Uniform overflow device for improving electroplating quality of wafer

Abstract

The utility model belongs to the field of electroplating overflow, and particularly relates to a uniform overflow device for improving wafer electroplating quality, which comprises a side wall baffle arranged on the circumference of an electroplating overflow cavity, and a uniform overflow device arranged at the opening end of the side wall baffle. The problems that the electroplating quality is affected and electroplating defects are caused due to the fact that by-products in the electroplating liquid cannot be discharged in time due to the non-uniformity of the flow direction of the electroplating liquid are solved, and the technical effects that the by-products in the electroplating liquid can be discharged in time, the electroplating quality is improved, and the defects such as cavities are avoided are achieved.

Description

Technical Field

[0001] The utility model belongs to the field of electroplating overflow, and in particular relates to a uniform overflow device for improving wafer electroplating quality. Background Art

[0002] In order to ensure the quality of electroplating, the wafer electroplating chamber needs to continuously replenish the plating solution, using an overflow structure;

[0003] The prior art wafer electroplating is provided with an electroplating overflow chamber, and the electroplating liquid flows in from the bottom center hole and flows upward. When it exceeds the height of the side wall baffle, the electroplating liquid flows outward and downward from the side wall baffle and flows back to the electroplating liquid tank through the drainage hole to replenish the filtered electroplating liquid with a higher ion concentration, and take away the byproducts of the electroplating process and the bubbles when entering the water;

[0004] In the prior art, the wafer electroplating is provided with an electroplating overflow chamber. The electroplating liquid flows upward from the bottom. When it exceeds the height of the side wall baffle, the electroplating liquid flows outward and downward from the side wall baffle. Due to surface tension, even if the level is adjusted well, the electroplating liquid will always find the weakest part of the side wall to flow away. This will cause a problem. The electroplating liquid does not flow uniformly from the center to the outside. The gray area travels a long path to reach the strong overflow area and is discharged. Figure 8 As shown in the figure, when the wafer is rotated for electroplating, the movement path is longer, and the by-products in the electroplating solution will not be discharged in time, affecting the electroplating quality, resulting in the following Fig. 9 In addition, the actual observation of 0.5mm to 10mm bubbles generated when electroplating into water, under the influence of surface tension during rotary electroplating, circles around the side baffle and is not easy to be discharged. It exists in the entire electroplating process, affecting the electroplating quality and causing defects.

[0005] In summary, the prior art has the problem that due to the uneven flow direction of the plating solution during the actual wafer rotation electroplating, the by-products in the plating solution are not discharged in time, which in turn affects the electroplating quality and causes electroplating defects. Utility Model Content

[0006] In view of this, the utility model aims to propose a uniform overflow device for improving the quality of wafer electroplating, so as to solve the problem in the prior art that due to the uneven flow direction of the plating solution during the actual wafer rotation electroplating, the by-products in the plating solution will not be discharged in time, thereby affecting the electroplating quality and causing electroplating defects.

[0007] In order to achieve the above object, the technical solution of the utility model is implemented as follows:

[0008] A uniform overflow device for improving wafer electroplating quality, comprising an electroplating overflow chamber (101), wherein the electroplating overflow chamber (101) contains an electroplating solution (104) and an electroplating solution circulation device (102), wherein the electroplating solution (104) is driven to rotate and flow by a driving mechanism (105), and the top end of the driving mechanism (105) is axially connected to a wafer (106) to be processed;

[0009] A side wall baffle (103) is arranged around the circumference of the electroplating overflow chamber (101), and a uniform overflow device (1030) is arranged at the mouth end of the side wall baffle (103).

[0010] Furthermore, the uniform overflow device (1030) comprises overflow notches (1031) circumferentially and radially distributed at the mouth end of the side wall baffle (103).

[0011] Furthermore, the overflow notch (1031) is arranged in a direction that radiates outward in a divergent manner with the axis of the driving mechanism (105) as the center.

[0012] Furthermore, the overflow notch (1031) is disposed in a direction opposite to the tangent direction of the rotating flow of the electroplating solution (104).

[0013] Furthermore, the number of the overflow notches (1031) is 10 to 100 and is circumferentially and radially distributed at the mouth of the side wall baffle (103).

[0014] Furthermore, the overflow notch (1031) is in the shape of a vertical notch perpendicular to the side wall baffle (103) with a width of 1 mm to 3 mm and a depth of 0.3 mm to 1 mm.

[0015] Furthermore, the electroplating liquid (104) is driven by the driving mechanism (105) to flow into the central hole at the bottom of the electroplating overflow chamber (101) and rotate and overflow upward.

[0016] Furthermore, the overflow notch (1031) extends radially outward to form a small guide baffle (10310).

[0017] Furthermore, the extension length of the small guide baffle (10310) is 5 mm to 15 mm and the extension thickness is 0.5 mm to 3 mm.

[0018] Furthermore, an anode plate (1032) is arranged on the inner surface of the side wall baffle (103) of the electroplating overflow chamber (101), and the space surrounded by the anode plate (1032) is an anode chamber (10320), a cathode cover (10321) is arranged at the top end of the anode chamber (10320), a diffusion plate (10322) is arranged in the anode chamber (10320) below the cathode cover (10321), and a filter membrane (10323) is arranged below the diffusion plate (10322).

[0019] Compared with the prior art, the uniform overflow device for improving the quality of wafer electroplating described in the utility model has the following beneficial effects:

[0020] The uniform overflow device of the utility model passes through the electroplating overflow chamber in the electroplating liquid tank, and the electroplating liquid in the electroplating overflow chamber flows in from the bottom center hole and rotates and overflows upward, so as to electroplate the wafer. At the same time, since the electroplating principle is to use the electroplating liquid to flow in from the bottom center hole and flow upward, when it exceeds the height of the side wall baffle, the electroplating flows outward and downward from the side wall baffle and flows back to the electroplating liquid tank through the drainage hole, replenishing the filtered electroplating liquid with a higher ion concentration, taking away the by-products of the electroplating process and the bubbles when entering the water, such as Fig.10 As shown, during the whole process, the wafer rotates into the liquid at an inclined angle, thereby avoiding bubbles entering the water, and its overflow process includes: the first step: the wafer surface is tilted at a certain angle under the control of the driving mechanism; the second step: the wafer rotates around the axis; the third step: the Z axis of the entire mechanism moves downward to contact the liquid surface; the fourth step: the inclination angle returns to 0 after contacting the liquid surface; in order to make the flow direction of the plating liquid uniform and discharge the by-products in the plating liquid in time, a side wall baffle is arranged on the circumference of the plating overflow cavity, and a uniform overflow device is arranged at the mouth end of the side wall baffle. Through the setting of the above-mentioned side wall baffle, because the notch is not deep, the surface tension of the baffle still exists at the non-notch position, and the liquid flows out evenly from the local artificially created weak point to the outside, and the by-products in the plating liquid will be discharged in time, thereby improving the plating quality and avoiding defects such as voids. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the accompanying drawings:

[0022] Figure 1 It is a structural schematic diagram of the uniform overflow device described in an embodiment of the utility model;

[0023] Figure 2 It is a schematic diagram of the principle of the electroplating overflow chamber according to an embodiment of the utility model;

[0024] Figure 3 A schematic diagram of the structure of the overflow notch of the uniform overflow device according to an embodiment of the utility model;

[0025] Figure 4 It is a structural schematic diagram of a divergent overflow notch of a uniform overflow device according to an embodiment of the utility model;

[0026] Figure 5 It is a structural schematic diagram of a tangent overflow notch of a uniform overflow device according to an embodiment of the utility model;

[0027] Figure 6 A schematic diagram of the structure of a small guide baffle of a uniform overflow device according to an embodiment of the utility model;

[0028] Figure 7 It is a structural schematic diagram of the electroplating overflow chamber according to an embodiment of the utility model;

[0029] Figure 8 This is a diagram of the rotational flow direction of the electroplating liquid during the prior art rotary electroplating of the utility model;

[0030] Fig. 9 This is a diagram of the void defect caused by the failure of timely removal of byproducts in the prior art of the utility model;

[0031] Fig.10 This is a flow chart of the overflow process of the wafer rotating at an inclined angle in the prior art of the utility model;

[0032] Description of reference numerals:

[0033] 101-electroplating overflow chamber, 102-electroplating solution circulation device, 103-side wall baffle, 104-electroplating solution, 105-driving mechanism, 106-wafer;

[0034] 1030-uniform overflow device, 1031-overflow notch, 10310-small guide baffle;

[0035] 1032- anode plate, 10320- anode chamber, 10321- cathode cover, 10322- diffusion plate, 10323- filter membrane. DETAILED DESCRIPTION

[0036] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0037] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "multiple" means two or more.

[0038] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it 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 it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0039] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0040] See also Figure 1 , 2 As shown, in the embodiment of the utility model, a uniform overflow device for improving the quality of wafer electroplating is provided, including an electroplating overflow chamber 101, wherein the electroplating overflow chamber 101 contains a plating solution 104 and a plating solution circulation device 102, wherein the plating solution 104 is driven to rotate and flow by a driving mechanism 105, and the top end of the driving mechanism 105 is axially connected to a wafer 106 to be processed;

[0041] A side wall baffle 103 is disposed around the electroplating overflow chamber 101 , and a uniform overflow device 1030 is disposed at the mouth of the side wall baffle 103 .

[0042] The uniform overflow device of the utility model passes through the electroplating overflow chamber in the electroplating liquid tank, and the electroplating liquid in the electroplating overflow chamber flows in from the bottom center hole and rotates and overflows upward, so as to electroplate the wafer. At the same time, since the electroplating principle is to use the electroplating liquid to flow in from the bottom center hole and flow upward, when it exceeds the height of the side wall baffle, the electroplating flows outward and downward from the side wall baffle and flows back to the electroplating liquid tank through the drainage hole, replenishing the filtered electroplating liquid with a higher ion concentration, taking away the by-products of the electroplating process and the bubbles when entering the water, such as Fig.10 As shown, during the whole process, the wafer rotates into the liquid at an inclined angle, thereby avoiding bubbles entering the water, and the overflow process includes: the first step: the wafer surface is tilted at a certain angle under the control of the driving mechanism; the second step: the wafer rotates around the axis; the third step: the Z axis of the entire mechanism moves downward to contact the liquid surface; the fourth step: the inclination angle returns to 0 after contacting the liquid surface; in order to make the flow direction of the plating liquid uniform and discharge the by-products in the plating liquid in time, a side wall baffle is arranged on the circumference of the plating overflow cavity, and a uniform overflow device is arranged at the mouth end of the side wall baffle. Through the setting of the above-mentioned side wall baffle, because the notch is not deep, the surface tension of the baffle still exists at the non-notch position, and the liquid flows out evenly from the local artificially created weak point to the outside, and the by-products in the plating liquid will be discharged in time, thereby improving the plating quality and avoiding defects such as voids.

[0043] See also Figure 3As shown, the uniform overflow device 1030 includes overflow notches 1031 circumferentially and radially distributed at the mouth end of the side wall baffle 103 .

[0044] The utility model utilizes the overflow notch as a uniform overflow device. Since a notch with a depth in the vertical direction is opened on the side wall baffle, since the notch is not deep, the surface tension of the baffle still exists at the non-notch position, and the liquid flows out uniformly from the local artificially created weak point to the outside, the by-products in the electroplating solution will be discharged in time, the electroplating quality will be improved, and defects such as voids will not be easily caused.

[0045] See also Figure 4 As shown, the setting direction of the overflow notch 1031 is divergent and radiates outward with the axis of the driving mechanism 105 as the center.

[0046] The utility model adopts a gap setting direction that takes the axis of the driving mechanism as the center of the circle and radiates outward in a divergent shape. As a gap shape setting method, the divergent form is conducive to timely discharge of by-products and bubbles generated in the electroplating process, thereby reducing electroplating defects.

[0047] See also Figure 5 As shown, the setting direction of the overflow notch 1031 may be opposite to the tangential direction of the rotating flow of the electroplating solution 104 .

[0048] The utility model adopts a notch setting direction that is opposite to the tangential direction of the rotating flow of the electroplating liquid as another notch shape setting method. Considering that during the electroplating process, the wafer rotates clockwise or counterclockwise, the electroplating liquid rotates with the wafer while overflowing upward, so the notch can also be opened in the tangential direction of the liquid rotation to facilitate liquid outflow.

[0049] The number of the overflow notches 1031 is 10 to 100 and is circumferentially and radially distributed at the mouth of the side wall baffle 103 .

[0050] The overflow notch 1031 is shaped as a vertical notch perpendicular to the side wall baffle 103 with a width of 1 mm to 3 mm and a depth of 0.3 mm to 1 mm.

[0051] The utility model adopts a notch with a depth of about 0.3-1mm in the vertical direction on the side wall baffle. The direction of the notch is through the center of the circle, and can also be the tangent direction of the liquid rotation. The width is 1mm-3mm, and 10-100 are evenly distributed around the circumference. As set above, the by-products in the electroplating solution can be discharged in time, which effectively improves the electroplating quality and is not easy to cause defects such as voids.

[0052] The electroplating solution 104 is driven by the driving mechanism 105 to flow into the electroplating overflow chamber 101 from the bottom center hole and rotate upward to overflow.

[0053] The utility model adopts a central spiral rotating overflow method. Since the wafer rotates into the liquid at an inclined angle during the whole process, bubbles entering the water are avoided. Under the control of the driving mechanism, the wafer surface is inclined at a certain angle, and the wafer rotates around the axis. The Z axis of the entire mechanism moves downward to contact the liquid surface. After contacting the liquid surface, the inclination angle returns to 0, thereby improving the electroplating effect.

[0054] See also Figure 6 As shown, the overflow notch 1031 extends radially outward to form a small guide baffle 10310 .

[0055] In order to further evenly and quickly bring out the plating liquid close to the inner wall and the bubbles generated when entering the water, the utility model can add a small guide baffle extending vertically downward in the direction of the notch. When the surface rotating plating liquid and bubbles that have participated in the reaction encounter the baffle, they will be blocked and discharged from the notch nearby along the shortest path.

[0056] The extension length of the guide baffle 10310 is 5 mm to 15 mm and the extension thickness is 0.5 mm to 3 mm.

[0057] The utility model has a small guide baffle plate that extends 5-15 mm downward in the vertical direction and has a thickness of 0.5-3 mm, which is the most optimized extension parameter.

[0058] See also Figure 7 As shown, an anode plate 1032 is arranged on the inner surface of the side wall baffle 103 of the electroplating overflow chamber 101, and the space surrounded by the anode plate 1032 is an anode chamber 10320. A cathode cover 10321 is arranged at the top end of the anode chamber 10320, a diffusion plate 10322 is arranged in the anode chamber 10320 below the cathode cover 10321, and a filter membrane 10323 is arranged below the diffusion plate 10322.

[0059] The utility model adopts an anode chamber surrounded by an anode plate, which is then covered by a cathode cover. At the same time, a diffusion plate is arranged in the anode chamber, a filter membrane is arranged under the diffusion plate, and an electroplating overflow chamber is arranged for wafer electroplating. The electroplating liquid flows in from the bottom center hole and flows upward. When it exceeds the height of the side wall baffle, the electroplating liquid flows outward and downward from the side wall baffle and flows back to the electroplating liquid tank through the drainage hole to supplement the filtered electroplating liquid with a higher ion concentration and take away the by-products in the electroplating process and the bubbles when entering the water.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A uniform overflow device for improving wafer electroplating quality, characterized in that: The electroplating overflow chamber (101) comprises an electroplating solution (104) and an electroplating solution circulation device (102) therein, the electroplating solution (104) is driven to rotate and flow by a driving mechanism (105), and the top end of the driving mechanism (105) is axially connected to a wafer (106) to be processed; A side wall baffle (103) is arranged around the circumference of the electroplating overflow chamber (101), and a uniform overflow device (1030) is arranged at the mouth end of the side wall baffle (103).

2. The uniform overflow device according to claim 1, characterized in that: The uniform overflow device (1030) comprises overflow notches (1031) circumferentially and radially distributed at the mouth end of the side wall baffle (103).

3. The uniform overflow device according to claim 2, characterized in that: The overflow notch (1031) is arranged in a direction that radiates outward in a divergent manner with the axis of the driving mechanism (105) as the center of the circle.

4. The uniform overflow device according to claim 2, characterized in that: The overflow notch (1031) is arranged in a direction opposite to the tangent direction of the rotating flow of the electroplating solution (104).

5. The uniform overflow device according to claim 3 or 4, characterized in that: The number of the overflow notches (1031) is 10 to 100 and is circumferentially and radially distributed at the mouth of the side wall baffle (103).

6. The uniform overflow device according to claim 3 or 4, characterized in that: The overflow notch (1031) is in the shape of a vertical notch perpendicular to the side wall baffle (103) with a width of 1 mm to 3 mm and a depth of 0.3 mm to 1 mm.

7. The uniform overflow device according to claim 1, characterized in that: Driven by the driving mechanism (105), the electroplating liquid (104) flows into the central hole at the bottom of the electroplating overflow chamber (101) and rotates and overflows upward.

8. The uniform overflow device according to claim 3 or 4, characterized in that: The overflow notch (1031) radially extends outward to form a small guide baffle (10310).

9. The uniform overflow device according to claim 8, characterized in that: The extension length of the small guide baffle (10310) is 5 mm to 15 mm and the extension thickness is 0.5 mm to 3 mm.

10. The uniform overflow device according to claim 1, characterized in that: An anode plate (1032) is arranged on the inner surface of the side wall baffle (103) of the electroplating overflow chamber (101); a space surrounded by the anode plate (1032) is an anode chamber (10320); a cathode cover (10321) is arranged at the top of the anode chamber (10320); a diffusion plate (10322) is arranged in the anode chamber (10320) below the cathode cover (10321); and a filter membrane (10323) is arranged below the diffusion plate (10322).

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