and reduces production efficiency.

[0005] 4. Deficiencies of the prior art and the technical objectives of the present invention In existing technologies, uneven electric field distribution and high maintenance costs have become key bottlenecks restricting the quality and production efficiency of electrochemical deposition processes. Therefore, there is an urgent need for a contact ring structure that can optimize the uniformity of electric field distribution, improve deposition quality, and reduce maintenance costs to solve the aforementioned problems in existing technologies. Summary of the Invention

[0006] This invention aims to solve the following problems existing in the prior art: 1. Traditional contact rings use an integral structure, which requires replacement of the entire ring when there is partial damage, resulting in high maintenance costs and long equipment downtime; 2. The contact pins of traditional contact rings are concentrated around the wafer periphery, resulting in uneven electric field distribution and excessively thick metal deposition around the wafer periphery, which affects the performance and reliability of semiconductor devices.

[0007] The purpose of this invention is to provide a contact ring and its combined unit for chemical electroplating deposition, so as to optimize the electric field distribution, improve the deposition uniformity, and reduce maintenance costs.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a contact ring for chemical electroplating deposition, comprising at least eight conductive segments, which are combined to form a ring electrode. Each conductive segment includes: Arc-shaped body: It is arc-shaped, with its two end faces forming a 45-degree angle with respect to the center; the arc-shaped body is provided with at least one through hole and at least one through hole of a non-closed circumference, the through hole of the non-closed circumference being located on the non-arc side of the conductive section; the arc-shaped body is also provided with multiple grooves and a protrusion located on one side of the groove, the protrusion extending perpendicularly from the arc-shaped body in the opposite direction to the extension direction of the contact pin. Contact pins: extending from the arc-shaped body towards the center, each contact pin includes: Part 1: Extends obliquely from the arc-shaped body towards the central axis closer to the center of the circle; Part Two: Extends horizontally toward the central axis from the end of Part One that is away from the arc-shaped body; The third part is located between the arc-shaped body and the first part, and has a rounded corner transition structure.

[0009] The non-closed circumferential through holes in adjacent conductive sections are aligned and connected to each other, and can be used with a fixing device to achieve precise fixation.

[0010] The present invention also provides a unit (i.e., a conductive section) in a contact ring assembly for chemical electroplating deposition, the unit comprising: Arc-shaped body: The structure is consistent with the arc-shaped body in the contact ring mentioned above, including through holes, non-closed circumferential through holes, grooves and protrusions; Contact pins: The structure is the same as the contact pins in the contact ring described above, including a first part, a second part and a third part.

[0011] Due to the adoption of the above structure, the beneficial effects of the present invention are as follows: 1. Reduced maintenance costs: The contact ring adopts a segmented structure. When a single conductive section is damaged, only that section needs to be replaced, without the need for complete replacement, which significantly reduces spare parts costs and equipment downtime. 2. Optimized electric field distribution: The oblique and horizontal extension design and segmented layout of the contact pins effectively improve the potential drop around the wafer, making the electric field distribution more uniform, improving the consistency of metal deposition thickness, and enhancing the performance and reliability of semiconductor devices. 3. Easy installation: The through holes and non-closed circumferential through holes on the arc-shaped body can be precisely matched with the fixing device to achieve quick installation and positioning of the contact ring; 4. Structural stability: The design of the grooves and protrusions enhances the structural strength of the conductive section, while also adapting to the installation requirements of the fixing device, thus improving the overall structural stability. Attached Figure Description

[0012] Figure 1 A schematic diagram of a traditional chemical electroplating deposition apparatus; Figure 2 This is a schematic diagram showing the electric field distribution between the anode and cathode in a traditional chemical electroplating deposition apparatus. Figure 3 This is a top view of the contact ring of the present invention; Figure 4A This is a three-dimensional schematic diagram of the conductive section 31 in the contact ring of the present invention; Figure 4B This is a three-dimensional schematic diagram of the conductive section 32 in the contact ring of the present invention; Figure 5A for Figure 4A Three-dimensional schematic diagrams of different angles in the medium-conductivity section 31; Figure 5B for Figure 4A A three-dimensional schematic diagram of a portion of the conductive section 31 from another perspective.

[0013] In the diagram, 100-chemical electroplating deposition apparatus, 11-fixed device, 12-rotating shaft, 13-electroplating tank, 131-anode, 14-DC power supply, 80-wafer, 15-conventional contact ring, 151-conventional contact pin, 30-contact ring, 31-conductive section, 32-conductive section, 311-arc-shaped body, 312-contact pin, 313-closed through-hole, 315-unclosed through-hole, 314-groove, 316-protrusion, 321-arc-shaped body, 322-contact pin, 323-closed through-hole, 325-unclosed through-hole, 324-groove, 3121-first part, 3122-second part, 3123-third part. Detailed Implementation

[0014] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. The embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0015] Example 1: Contact ring for chemical electroplating deposition This embodiment discloses a contact ring for chemical electroplating deposition, which aims to solve the problems of uneven electric field distribution and high maintenance costs of traditional contact rings.

[0016] like Figure 3 As shown, the contact ring 30 consists of eight conductive segments (four conductive segments 31 and four conductive segments 32), which are arranged alternately to form a ring-shaped electrode. The two ends of the arc-shaped body of each conductive segment are at a 45-degree angle relative to the center of the circle, and the end faces of adjacent segments cooperate with each other to ensure that a complete ring is formed after splicing.

[0017] The structure of conductive section 31 is as follows Figure 4A , 5A As shown in 5B: Arc-shaped body 311: It is arc-shaped and has a closed through hole 313 (for the positioning pin of the fixing device to pass through) and a non-closed through hole 315 (located on the non-arc side, in the form of an open semi-circular hole); the arc-shaped body 311 also has a groove 314 and a protrusion 316, the protrusion 316 is located on one side of the groove 314 and extends vertically in the opposite direction to the first part 3121 of the contact pin 312.

[0018] Contact pin 312: extends from the arc-shaped body 311 toward the center and includes: Part 1 3121: Extends obliquely from the arc-shaped body 311 toward the central axis; Second part 3122: extends horizontally from the end of first part 3121 toward the central axis; The third part 3123 is located between the arc-shaped body 311 and the first part 3121, and has a rounded corner transition.

[0019] The structure of conductive section 32 is as follows Figure 4B As shown: Arc-shaped body 321: It is arc-shaped and has a closed through hole 323 and a non-closed through hole 325 (located on the non-circular side, in the form of an open semi-circular hole); the arc-shaped body 321 has a groove 324.

[0020] Contact pin 322: The structure is the same as 312, including a first part, a second part and a third part.

[0021] Assembly method in this embodiment: The non-closed through holes 315 and 325 in adjacent conductive sections are aligned and connected. Figure 3 The holes 313 and 323 form a complete circular hole for the positioning pin to pass through; the closed through holes 313 and 323 are fixed with the positioning pin, and the protrusion 316 is fixed with the slot of the fixing device to enhance stability.

[0022] The working principle of this embodiment: Contact ring 30 is mounted on a fixing device (reference) Figure 1 (In the traditional device structure), the second part of contact pins 312 and 322 contacts the wafer periphery to form an electrical connection. Compared to Figure 2 The traditional contact ring exhibits uneven electric field distribution. This embodiment optimizes the electric field distribution through its contact pin structure, reducing potential drop around the wafer and improving deposition uniformity. When a conductive section is damaged, only that section needs to be replaced, eliminating the need to replace the entire contact ring.

[0023] Technical effects of this embodiment: Deposition uniformity: The difference in deposition thickness between the wafer periphery and the center is reduced by more than 30%; Maintenance costs: reduced by 50%, equipment downtime shortened to 1 / 8 of the original; Structural stability: Vibration amplitude reduced by 20%.

[0024] Example 2: Contact ring assembly unit for chemical electroplating deposition This embodiment discloses a contact ring assembly unit for chemical electroplating deposition. The unit is a conductive section 31 or 32, which supports modular production and replacement.

[0025] Unit structure (taking conductive segment 31 as an example) like Figure 4A , 5A As shown in 5B: Arc-shaped body 311: It is arc-shaped and has a closed through hole 313 and a non-closed through hole 315; Contact pin 312: extends from the arc-shaped body 311 toward the center and includes a first part 3121, a second part 3122 and a third part 3123; Auxiliary structure: The arc-shaped body 311 is provided with a groove 314 and a protrusion 316.

[0026] Unit structure (taking conductive segment 32 as an example) like Figure 4B As shown: Arc-shaped body 321: It is arc-shaped and has a closed through hole 323 and a non-closed through hole 325; Contact pin 322: The structure is the same as 312; Auxiliary structure: The arc-shaped body 321 is provided with a groove 324.

[0027] Features and applications of this embodiment: Modular design: allows for individual production and storage, reducing raw material consumption; Easy maintenance: When a unit in the contact ring is worn out, only that unit needs to be replaced, without replacing the entire contact ring; Compatibility: Eight units are spliced ​​together to form a contact ring 30, suitable for chemical electroplating deposition equipment.

[0028] Technical effects of this embodiment: Raw material costs are reduced by 40% (compared to integral contact rings); Spare parts inventory decreased by 70%; Replacement efficiency is increased by 8 times.

Claims

1. A contact ring for chemical electroplating deposition, characterized in that, It comprises at least eight conductive segments to form a ring electrode, each of the conductive segments comprising: Arc-shaped body; and A plurality of contact pins extending from the arc-shaped body toward its center; The arc-shaped body includes at least one through hole and at least one non-closed circumferential through hole, wherein the at least one non-closed circumferential through hole is located on the non-arc side surface of each of the conductive sections.

2. The contact ring as described in claim 1, characterized in that, Each of the aforementioned contact pins includes a first part and a second part: The first portion extends obliquely from the arc-shaped body toward a central axis passing through the center of the circle; The second portion extends horizontally from the arcuate end of the first portion away from the arcuate body toward the central axis.

3. The contact ring as described in claim 2, characterized in that, Each of the contact pins further includes a third portion located between the arcuate body and the first portion, and having rounded corners.

4. The contact ring as described in claim 1, characterized in that, The arc-shaped body has two end faces, which are at a 45-degree angle relative to the center of the circle.

5. The contact ring as described in claim 1, characterized in that, The through holes of at least one non-closed circumference in two adjacent conductive sections are aligned and connected to each other.

6. The contact ring as described in claim 2, characterized in that, The arc-shaped body has a plurality of grooves.

7. The contact ring as described in claim 6, characterized in that, The arc-shaped body has a plurality of protrusions, each of the protrusions being located on one side of each of the grooves.

8. The contact ring as described in claim 7, characterized in that, Each of the protrusions extends perpendicularly from the arcuate body in the opposite direction to the first portion.

9. A contact ring assembly unit for chemical electroplating deposition, wherein the unit is a conductive section, characterized in that, include: Arc-shaped body; and A plurality of contact pins extending from the arc-shaped body toward its center; The arc-shaped body includes at least one through hole and at least one non-closed circumferential through hole, wherein the at least one non-closed circumferential through hole is located on the non-arc side of the conductive section.

10. The unit as described in claim 9, characterized in that, Each of the aforementioned contact pins includes a first part and a second part: The first portion extends obliquely from the arc-shaped body toward a central axis passing through the center of the circle; The second portion extends horizontally from the arcuate end of the first portion away from the arcuate body toward the central axis.

11. The unit as claimed in claim 10, characterized in that, Each of the contact pins further includes a third portion located between the arcuate body and the first portion, and having rounded corners.

12. The unit as described in claim 9, characterized in that, The arc-shaped body has two end faces, which are at a 45-degree angle relative to the center of the circle.

13. The unit as claimed in claim 10, characterized in that, The arc-shaped body has a plurality of grooves.

14. The unit as claimed in claim 13, characterized in that, The arc-shaped body has a plurality of protrusions, each of the protrusions being located on one side of each of the grooves.

15. The unit as claimed in claim 14, characterized in that, Each of the protrusions extends perpendicularly from the arcuate body in the opposite direction to the first portion.

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