JP7027622B1 - Resistors and plating equipment - Google Patents

Abstract

Provided is a resistor or the like that can improve the uniformity of the plating film formed on the substrate. A resistor placed between the substrate and the anode in the plating tank is provided. The resistor has a plurality of first holes formed on three or more reference circles that are concentric and have different diameters, and at least a part of an outer peripheral reference line that surrounds the three or more reference circles. A second plurality of holes formed on the outer peripheral reference line, which is a trochoidal curve, are formed.

Description

The present invention relates to a resistor and a plating apparatus.

Conventionally, wiring, bumps (projective electrodes) and the like have been formed on the surface of a substrate such as a semiconductor wafer or a printed circuit board. An electrolytic plating method is known as a method for forming the wiring, bumps, and the like.

In a plating apparatus by an electrolytic plating method, it is known to arrange a resistor for electric field adjustment having a large number of holes between a circular substrate such as a wafer and an anode (see, for example, Patent Document 1).

Further, a cup-type electrolytic plating apparatus is known as an example of a plating apparatus (see, for example, Patent Document 2). In a cup-type electroplating apparatus, a substrate (for example, a semiconductor wafer) held in a substrate holder with the surface to be plated facing downward is immersed in a plating solution, and a voltage is applied between the substrate and the anode to apply a substrate. A conductive film is deposited on the surface of the above. In the cup-type plating apparatus, the plating process is also performed while rotating the substrate so that the plating layer is uniformly formed on the substrate.

Japanese Unexamined Patent Publication No. 2004-225129 Japanese Unexamined Patent Publication No. 2008-19496

Even in a cup-type electrolytic plating apparatus, it is conceivable to provide a punching plate having a large number of holes as a resistor for adjusting an electric field. In such a case, the electric field can be suitably adjusted by forming a large number of holes on a plurality of concentric reference circles in the resistor. However, according to the research by the present inventors, it has been found that when the resistor thus formed is used, the film thickness uniformity in the vicinity of the outer peripheral portion of the wafer may be lowered. This is considered to be due to, for example, the influence of the formation accuracy of a large number of holes or the dimensional accuracy of the plating tank.

The present invention has been made in view of the above problems. One of the purposes is to propose a resistor capable of improving the uniformity of the plating film formed on the substrate and a plating apparatus.

According to one embodiment of the present invention, there is proposed a resistor arranged between the substrate and the anode in the plating tank. The resistor is a first plurality of holes formed on three or more reference circles that are concentric and have different diameters, and an outer peripheral reference line that surrounds the three or more reference circles, and at least a part thereof is a trochoid. A second plurality of holes formed on the outer peripheral reference line, which is a curve, are formed.

According to another embodiment of the present invention, a plating apparatus is provided. This plating apparatus includes the resistor and a plating tank for accommodating the resistor.

FIG. 1 is a perspective view showing the overall configuration of the plating apparatus of the present embodiment. FIG. 2 is a plan view showing the overall configuration of the plating apparatus of the present embodiment. FIG. 3 is a vertical sectional view schematically showing the configuration of the plating module of the present embodiment. FIG. 4 is a plan view schematically showing the resistor of the present embodiment. FIG. 5 is a schematic diagram for explaining a plurality of holes formed in the resistor of the present embodiment. FIG. 6 shows a second example of a plurality of holes formed in the resistor. FIG. 7 shows a third example of a plurality of holes formed in the resistor. FIG. 8 shows a fourth example of a plurality of holes formed in the resistor. FIG. 9 shows a fifth example of a plurality of holes formed in the resistor. FIG. 10 is a diagram showing a modified example of the outer peripheral reference line.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings described below, the same or corresponding components are designated by the same reference numerals and duplicated description will be omitted.

<Overall configuration of plating equipment>
FIG. 1 is a perspective view showing the overall configuration of the plating apparatus of the present embodiment. FIG. 2 is a plan view showing the overall configuration of the plating apparatus of the present embodiment. The plating apparatus of this embodiment is used to perform a plating process on a substrate. The substrate includes a square substrate and a circular substrate. As shown in FIGS. 1 and 2, the plating apparatus 1000 includes a load / unload module 100, a transfer robot 110, an aligner 120, a pre-wet module 200, a pre-soak module 300, a plating module 400, a cleaning module 500, and a spin rinse dryer module. It includes 600, a transfer device 700, and a control module 800.

The load / unload module 100 is a module for carrying a substrate such as a semiconductor wafer into the plating apparatus 1000 and carrying out the substrate from the plating apparatus 1000, and is equipped with a cassette for accommodating the substrate. In the present embodiment, four load / unload modules 100 are arranged side by side in the horizontal direction, but the number and arrangement of the load / unload modules 100 are arbitrary. The transfer robot 110 is a robot for transferring the substrate, and is configured to transfer the substrate between the load / unload module 100, the aligner 120, and the transfer device 700. When the transfer robot 110 and the transfer device 700 transfer the substrate between the transfer robot 110 and the transfer device 700, the transfer robot 110 and the transfer device 700 can transfer the substrate via a temporary stand (not shown). The aligner 120 is a module for aligning the positions of the orientation flat (orientation flat) and the notch of the substrate in a predetermined direction. In the present embodiment, the two aligners 120 are arranged side by side in the horizontal direction, but the number and arrangement of the aligners 120 are arbitrary.

The pre-wet module 200 is a module for adhering a treatment liquid (pre-wet liquid) such as pure water or degassed water to the surface to be plated of the substrate before the plating treatment. In the present embodiment, the two pre-wet modules 200 are arranged side by side in the vertical direction, but the number and arrangement of the pre-wet modules 200 are arbitrary. The pre-soak module 300 is a module for etching the oxide film on the surface to be plated of the substrate before the plating treatment. In the present embodiment, the two pre-soak modules 300 are arranged side by side in the vertical direction, but the number and arrangement of the pre-soak modules 300 are arbitrary.

The plating module 400 is a module for applying a plating process to a substrate. In the present embodiment, there are two sets of 12 plating modules 400 arranged three in the vertical direction and four in the horizontal direction, and a total of 24 plating modules 400 are provided. However, the plating module 400 is provided. The number and arrangement of are arbitrary.

The cleaning module 500 is a module for cleaning the substrate after the plating treatment. In the present embodiment, the two cleaning modules 500 are arranged side by side in the vertical direction, but the number and arrangement of the cleaning modules 500 are arbitrary. The spin rinse dryer module 600 is a module for rotating the substrate after the cleaning treatment at high speed to dry it. In the present embodiment, the two spin rinse dryer modules are arranged side by side in the vertical direction, but the number and arrangement of the spin rinse dryer modules are arbitrary.

The transport device 700 is a device for transporting a substrate between a plurality of modules in the plating device 1000. The control module 800 is a module for controlling a plurality of modules of the plating apparatus 1000, and can be composed of, for example, a general computer or a dedicated computer having an input / output interface with an operator.

An example of a series of plating processes by the plating apparatus 1000 will be described. First, the board is carried into the load / unload module 100. Subsequently, the transfer robot 110 takes out the board from the load / unload module 100 and transfers the board to the aligner 120. The aligner 120 aligns the positions of the orifra, the notch, and the like in a predetermined direction. The transfer robot 110 transfers the substrate aligned with the aligner 120 to the transfer device 700.

The transfer device 700 transfers the substrate received from the transfer robot 110 to the pre-wet module 200. The pre-wet module 200 applies a pre-wet treatment to the substrate. The transport device 700 transports the pre-wet-treated substrate to the pre-soak module 300. The pre-soak module 300 applies a pre-soak treatment to the substrate. The transport device 700 transports the pre-soaked substrate to the plating module 400. The plating module 400 applies a plating process to the substrate.

The transport device 700 transports the plated substrate to the cleaning module 500. The cleaning module 500 performs a cleaning process on the substrate. The transport device 700 transports the cleaned substrate to the spin rinse dryer module 600. In the spin rinse dryer module 600, the substrate is subjected to a drying process. The transfer device 700 transfers the dried substrate to the transfer robot 110. The transfer robot 110 transfers the board received from the transfer device 700 to the load / unload module 100. Finally, the board is unloaded from the load / unload module 100.

<Plating module configuration>
Next, the configuration of the plating module 400 will be described. Since the 24 plating modules 400 in this embodiment have the same configuration, only one plating module 400 will be described. FIG. 3 is a vertical sectional view schematically showing the configuration of the plating module 400 of the present embodiment. As shown in FIG. 3, the plating module 400 includes a plating tank 410 for accommodating a plating solution. The plating tank 410 includes a cylindrical inner tank 412 having an open upper surface and an outer tank (not shown) provided around the inner tank 412 so that the plating solution overflowing from the upper edge of the inner tank 412 can be stored. Consists of.

The plating module 400 includes a substrate holder 440 for holding the substrate Wf with the surface to be plated Wf-a facing downward. Further, the substrate holder 440 includes a feeding contact for supplying power to the substrate Wf from a power source (not shown). The plating module 400 includes an elevating mechanism 442 for elevating and lowering the substrate holder 440. Further, in one embodiment, the plating module 400 includes a rotation mechanism 448 that rotates the substrate holder 440 around a vertical axis. The elevating mechanism 442 and the rotation mechanism 448 can be realized by a known mechanism such as a motor.

The plating module 400 includes a membrane 420 that vertically separates the inside of the inner tank 412. The inside of the inner tank 412 is divided into a cathode region 422 and an anode region 424 by a membrane 420. The cathode region 422 and the anode region 424 are each filled with a plating solution. In this embodiment, an example in which the membrane 420 is provided is shown, but the membrane 420 may not be provided.

An anode 430 is provided on the bottom surface of the inner tank 412 of the anode region 424. Further, in the anode region 424, an anode mask 426 for adjusting the electrolysis between the anode 430 and the substrate Wf is arranged. The anode mask 426 is a substantially plate-shaped member made of, for example, a dielectric material, and is provided on the front surface (upper side) of the anode 430. The anode mask 426 has an opening through which the current flowing between the anode 430 and the substrate Wf passes. In this embodiment, an example in which the anode mask 426 is provided is shown, but the anode mask 426 may not be provided. Further, the above-mentioned membrane 420 may be provided in the opening of the anode mask 426.

A resistor 450 facing the membrane 420 is arranged in the cathode region 422. The resistor 450 is a member for making the plating process uniform on the surface to be plated Wf—a of the substrate Wf. FIG. 4 is a plan view schematically showing the resistor of the present embodiment. In addition, in FIG. 4, a part of the resistor is enlarged and shown together for the sake of easy understanding. Further, the example shown in FIG. 4 corresponds to the fifth example (FIG. 9) described later. As shown in FIG. 4, the resistor 450 has a plurality of holes 452 and 454. The holes 452 and 454 penetrate between the front surface and the back surface of the resistor 450 and form a path for passing the plating solution and ions in the plating solution. The resistor 450 according to the present embodiment is formed with a first plurality of holes 452 and a second plurality of holes 454.

The first plurality of holes 452 are arranged on three or more virtual reference circles (see the alternate long and short dash line in FIG. 4) that are concentric and have different diameters. In other words, the first plurality of holes 452 are arranged so as to be dispersed in the radial direction of the resistor 450. The first plurality of holes 452 are preferably arranged at equal intervals along the circumferential direction on the reference circle. As a result, the holes 452 can be distributed and arranged along the circumferential direction of the reference circle. Further, in the resistor 450, it is preferable that the difference between the diameter of an arbitrary reference circle and the diameter of the adjacent reference circle is constant. In other words, the holes 452 are preferably arranged at equal intervals in the radial direction. Thereby, the holes 452 can be dispersedly arranged along the radial direction of the reference circle. Further, in one embodiment, each of the first plurality of holes 452 is a perfect circle when viewed from the upper surface. Each of the first plurality of holes 452 may have the same dimensions as each other. In addition, in this specification, "equal spacing" and "same" are not limited to mathematically perfect equidistant intervals, but may include some deviations due to errors in machining and the like.

The second plurality of holes 454 are arranged on the outer peripheral side of the first plurality of holes 452. Specifically, the second plurality of holes 454 are formed on an outer peripheral reference line (see a two-dot chain line in FIG. 4) surrounding a reference circle in which the first plurality of holes 452 are arranged. Here, in the present embodiment, the outer peripheral reference line is a trochoid curve. According to the research by the present inventors, the second plurality of holes 454 on the outer peripheral side are formed on the substrate Wf in the plating module 400 by arranging at least a part of them on the outer peripheral reference line having a trochoidal curve. It has been found that the uniformity of the plating film can be improved.

FIG. 5 is a schematic diagram for explaining a plurality of holes formed in the resistor of the present embodiment. In the upper part of FIG. 5, as a comparative example, the second plurality of holes 452 are arranged on a reference circle (see the broken line in FIG. 5, hereinafter referred to as “reference circle”) which is a perfect circle. Here is an example. Further, in the lower part of FIG. 5, as a first example of the plurality of holes formed in the resistor, the outer peripheral reference line in which the second plurality of holes 452 are trochoidal curves (see the two-dot chain line in FIG. 5). The example placed above is shown. As shown in the lower part of FIG. 5, the outer peripheral reference line may be a trochoid curve drawn by a predetermined fixed point of the moving circle when the predetermined moving circle is moved along the inner circumference of the reference circle. However, the outer peripheral reference line is not limited to such an example, and may be a trochoid curve drawn by a predetermined fixed point of the moving circle when the predetermined moving circle is moved along the outer circumference of the reference circle. Here, as an example, the moving circle may be determined to make 7 rotations (2520 ° rotation) when making a circle along the reference circle.

FIG. 6 shows a second example of a plurality of holes formed in the resistor. As shown in FIG. 6, in the region of the outer peripheral reference line which is a trochoid curve and the distance from the first plurality of holes 452 is short (the region with hatching in FIG. 6, also referred to as “predetermined region”). May not form the second plurality of holes 454. As an example, the predetermined region is a region in which the distance between the outer peripheral reference line and the reference circle of the first plurality of holes 452 is smaller than a predetermined threshold value. According to the second example, it is possible to prevent the distance between the first plurality of holes 452 and the second plurality of holes 454 from becoming too close, and it is possible to prevent the aperture ratio from becoming excessive in a predetermined region. In the above-mentioned first example (FIG. 5), a part of the first plurality of holes 452 and the second plurality of holes 454 overlap each other for easy understanding, but this example is exaggerated. It is preferable that the first plurality of holes 452 and the second plurality of holes 454 do not overlap each other.

FIG. 7 shows a third example of a plurality of holes formed in the resistor. In the above-mentioned second example (FIG. 6), in the region where the second plurality of holes 454 are not formed (the region with hatching in FIG. 7, also referred to as “predetermined region”), in the third example, the first example. The plurality of holes 452 of the above are made larger than the holes 452 of the other regions. That is, in the third example, the diameter ra of the first plurality of holes 452 in the predetermined region is larger than the diameter rb of the first plurality of holes 452 outside the predetermined region. According to such an example, it is possible to suppress a sudden change in the aperture ratio of the resistor in the vicinity of the boundary of the predetermined region, and it is possible to improve the uniformity of the plating film formed on the substrate Wf.

FIG. 8 shows a fourth example of a plurality of holes formed in the resistor. As shown in FIG. 8, the second plurality of holes 454 may be elongated holes long in the circumferential direction. In this case, as an example, the second plurality of holes 454 may be elongated in the circumferential direction as the holes are arranged at positions farther from the first plurality of holes 452 (or their reference circles). .. As described above, since at least a part of the second plurality of holes 454 is elongated holes, the change in the aperture ratio along the outer peripheral reference line can be reduced, and the plating film formed on the substrate Wf is uniform. It is possible to improve the sex. In the example shown in FIG. 8, similarly to the second example (FIG. 6) described above, in the region (predetermined region) where the distance from the first plurality of holes 452 is short, the second plurality of holes 454 are formed. It is not formed, but is not limited to these examples.

FIG. 9 shows a fifth example of a plurality of holes formed in the resistor. In the fifth example shown in FIG. 9, the second plurality of holes 454 are elongated holes long in the circumferential direction, as in the fourth example (FIG. 8). Further, in the fifth example shown in FIG. 9, as in the third example (FIG. 7), the second plurality of holes 454 are not formed in the predetermined region, and the first plurality of holes 452 are enlarged. .. According to such an example, the aperture ratio of the resistor can be smoothly changed, and the uniformity of the plating film formed on the substrate Wf can be improved.

Here, the plating process in the plating module 400 of the present embodiment will be described in more detail. By immersing the substrate Wf in the plating solution of the cathode region 422 using the elevating mechanism 442, the substrate Wf is exposed to the plating solution. By applying a voltage between the anode 430 and the substrate Wf in this state, the plating module 400 can perform a plating process on the surface to be plated Wf—a of the substrate Wf. In one embodiment, the plating process is performed while rotating the substrate holder 440 using the rotation mechanism 448. By the plating treatment, a conductive film (plating film) is deposited on the surface to be plated Wf-a of the substrate Wf-a. Then, in the present embodiment, by adopting the above-mentioned resistor 450, the pore density formed in the resistor 450 is uniform, and the uniformity of the plating film formed on the substrate can be improved. ..

(Modification example)
In the above embodiment, it is assumed that the outer peripheral reference line on which the second plurality of holes 454 are formed is a trochoid curve. However, the outer peripheral reference line may be at least partially a trochoid curve, and as shown in FIG. 10, two trochoid curves having opposite displacement phases (unevenness) with respect to a fixed circle (dotted chain line in FIG. 10). It may be a line consisting of a bourian sum of C1 and the two-dot chain line C2 (see the thick line in FIG. 10). Further, in this case, the two trochoidal curves may be curves that are the same fixed circles but have different radii of the moving circles. It should be noted that the two trochoidal curves may be set so that the moving circle makes seven rotations (2520 ° rotation) when it goes around the reference circle.

The present invention can also be described as the following forms.
[Form 1] According to Form 1, a resistor arranged between the substrate and the anode in the plating tank is proposed, and the resistors are formed on three or more reference circles that are concentric and have different diameters. The first plurality of holes formed and the second plurality of holes formed on the outer peripheral reference line which is the outer peripheral reference line surrounding the three or more reference circles and whose at least a part is a trochoidal curve are formed. ing.
According to the first embodiment, it is possible to improve the uniformity of the plating film formed on the substrate when it is used in a plating apparatus.

[Form 2] According to Form 2, in Form 1, at least a part of the second plurality of holes is an elongated hole long along the circumferential direction.
According to the second embodiment, the uniformity of the plating film formed on the substrate when used in a plating apparatus can be further improved.

[Form 3] According to Form 3, in Form 2, the elongated hole is so long along the circumferential direction that it is formed in a region distant from the reference circle of 3 or more.
According to the third embodiment, the uniformity of the plating film formed on the substrate when used in a plating apparatus can be further improved.

[Form 4] According to Form 4, in the first to third forms, in the predetermined region where the distance between the outermost reference circle and the outer peripheral reference line in the three or more reference circles is less than the first distance, the second Multiple holes are not formed.
According to the fourth embodiment, the uniformity of the plating film formed on the substrate can be further improved when used in a plating apparatus.

[Form 5] According to Form 5, in the predetermined region, the first plurality of holes formed in the outermost reference circle are formed in the outermost reference circle that is not the predetermined region. It is larger than the first plurality of formed holes.
According to the fifth embodiment, the uniformity of the plating film formed on the substrate can be further improved when used in a plating apparatus.

[Form 6] According to Form 2, in Forms 1 to 5, the first plurality of holes are arranged at equal intervals along the circumferential direction on the reference circle.

[Form 7] According to Form 7, in Forms 1 to 6, each of the first plurality of holes has the same dimensions except for the holes formed in the outermost reference circle in at least the three or more reference circles. Is

[Form 8] According to Form 8, in FIGS. 1 to 7, the difference between the diameter of the arbitrary reference circle and the diameter of the adjacent reference circle is constant.

[Form 9] According to Form 9, a plating apparatus including the resistor according to any one of Forms 1 to 8 and a plating tank accommodating the resistor is proposed.
According to the ninth embodiment, the uniformity of the plating film formed on the substrate can be further improved.

[Form 10] According to Form 10, a board holder for holding the board and a rotation mechanism for rotating the board holder are further provided in the form 9.

Although the embodiments of the present invention have been described above, the embodiments of the invention described above are for facilitating the understanding of the present invention and do not limit the present invention. The present invention can be modified and improved without departing from the spirit thereof, and it goes without saying that the present invention includes an equivalent thereof. In addition, any combination of embodiments and modifications is possible within a range that can solve at least a part of the above-mentioned problems, or a range that exhibits at least a part of the effect, and is described in the claims and the specification. Any combination of each component or omission is possible.

400 ... Plating module 410 ... Plating tank 420 ... Membrane 422 ... Cathode area 424 ... Anode area 430 ... Anode 440 ... Board holder 442 ... Elevating mechanism 448 ... Rotation mechanism 450 ... Resistor 452 ... First plurality of holes 454 ... Second Multiple holes 800 ... Control module 1000 ... Plating device Wf ... Substrate

Claims (10)

A resistor for adjusting the electric field placed between the substrate and the anode in the plating tank.
A plurality of first holes formed on three or more reference circles that are concentric and have different diameters, respectively.
A second plurality of holes formed on the outer peripheral reference line which is the outer peripheral reference line surrounding the three or more reference circles and whose at least a part is a trochoidal curve.
The resistor that is formed. The resistor according to claim 1, wherein at least a part of the second plurality of holes is an elongated hole long in the circumferential direction. The resistor according to claim 2, wherein the elongated hole is so long along the circumferential direction that it is formed in a region away from the reference circle of 3 or more. Any of claims 1 to 3, wherein the second plurality of holes are not formed in a predetermined region where the distance between the outermost reference circle and the outer peripheral reference line in the three or more reference circles is less than the first distance. The resistor according to item 1. In the predetermined region, the first plurality of holes formed in the outermost reference circle are compared with the first plurality of holes formed in the outermost reference circle which is not the predetermined region. The large resistor according to claim 4. The resistor according to any one of claims 1 to 5, wherein the first plurality of holes are arranged at equal intervals along the circumferential direction on the reference circle. The first plurality of holes have the same dimensions except for the holes formed in the outermost reference circle in at least the three or more reference circles, according to any one of claims 1 to 6. Resistor. The resistor according to any one of claims 1 to 7, wherein the difference between the diameter of any reference circle and the diameter of an adjacent reference circle is constant. The resistor according to any one of claims 1 to 8 and the resistor.
A plating apparatus including a plating tank for accommodating the resistor. The board holder that holds the board and
A rotation mechanism that rotates the substrate holder and
9. The plating apparatus according to claim 9.

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