Shielding module and electroplating apparatus

Abstract

The application relates to the technical field of wafer electroplating, in particular to a shielding module and electroplating equipment. The shielding module comprises an insulating ring, which is arranged in an electroplating cavity; the shielding module further comprises a conductive ring connected to the insulating ring and arranged around the outer circumferential side of the insulating ring; and an auxiliary electrode arranged in the electroplating cavity and electrically connected with the conductive ring, so as to electrically connect the conductive ring to the ground potential or the negative electrode of a power supply. The shielding module of the application shields the electric field through the insulating ring and shunts through the conductive ring. Compared with the insulating ring made of a single material, the refracted current in the electroplating cavity can be conducted to the outside of the electroplating cavity through the conductive ring, so that the thickness of the wafer edge can be more accurately controlled. Through the synergistic effect of the insulating ring and the conductive ring, the edge effect in the electroplating process is improved, so that the abnormal plating layer caused by the refraction of the electric field is avoided, and the uniformity and consistency of the plating layer are improved.

Description

Technical Field

[0001] This invention relates to the field of wafer electroplating technology, and in particular to a shielding module and electroplating equipment. Background Technology

[0002] In semiconductor manufacturing, during the electroplating process of depositing conductive metal layers (hereinafter referred to as coatings) on wafer surfaces, the wafer typically serves as the cathode. Due to the influence of wafer geometry, the abrupt change in geometric curvature at its edges causes electric field lines to concentrate at the wafer edges, resulting in a phenomenon where the electric field strength at the wafer edges is higher than that in the center region—a phenomenon known as the "edge effect." Under the influence of an uneven electric field, metal ions in the electrolyte lead to uneven coating thickness at the wafer edges. Specifically, the coating thickness at the wafer edges is greater than that in the center region, increasing the difficulty of subsequent chemical mechanical polishing processes and affecting the electrical performance, reliability, and mass production yield of integrated circuits and other devices. Furthermore, in electroplating processes using high-resistivity electrolytes, the poor conductivity of the electrolyte makes the current distribution more susceptible to the influence of wafer geometry, exacerbating the edge effect and resulting in uneven coating distribution and poor thickness consistency at the wafer edges. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the defects of uneven coating thickness at the edge of the wafer and difficulty in accurately controlling the coating thickness at the edge of the wafer in the prior art, and to provide a shielding module and electroplating equipment.

[0004] The present invention solves the above-mentioned technical problems through the following technical solution:

[0005] A shielding module includes an insulating ring disposed within an electroplating chamber. The shielding module further includes a conductive ring connected to the insulating ring and disposed around the outer periphery of the insulating ring; and an auxiliary electrode disposed within the electroplating chamber and electrically connected to the conductive ring to electrically connect the conductive ring to ground potential or the negative terminal of a power supply.

[0006] In this solution, the electric field is blocked by an insulating ring and the current is diverted by a conductive ring. Compared with an insulating ring made of a single material, the current refracted in the electroplating cavity can be led out to the outside of the electroplating cavity through the conductive ring, so as to achieve more precise control of the coating thickness at the wafer edge. Through the synergistic effect of the insulating ring and the conductive ring, the edge effect in the electroplating process is improved, thereby avoiding coating abnormalities caused by electric field refraction and improving the uniformity and consistency of the coating.

[0007] Optionally, the shielding module further includes a transmission mechanism, which includes a rotary drive for being disposed within the electroplating chamber. The outer circumferential surface of the conductive ring contacts the rotary drive, so that the conductive ring and the insulating ring rotate under the drive of the rotary drive. The conductive ring is electrically connected to the auxiliary electrode through a sliding contact.

[0008] In this scheme, during the electroplating process, the electric field distribution and current density of the edge region can be adjusted by rotating the conductive ring, thereby improving the uniformity of the current density in the wafer edge region, enhancing the uniformity and consistency of the coating thickness, and thus improving the surface quality of the coating.

[0009] Optionally, the rotary drive member and the outer peripheral surface of the conductive ring are driven by gear meshing; and / or, the transmission mechanism includes a driven member disposed between the rotary drive member and the conductive ring, and the rotary drive member drives the conductive ring and the insulating ring to rotate through the driven member.

[0010] In this solution, the rotary drive component and the outer circumferential surface of the conductive ring can be driven by tooth meshing, making the shielding module structure more compact, saving space, with higher reliability and convenient maintenance.

[0011] Optionally, the shielding module includes a limiting portion for fixing relative to the electroplating cavity. The limiting portion includes a limiting plate having an inner circumferential surface facing the axial direction of the conductive ring. The limiting plate is used to define the relative position of the insulating ring with respect to the electroplating cavity along the radial direction of the conductive ring. The limiting plate extends radially from its inner circumferential surface to form a limiting edge, which is located on the side of the conductive ring away from the auxiliary electrode. A portion of the conductive ring is sandwiched between the limiting edge and the auxiliary electrode to define the relative position of the insulating ring with respect to the electroplating cavity along the axial direction of the conductive ring.

[0012] In this solution, the position of the shielding part relative to the electroplating cavity is limited by the limiting part, thereby improving the stability of the transmission, and thus improving the consistency of electroplating and the uniformity of the plating thickness.

[0013] Optionally, the auxiliary electrode includes a conductive base and a conductive ball. The conductive base is fixed to the electroplating chamber, and the conductive ball abuts against the conductive ring. A portion of the conductive ball is embedded in the conductive base and is rotatable relative to the conductive base. The auxiliary electrode also includes a ball bearing. The conductive base has a communicating receiving cavity and a receiving groove for accommodating the conductive ball and the ball bearing, respectively. When the conductive ring is driven to rotate by the rotary drive, the conductive ball can rotate relative to the conductive base via the ball bearing.

[0014] In this design, the conductive ball abuts against the conductive ring, allowing the conductive ring to rotate more smoothly.

[0015] Optionally, the conductive base includes a mounting post section, the receiving cavity and the receiving groove are disposed in the mounting post section, and a mounting flange is provided at the end of the mounting post section away from the conductive ring.

[0016] In this solution, the installation of flanges facilitates installation and improves installation stability and reliability.

[0017] An electroplating apparatus includes an electroplating chamber, a plating head, and a shielding module. The electroplating chamber is used to hold an electrolyte, the plating head is used to hold a wafer into or away from the electroplating chamber, an anode is provided in the area of ​​the electroplating chamber corresponding to the plating head, and the shielding module is located between the anode and the wafer.

[0018] In this solution, the uniformity and consistency of the coating at the wafer edge can be improved by using a shielding module.

[0019] Optionally, a flow equalization plate is provided inside the electroplating chamber. The flow equalization plate is located between the shielding module and the plating head and can rotate relative to the electroplating chamber. The flow equalization plate is used to improve the flow field inside the electroplating chamber.

[0020] In this scheme, the flow field inside the electroplating chamber is improved by using a flow equalization plate, thereby enhancing the uniformity of the coating.

[0021] Optionally, the electroplating chamber further includes a driven member and a transmission member arranged coaxially. The transmission member is fixed relative to the driven member, and the outer peripheral surface of the flow equalizing plate is in contact with the transmission member, so that the flow equalizing plate can rotate under the drive of the driven member through the transmission member.

[0022] In this design, the driven and transmission components are arranged coaxially, reducing the number of parts, resulting in a compact structure and saving space.

[0023] The positive and progressive effects of this invention are as follows:

[0024] The shielding module of this invention uses an insulating ring to shield the electric field and a conductive ring to shunt the current. Compared with an insulating ring made of a single material, it can conduct the refracted current in the electroplating cavity to the outside of the electroplating cavity through the conductive ring, thereby achieving more precise control of the coating thickness at the wafer edge. Through the synergistic effect of the insulating ring and the conductive ring, the edge effect in the electroplating process is improved, thereby avoiding coating abnormalities caused by electric field refraction and improving the uniformity and consistency of the coating. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the electroplating equipment according to Embodiment 2 of the present invention.

[0026] Figure 2 This is a schematic diagram of the structure of the shielding part of the present invention.

[0027] Figure 3 This is a cross-sectional schematic diagram of the auxiliary electrode of the present invention.

[0028] Figure 4 This is a cross-sectional schematic diagram of the electroplating equipment according to Embodiment 1 of the present invention.

[0029] Figure 5 This is a cross-sectional schematic diagram of the electroplating equipment according to Embodiment 2 of the present invention.

[0030] Explanation of reference numerals in the attached figures:

[0031] Shielding part 1

[0032] Insulating ring 11

[0033] Conductive ring 12

[0034] Auxiliary electrode 2

[0035] Conductive base 21

[0036] Install column segment 211

[0037] Mounting flange 212

[0038] Mounting hole 212a

[0039] 21a of the accommodating cavity

[0040] Receiving slot 21b

[0041] Conductive ball 22

[0042] Ball bearing 23

[0043] Transmission mechanism 3

[0044] Rotary drive component 31

[0045] Follower 32

[0046] Transmission component 33

[0047] Motor 34

[0048] Limiting part 4

[0049] Limit plate 41

[0050] Limiting edge 42

[0051] 43 clearance slot

[0052] Flow equalizer 5

[0053] Base 6

[0054] Electroplating cavity 6a

[0055] Plating head 61

[0056] Wafer 62

[0057] Anode 63

[0058] Ground potential 64 Detailed Implementation

[0059] The present invention is further illustrated below by way of embodiments, but these embodiments are not intended to limit the invention to their scope. Based on the description of the present invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present invention.

[0060] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connection," "setup," "installation," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can mean that two components are internally connected. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0061] The terms “upper,” “lower,” “left,” “right,” “front,” “back,” “center,” “top,” “bottom,” “inner,” “outer,” “vertical,” “horizontal,” “axial,” “radial,” and “circumferential” indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use. They are used only for the convenience of description and simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0062] The terms “first”, “second”, etc., are used merely to distinguish elements with similar properties, not to indicate or imply relative importance or a specific order.

[0063] The terms “including,” “comprising,” or any other variations thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.

[0064] See Figure 1This invention provides an electroplating apparatus, including a base 6, a plating head 61, and a shielding module. The base 6 has an electroplating cavity 6a for holding electrolyte. The plating head 61 is used to hold a wafer 62 into or away from the electroplating cavity 6a. An anode 63 is provided in the area corresponding to the plating head 61 within the electroplating cavity 6a. The shielding module is located between the anode 63 and the wafer 62. Specifically, the shielding module includes an annular shielding part 1, which is disposed within the electroplating cavity 6a and corresponds to the position of the wafer 62. It is used to shield the edge of the wafer 62, thereby shielding the electric field in the edge region of the wafer 62 and improving the edge effect during the electroplating process. In one embodiment, the shielding part 1 is located in the region within the electroplating cavity 6a near the anode 63, providing shielding from the source of the electric field, thus improving the shielding effect and control sensitivity.

[0065] See Figure 2 The shielding part 1 includes an insulating ring 11 and a conductive ring 12. The conductive ring 12 is connected to the insulating ring 11 and is disposed around the outer periphery of the insulating ring 11. (See reference...) Figure 3 Furthermore, the shielding module also includes an auxiliary electrode 2, which is at least partially disposed in the electroplating cavity 6a and electrically connected to the conductive ring 12, so as to electrically connect the conductive ring 12 to the ground potential 64 or the negative terminal of the power supply, and guide the current refracted to the surface of the conductive ring 12 in the electroplating cavity 6a to the outside of the electroplating cavity 6a, thereby precisely controlling the thickness of the electroplating layer in the edge region of the wafer 62.

[0066] Specifically, the insulating ring 11 is made of insulating materials such as PEEK (Polyetheretherketone), and the conductive ring 12 is made of metal materials such as titanium alloy. When the edge of the wafer 62 is blocked by the insulating ring 11 of a single material, the blocked electric field is refracted within the electroplating cavity 6a, forming a current. This makes it difficult to precisely control the plating thickness at the edge of the wafer 62 during the electroplating process. The blocking module of this invention blocks the electric field through the insulating ring 11 and shunts it through the conductive ring 12. Compared with the insulating ring 11 of a single material, it can conduct the refracted current within the electroplating cavity 6a to the outside of the electroplating cavity 6a through the conductive ring 12, achieving more precise control over the plating thickness at the edge of the wafer 62. Through the synergistic effect of the insulating ring 11 and the conductive ring 12, the edge effect during the electroplating process is improved, thereby avoiding plating abnormalities caused by electric field refraction, improving the uniformity and consistency of the plating, and thus improving the electrical performance and mass production yield of the device.

[0067] Furthermore, the inner diameter of the insulating ring 11 is smaller than the diameter of the wafer 62, and the outer diameter of the insulating ring 11 is larger than the diameter of the wafer 62, so that the insulating ring 11 can cover the edge region of the wafer 62. In one embodiment, the radial width of the insulating ring 11 is 2-5 mm, and the radial width of the conductive ring 12 is 2-5 mm. It should be noted that the present invention does not limit the size of the insulating ring 11, and the sizes of the insulating ring 11 and the conductive ring 12 can be adaptively adjusted according to the size of the wafer 62 and the electric field strength.

[0068] Example 1

[0069] In one embodiment, the shielding module further includes a motor 34 and a transmission mechanism 3. The motor 34 drives the shielding part 1 to rotate along the axial direction of the conductive ring 12 through the transmission mechanism 3. The conductive ring 12 is electrically connected to the auxiliary electrode 2 through a sliding contact.

[0070] See Figure 4 The transmission mechanism 3 includes a rotary drive 31, which is disposed within the electroplating chamber 6a and connected to the output shaft of the motor 34. During the electroplating process, the outer peripheral surface of the conductive ring 12 contacts the rotary drive 31, causing the conductive ring 12 and the insulating ring 11 to rotate under the drive of the rotary drive 31. This adjusts the electric field distribution and current density in the edge region of the wafer 62, improves the uniformity of the current density in the edge region of the wafer 62, and enhances the uniformity and consistency of the plating thickness at the edge of the wafer 62. The rotary drive 31 and the outer peripheral surface of the conductive ring 12 are driven by gear meshing, making the shielding module structure more compact, saving space, with higher reliability, and convenient maintenance.

[0071] See Figure 3 In some embodiments, the auxiliary electrode 2 includes a conductive base 21 and a conductive ball 22. A portion of the conductive ball 22 is embedded in the conductive base 21 and can rotate relative to it. The conductive ball 22 abuts against the conductive ring 12, allowing the shielding part 1 to rotate more smoothly. Further, the conductive base 21 is fixed to the electroplating cavity 6a and electrically connected to ground potential 64 or the negative terminal of the power supply via a wiring harness. The conductive path of the current refracted to the shielding part 1 within the electroplating cavity 6a is: conductive ring 12 - conductive ball 22 - conductive base 21 - ground potential 64 or the negative terminal of the power supply, guiding this current to the outside of the electroplating cavity 6a, improving the uniformity of the plating layer. Furthermore, this process requires no manual intervention and is convenient to operate.

[0072] Optionally, the auxiliary electrode 2 also includes a ball 23. The conductive seat 21 is provided with a connected receiving cavity 21a and a receiving groove 21b for accommodating the conductive ball 22 and the ball 23, respectively. When the conductive ring 12 is driven to rotate by the rotary drive 31, the conductive ball 22 can rotate relative to the conductive seat 21 through the ball 23, so that the rotation of the conductive ring 12 is smoother.

[0073] In one embodiment, the conductive base 21 includes a mounting post segment 211, a receiving cavity 21a, and a receiving groove 21b disposed on the mounting post segment 211. A mounting flange 212 is provided at the end of the mounting post segment 211 away from the conductive ring 12. The mounting flange 212 facilitates installation and improves installation stability and reliability. Specifically, the mounting flange 212 and the base 6 are respectively provided with corresponding mounting holes 212a for fasteners to pass through. The fasteners pass through the mounting holes 212a of the mounting flange 212 and are fixedly connected to the base 6 by means of threaded connection or riveting, thus fixing the conductive base 21 into the electroplating cavity 6a of the base 6.

[0074] Example 2

[0075] See Figure 1 and Figure 5 The main difference between this embodiment and Embodiment 1 is that the transmission mechanism 3 further includes a driven member 32, which is disposed between the rotary drive member 31 and the conductive ring 12. The rotary drive member 31 drives the blocking part 1 to rotate through the driven member 32. It should be noted that in other embodiments, the rotary drive member 31 and the outer peripheral surface of the conductive ring 12 can also be driven by belt transmission. The blocking module of the present invention does not limit the specific transmission method of the transmission structure 3.

[0076] In one embodiment, the shielding module further includes a limiting part 4, which is fixed relative to the electroplating cavity 6a. The limiting part 4 can be integrally formed with the base 6, or fixed to the electroplating cavity 6a by means of fastener connection, interference fit, or riveting. The limiting part 4 is used to limit the position of the shielding part 1 relative to the electroplating cavity 6a, improving the stability of the transmission, thereby improving the uniformity and consistency of the wafer plating thickness. Specifically, the limiting part 4 has a through clearance groove 43 for avoiding the transmission mechanism 3 (e.g., Figure 5 As shown), the edge of the follower 32 passes through the clearance groove 43 and contacts the conductive ring 12.

[0077] Furthermore, the limiting part 4 includes a limiting plate 41 and a limiting edge 42. The limiting plate 41 is used to limit the relative position between the shielding part 1 and the electroplating cavity 6a along the radial direction of the conductive ring 12, and the limiting edge 42 is used to limit the relative position between the shielding part 1 and the electroplating cavity 6a along the axial direction of the conductive ring 12. Specifically, the limiting plate 41 has an inner circumferential surface facing the axial direction of the conductive ring 12, and the limiting plate 41 protrudes radially from its inner circumferential surface to form the limiting edge 42. The limiting edge 42 is located on the side of the conductive ring 12 away from the auxiliary electrode 2, and a portion of the conductive ring 12 is sandwiched between the limiting edge 42 and the auxiliary electrode 2.

[0078] Continue reading Figure 1 and Figure 5A flow equalization plate 5 is provided inside the electroplating chamber 6a. The flow equalization plate 5 is located between the shielding part 1 and the plating head 61 and can rotate relative to the electroplating chamber 6a. When the shielding module of the present invention is used in electroplating processes such as high resistivity electroplating solutions or precious metal alloy electroplating solutions (such as Au and Ag alloy solutions), the flow equalization plate 5 can improve the flow field in the electroplating chamber 6a, making the current distribution more uniform, thereby improving the edge effect and enhancing the uniformity of the wafer plating thickness. In this embodiment, the transmission mechanism 3 also includes a transmission member 33 coaxially arranged with the driven member 32. The transmission member 33 is located above the driven member 32 and fixed relative to the driven member 32. The outer peripheral surface of the flow equalization plate 5 is in contact with the transmission member 33 so that the flow equalization plate 5 can rotate under the drive of the driven member 32 through the transmission member 33.

[0079] like Figure 5 As shown, both the transmission component 33 and the flow equalizer 5 are gear-shaped. The transmission component 33 and the flow equalizer 5 are connected by gear meshing. The edge of the transmission component 33 passes through the clearance groove 43 and meshes with the flow equalizer 5. The limiting plate 41 and the limiting edge 42 are also used to limit the position of the flow equalizer 5 relative to the electroplating cavity 6a along the radial and axial directions of the conductive ring 12, thereby improving reliability. The flow equalizer 5 and the conductive ring 12 are located on the upper and lower sides of the limiting edge 42, respectively, making the structure of the shielding module compact and thus saving space.

[0080] During the electroplating process, the motor 34 drives the rotary drive component 31 to rotate, which in turn drives the driven component 32 and the transmission component 33 to rotate, thereby causing the shielding part 1 and the flow equalizing plate 5 to rotate, thus achieving the same rotational speed between the flow equalizing plate 5 and the insulating ring 11. By coaxially arranging the driven component 32 and the transmission component 33, the number of parts is reduced, the structure is compact, and space is saved. It is understood that in other embodiments, the electroplating equipment may also add a rotary drive component to independently drive the flow equalizing plate 5 to rotate, so that the insulating ring 11 and the flow equalizing plate 5 have different rotational speeds, so that the difference in rotational angular velocity between the insulating ring 11 and the flow equalizing plate 5 can adapt to different electroplating process requirements. In this embodiment, the installation method of the flow equalizing plate 5 and the shielding part 1 is roughly the same, and will not be described again here.

[0081] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A shielding module, the shielding module comprising an insulating ring for being disposed within an electroplating chamber, characterized in that, The blocking module also includes: A conductive ring is connected to the insulating ring and is disposed around the outer periphery of the insulating ring; An auxiliary electrode is provided, which is disposed in the electroplating chamber and electrically connected to the conductive ring to connect the conductive ring to ground potential or the negative terminal of the power supply. The shielding module also includes a transmission mechanism, which includes a rotary drive member disposed in the electroplating chamber. The outer circumferential surface of the conductive ring contacts the rotary drive member so that the conductive ring and the insulating ring rotate under the drive of the rotary drive member. The conductive ring is electrically connected to the auxiliary electrode via a sliding contact method; The shielding module includes a limiting part for fixing relative to the electroplating cavity. The limiting part includes a limiting plate with an inner circumferential surface facing the conductive ring in the axial direction. The limiting plate is used to define the relative position of the insulating ring and the electroplating cavity along the radial direction of the conductive ring. The limiting plate extends radially from its inner circumferential surface along the conductive ring to form a limiting edge. The limiting edge is located on the side of the conductive ring away from the auxiliary electrode. A portion of the conductive ring is sandwiched between the limiting edge and the auxiliary electrode to define the relative position of the insulating ring along the axial direction of the conductive ring and the electroplating cavity. The auxiliary electrode includes a conductive base and a conductive ball. The conductive base is used to fix it to the electroplating chamber. The conductive ball abuts against the conductive ring. A portion of the conductive ball is embedded in the conductive base and rotates relative to the conductive base. The auxiliary electrode includes a ball bearing, and the conductive base is provided with a communicating receiving cavity and a receiving groove for accommodating the conductive ball and the ball bearing, respectively. When the conductive ring is driven to rotate by the rotary drive, the conductive ball rotates relative to the conductive seat via the ball bearing.

2. The shading module as described in claim 1, characterized in that, The rotary drive component and the outer peripheral surface of the conductive ring are driven by tooth meshing; And / or, the transmission mechanism includes a driven member disposed between the rotary drive member and the conductive ring, wherein the rotary drive member drives the conductive ring and the insulating ring to rotate through the driven member.

3. The blocking module as described in claim 1, characterized in that, The conductive base includes a mounting column section, the receiving cavity and the receiving groove are disposed in the mounting column section, and a mounting flange is provided at the end of the mounting column section away from the conductive ring.

4. An electroplating device, characterized in that, The device includes an electroplating chamber, a plating head, and a shielding module as described in any one of claims 1 to 3. The electroplating chamber is used to hold an electrolyte, the plating head is used to hold a wafer into or away from the electroplating chamber, an anode is provided in the area of ​​the electroplating chamber corresponding to the plating head, and the shielding module is located between the anode and the wafer.

5. The electroplating equipment as described in claim 4, characterized in that, A flow equalization plate is provided inside the electroplating chamber. The flow equalization plate is located between the shielding module and the plating head and rotates relative to the electroplating chamber. The flow equalization plate is used to improve the flow field inside the electroplating chamber.

6. The electroplating equipment as described in claim 5, characterized in that, It also includes a driven member and a transmission member arranged coaxially. The transmission member is fixed relative to the driven member, and the outer peripheral surface of the flow equalizer is in contact with the transmission member so that the flow equalizer rotates under the drive of the driven member through the transmission member.

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