JP2000319797A - Plating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plating device capable of forming a metal plating uniform in film thickness which is capable of reducing the depth of a plating tank, and preventing abnormal consumption of an additive in a plating solution through oxidizing decomposition, or generation of plating defects on a surface of a substrate to be plated or in small pores and grooves formed in the surface caused by the generated oxygen. SOLUTION: In the plating device provided with a plating bath and to execute the metal plating by bringing a plating solution in contact with a surface to be plated of a substrate to be plated in the plating bath, a plating bath 10 comprises a plating solution chamber 20 formed between a substrate 13 to be plated which is arranged with its plating surface downward and a porous plate 21 arranged oppositely thereto with a specified clearance therebelow, and a flat plating solution introducing chamber 22 formed below the porous plate 21, and the plating solution Q flows into a plating solution introducing chamber 22 in the horizontal direction, the flow of the plating solution Q which is perpendicular to the plating surface of the substrate 13 is formed through pores 21a in the porous plate 21, and guided to the plating solution chamber 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plating apparatus for performing metal plating such as copper plating on a substrate to be plated such as a semiconductor wafer.

[0002]

2. Description of the Related Art In recent years, a metal plating apparatus such as copper plating has been used to fill the grooves, holes and the like of a substrate to be plated having fine grooves and holes for wiring formed on the surface of a semiconductor wafer or the like. A technique of filling the grooves and holes with metal plating is employed. Conventionally, there is a face-down type plating apparatus as this type of plating apparatus. As shown in FIG. 1, the plating apparatus includes a substrate 102 to be plated such as a semiconductor wafer on a plating tank 100.
With the plating surface facing down, and the plating tank 103
The plating solution Q in the inside is ejected from the bottom of the plating tank main body 101 by the pump 104 through the plating solution supply pipe 105, and the jet of the plating solution Q is applied vertically to the plating surface of the substrate 102 to be plated.

[0003] The plating solution Q overflowing the plating tank body 101 is collected by a collection tank 106 disposed outside the plating tank body 101. By applying a predetermined voltage between the anode electrode 107 and the cathode electrode 108, a plating current flows between the anode electrode 107 and the substrate 102 to be plated, and a plating film is formed on the plating surface of the substrate 102 to be plated. .

In the conventional face-down type plating apparatus having the above structure, the jet of the plating solution Q is applied to the substrate 102 to be plated.
It is necessary to make the flow equally distributed in the circumferential direction on the substrate to be plated in order to apply the flow vertically, and it is necessary to make the flow a laminar flow and take a running distance. There was a problem of becoming larger.

When the anode electrode 107 is an insoluble electrode, the additives in the plating solution are oxidized and decomposed to be consumed abnormally, or the additive formed on the surface of the substrate to be plated or the surface due to oxygen generated. There has been a problem that plating defects occur in fine holes and grooves.

In the face-down type plating apparatus, means for improving the uniformity of the thickness of the plating film formed on the plating surface of the substrate to be plated 102 include the distance between the substrate to be plated 102 and the anode electrode 107. In order to adjust the state of the electric field in addition to the changes and the uniformity of the plating solution flow, FIG.
As shown in (1), there is optimization of the shape of the shielding plate 109 provided between the substrate to be plated 102 and the anode electrode 107.

Normally, the shielding plate 109 is connected to the anode electrode 107.
When the cathode and the substrate (substrate to be plated 102) are parallel plates, the uniformity of the electric field can be improved in the plane of the substrate to be plated 102 by adjusting the size of the opening hole 109a provided at the center thereof. is there. However, in this case, the substrate to be plated 1
In the vicinity of 02, there is a tendency that the thickness of the surrounding film is increased due to the electric current flowing around the substrate to be plated.
Needs to be reduced, and as a result, as shown in FIG. 12, there is a problem that an M-type film thickness distribution tends to occur.

In FIG. 12, the vertical axis represents the plating film thickness (nm), the horizontal axis represents the distance (mm) from the edge of the wafer to be plated, and SSW-NNE is the south-southwest-north-northeast cross section of the wafer. WSW-ENE is the film thickness of the west-southwest-west-northwest section of the wafer, WNW-ESE is the film thickness of the west-northwest-east-southeast section of the wafer, and NNW-SSE is the north-northwest-section.
The thickness of the south-southeast section is shown.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and can reduce the depth of a plating tank, and oxidatively decompose additives in a plating solution to cause abnormal consumption or generation. It is an object of the present invention to provide a plating apparatus capable of performing metal plating with a uniform film thickness without generating plating defects on the surface of a substrate to be plated or fine holes or grooves formed on the surface by the oxygen to be plated.

It is another object of the present invention to provide a plating apparatus capable of adjusting an electric field in a plating surface of a substrate to be plated to perform metal plating with a uniform film thickness.

[0011]

In order to solve the above problems, the invention according to claim 1 is provided with a plating tank, and a plating solution is brought into contact with a plating surface of a substrate to be plated in the plating tank to perform metal plating. In the plating apparatus to be applied, the plating tank has a plating solution chamber formed between a substrate to be plated disposed with the plating surface facing downward and a perforated plate disposed opposite to the substrate at a predetermined interval below the substrate. A flat plating solution introduction chamber formed below the perforated plate is provided, and a plating solution is poured into the plating solution introduction chamber from a horizontal direction, and a plating solution perpendicular to the plating surface of the substrate to be plated is passed through the perforated plate. It is characterized in that it is configured to form a flow and guide it to the plating solution chamber.

As described above, the plating solution chamber formed between the substrate to be plated and the perforated plate disposed opposite to and provided with a predetermined space below the substrate, and the plating solution chamber formed below the perforated plate. A flat plating solution introduction chamber is provided, and the plating solution is flowed into the plating solution introduction chamber from the horizontal direction, and a flow of the plating solution perpendicular to the plating surface of the substrate to be plated is formed through the perforations of the perforated plate. By appropriately setting the distance between the substrate and the substrate to be plated, it is possible to lengthen the rising distance of the plating solution, eliminate the need for rectification, and make the plating tank a flat configuration with a small depth dimension.

The invention described in claim 2 is the first invention.
In the plating apparatus according to the above, the plating tank is provided with a flat anode chamber via an ion exchange membrane or a porous neutral diaphragm below the plating solution introduction chamber, and faces the substrate to be plated at the bottom of the anode chamber. An anode electrode is provided, and a plating solution or another conductive solution is caused to flow through the anode chamber.

As described above, an anode chamber is provided below the plating solution introduction chamber via an ion exchange membrane or a porous neutral diaphragm, and a plating solution or another conductive solution is caused to flow through the anode chamber.
The oxidative decomposition of the additives in the plating solution on the anode electrode surface is prevented, preventing the abnormal consumption of the additives in the plating solution, and the generated oxygen gas is blocked by the ion exchange membrane or the porous neutral diaphragm and the substrate to be plated Therefore, it is possible to prevent the formation of plating defects in fine holes and grooves on the surface of the substrate to be plated.

[0015] The invention described in claim 3 is based on claim 1.
Alternatively, in the plating apparatus described in 2, the plating tank includes a substrate rotating mechanism that rotates the substrate to be plated in the plating tank with the plating surface facing downward.

By providing the substrate rotating mechanism as described above and rotating the substrate with the plating surface facing downward during plating, the plating surface can be brought into contact with the plating solution uniformly, and a uniform film can be formed. A thick plating film can be formed. In addition, after plating is completed, the substrate to be plated is pulled up from the plating solution surface and rotated at a high speed so that the plating solution adhered in the plating bath can be shaken off, and the outside of the plating bath is less contaminated by the plating solution. Become.

Further, in the plating apparatus according to any one of the first to third aspects, the distance between the substrate to be plated and the perforated plate is 5 to 15 mm.

By setting the distance between the substrate to be plated and the perforated plate to be 5 to 15 mm as described above, the plating substrate is rotated and the plating solution discharged in the circumferential direction of the substrate by viscous force of the plating solution. Due to the influence of the liquid, the pressure decreases toward the center of the substrate to be plated, and the upward flow from the center of the perforated plate increases, whereby a uniform vertical component speed can be obtained over the entire surface of the substrate to be plated. Therefore, it is not necessary to increase the approach distance of the upward flow in the depth direction as in the related art, so that the depth dimension of the plating tank can be reduced.

The plating apparatus according to any one of claims 1 to 3, further comprising a plating stage in which a plurality of plating tanks are arranged.

By arranging a plurality of plating tanks on the plating stage as described above, the planar arrangement of the entire plating apparatus can be reduced, and the installation space can be saved.

The invention described in claim 4 is the first invention.
4. The plating apparatus according to any one of Items 3 to 3, wherein one or a plurality of holes having a diameter larger than the diameter of the surrounding holes are provided in a central portion of the perforated plate.

By providing one or more holes having a diameter larger than the diameter of the surrounding holes at the center of the perforated plate as described above, the center of the vertical jet of the plating solution passing through the perforated plate is strengthened. Thus, the vertical jet contacting the plating surface of the substrate to be plated flows to the outer periphery without being disturbed along the surface to be plated. When the substrate to be plated is carried into the plating tank, the substrate is immersed in liquid from the center of the substrate to be plated, so that bubbles on the surface to be plated can be quickly released.

Further, in the plating apparatus according to any one of the first to fourth aspects, the distance between the substrate to be plated and the anode electrode is 10 to 30 mm.

As described above, the electric field between the anode electrode and the substrate to be plated can be made uniform by bringing the substrate to be plated and the anode electrode close to each other so that the distance between them is 10 to 30 mm. The uniformity of the plating film on the substrate to be plated is improved. In addition, the plating tank can be reduced in size.

The invention described in claim 5 is the first invention.
5. The plating apparatus according to any one of claims 4 to 4, further comprising a plurality of plating solution nozzles for allowing the plating solution to flow into the plating solution introduction chamber, wherein the plating solution flowing from the plating solution nozzle is horizontal and the plating solution flows in the plating solution nozzle. It is characterized by being eccentric from the center of the introduction chamber.

As described above, the flowing direction of the plating solution flowing from the plating solution nozzle is horizontal and eccentric from the center of the plating solution introduction chamber, so that the rotating flow of the plating solution is formed in the plating solution introduction chamber. Then, the rotating flow of the plating solution is ejected through the perforated plate into the plating solution chamber, thereby generating a jet of the plating solution having a rotating component in the plating solution chamber. The rotational flow of the plating solution in the plating chamber has the same direction as the rotational flow of the plating solution in the plating solution introduction chamber. By rotating the substrate to be plated in the direction opposite to the rotational flow in the plating solution chamber, the relative speed between the plating surface and the plating solution is increased, the concentration diffusion layer near the plating surface is thinned, and a uniform plating film is formed. Make it possible. Further, even if the number of rotations of the substrate to be plated is kept low, the same effect as a high number of rotations can be obtained.

Further, in the plating apparatus according to the present invention, a spiral guide vane for collecting a flow of the plating solution flowing from the plurality of plating solution nozzles at a central portion of the plating solution introduction chamber is provided.

As described above, by providing the spiral guide vanes for collecting the plating solution flows flowing from the plurality of plating solution nozzles at the center of the plating solution introduction chamber, the plating generated by the plating solution flow from the plating solution nozzles is provided. With the rotating flow of the solution, the plating solution is collected in the central part below the perforated plate,
Since the pressure of the plating solution at the center can be increased, the vertical jet flow passing through the center of the perforated plate is increased.

According to a sixth aspect of the present invention, there is provided a plating apparatus comprising a plating tank, wherein a plating solution is brought into contact with a plating surface of a substrate to be plated in the plating tank to perform metal plating. The substrate to be plated is disposed with the surface facing downward, and an anode electrode is disposed facing the substrate at a predetermined interval below the substrate, and the effective diameter of the substrate to be plated is between the substrate to be plated and the anode electrode. A cylindrical electric field correction ring having a smaller inner diameter, the upper end of the electric field correction ring approaching the substrate to be plated, and the center of the electric field correction ring and the center of the substrate to be plated are positioned substantially coaxially. It is characterized by being arranged in.

The length of the electric field correction ring is 10 to 50 mm, and the distance between the upper end of the electric field correction ring and the plating surface of the substrate to be plated is 1 to 10 mm. It is characterized by the following.

As described above, the cylindrical electric field correction ring having an inner diameter smaller than the effective diameter of the substrate to be plated is
By arranging the upper end of the electric field correction ring close to the substrate to be plated, electricity is prevented from flowing to the outer peripheral portion of the substrate to be plated, and the film thickness around the substrate to be plated is not increased. However, there is a sheet resistance of the substrate to be plated, and if power is taken from the outer periphery, a large amount of current will flow to the outer periphery. It is necessary to arrange a shielded plate.

[0032]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 is a diagram showing a configuration example of a plating tank of the plating apparatus according to the present invention. As shown
In the main plating tank 10, a substrate holder 12 for holding a substrate 13 to be plated such as a semiconductor wafer is accommodated in a plating tank main body 11. The substrate holder 12 includes a substrate holder 12-
1 and a shaft portion 12-2.
2 is rotatably supported on the inner wall of a cylindrical guide member 14 via bearings 15 and 15. The guide member 14 and the substrate holder 12 can be moved up and down by a predetermined stroke by a cylinder 16 provided at the top of the plating tank main body 11.

The substrate holder 12 is driven by a motor 18 provided above the inside of the guide member 14.
It can be rotated in the direction of arrow A via 2-2. Further, the substrate holding portion 17 has a substrate holding portion 17-.
A space C is provided for accommodating the substrate pressing member 17 composed of the shaft 1 and the shaft portion 17-2.
Can be moved up and down by a predetermined stroke by a cylinder 19 provided at an upper part in the shaft portion 12-2 of the substrate holder 12.

An opening 12-1a communicating with the space C is provided below the substrate holding portion 12-1 of the substrate holding body 12, and above the opening 12-1a, as shown in FIG. A step portion 12-1b on which the edge portion 13 is placed is formed. The edge of the substrate 13 to be plated is placed on the stepped portion 12-1b, and the upper surface of the substrate 13 to be plated is pressed by the substrate pressing portion 17-1 of the substrate pressing member 17 so that the edge of the substrate 13 to be plated is pressed. Is sandwiched between the board holding part 17-1 and the step part 12-1b. Then, the lower surface (plating surface) of the substrate 13 is exposed to the opening 12-1a. FIG. 4 shows FIG.
It is an enlarged view of B part of FIG.

The substrate 13 to be plated, which is exposed below the substrate holding portion 12-1 of the plating tank body 11, that is, in the opening 12-1a.
A flat plating solution chamber 20 is provided below the plating surface of FIG. 1, and a flat plating solution introduction chamber 22 is provided below the plating solution chamber 20 via a porous plate 21 in which a number of holes 21a are formed. I have. Further, outside the plating solution chamber 20, a collecting gutter 23 for collecting the plating solution Q overflowing the plating solution chamber 20 is provided.

The plating solution Q collected by the collecting gutter 23 returns to the plating solution tank 24. The plating solution Q in the plating solution tank 24 is introduced horizontally from both sides of the plating solution chamber 20 by the pump 25. Plating solution chamber 20
The plating solution Q introduced from both sides of the perforated plate 21
a and flows into the plating solution chamber 20 as a vertical jet. The distance between the perforated plate 21 and the substrate 13 to be plated is 5 to 15 m.
m, and the jet of the plating solution Q passing through the holes 21a of the perforated plate 21 contacts the plating surface of the substrate 13 as a uniform jet while maintaining the vertical ascent. The plating solution Q that has overflowed the plating solution chamber 20 is collected by the collecting gutter 23 and flows into the plating solution tank 24. That is, the plating solution Q circulates between the plating solution chamber 20 of the plating tank main body 11 and the plating solution tank 24.

[0037] Plating liquid level L _Q of the plating solution chamber 20 is slightly higher than the plating liquid level L _W to be plated substrate 13 [Delta] L
And the entire surface of the plating surface of the substrate 13 to be plated is in contact with the plating solution Q.

The step 12-1b of the substrate holder 12-1 of the substrate holder 12 is provided with an electric contact 27 which is electrically connected to the conductive part of the substrate 13 to be plated. (Not shown), and is electrically connected to the brush 26, and further connected to a cathode of an external plating power supply (not shown) via the brush 26. The substrate 1 to be plated is provided at the bottom of the plating solution introduction chamber 22 of the plating tank body 11.
3 and an anode electrode 28 is provided.
Is connected to the anode of the plating power supply. A loading / unloading slit 29 is provided at a predetermined position on the wall surface of the plating tank main body 11 for loading / unloading the substrate 13 with a substrate loading / unloading jig such as a robot arm.

In the plating apparatus having the above structure, when plating is performed, first, the cylinder 16 is operated to move the substrate holder 12 together with the guide member 14 by a predetermined amount (the substrate holder 12).
−1 is held in the loading / unloading slit 2
9) and the cylinder 19 is operated to raise the substrate pressing member 17 by a predetermined amount (to a position where the substrate pressing portion 17-1 reaches the upper portion of the carry-in / out slit 29). In this state, the substrate to be plated 13 is moved into the space C of the substrate holder 12 by a substrate carrying-in / out jig such as a robot arm.
The substrate 13 is placed on the step 12-1b such that the plating surface faces downward. In this state, the cylinder 19 is operated and lowered until the lower surface of the substrate pressing portion 17-1 comes into contact with the upper surface of the substrate 13 to be plated.
Pinch the edge of.

In this state, the cylinder 16 is operated to move the substrate holder 12 together with the guide member 14 until the plating surface of the substrate 13 to be plated contacts the plating solution Q in the plating solution chamber 20 (from the plating solution level _LQ , (To a position lower by ΔL). At this time, the motor 18 is started, and the substrate holder 12 and the substrate 13 are lowered while rotating at a low speed. The plating solution chamber 20 is filled with the plating solution Q, and a vertical upward flow through a large number of holes 21 a of the perforated plate 21 is jetted. When a predetermined voltage is applied from a plating power source between the anode electrode 28 and the electric contact 27 in this state, a plating current flows from the anode electrode 28 to the substrate 13 to be plated,
A plating film is formed on the plating surface of the substrate 13 to be plated.

During the plating, the motor 18 is operated to rotate the substrate holder 12 and the substrate 13 at low speed. The low-speed rotation is set so that a plating film having a uniform thickness can be formed on the plating surface of the substrate 13 without disturbing the vertical jet of the plating solution Q in the plating solution chamber 20.

[0042] actuating the the plating is completed cylinder 16 is raised to be plated substrate 13 and the substrate holder 12, when the lower surface of the substrate holding portion 12-1 becomes above the plating liquid surface level L _Q, the motor 18 The plating solution is rotated at a high speed, and the plating solution attached to the plating surface of the substrate to be plated and the lower surface of the substrate holding unit 12-1 is shaken off by centrifugal force. When the plating solution is shaken off, the substrate 13 to be plated is raised to the position of the carry-in / out slit 29, and the cylinder 19 is operated to raise the substrate holding portion 17-1. It is placed on the step 12-1b of the section 12-1. In this state, a substrate loading / unloading jig such as a robot arm is made to enter the space C of the substrate holder 12 through the loading / unloading slit 29, and the substrate 13 to be plated is picked up and carried out.

With the plating apparatus having the above configuration,
A vertical upward flow of the plating solution is formed in the plating solution chamber 20 through the large number of holes 21a of the perforated plate 21. Therefore, a face-down type plating tank in which a plating solution jet is vertically applied to a substrate to be plated as in the related art. As compared with the above, the approach distance of the plating solution may be small, and the dimension of the plating tank 10 in the depth direction can be reduced. Therefore, it becomes possible to arrange a plurality of plating tanks 10 in a stacked manner.

In the above embodiment, electrolytic plating is described as an example. However, electroless plating can be used without providing the electric contact 27 and the anode electrode 28.

FIG. 5 is a view showing another configuration example of the plating tank of the plating apparatus according to the present invention. In FIG. 5, the upper part from the substrate holder 12 is the same as that of FIG. The plating bath 10 is provided below the plating solution introduction chamber 22 with an anode chamber 31 for introducing a plating solution or a conductive liquid Q ′ through an ion exchange membrane or a porous neutral diaphragm 30, and at the bottom of the anode chamber 31. An anode electrode 28 is provided. Liquid tank 3
The plating solution or conductive liquid Q ′ in 3 is introduced into the anode chamber 31 by the pump 32, and the plating solution or conductive liquid Q ′ flowing out of the anode chamber 31 returns to the liquid tank 33. That is, the plating solution or the conductive liquid Q ′ in the liquid tank 33 circulates between the anode chamber 31 and the liquid tank 33.

As described above, the anode chamber 31 is provided in the plating tank 10 below the plating solution introduction chamber 22 via the ion exchange membrane or the porous neutral diaphragm 30, and the plating solution or the conductive liquid Q 'is provided.
By flowing the gas, it is possible to prevent the oxidative decomposition of the additive on the surface of the anode electrode 28 even if an insoluble electrode is used as the anode electrode 28, and the generated oxygen gas is an ion exchange membrane or a porous neutral diaphragm. Substrate to be plated 1 blocked by 30
The plating surface of No. 3 is not reached. Thereby, abnormal consumption of the additive in the plating solution Q can be prevented, and generation of plating defects in fine holes, grooves and surfaces of the plating surface of the substrate to be plated due to oxygen gas can be prevented.

In the plating apparatus having the above-described structure, the electric field between the anode electrode 28 and the substrate 13 can be made uniform by reducing the distance between the substrate 13 and the anode electrode 28. A plating film having a uniform thickness can be formed on the plating surface of the substrate 13. The distance between the substrate 13 to be plated and the anode electrode 28 is preferably 10 mm to 30 mm.

In the above-described plating apparatus, the porous plate 21 has a large number of holes 21a uniformly formed on the entire surface. However, the porous plate 21 is not limited to this, and as shown in FIG. At the center of the plate 21, a hole 21b having a diameter larger than the hole diameter of the surrounding perforations 21a may be provided.

By providing a hole 21b having a diameter larger than that of the surrounding perforations 21a at the center of the perforated plate 21 as described above, the center of the vertical jet of the plating solution passing through the perforated plate 21 is strengthened, The vertical jet contacting the plating surface of the substrate to be plated 13 flows to the outer periphery without being disturbed along the surface to be plated. When the substrate to be plated 13 is carried into the plating bath 10, the substrate is immersed in liquid from the center of the substrate to be plated 13, so that bubbles on the surface to be plated can be quickly released. The number of the holes 21b having a diameter larger than the diameter of the pores 21a is not limited to one.
A plurality may be provided at the center.

FIGS. 7 and 8 are views showing another example of the configuration of the plating tank of the plating apparatus according to the present invention. In FIG.
Since the upper part from the substrate holder 12 is the same as that in FIG. 3, its illustration is omitted. FIG. 8 is a sectional view taken along line AA of FIG. As shown in FIG.
A cylindrical nozzle plate 34 is provided around the outer periphery of the plating solution introduction chamber 22.
Is arranged on the outer periphery of the nozzle plate 34,
5 are provided. The nozzle plate 34 is provided with the plating solution supply unit 3.
Nozzle holes 34 a for ejecting the plating solution Q supplied to 5 into the plating solution introduction chamber 22 are formed. Nozzle hole 34
The flow direction of the plating solution Q ejected from a is horizontal and eccentric from the center of the plating solution introduction chamber 22.

A spiral guide vane 38 for collecting the flow of the plating solution Q flowing from the nozzle hole 34a of the nozzle plate 34 at the center is provided in the plating solution introduction chamber 22. The plating solution supply section 35 is provided with a plating solution inlet 36, and the flow direction of the plating solution Q flowing from the plating solution inlet 36 is also horizontal and eccentric from the center of the plating solution introduction chamber 22.

In the plating apparatus having the above-described structure, the plating solution Q flowing from the plating solution inlet 36 into the plating solution supply unit 35 turns into the annular plating solution supply unit 35,
Further, the gas flows horizontally from the nozzle hole 34a of the nozzle plate 34 and in a direction eccentric from the center of the plating solution introduction chamber 22, flows into the plating solution introduction chamber 22, and further flows into the guide vanes 38.
Will guide you to concentrate in the center. As a result, the vertical jet ejected from the large-diameter hole 21b at the center of the perforated plate 21 becomes a stronger jet than the surrounding small-diameter holes 21a.

As described above, the direction of inflow of the plating solution Q flowing from the plating solution nozzle plate 34 is horizontal and eccentric from the center of the plating solution introduction chamber 22, so that the plating solution is introduced into the plating solution introduction chamber 22. A rotating flow of the plating solution Q is formed, and the rotating flow of the plating solution Q
Accordingly, a jet of the plating solution Q having a rotating component is generated in the plating solution chamber 20. The rotation of the plating solution in the plating solution chamber 20 has the same direction as the rotation of the plating solution in the plating solution introduction chamber 22. Substrate 13 to be plated
Is rotated in a direction opposite to the rotational flow in the plating solution introduction chamber 22, thereby increasing the relative speed between the plating surface and the plating solution Q, reducing the concentration diffusion layer near the plating surface, and forming a uniform plating film. Formation is possible.

Further, by providing the spiral guide vanes 38, the plating solution flow from the nozzle holes 34a of the nozzle plate 34 is collected in the central portion below the porous plate 21, and the pressure of the plating solution Q in the central portion is increased. Therefore, the vertical jet flow passing through the central portion of the perforated plate is increased. The nozzle plate 34
When the plating solution flow from the nozzle hole 34a is smoothly collected in the central portion below the perforated plate 21, the guide vane 3
8 is not necessary.

FIG. 9 is a view showing another configuration example of the plating tank of the plating apparatus according to the present invention. In FIG. 9, the upper part from the substrate holder 12 is the same as that of FIG. As shown in the figure, in the present plating apparatus, an annular plating solution supply chamber 50 is provided on the inner periphery of the plating solution chamber 20, and the plating solution Q is supplied from the inner periphery of the plating solution supply chamber 50 through a number of nozzle holes 51. 20 flows in the horizontal direction.

A cylindrical electric field correction ring 52 is provided between the substrate 13 to be plated and the anode electrode 28. If the film thickness is not made uniform due to the sheet resistance of the substrate to be plated 13 by reducing the distance between the substrate to be plated 13 and the anode electrode 28, the electric current flows around the periphery of the substrate to be plated 13. As shown in FIG. 12, there is a problem that the thickness of the plating film formed on the substrate 13 to be plated is not uniform. Therefore, here, the electric field correction ring 52 is provided to prevent the electricity from flowing into the outer periphery of the substrate 13 to be plated.

The influence of the electric sneaking around the outer periphery of the substrate 13 varies depending on the distance between the substrate 13 and the anode electrode 28.
Since the distance between the anode electrode 28 and the anode electrode 28 is assumed to be 20 to 60 mm, the length of the electric field correction ring 52 is set to 10 to 50 mm and the inner diameter is smaller than the effective diameter of the substrate 13 to be plated. It is effective to arrange the electric field correction ring 52 such that the upper end is located at a position 1 to 10 mm away from the lower surface of the substrate 13 to prevent the electric sneak.

As an example, the distance between the substrate 13 to be plated and the anode electrode 28 is 35 mm, and the substrate to be plated (semiconductor wafer)
13, the distance between the upper end of the electric field correction ring 52 and the lower surface of the substrate 13 to be plated is 3 mm, and the electric field correction ring 5
2, inner diameter φ190, electric field correction ring 52 length 15 mm
And Under these conditions, a current density of 2.5 A / dm ² and a time of 1
FIG. 1 shows the result of plating for 1 second with a thickness of 1100 nm for 20 seconds.
3 is shown. Comparing FIG. 12 and FIG. 13, the provision of the electric field correction ring 52 prevents the sneaking of electricity and provides plating with a uniform film thickness.

FIG. 10 is a view showing an example of the overall configuration of a plating apparatus using the plating tank 10 having the above-described configuration according to the present invention.
0 (a) shows a planar configuration, and FIG. 10 (b) shows a side configuration. As shown in FIG. 10, the plating apparatus 40 includes a loading unit 41, an unloading unit 42, a washing / drying tank 43, a load stage 44, a coarse water washing tank 45, a plating stage 46, a pretreatment tank 47, a first robot 48, and a second robot 48. This is a configuration including a robot 49. In each plating stage 46, the plating tanks 10 having the configuration shown in FIG. That is, a total of four plating tanks 10 are arranged in the entire plating apparatus. This can be realized because the plating tank 10 can have a smaller depth dimension than the conventional plating tank 100 shown in FIG.

In the plating apparatus 40 having the above-described structure, the substrates 13 to be plated stored in the cassette mounted on the load section 41 are taken out one by one by the first robot 48 and transferred to the load stage 44. The substrate 13 to be plated transferred to the load stage 44 is moved by the second robot 49.
It is transferred to the pretreatment tank 47 and subjected to pretreatment in the pretreatment tank 47. The pre-processed substrate 13 is transferred to the plating tank 10 of the plating stage 46 by the second robot 49 and subjected to plating. The plating target substrate 13 after the plating process is transferred to the coarse water washing tank 45 by the second robot 49 and subjected to the coarse water cleaning process. The substrate 13 to be plated after the rough water cleaning process is further transferred to the cleaning and drying tank 43 by the first robot 48, washed and dried, and then transferred to the unloading unit 42.

As described above, the plating tank 10 according to the present invention
Is a plating solution chamber 20 formed between a perforated plate 21 disposed opposite to the plating surface of the substrate 13 at a predetermined interval and a flattened plate formed below the perforated plate 21. A plating solution introduction chamber 22 is provided, and the plating solution Q is flowed into the plating solution introduction chamber 22 from the horizontal direction, and a flow of the plating solution perpendicular to the plating surface of the substrate 13 to be plated is formed through the many holes 21 a of the perforated plate 21. Therefore, the depth dimension can be reduced as compared with the conventional plating bath of the face-down type in which the plating solution jet is applied perpendicularly to the substrate to be plated. Therefore, a plurality of plating tanks 10 can be arranged in an overlapping manner, and the installation space of the entire plating apparatus is reduced. If a conventional plating tank is used, as shown in FIG.
Since only one plating tank can be arranged on each plating stage 46, the area of the plating stage 46 is twice as large as that of FIG.

As the plating solution Q, a plating solution for performing other metal plating can be used in addition to a copper sulfate plating solution for performing copper plating.

[0063]

As described above, according to the first aspect of the present invention, the plating formed between the substrate to be plated and the perforated plate disposed below and opposed to the substrate at a predetermined interval. A liquid chamber and a flat plating solution introduction chamber formed below the perforated plate are provided, and a plating solution is poured from the horizontal direction into the plating solution introduction chamber, and is perpendicular to the plating surface of the substrate to be plated through the perforations of the perforated plate. By setting the distance between the perforated plate and the substrate to be plated appropriately, it is possible to lengthen the rising distance of the plating solution and eliminate the need for rectification. It is possible to obtain a flat configuration with a small value.

According to the second aspect of the present invention, an anode chamber is provided below the plating solution introduction chamber via an ion exchange membrane or a porous neutral diaphragm, and the plating chamber or another conductive material is provided in the anode chamber. By flowing the acidic solution, the oxidative decomposition of the additive in the plating solution on the anode electrode surface is prevented, and the abnormal consumption of the additive in the plating solution is prevented, and the generated oxygen gas is supplied to the ion exchange membrane or porous neutral. Since it is prevented by the diaphragm and does not reach the substrate to be plated, it is possible to prevent the formation of plating defects in minute holes and grooves on the surface of the substrate to be plated.

Further, according to the third aspect of the present invention, a plating substrate rotating mechanism is provided, and the plating substrate is rotated with the plating surface facing downward during plating, so that the plating surface can be made uniform. It can be in contact with the plating solution and can form a plating film having a uniform thickness. In addition, after plating is completed, the substrate to be plated is pulled up from the plating solution surface and rotated at a high speed so that the plating solution adhered in the plating bath can be shaken off, and the outside of the plating bath is less contaminated by the plating solution. Become.

According to the fourth aspect of the present invention, a hole having a diameter larger than that of the surrounding holes is formed in the center of the perforated plate.
By providing one or more, the central part of the vertical jet of the plating solution passing through the perforated plate is strengthened, and the vertical jet contacting the plating surface of the substrate to be plated is disturbed along the surface to be plated. Without flowing to the outer periphery. When the substrate to be plated is carried into the plating tank, the substrate is immersed in liquid from the center of the substrate to be plated, so that bubbles on the surface to be plated can be quickly released.

According to the fifth aspect of the invention, the direction of inflow of the plating solution flowing from the plating solution nozzle is horizontal and eccentric from the center of the plating solution introduction chamber.
A rotating flow of the plating solution is formed in the plating solution introduction chamber,
The rotating flow of the plating solution will be ejected to the plating solution chamber through the perforated plate, and the plating solution chamber generates a jet of the plating solution having a rotation component in the same direction as the plating solution rotating flow in the plating solution introduction chamber, The relative speed between the plating surface of the substrate to be plated and the plating solution is increased, the concentration diffusion layer near the plating surface is made thinner, and a uniform plating film can be formed.

According to the sixth aspect of the present invention, the cylindrical electric field correction ring having an inner diameter smaller than the effective diameter of the substrate to be plated is placed closer to the substrate to be plated. With this arrangement, electricity does not flow into the outer peripheral portion of the substrate to be plated, and the film thickness around the substrate to be plated does not increase.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration example of a conventional face-down plating bath.

FIG. 2 is a diagram showing a conventional method for adjusting an electric field between a substrate to be plated and an anode electrode.

FIG. 3 is a diagram showing a configuration example of a plating tank of a plating apparatus according to the present invention.

FIG. 4 is an enlarged view of a portion B in FIG. 3;

FIG. 5 is a diagram showing a configuration example of a plating tank of a plating apparatus according to the present invention.

FIG. 6 is a view showing a shape of a perforated plate used in the plating apparatus according to the present invention.

FIG. 7 is a diagram showing a configuration example of a plating tank of a plating apparatus according to the present invention.

FIG. 8 is a sectional view taken along line AA of FIG. 7;

FIG. 9 is a diagram showing a configuration example of a plating tank of the plating apparatus according to the present invention.

FIG. 10 is a view showing an example of the overall configuration of a plating apparatus according to the present invention, wherein FIG. 10 (a) is a plan view thereof, and FIG. 10 (b) is a side view thereof.

FIG. 11 is a diagram showing an example of the overall plan configuration of a conventional plating apparatus.

FIG. 12 is a view showing a state of a plating film distribution when plating is performed by a conventional plating apparatus.

FIG. 13 is a view showing a state of a plating film distribution when plating is performed by a plating apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Plating tank 11 Plating tank main body 12 Substrate holder 13 Substrate to be plated 14 Guide member 15 Bearing 16 Cylinder 17 Substrate holding member 18 Motor 19 Cylinder 20 Plating solution chamber 21 Perforated plate 22 Plating solution introduction chamber 23 Collection gutter 24 Plating solution tank Reference Signs List 25 pump 26 brush 27 electrical contact 28 anode electrode 29 carry-in / out slit 30 ion exchange membrane or porous neutral diaphragm 31 anode chamber 32 pump 33 liquid tank 34 nozzle plate 35 plating solution supply section 36 plating solution inflow port 38 guide vane 40 plating Apparatus 41 Load section 42 Unload section 43 Washing / drying tank 44 Load stage 45 Rough water washing tank 46 Plating stage 47 Pretreatment tank 48 First robot 49 Second robot 50 Plating solution supply chamber 51 Nozzle hole 52 Electric field correction ring

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Koji Mishima, Inventor Koji Mishima 11-1, Haneda Asahimachi, Ota-ku, Tokyo Ebara Corporation (72) Inventor Satoshi Chiyo 11-1, Asahicho, Haneda, Ota-ku, Tokyo Co., Ltd. EBARA F term (reference) 4K022 AA05 AA41 BA08 DA01 DB15 DB17 DB18 4K024 AA09 BA11 BB12 CB02 CB13 CB15 GA16 4M104 BB04 DD52 HH20

Claims (6)

[Claims] 1. A plating apparatus comprising a plating tank, wherein a plating solution is brought into contact with a plating surface of a substrate to be plated in the plating tank to perform metal plating, wherein the plating tank is disposed with the plating surface facing downward. A plating solution chamber is formed between the substrate to be plated and a perforated plate disposed opposite to the substrate at a predetermined interval below the plate, and a flat plating solution introduction chamber formed below the perforated plate. Then, a plating solution is poured into the plating solution introduction chamber from the horizontal direction, and a flow of the plating solution perpendicular to the plating surface of the substrate to be plated is formed through the perforations of the perforated plate to guide the plating solution to the plating solution chamber. A plating apparatus. 2. The plating apparatus according to claim 1, wherein the plating tank has a flat anode chamber below the plating solution introduction chamber via an ion exchange membrane or a porous neutral diaphragm. A plating apparatus, wherein an anode electrode facing a substrate to be plated is arranged at the bottom of a chamber, and the plating solution or another conductive liquid is caused to flow through the anode chamber. 3. The plating apparatus according to claim 1, wherein the plating tank includes a substrate-to-be-plated rotating mechanism that rotates the substrate to be plated in a plating tank with the plating surface facing downward. A plating apparatus characterized by the above-mentioned. 4. The plating apparatus according to claim 1, wherein one or a plurality of holes having a diameter larger than a diameter of a peripheral hole are provided in a central portion of the perforated plate. A plating apparatus characterized by the above-mentioned. 5. The plating apparatus according to claim 1, further comprising a plurality of plating solution nozzles for allowing a plating solution to flow into the plating solution introduction chamber, and a plating solution flowing from the plating solution nozzle. A plating apparatus, wherein the inflow direction is horizontal and eccentric from the center of the plating solution introduction chamber. 6. A plating apparatus comprising a plating tank, wherein a plating solution is brought into contact with a plating surface of a substrate to be plated in the plating tank to perform metal plating, wherein the plating surface is directed downward in the plating tank. Along with disposing the substrate, a predetermined interval is provided below and the anode electrode is disposed facing the anode electrode, and has an inner diameter smaller than the effective diameter of the substrate to be plated between the substrate to be plated and the anode electrode. The cylindrical electric field correction ring is arranged such that the upper end of the electric field correction ring is close to the substrate to be plated, and the center of the electric field correction ring and the center of the substrate to be plated are located substantially coaxially. Characteristic plating equipment.