Wafer electroplating device

Abstract

The present application provides a wafer electroplating apparatus, wherein the wafer electroplating apparatus comprises: an electroplating tank used to receive an electroplating solution and having an anode electrode installed therein; and a flow field plate installed between the anode electrode and the wafer, wherein a plurality of through holes are installed in the flow field plate to allow the electroplating solution to pass through and form a flow field, and the flow field plate comprises at least one flow field transition region, and each flow field transition region comprises at least two flow field regions with different electrical resistivity, wherein the maximum electrical resistivity in each flow field transition region is the minimum electrical resistivity in the flow field on one side where the maximum electrical resistivity is located among the two flow fields adjacent to each other in the radial direction, or the minimum electrical resistivity in the flow field transition region is the maximum electrical resistivity in the flow field on one side where the minimum electrical resistivity is located among the two flow fields adjacent to each other in the radial direction, and the flow field region with the maximum electrical resistivity or the flow field region with the minimum electrical resistivity within the flow field transition region extends to the boundary of one side of the flow field having the same electrical resistivity. The wafer electroplating device of the present application can uniformly form a wafer plating film.

Description

Technology Field

[0001] This application relates to the field of semiconductor technology, specifically to a wafer electroplating apparatus. Background Technology

[0002] In the integrated circuit manufacturing process, a plating film must typically be formed on the device, and methods for forming this film include electroplating, deposition, and printing. Electroplating is widely applied due to its relatively stable performance.

[0003] For example, in the case of plating a copper film on a wafer, in the conventional technology, a seed layer is typically formed on the wafer first, and then copper is electroplated on the seed layer. In order to obtain the largest possible copper plating area, the electrode is electrically in contact with the seed layer only at the wafer edge, and current flows from the wafer edge to the center of the wafer so that a plating film is formed over the entire wafer.

[0004] However, since the seed layer itself has electrical resistance, when current flows from the wafer edge to the center of the wafer through the seed layer, the current gradually decreases as the distance of flow increases. Therefore, at locations equidistant from the wafer edge, the current is equal and the film thickness is equal, but at locations equidistant from the wafer edge, the film thickness differs, forming a distinct thickness difference between different circumferences of the wafer, which affects the uniformity of the wafer plating film.

[0005] An embodiment of the present application provides a wafer electroplating apparatus and can form a wafer plating film more uniformly.

[0006] The present application provides a wafer electroplating apparatus, wherein the wafer electroplating apparatus is used to receive an electroplating solution and includes an electroplating tank in which an anode electrode is installed inside; and a flow field plate installed between the anode electrode and the wafer, wherein a plurality of through holes are installed in the flow field plate to allow the electroplating solution to pass through and form a flow field, and the flow field plate includes at least one flow field transition region, and each flow field transition region includes at least two flow field regions with different electrical resistivity, wherein the maximum electrical resistivity in each flow field transition region is the minimum electrical resistivity in the flow field on one side where the maximum electrical resistivity is located among the two flow fields adjacent to each other in the radial direction, or the minimum electrical resistivity in the flow field transition region is the maximum electrical resistivity in the flow field on one side where the minimum electrical resistivity is located among the two flow fields adjacent to each other in the radial direction, and the flow field region with the maximum electrical resistivity or the flow field region with the minimum electrical resistivity within the flow field transition region extends to the boundary of one side of the flow field having the same electrical resistivity.

[0007] Specifically, the maximum electrical resistivity in the flow field transition region is the minimum electrical resistivity in the flow field on one side where the maximum electrical resistivity is located among the adjacent two flow fields, and the minimum electrical resistivity in the flow field transition region is the maximum electrical resistivity in the flow field on the one side where the minimum electrical resistivity is located among the adjacent two flow fields.

[0008] Specifically, the flow field plate includes a central region, and the flow field transition region is installed to surround the central region.

[0009] Specifically, the electrical resistivity of each point within the central region is the same.

[0010] Specifically, each flow field transition region includes multiple flow field regions and fills the entire flow field transition region.

[0011] Specifically, in each flow field transition region, the electrical resistivity of any two adjacent flow field regions is different.

[0012] Specifically, in each flow field transition region, there are multiple flow field regions of each electrical resistivity, and flow field regions with the same electrical resistivity are uniformly distributed in the flow field transition region.

[0013] Specifically, each flow field transition region is annular.

[0014] Specifically, it includes multiple flow field transition regions, and the multiple flow field transition regions are installed adjacent to each other.

[0015] Specifically, the distance between the outermost annular line of the flow field transition region on the flow field plate and the center of the flow field plate is less than or equal to the wafer radius.

[0016] Specifically, in the radial direction of each flow field transition region, the flow field region with maximum electrical resistivity and / or the flow field region with minimum electrical resistivity occupies the maximum proportion on the annular boundary line on one side of the flow field transition region having the same electrical resistivity.

[0017] Specifically, the flow field region with maximum electrical resistivity and / or the flow field region with minimum electrical resistivity occupies 100% of the annular boundary line on one side of the flow field transition region having the same electrical resistivity.

[0018] Specifically, on the half-circular width line of each flow field transition region, the proportion occupied by the flow field region of each electric resistivity is the same.

[0019] Specifically, in the radial direction of each flow field transition region, the proportion occupied by the flow field region of maximum and / or minimum electrical resistivity changes gradually.

[0020] Specifically, in the radial direction of each flow field transition region, the proportion occupied by the flow field region of maximum and / or minimum electrical resistivity changes in a stepwise manner.

[0021] Specifically, the ratio of a flow field region with the same electrical resistivity within two adjacent flow field transition regions in the radial direction increases and then decreases again.

[0022] Specifically, at least two flow field regions are formed by dividing each flow field transition region equally in the periphery.

[0023] Specifically, in the flow field plate, the through holes within the flow field region where at least some of the electrical resistivity is the same are identical.

[0024] Specifically, in the flow field plate, the through hole size of the flow field region with at least some different electrical resistivity is different.

[0025] Specifically, in the flow field plate, the through-hole distribution density of the flow field region, where at least some of the electrical resistivity is different, is different.

[0026] Specifically, in the flow field plate, the through-hole depth of the flow field region, where at least some of the electrical resistivity is different, is different.

[0027] In the wafer electroplating apparatus of the present application, there is at least one flow field transition region on the flow field plate, and the electrical resistivity in the flow field transition region is located between the electrical resistivity of adjacent two flow fields, and the electrical resistivity of the flow field transition region can provide a transition with respect to the electrical resistivity of adjacent two flow fields, thereby enabling the wafer plating film to be formed more uniformly.

[0028] Other features and advantages of the present application will become apparent from the detailed description below or will be acquired in part through the practice of the present application.

[0029] It should be understood that the foregoing general description and the following detailed description are illustrative and interpretive only and are not intended to limit the present application. Brief explanation of the drawing

[0030] The attached drawings herein are incorporated into the specification and constitute part of the specification, illustrate embodiments conforming to the present application, and are used together with the specification to explain the principles of the present application. Clearly, in the following description, the attached drawings are merely some embodiments of the present application, and a person skilled in the art can obtain other drawings based on these drawings without creative effort. FIG. 1 is a structural diagram of a wafer electroplating apparatus according to one embodiment of the present application. FIG. 2 is a structural diagram of a flow field plate according to one embodiment of the present application. FIG. 3 is a structural diagram of a flow field transition region according to one embodiment of the present application. FIG. 4 is a structural diagram of a flow field plate according to one embodiment of the present application. FIG. 5 is a structural diagram of a flow field plate according to one embodiment of the present application. FIG. 6 is a structural diagram of a flow field plate according to one embodiment of the present application. FIG. 7 is a structural diagram of a flow field transition region according to one embodiment of the present application. FIG. 8 is a structural diagram of a flow field transition region according to one embodiment of the present application. FIG. 9 is a structural diagram of a flow field transition region according to one embodiment of the present application. FIG. 10 is a structural diagram of a flow field plate according to one embodiment of the present application. Specific details for implementing the invention

[0031] Exemplary embodiments are described more comprehensively below with reference to the accompanying drawings. However, exemplary embodiments may be implemented in various forms and should not be understood as being limited to the examples described herein. On the contrary, by providing such embodiments, this application becomes more comprehensive and complete, and the concept of exemplary embodiments is fully conveyed to those skilled in the art.

[0032] Additionally, the described features, structures, or properties may be combined in any suitable manner in one or more embodiments. In the following description, many specific details are provided to facilitate a full understanding of the embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application may be implemented without one or more of the specific details, or that other methods, components, devices, steps, etc. may be adopted. In other cases, known methods, devices, implementations, or operations are not illustrated or described in detail to prevent obscurity of each aspect of this application.

[0033] Referring to FIGS. 1 to 10, the present embodiment provides a wafer electroplating apparatus capable of improving the uniformity of the plating film on a wafer (1).

[0034] As illustrated in FIG. 1, a wafer electroplating apparatus comprises an electroplating tank (2), a chuck (3) that clamps and rotates a wafer (1), and a flow field plate (4) having a plurality of through holes. The electroplating solution (5) in the electroplating tank (2) contains plating layer cations, and an anode electrode (6) is further installed in the electroplating tank (2), and the electroplating solution (5) typically immerses the anode electrode (6). A cathode electrode (7) is installed in the chuck (3), and the chuck (3) is used to introduce the wafer (1) into the electroplating tank (2) or to remove it from the electroplating tank (2). The flow field plate (4) is installed between the anode electrode (6) and the wafer (1), and the electroplating solution (5) flows through the through holes on the flow field plate (4) to form a flow field on the flow field plate (4). The electrical resistance of the flow field affects the number of passing cations; if the electrical resistance of the flow field is high, the number of passing cations is small, and if the electrical resistance of the flow field is low, the number of passing cations is large. When the anode electrode (6) and the cathode electrode (7) are energized, plating layer cations in the electroplating solution (5) are precipitated, and the precipitated cations move to the cathode electrode (7) through the flow field, and the cations attach to the wafer (1) to form a plating layer. The flow field plate (4) is fitted to the shape of the electroplating tank (2) and may be square or circular, and the distribution range of through holes on the flow field plate (4) may be less than or equal to the area of ​​the wafer (1). In another embodiment of the present application, the distribution range of through holes on the flow field plate (4) may be larger than the area of ​​the wafer (1) and may be set as necessary.

[0035] As illustrated in FIG. 2, the flow field plate (4) includes a central region (41) and a flow field transition region (42) installed to surround the central region (41). The electrical resistivity of the flow field at each location within the central region (41) is the same, and the electrical resistivity of the flow field within the flow field transition region (42) varies. In the flow field transition region (42), some flow fields are flow field regions, and the electrical resistivity of the flow field at each location within the same flow field region is the same, and the flow field transition region (42) includes a plurality of flow field regions with different electrical resistivity. For example, the flow field transition region (42) may include a flow field region (421) with an electrical resistivity R1 and a flow field region (422) with an electrical resistivity R2, and R1 <R2이다. 유동장 플레이트(4)의 반경 방향에서, 유동장 전이 영역(42)에서의 최대 전기 저항률은 서로 인접한 양측 유동장(43) 중 최대 전기 저항률이 위치하는 일측의 유동장에서의 최소 전기 저항률일 수 있다. 예를 들면, 서로 인접한 양측 유동장(43) 중 일측의 유동장의 전기 저항률은 R0및 R1을 포함하고, 타측 유동장의 전기 저항률은 R2및 R3을 포함하고, R0<R1<R2<R3이면, 서로 인접한 양측 유동장(43) 중 최대 전기 저항률은 R3이고, 서로 인접한 양측 유동장(43) 중 최대 전기 저항률이 위치하는 일측의 유동장이 전기 저항률 R3의 유동장 영역이 위치하는 일측의 유동장이면, 유동장 전이 영역(42)에서의 최대 전기 저항률은 전기 저항률 R3의 유동장 영역이 위치하는 일측의 유동장에서의 최소 전기 저항률 R2이며, 이는 유동장 전이 영역(42)이 반경 방향에서 서로 인접한 일측의 유동장과 동일한 전기 저항률을 갖도록 한다. 유동장 전이 영역(42) 내 전기 저항률이 최대인 유동장 영역은 그와 동일한 전기 저항률을 갖는 일측의 유동장의 경계까지 연장되어, 경계와 서로 인접한 일측의 유동장이 동일한 전기 저항률을 갖도록 한다.For example, a flow field region (422) having an electrical resistivity of R2 within a flow field transition region (42) is extended to the boundary of a flow field on one side having an electrical resistivity of R2, so that when electroplating is performed on a rotating wafer (1) during the electroplating process, the film layer formed by cations passing through the flow field transition region (42) and the film layer formed by cations passing through a flow field on one side where the maximum electrical resistivity is located are smoothly transitioned at the boundary point, thereby causing the film layer thickness of the wafer (1) to change smoothly in the radial direction and mitigating the thickness difference between different circumferences on the wafer (1), thereby improving the uniformity of the plating film. In one embodiment of the present application, if the electrical resistivity of the flow field on one side where the maximum electrical resistivity is located among the two adjacent flow fields (43) is of one type, the maximum electrical resistivity in the flow field transition region (42) is the electrical resistivity of the flow field on the one side where the maximum electrical resistivity is located, and the flow field region where the maximum electrical resistivity is located in the flow field transition region (42) extends to the boundary of the flow field on the one side where the maximum electrical resistivity is located among the two adjacent flow fields (43). For example, the electrical resistivitys of the two adjacent flow fields (43) are R1 and R2, respectively, and R1 <R2이면, 유동장 전이 영역(42) 중 최대 전기 저항률은 서로 인접한 양측 유동장(43) 중 최대 전기 저항률이 위치하는 일측의 유동장의 전기 저항률 R2이며, 유동장 전이 영역(42) 중 전기 저항률이 R2인 유동장 영역(422)은 서로 인접한 양측 유동장(43) 중 최대 전기 저항률 R2가 위치하는 일측의 유동장의 경계까지 연장된다.

[0036] Specifically, the radial direction of the flow field plate (4) is a direction from the center of the flow field plate toward the edge of the flow field plate, or from the edge of the flow field plate toward the center of the flow field plate. Hereinafter, the radial direction refers to the radial direction of the flow field plate (4). The two adjacent flow fields (43) in the radial direction of the flow field transition area (42) refer to flow fields located in the radial direction of the flow field transition area (42) while adjacent to the boundary of the flow field transition area (42). The adjacent flow fields refer to flow fields adjacent to the inner boundary of the flow field transition area (42) or flow fields adjacent to the outer boundary of the flow field transition area (42). The inner boundary of the flow field transition region (42) refers to the boundary of the flow field transition region (42) that is closer to the center of the flow field plate, and the outer boundary of the flow field transition region (42) refers to the boundary of the flow field transition region (42) that is closer to the edge of the flow field plate. The center of the flow field plate refers to the location where the electroplating solution (5) passes through to perform electroplating on the center of the wafer (1) on the flow field plate (4), and if the flow field plate (4) is circular, the center of the flow field plate may be the center of the circle of the flow field plate (4). Electrical resistivity refers to the resistance value per unit area of ​​the flow field plate (4). In another embodiment of the present application, the number of flow field transition regions (42) may be multiple.

[0037] In the radial direction of the flow field plate (4), the minimum electrical resistivity in the flow field transition region (42) may be the maximum electrical resistivity in the flow field on one side where the minimum electrical resistivity is located among the two adjacent flow fields (43), and the flow field region with the minimum electrical resistivity within the flow field transition region (42) extends to the boundary of the flow field on one side having the same electrical resistivity. For example, the electrical resistivity of the flow field on one side among the two adjacent flow fields (43) includes R0 and R1, and the electrical resistivity of the flow field on the other side includes R2 and R3, and R0 <R1<R2<R3이면, 서로 인접한 양측 유동장(43) 중 최소 전기 저항률은 R0이고, 서로 인접한 양측 유동장(43) 중 최소 전기 저항률이 위치하는 일측의 유동장이 전기 저항률 R0의 유동장 영역이 위치하는 일측의 유동장이면, 유동장 전이 영역(42)에서의 최소 전기 저항률이 전기 저항률 R0의 유동장 영역이 위치하는 일측의 유동장에서의 최대 전기 저항률 R1이며, 전기 저항률이 R1인 유동장 영역(421)은 전기 저항률이 R0인 일측의 유동장까지 연장되어, 유동장 전이 영역(42)과 최소 전기 저항률이 위치하는 일측의 유동장 사이에 동일한 전기 저항률이 존재하게 되고, 경계와 최소 전기 저항률이 위치하는 일측의 유동장 사이에 동일한 전기 저항률이 존재하게 되므로, 유동장 전이 영역(42)을 통과한 양이온에 의해 형성된 막층과 최소 전기 저항률이 위치하는 일측의 유동장을 통과한 양이온에 의해 형성된 막층이 경계 지점에서 매끄럽게 전이되도록 하여, 도금막의 균일성을 향상시킨다. 전기 저항률은 최소 전기 저항률이 위치하는 일측의 유동장, 유동장 전이 영역(42)으로부터 최대 전기 저항률이 위치하는 일측의 유동장까지 점차 증가하며, 유동장 전이 영역(42)의 서로 인접한 양측 유동장(43)이 유동장 전이 영역(42) 없이 직접 서로 인접하는 경우에 비해, 유동장 플레이트(4)에서 전기 저항률 변화를 더욱 매끄럽게 할 수 있어, 균일한 도금막 형성에 더욱 유리하다.In one embodiment of the present application, if the electrical resistivity of the flow field on one side where the minimum electrical resistivity is located among the two adjacent flow fields (43) is of one type, the minimum electrical resistivity in the flow field transition region (42) is the electrical resistivity of the flow field on the one side where the minimum electrical resistivity is located, and the flow field region with the minimum electrical resistivity in the flow field transition region (42) extends to the boundary of the flow field on the one side where the minimum electrical resistivity is located among the two adjacent flow fields (43). For example, the electrical resistivitys of the two adjacent flow fields (43) are R1 and R2, respectively, and R1 <R2이면, 유동장 전이 영역(42) 중 최소 전기 저항률은 서로 인접한 양측 유동장(43) 중 최소 전기 저항률이 위치하는 일측의 유동장의 전기 저항률 R1이며, 유동장 전이 영역(42)에서의 최소 전기 저항률 유동장 영역은 서로 인접한 양측 유동장(43) 중 최소 전기 저항률 R1이 위치하는 일측의 유동장의 경계까지 연장된다.

[0038] In the adjacent flow fields (43) on both sides of the flow field transition area (42), the electrical resistivity of each flow field on one side may be one or more, and the electrical resistivity in the flow field on the side where the maximum electrical resistivity is located is greater than the electrical resistivity in the flow field on the side where the minimum electrical resistivity is located. For example, the electrical resistivity of the flow field on the inner side of the flow field transition area (42) may all be greater than the electrical resistivity of the flow field on the outer side, or the electrical resistivity of the flow field on the outer side of the flow field transition area (42) may all be greater than the electrical resistivity of the flow field on the inner side, wherein the inner flow field is a flow field closer to the center of the flow field plate than the flow field transition area (42), and the outer flow field is a flow field closer to the edge of the flow field plate than the flow field transition area (42). For example, the electrical resistivity at each point of the adjacent inner flow field is all R1, and the electrical resistivity at each point of the adjacent outer flow field is all R2, and R1 <R2이면, 유동장 전이 영역(42)은 전기 저항률 R1과 R2의 두 가지 유동장 영역을 포함할 수 있다.

[0039] The number of flow field regions in the flow field transition region (42) may exceed two, and the types of electrical resistivity may also exceed two. Each flow field region may have one or more flow field regions, and multiple flow field regions may fill the flow field transition region (42) to allow the plating film thickness to be controlled at all points in the flow field transition region (42). As shown in FIG. 3, there may be three types of electrical resistivity, R1, R2, and R3, respectively, where R1 <R2<R3이다. 도 4에 도시된 바와 같이, 전기 저항률의 종류는 4가지일 수 있으며, 각각 R1, R2, R3및 R4이고, 여기에서 R1<R2<R3<R4이다. 본 출원 실시예의 다른 실시방식에서, 유동장 전이 영역(42)에서, 유동장 영역 사이에 간격을 남길 수 있으며, 즉 유동장 전이 영역(42)에서의 일부 위치에 대해서만 전이를 수행하며, 회전하는 웨이퍼(1)에 전기도금을 수행할 때, 막층의 균일성도 향상시킬 수 있다.

[0040] In a plurality of flow field regions within a flow field transition region (42), the electrical resistivity of any two adjacent flow field regions is different, so that flow field regions with the same electrical resistivity are dispersed within the flow field transition region (42). This allows plating layer ions of different concentrations passing through the flow field transition region (42) to be mixed with each other, which is advantageous for forming a uniform plating film. Furthermore, flow field regions with the same electrical resistivity are uniformly distributed in each flow field transition region, thereby further improving the uniformity of the plating film. Here, each flow field region includes one or more rows of through holes, and the through holes within the same flow field region are identically and uniformly distributed. In each flow field transition region, the through holes in the flow field regions having the same electrical resistivity are identical, making the drilling operation easy. In each flow field transition region, flow field regions with different electrical resistivity have one or more of different through hole sizes, different through hole distribution densities, and different through hole depths. Specifically, when the through hole distribution density is the same and the through hole depth is the same, the electrical resistivity is lower as the through hole diameter is larger, and the electrical resistivity is higher as the through hole diameter is smaller. When the through hole depth is the same and the through hole diameter is the same, the electrical resistivity is lower as the through hole distribution is denser, and the electrical resistivity is higher as the through hole distribution is sparser. When the through hole distribution density is the same and the through hole diameter is the same, the electrical resistivity is lower as the through hole depth is shallower, and the electrical resistivity is higher as the through hole depth is deeper. In another embodiment of the present application, the through holes in the flow field region having the same electrical resistivity may differ, for example, the electrical resistivity of a flow field region having relatively deep and relatively high-density through holes may be the same as the electrical resistivity of a flow field region having relatively shallow and relatively low-density through holes.

[0041] Referring again to FIG. 4, the flow field transition region (42) may be an annular shape surrounding the central region (41) (the boundary of the flow field transition region is indicated by a dotted line in the drawing), which ensures that each point on the circumference corresponding to the flow field transition region (42) on the wafer (1) is uniformly plated, thereby further reducing the thickness difference between different circumferences on the wafer (1), and the center of the annular flow field transition region (42) may overlap with the center of the flow field plate, so that each point on the circumference of the wafer (1) corresponding to the annular flow field transition region (42) is uniformly plated.

[0042] The number of annular flow field transition regions (42) is multiple, and in FIG. 4, there may be three. Radial sides of the three flow field transition regions are, respectively, inner and outer flow fields (43). Multiple annular flow field transition regions (42) are installed adjacent to each other so that the electrical resistivity can be gradually changed between the multiple annular flow field transition regions (42). In the multiple annular flow field transition regions (42) installed adjacent to each other, the electrical resistivity can be gradually changed along the radial direction of the flow field plate (4), and the electrical resistivity is gradually changed from the electrical resistivity of the inner flow field (43) of the innermost annular flow field transition region (42) to the electrical resistivity of the outer flow field (43) of the outermost annular flow field transition region (42). In another embodiment of the present application, there may be only one annular flow field transition region (42).

[0043] If the electrical resistivity of the flow field changes continuously from the center of the flow field plate to the edge of the flow field plate and the trend of change is constant, that is, always changing from a small value to a large value or from a large value to a small value, then all annular flow field transition regions (42) on the flow field plate (4) can be installed adjacent to each other.

[0044] If the change trend of the flow field electrical resistivity changes from the center of the flow field plate to the edge of the flow field plate, that is, if the change trend includes at least two of the three change trends in which the electrical resistivity changes from a small value to a large value, the electrical resistivity changes from a large value to a small value, and the electrical resistivity does not change, then in the flow field of the flow field of the flow field plate (4), in some flow fields where the electrical resistivity changes continuously from a small value to a large value or the electrical resistivity changes continuously from a large value to a small value, a plurality of annular flow field transition regions (42) are installed adjacent to each other, and in some flow fields where the electrical resistivity does not change, annular flow field transition regions (42) are not installed.

[0045] For example, referring to FIG. 5, in a flow field where the electrical resistivity changes from a small value to a large value and then changes from a large value to a small value from the center of the flow field plate to the edge of the flow field plate, a first inner annular flow field transition region (42a), a first intermediate annular flow field transition region (42b), and a first outer annular flow field transition region (42c) adjacent to each other are sequentially installed, and the minimum electrical resistivity R2 in the first intermediate annular flow field transition region (42b) is the maximum electrical resistivity R2 in the first inner annular flow field transition region (42a), and the flow field region where the electrical resistivity is minimum (R2) within the first intermediate annular flow field transition region (42b) extends to the inner annular boundary line of the first intermediate annular flow field transition region (42b), and the maximum electrical resistivity R3 in the first intermediate annular flow field transition region (42b) is the first The flow field region in which the minimum electrical resistivity R3 is in the outer annular flow field transition region (42c) and the maximum electrical resistivity R3 is in the first intermediate annular flow field transition region (42b) extends to the outer annular boundary line of the first intermediate annular flow field transition region (42b).In a flow field where the electrical resistivity changes continuously from a large value to a small value, adjacent second inner annular flow field transition area (42d), second intermediate annular flow field transition area (42e), and second outer annular flow field transition area (42f) are installed sequentially, and the minimum electrical resistivity R2 in the second intermediate annular flow field transition area (42e) is the maximum electrical resistivity R2 in the second outer annular flow field transition area (42f), and the flow field area where the electrical resistivity is minimum (R2) within the second intermediate annular flow field transition area (42e) extends to the outer annular boundary line of the second intermediate annular flow field transition area (42e), and the maximum electrical resistivity R3 in the second intermediate annular flow field transition area (42e) is the minimum electrical resistivity R3 in the second inner annular flow field transition area (42d), and the electrical resistivity within the second intermediate annular flow field transition area (42e) The maximum (R3) flow field region extends to the inner annular boundary of the second intermediate annular flow field transition region (42e).

[0046] There may be another flow field between the inner annular line of the innermost annular flow field transition region (42) of the flow field plate (4) and the boundary of the center region (41), and there may also be another flow field between the outer annular line of the outermost annular flow field transition region (42) of the flow field plate (4) and the edge of the flow field plate. The distance between the outer annular line of the outermost flow field transition region (42) on the flow field plate (4) and the center of the flow field plate may be smaller or larger than the radius of the wafer (1). Since a certain distance remains between the flow field plate (4) and the wafer (1), when cations move from the flow field plate (4) to the wafer (1), they are diffused or concentrated according to the shape of the electroplating bath (2), and the cations reach the wafer (1). In another embodiment of the present application, as shown in FIG. 6, the flow field plate (4) includes three flow field transition regions, each of which is a flow field transition region (42g, 42f, and 42h), and the inner annular line of the innermost annular flow field transition region (42g) of the flow field plate (4) may be the boundary of the center region (41), and the distance between the outer annular line of the outermost flow field transition region (42h) on the flow field plate (4) and the center of the flow field plate may be equal to the radius of the wafer (1).

[0047] Referring again to FIG. 6, in a plurality of annular flow field transition regions (42g, 42f, and 42h) installed adjacent to each other, the maximum electrical resistivity flow field region of any one flow field transition region (42g, 42f, and 42h) occupies a maximum proportion on the annular boundary line on one side of an adjacent flow field transition region having the same electrical resistivity, preferably 100%. For example, in the flow field transition regions (42g, 42f, and 42h) of FIG. 5, the electrical resistivity is R0 <R1<R2<R3<R4이면, 유동장 전이 영역(42f)에서, 전기 저항률이 R2인 유동장 영역은 마찬가지로 전기 저항률이 R2인 유동장 전이 영역(42h) 일측의 환형 경계선 상에서 차지하는 비율이 최대이며, 즉 전기 저항률이 R2인 유동장 영역은 유동장 전이 영역(42f)의 외측 환형선 상에서 차지하는 비율이 최대이므로, 해당 측 환형 경계선 상의 전기 저항률이 유동장 전이 영역(42f)에서의 최대 전기 저항률이 되며, 그와 동일한 전기 저항률을 갖는 서로 인접한 유동장 전이 영역(42h)에서의 전기 저항률은 모두 최대 전기 저항률 R2이상이 되도록 하고, 해당 측 환형 경계선은 유동장 전이 영역(42h)과 서로 인접한 유동장 전이 영역(42f)에 전이를 제공하여, 도금막을 더욱 균일하게 한다.

[0048] Furthermore, in the radial direction of each flow field transition region (42), the proportion of the flow field region with maximum electrical resistivity changes gradually, where the proportion of the flow field region refers to the proportion of the flow field in the flow field region to the length of the annular line where the flow field is located. Specifically, the proportion of the flow field region with maximum electrical resistivity can all change gradually. For example, among flow field regions with different electrical resistivity, the size and depth of the through holes are the same and the number of through holes is different. Along the radial direction, the proportion of the number of through holes in the flow field region to the number of through holes in the annular line where the through holes are located changes gradually, and the arrangement of through holes located at the edge of the flow field region (421) can form a smooth straight line or a smooth curve, which is more advantageous for forming a uniform plating film as shown in FIG. 7. In another embodiment of the present application, as shown in FIG. 8, the proportion of the flow field region with maximum electrical resistivity may gradually change in a stepped shape, that is, the proportion of the flow field region changes again after the flow field region is extended a certain distance along the radial direction of the flow field plate (4), and the arrangement of through holes located at the edge of the flow field region forms a stepped shape, and in another embodiment of the present application, the proportion of the flow field region with maximum electrical resistivity may gradually change in a sawtooth shape or other shape.

[0049] Likewise, in a plurality of annular flow field transition regions (42) installed adjacent to each other, the minimum electrical resistivity flow field region of any one flow field transition region (42) has a maximum proportion, preferably 100%, on the annular boundary line on one side of the flow field transition region (42) having the same electrical resistivity, and the plating film may be made more uniform. For example, when the minimum electrical resistivity of a specific flow field transition region (42) is the same as the maximum electrical resistivity of the outer flow field transition region (42) adjacent to it, the proportion of the minimum electrical resistivity flow field region on the outer annular line of the flow field transition region (42) is 100%, and when the minimum electrical resistivity of the flow field transition region (42) is the same as the maximum electrical resistivity of the inner flow field transition region (42) adjacent to it, the proportion of the minimum electrical resistivity flow field region on the inner annular line of the flow field transition region (42) is 100%. Furthermore, in the radial direction of each flow field transition region (42), the proportion of the flow field region with the minimum electrical resistivity changes gradually, becomes stepped, or changes other shapes. In another embodiment of the present application, as shown in FIG. 8, a plurality of types of electrical resistivity may be included on the annular boundary line on the flow field transition region (42).

[0050] Referring again to FIG. 7, the ratio occupied by the flow field region of each electrical resistivity on the 1 / 2 annular width line of each annular flow field transition region (42) is the same, so that the resistance value on the 1 / 2 annular width line of each annular flow field transition region (42) is located between the resistance values ​​of the two annular lines, thereby causing the electrical resistivity within each annular flow field transition region (42) to gradually change, which is more advantageous for forming a uniform plating film. For example, the annular flow field transition region (42) includes two types of flow field regions with electrical resistivitys R1 and R2, respectively, and R1 <R2이면, 전기 저항률이 R1및 R2인 유동장 영역은 환형 유동장 전이 영역(42)의 1 / 2 환형 폭선 상에서 각각 50%의 비율을 차지한다.

[0051] Referring again to FIG. 4, the proportion of a flow field region with the same electrical resistivity within two adjacent flow field transition regions (42) increases and then decreases again in the radial direction. Taking the flow field regions (423 and 424) in FIG. 4, where both have an electrical resistivity of R3, as an example, the flow field region with the same electrical resistivity on the two adjacent flow field transition regions (42) is the maximum electrical resistivity flow field region in the flow field transition region (42) with relatively low electrical resistivity, and is also the minimum electrical resistivity flow field region in the flow field transition region (42) with relatively high electrical resistivity. The proportion of a flow field region with the same electrical resistivity in the radial direction increases and then decreases again, and since the flow field region with the same electrical resistivity among the two adjacent flow field transition regions (42) is installed adjacent to each other, drilling work becomes easier. Next, the electrical resistivity of the flow field region with the same electrical resistivity is the same on the annular boundary line between two adjacent flow field transition regions (42) and on both sides of the annular boundary line, so that the electrical resistivity can be reduced on the annular boundary line between two adjacent flow field transition regions (42), which is more advantageous for forming a uniform plating film.

[0052] In another embodiment of the present application, as shown in FIG. 10, the flow field region (421) is formed by dividing the flow field transition region (42) equally.

[0053] Those skilled in the art can readily conceive of other embodiments of this application after practicing the embodiments disclosed in the specification and herein. This application is intended to include any modification, use, or adaptive variation of this application, such modification, use, or adaptive variation follows the general principles of this application and includes known common sense or conventional technical means in the art that are not disclosed in this application.

[0054] It should be understood that the present application is not limited to the exact structure described above and illustrated in the accompanying drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims. Explanation of the symbols

[0055] 1-Wafer, 2-Electroplating bath, 3-Chuck, 4-Flow field plate, 5-Electroplating solution, 6-Anode electrode, 7-Cathode electrode, 41-Central region, 42-Flow field transition region, 421-Flow field region

Claims

Claim 1 A wafer electroplating apparatus comprising: an electroplating tank used to receive an electroplating solution and having an anode electrode installed therein; and a flow field plate installed between the anode electrode and the wafer, wherein a plurality of through holes are installed in the flow field plate to allow the electroplating solution to pass through and form a flow field, and wherein the flow field plate includes at least one flow field transition region, and each flow field transition region includes at least two flow field regions with different electrical resistivity, wherein the maximum electrical resistivity in each flow field transition region is the minimum electrical resistivity in the flow field on one side where the maximum electrical resistivity is located among the two flow fields adjacent to each other in the radial direction, or the minimum electrical resistivity in the flow field transition region is the maximum electrical resistivity in the flow field on one side where the minimum electrical resistivity is located among the two flow fields adjacent to each other in the radial direction, and wherein the flow field region with the maximum electrical resistivity or the flow field region with the minimum electrical resistivity within the flow field transition region extends to the boundary of the flow field on one side having the same electrical resistivity. Claim 2 A wafer electroplating apparatus according to claim 1, wherein the maximum electrical resistivity in the flow field transition region is the minimum electrical resistivity in the flow field on one side where the maximum electrical resistivity is located among the two adjacent flow fields, and the minimum electrical resistivity in the flow field transition region is the maximum electrical resistivity in the flow field on the one side where the minimum electrical resistivity is located among the two adjacent flow fields. Claim 3 A wafer electroplating apparatus according to paragraph 2, characterized in that the flow field plate includes a central region, and the flow field transition region is installed to surround the central region. Claim 4 A wafer electroplating apparatus characterized in that, in paragraph 3, the electrical resistivity of each point within the central region is the same. Claim 5 A wafer electroplating apparatus according to paragraph 2, characterized in that each flow field transition region includes a plurality of flow field regions and fills the entire flow field transition region. Claim 6 A wafer electroplating apparatus according to claim 5, characterized in that the electrical resistivity of any two adjacent flow field regions in each flow field transition region is different. Claim 7 A wafer electroplating apparatus according to claim 6, characterized in that in each flow field transition region, there are multiple flow field regions of each electrical resistivity, and flow field regions with the same electrical resistivity are uniformly distributed in the flow field transition region. Claim 8 A wafer electroplating apparatus characterized in that, in claim 7, each flow field transition region is annular. Claim 9 A wafer electroplating apparatus according to claim 8, characterized in that it includes a plurality of flow field transition regions, and the plurality of flow field transition regions are installed adjacent to each other. Claim 10 A wafer electroplating apparatus according to claim 9, characterized in that the distance between the outer ring line of the outermost flow field transition region on the flow field plate and the center of the flow field plate is less than or equal to the wafer radius. Claim 11 A wafer electroplating apparatus according to claim 10, characterized in that, in the radial direction of each flow field transition region, the flow field region with the maximum electrical resistivity and / or the flow field region with the minimum electrical resistivity occupy the maximum proportion on an annular boundary line on one side of the flow field transition region having the same electrical resistivity. Claim 12 A wafer electroplating apparatus according to claim 11, characterized in that the flow field region with maximum electrical resistivity and / or the flow field region with minimum electrical resistivity occupy 100% of the ratio on an annular boundary line on one side of a flow field transition region having the same electrical resistivity. Claim 13 A wafer electroplating apparatus according to claim 12, characterized in that the ratio occupied by the flow field region of each electrical resistivity on the 1 / 2 annular width line of each of the above-mentioned flow field transition regions is the same. Claim 14 A wafer electroplating apparatus according to claim 13, characterized in that, in the radial direction of each flow field transition region, the ratio occupied by the flow field region of the maximum and / or minimum electrical resistivity exhibits a gradual change. Claim 15 A wafer electroplating apparatus according to claim 13, characterized in that, in the radial direction of each flow field transition region, the ratio occupied by the flow field region of the maximum and / or minimum electrical resistivity exhibits a stepwise change. Claim 16 A wafer electroplating apparatus according to claim 13, characterized in that the ratio of a flow field region with the same electrical resistivity within two adjacent flow field transition regions in the radial direction increases and then decreases again. Claim 17 A wafer electroplating apparatus according to claim 1, characterized in that the at least two flow field regions are formed by dividing each flow field transition region equally in the circumferential direction. Claim 18 A wafer electroplating apparatus according to claim 1, characterized in that at least some of the through holes within the flow field region having the same electrical resistivity in the flow field plate are the same. Claim 19 A wafer electroplating apparatus according to claim 1, characterized in that the through hole size of a flow field region having at least some different electrical resistivity in the flow field plate is different. Claim 20 A wafer electroplating apparatus according to claim 1, characterized in that the through-hole distribution density of a flow field region with at least some electrical resistivity differs in the flow field plate. Claim 21 A wafer electroplating apparatus according to claim 1, characterized in that the through-hole depth of at least some of the flow field regions with different electrical resistivity in the flow field plate is different.

Images