JP3639151B2 - Plating equipment - Google Patents

Description

[0001]
BACKGROUND 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]
[Prior art]
In recent years, a metal plating apparatus such as copper plating is used to fill the groove or hole of a substrate to be plated in which fine grooves or holes for wiring are formed on the surface of a semiconductor wafer or the like. A method of filling holes and holes is used. Conventionally, there is a face-down type plating apparatus as this type of plating apparatus. As shown in FIG. 1, the plating apparatus has a substrate 102 such as a semiconductor wafer disposed on the plating tank 100 with its plating surface facing downward, and the plating solution Q in the plating tank 103 is supplied to the plating solution supply pipe by a pump 104. Through 105, it is made to eject from the bottom part of the plating tank main body 101, and the jet flow of the plating solution Q is applied perpendicularly to the plating surface of the substrate 102 to be plated.
[0003]
The plating solution Q that has overflowed 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. .
[0004]
In the conventional face-down type plating apparatus having the above configuration, in order to apply the jet of the plating solution Q perpendicularly to the substrate 102 to be plated, it is necessary to create a flow equally distributed in the circumferential direction on the substrate to be plated. Therefore, there is a problem that the dimension in the depth direction of the plating tank 100 becomes large.
[0005]
Further, when the anode electrode 107 is an insoluble electrode, the additive in the plating solution is oxidized and decomposed and is abnormally consumed, or the surface of the substrate to be plated and the fine holes formed on the surface by the generated oxygen. There was a problem that plating defects occurred in the grooves.
[0006]
Further, in the face-down type plating apparatus, means for improving the uniformity of the film thickness of the plating film formed on the plating surface of the substrate 102 to be plated include changing the distance between the substrate 102 and the anode electrode 107, In addition to the uniform flow of the plating solution, there is optimization of the shape of the shielding plate 109 placed between the substrate 102 and the anode electrode 107 as shown in FIG. 2 in order to adjust the state of the electric field.
[0007]
Normally, when the anode electrode 107 and the cathode (substrate 102 to be plated) are parallel plates, the shielding plate 109 adjusts the size of the opening hole 109a provided in the center thereof, thereby allowing an electric field within the surface of the substrate 102 to be plated. It is possible to improve the uniformity. However, in this case, the surrounding film thickness tends to increase due to the wrapping of electricity around the substrate to be plated 102 in the vicinity of the substrate to be plated 102, and the size of the opening hole 109a needs to be reduced, resulting in FIG. As shown in FIG. 2, there is a problem that an M-type film thickness distribution is likely to be obtained.
[0008]
In FIG. 12, the vertical axis indicates the plating film thickness (nm), the horizontal axis indicates the distance (mm) from the wafer edge that is the substrate to be plated, and SSW-NNE is the film thickness of the south-southwest-north-north-east section of the wafer. WSW-ENE indicates the film thickness of the west-southwest-west-northwest section of the wafer, WNW-ESE indicates the film thickness of the west-northwest-east-southeast section of the wafer, and NNW-SSE indicates the film thickness of the north-northwest-southeast section.
[0009]
[Problems to be solved by the invention]
The present invention has been made in view of the above points, and can reduce the depth dimension of the plating tank. The additive in the plating solution is oxidatively decomposed and consumed abnormally. It is an object of the present invention to provide a plating apparatus capable of performing metal plating with a uniform film thickness without causing plating defects in fine holes and grooves formed on the surface.
[0010]
It is another object of the present invention to provide a plating apparatus capable of performing metal plating with a uniform film thickness by adjusting the electric field in the plating surface of the substrate to be plated.
[0011]
[Means for Solving the Problems]
  In order to solve the above problems, the invention according to claim 1 comprises a plating tank, and in the plating apparatus for performing metal plating by bringing a plating solution into contact with the plating surface of the substrate to be plated in the plating tank,
  The plating tank includes a plating solution chamber formed between the substrate to be plated disposed with a plating surface facing downward and a perforated plate disposed at a predetermined interval below the substrate to be plated, and the perforated plate. A flat plating solution introduction chamber formed belowA plurality of plating solution nozzles for introducing the plating solution into the plating solution introduction chamber are provided, and the inflow direction of the plating solution flowing into the plating solution introduction chamber from the plating solution nozzle is horizontal and deviated from the center of the plating solution introduction chamber. MindTheThe plating solution flowing into the plating solution introduction chamberA flow of a plating solution perpendicular to the plating surface of the substrate to be plated is formed through the perforated plate and guided to the plating solution chamber.
[0012]
  As described above, the plating solution chamber formed between the substrate to be plated and the perforated plate disposed below and facing the substrate, and the flat plating formed below the perforated plate A plating solution is provided, and the plating solution is poured into the plating solution introduction chamber from the horizontal direction to form a flow of plating solution perpendicular to the plating surface of the substrate to be plated through the perforations of the porous plate. By appropriately setting the distance of the substrate, it is not necessary to increase the rising distance of the plating solution and perform rectification, and the plating layer can have a flat configuration with a small depth dimension.In addition, the plating solution inflow direction flowing from the plating solution nozzle is horizontal and decentered from the center of the plating solution introduction chamber, so that a rotating flow of the plating solution is formed in the plating solution introduction chamber. The flow is ejected through the perforated plate into the plating solution chamber, and a plating solution jet with a rotating component in the same direction as the plating solution rotation flow in the plating solution introduction chamber is generated in the plating solution chamber to plate the substrate to be plated. The relative speed between the surface and the plating solution is increased, and the concentration diffusion layer is thinned in the vicinity of the plating surface, so that a uniform plating film can be formed.
[0013]
  According to a second aspect of the present invention, in the plating apparatus of the first aspect, the plating tank has a flat anode chamber below the plating solution introduction chamber via an ion exchange membrane or a porous neutral diaphragm. And an anode electrode facing the substrate to be plated is disposed at the bottom of the anode chamber, and a plating solution or another conductive solution is placed in the anode chamber.I will introduceIt is configured as described above.
[0014]
  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 placed in the anode chamber.IntroduceAs a result, the oxidative decomposition of the additive in the plating solution on the anode electrode surface is prevented and abnormal consumption of the additive in the plating solution is prevented, and the generated oxygen gas is blocked by the ion exchange membrane or the porous neutral diaphragm. Since it does not reach the substrate to be plated, it is possible to prevent plating defects from being formed in fine holes and grooves on the surface of the substrate to be plated.
[0015]
The invention according to claim 3 is the plating apparatus rotating mechanism according to claim 1 or 2, wherein the plating tank rotates the substrate to be plated with the plating surface facing downward in the plating tank. It is characterized by comprising.
[0016]
By providing the plating substrate rotation mechanism as described above and rotating the substrate to be plated with the plating surface facing downward during plating, the plating surface can be uniformly contacted with the plating solution, and plating with a uniform film thickness can be achieved. A film can be formed. In addition, after plating is finished, the substrate to be plated is lifted from the surface of the plating solution and rotated at a high speed, so that the plating solution adhering in the plating bath can be shaken off, and the plating solution is less likely to be contaminated outside. Become.
[0017]
The plating apparatus according to any one of claims 1 to 3, wherein a distance between the substrate to be plated and the porous plate is 5 to 15 mm.
[0018]
By setting the distance between the substrate to be plated and the perforated plate to 5 to 15 mm as described above, the influence of the plating solution discharged in the circumferential direction of the substrate by the viscous force of the plating solution by rotating the substrate to be plated. Thus, the pressure becomes lower at the center of the substrate to be plated, and the upward flow from the center of the perforated plate increases, so that a uniform vertical component velocity can be obtained over the entire surface of the substrate to be plated. Therefore, it is not necessary to increase the run-up distance of the upward flow in the depth direction as in the prior art, so that the depth dimension of the plating tank can be reduced.
[0019]
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 in a stacked manner.
[0020]
By arranging a plurality of plating tanks on the plating stage as described above, the planar arrangement configuration of the entire plating apparatus can be reduced, and the installation space can be saved.
[0021]
According to a fourth aspect of the present invention, in the plating apparatus according to any one of the first to third aspects, the central portion of the porous plate has one or a plurality of holes having a diameter larger than the diameter of the surrounding porous holes. It is characterized by being provided.
[0022]
As described above, by providing one or more holes having a diameter larger than the diameter of the surrounding porous holes in the center of the perforated plate, the center of the vertical jet of the plating solution passing through the perforated plate is strengthened, The vertical jet contacted with the plating surface of the substrate flows to the outer peripheral portion without being disturbed along the surface to be plated. When the substrate to be plated is carried into the plating tank, it is immersed from the center of the substrate to be plated, and the bubbles on the surface to be plated can be quickly released.
[0023]
The plating apparatus according to any one of claims 1 to 4, wherein the distance between the substrate to be plated and the anode electrode is 10 to 30 mm.
[0024]
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 is 10 to 30 mm. The uniformity of the plating film is improved. It is also possible to reduce the size of the plating tank.
[0025]
  The invention according to claim 5 is the plating apparatus according to any one of claims 1 to 4,A spiral guide vane is provided that collects the flow of the plating solution flowing into the plating solution introduction chamber from a plurality of plating solution nozzles in the central portion of the plating solution introduction chamber.
[0026]
  By providing a spiral guide vane that collects the flow of plating solution flowing in from a plurality of plating solution nozzles in the center of the plating solution introduction chamber as described above, the plating solution generated by the plating solution flow from the plating solution nozzle With the rotating flow, the plating solution is collected in the central part below the perforated plate, and the pressure of the plating solution in the central part can be increased, so that the vertical jet flow through the central part of the perforated plate can be increased. A uniform plating film can be formed on the surface.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
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 figure, the main plating tank 10 contains a substrate holder 12 for holding a substrate to be plated 13 such as a semiconductor wafer in a plating tank body 11. The substrate holding body 12 includes a substrate holding portion 12-1 and a shaft portion 12-2. The shaft portion 12-2 is rotatably supported on the inner wall of a cylindrical guide member 14 via bearings 15 and 15. Yes. The guide member 14 and the substrate holder 12 can be moved up and down with a predetermined stroke by a cylinder 16 provided at the top of the plating tank body 11.
[0033]
The substrate holder 12 can be rotated in the direction of arrow A via a shaft portion 12-2 by a motor 18 provided in the upper part of the guide member 14. The substrate holder 12 is provided with a space C for accommodating the substrate pressing member 17 including the substrate pressing portion 17-1 and the shaft portion 17-2. The substrate pressing member 17 is provided on the substrate holding member 12. The cylinder 19 provided at the upper part in the shaft portion 12-2 can be moved up and down with a predetermined stroke.
[0034]
An opening 12-1a communicating with the space C is provided below the substrate holding portion 12-1 of the substrate holder 12, and an edge of the substrate 13 to be plated is formed above the opening 12-1a as shown in FIG. A step portion 12-1b on which the portion is placed is formed. The edge portion 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 portion of the substrate 13 to be plated is pressed. Is sandwiched between the substrate pressing portion 17-1 and the stepped portion 12-1b. And the lower surface (plating surface) of the to-be-plated board | substrate 13 is exposed to the opening 12-1a. 4 is an enlarged view of a portion B in FIG.
[0035]
A flat plating solution chamber 20 is provided below the substrate holding portion 12-1 of the plating tank body 11, that is, below the plating surface of the substrate 13 to be exposed exposed to the opening 12-1 a, and below the plating solution chamber 20. A flat plating solution introduction chamber 22 is provided through a perforated plate 21 in which a large number of holes 21a are formed. In addition, a collecting rod 23 is provided outside the plating solution chamber 20 for collecting the plating solution Q that overflows the plating solution chamber 20.
[0036]
The plating solution Q collected by the collecting rod 23 is returned 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. The plating solution Q introduced from both sides of the plating solution chamber 20 flows into the plating solution chamber 20 through a hole 21a of the perforated plate 21 as a vertical jet. The gap between the perforated plate 21 and the substrate to be plated 13 is 5 to 15 mm, and the jet of the plating solution Q through the hole 21a of the perforated plate 21 is maintained as a uniform jet while maintaining the vertical rise. Contact the plating surface. The plating solution Q that has overflowed the plating solution chamber 20 is collected by the collecting rod 23 and flows into the plating solution tank 24. That is, the plating solution Q is circulated between the plating solution chamber 20 of the plating tank body 11 and the plating solution tank 24.
[0037]
Plating solution surface level L in the plating solution chamber 20_QIs the plating solution level L of the substrate 13 to be plated_WIt is slightly higher by ΔL, and the entire plating surface of the substrate to be plated 13 is in contact with the plating solution Q.
[0038]
The step 12-1b of the substrate holder 12-1 of the substrate holder 12 is provided with an electrical contact 27 that is electrically connected to the conductive portion of the substrate 13 to be plated. The electrical contact 27 is an electric wire (not shown). Are electrically connected to the brush 26 and further connected to the cathode of an external plating power source (not shown) via the brush 26. Further, an anode electrode 28 is provided at the bottom of the plating solution introduction chamber 22 of the plating tank main body 11 so as to face the substrate 13 to be plated, and the anode electrode 28 is connected to the anode of the plating power source. At a predetermined position on the wall surface of the plating tank body 11, a carry-in / out slit 29 for taking in and out the substrate to be plated 13 with a substrate carry-in / out jig such as a robot arm is provided.
[0039]
In the plating apparatus having the above-described configuration, when performing plating, first, the cylinder 16 is operated, and the substrate holder 12 and the guide member 14 together with a predetermined amount (the substrate to be plated 13 held by the substrate holding portion 12-1 is brought into the loading / unloading slit). 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 carried into the space C of the substrate holder 12 with a substrate carry-in / out jig such as a robot arm, and the substrate to be plated 13 is placed on the stepped portion 12-1b so that the plating surface faces downward. Place. In this state, the cylinder 19 is operated and lowered until the lower surface of the substrate pressing portion 17-1 contacts the upper surface of the substrate to be plated 13, and the substrate to be plated 13 is placed between the substrate pressing portion 17-1 and the stepped portion 12-1b. Hold the edge of the.
[0040]
In this state, the cylinder 16 is operated until the plating surface of the substrate to be plated 13 together with the guide member 14 contacts the plating solution Q in the plating solution chamber 20 (the plating solution level L)._QTo a position lower by ΔL). At this time, the motor 18 is started and lowered while rotating the substrate holder 12 and the substrate to be plated 13 at a low speed. The plating solution chamber 20 is filled with the plating solution Q, and a vertical upward flow through the numerous holes 21 a of the perforated plate 21 is ejected. In this state, when a predetermined voltage is applied between the anode electrode 28 and the electrical contact 27 from the plating power source, a plating current flows from the anode electrode 28 to the substrate 13 to be plated, and a plating film is formed on the plating surface of the substrate 13 to be plated. Is done.
[0041]
During the plating, the motor 18 is operated to rotate the substrate holder 12 and the substrate to be plated 13 at a low speed. This low speed rotation is set so that a plating film having a uniform film thickness can be formed on the plating surface of the substrate to be plated 13 without disturbing the vertical jet of the plating solution Q in the plating solution chamber 20.
[0042]
When plating is completed, the cylinder 16 is operated to raise the substrate holder 12 and the substrate to be plated 13, and the lower surface of the substrate holding portion 12-1 has a plating solution level L._QIf it becomes higher, the motor 18 is rotated at high speed, and the plating solution adhering to the plating surface of the substrate to be plated and the lower surface of the substrate holding portion 12-1 is shaken off by centrifugal force. When the plating solution is shaken off, the substrate to be plated 13 is raised to the position of the carry-in / out slit 29, and when the cylinder 19 is operated to raise the substrate pressing portion 17-1, the substrate to be plated 13 is released and the substrate is held. It will be in the state mounted in the step part 12-1b of the part 12-1. In this state, a substrate carry-in / out jig such as a robot arm is caused to enter the space C of the substrate holder 12 through the carry-in / out slit 29, and the substrate 13 to be plated is picked up and carried out to the outside.
[0043]
By configuring the plating apparatus as described above, a vertical upward flow of the plating solution is formed through the numerous holes 21a of the perforated plate 21 in the plating solution chamber 20, so that the plating solution jet is applied to the substrate to be plated as in the prior art. Compared to the face-down type plating tank applied perpendicularly to the plating tank, the running distance of the plating solution is small, and the depth dimension of the plating tank 10 can be reduced. Therefore, it is possible to arrange a plurality of plating tanks 10 in a stacked manner.
[0044]
In the above embodiment, electrolytic plating has been described as an example, but electroless plating can be performed without providing the electrical contact 27 and the anode electrode 28.
[0045]
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, since the upper part from the substrate holder 12 is the same as FIG. The plating tank 10 is provided 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 below the plating solution introduction chamber 22, and at the bottom of the anode chamber 31. An anode electrode 28 is provided. The plating solution or conductive liquid Q ′ in the liquid tank 33 is introduced into the anode chamber 31 by the pump 32, and the plating solution or conductive liquid Q ′ flowing out from the anode chamber 31 returns to the liquid tank 33. Yes. 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.
[0046]
As described above, the anode chamber 31 is provided in the plating tank 10 via the ion exchange membrane or the porous neutral diaphragm 30 below the plating solution introduction chamber 22, and the plating solution or the conductive liquid Q ′ is allowed to flow, whereby the anode electrode Even if an insoluble electrode is used for the electrode 28, the oxidative decomposition of the additive can be prevented on the surface of the anode electrode 28, and the generated oxygen gas is blocked by the ion exchange membrane or the porous neutral diaphragm 30 and the substrate to be plated. 13 plating surface is not reached. Thereby, abnormal consumption of the additive in the plating solution Q can be prevented, and it is possible to prevent plating defects from being generated in the fine holes, grooves and surface of the plating surface of the substrate to be plated by the oxygen gas.
[0047]
In the plating apparatus having the above configuration, by reducing the distance between the substrate 13 to be plated and the anode electrode 28, the electric field between the anode electrode 28 and the substrate 13 to be plated can be made uniform. A plating film having a uniform film thickness can be formed on the plating surface. The distance between the substrate to be plated 13 and the anode electrode 28 is preferably 10 mm to 30 mm.
[0048]
In the above-described plating apparatus, the porous plate 21 is a plate in which a large number of holes 21a are uniformly formed on the entire surface. However, the porous plate 21 is not limited to this, and as shown in FIG. A hole 21b having a diameter larger than that of the surrounding porous 21a may be provided in the central portion.
[0049]
As described above, by providing the hole 21b having a diameter larger than the hole diameter of the surrounding porous 21a in the central part of the porous plate 21, the central part of the vertical jet of the plating solution passing through the porous plate 21 is strengthened, and the substrate to be plated The vertical jet contacted with the 13 plating surfaces flows to the outer peripheral portion without being disturbed along the surface to be plated. When the substrate to be plated 13 is carried into the plating tank 10, it is immersed from the central portion of the substrate to be plated 13, and the bubbles on the surface to be plated can be quickly released. The number of holes 21b having a diameter larger than the diameter of the hole 21a is not limited to one, and a plurality of holes 21b may be provided in the center.
[0050]
7 and 8 are diagrams showing another configuration example of the plating tank of the plating apparatus according to the present invention. 7, since the upper part from the substrate holder 12 is the same as FIG. 3, its illustration is omitted. 8 is a cross-sectional view taken along the line AA in FIG. As shown in the figure, in this plating apparatus, a cylindrical nozzle plate 34 is disposed on the outer periphery of the plating solution introduction chamber 22 of the plating tank body 11, and a plating solution supply unit 35 is provided on the outer periphery of the nozzle plate 34. Yes. The nozzle plate 34 is formed with a nozzle hole 34 a for ejecting the plating solution Q supplied to the plating solution supply unit 35 into the plating solution introduction chamber 22. The flow direction of the plating solution Q ejected from the nozzle hole 34 a is horizontal and eccentric from the center of the plating solution introduction chamber 22.
[0051]
A spiral guide vane 38 is provided in the plating solution introduction chamber 22 to collect the flow of the plating solution Q flowing from the nozzle hole 34a of the nozzle plate 34 at the center. 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 decentered from the center of the plating solution introduction chamber 22.
[0052]
In the plating apparatus having the above-described configuration, the plating solution Q that has flowed into the plating solution supply unit 35 from the plating solution inlet 36 turns into the annular plating solution supply unit 35, and further horizontally from the nozzle hole 34 a of the nozzle plate 34. In addition, the flow flows in an eccentric direction from the center of the plating solution introduction chamber 22 and flows into the plating solution introduction chamber 22, and is further guided by the guide vane 38 so as to be concentrated in the central portion. Thereby, the vertical jet ejected from the hole 21b having a large hole diameter at the center of the perforated plate 21 becomes a stronger jet than the surrounding hole 21a having a small hole diameter.
[0053]
As described above, by rotating the inflow direction of the plating solution Q flowing from the plating solution nozzle plate 34 horizontally and from the center of the plating solution introduction chamber 22, the rotation of the plating solution Q into the plating solution introduction chamber 22 is performed. A flow is formed, and the rotating flow of the plating solution Q is ejected to the plating solution chamber 20 through the perforated plate 21, and a jet of the plating solution Q having a rotating component is generated in the plating solution chamber 20. The plating solution rotation flow in the plating solution chamber 20 has the same direction as the plating solution rotation flow in the plating solution introduction chamber 22. By rotating the substrate to be plated 13 in the direction opposite to the rotational flow in the plating solution introduction chamber 22, the relative speed of the plating surface and the plating solution Q is increased, the concentration diffusion layer near the plating surface is thinned, and uniform. It is possible to form a plated film.
[0054]
Further, by providing the spiral guide vane 38, the plating solution flow from the nozzle hole 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 can be increased. Increase the vertical jet flow through the center of the perforated plate. Note that the guide vane 38 is not necessarily required when the plating solution flow from the nozzle hole 34 a of the nozzle plate 34 is smoothly collected in the central portion below the porous plate 21.
[0055]
FIG. 9 is a view showing another configuration example of the plating tank of the plating apparatus according to the present invention. 9, since the upper part from the board | substrate holding body 12 is the same as FIG. 3, the illustration is abbreviate | omitted. As shown in the figure, in the present plating apparatus, an annular plating solution supply chamber 50 is provided in 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.
[0056]
A cylindrical electric field correction ring 52 is provided between the substrate to be plated 13 and the anode electrode 28. If the film thickness is not 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 electrical wrap around the periphery of the substrate 13 to be plated As shown in FIG. 12, there is a problem that the film thickness of the plating film formed on the substrate to be plated 13 is not uniform. Therefore, here, an electric field correction ring 52 is provided to prevent electricity from wrapping around the outer periphery of the substrate 13 to be plated.
[0057]
The influence of the electrical wrap around the outer periphery of the substrate to be plated 13 varies depending on the distance between the substrate to be plated 13 and the anode electrode 28, but the distance between the substrate to be plated 13 and the anode electrode 28 assumed here is 20 to 60 mm. Therefore, the electric field correction ring 52 having a length of 10 to 50 mm and an inner diameter smaller than the effective plating diameter of the substrate 13 to be plated is used. It is effective to prevent the electricity from wrapping around to be located at a position 1 to 10 mm away from the lower surface of 13.
[0058]
As an example, the distance between the substrate to be plated 13 and the anode electrode is 35 mm, the effective diameter φ194 of 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 to be plated 13, and the electric field correction ring 52. And the length of the electric field correction ring 52 was 15 mm. Under this condition, the current density is 2.5 A / dm.²FIG. 13 shows the result of plating with a time of 120 seconds and a film thickness of 1100 nm. Comparing FIG. 12 and FIG. 13, by providing the electric field correction ring 52, wraparound of electricity is prevented and plating with a uniform film thickness is performed.
[0059]
FIG. 10 is a diagram 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. FIG. 10 (a) shows a plan 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 rough water washing tank 45, a plating stage 46, a pretreatment tank 47, a first robot 48 and a second robot. In this configuration, a robot 49 is provided. In each plating stage 46, the plating tank 10 having the configuration shown in FIG. That is, a total of four plating tanks 10 are arranged as a whole plating apparatus. This can be realized because the plating tank 10 can be made smaller in depth than the conventional plating tank 100 shown in FIG.
[0060]
In the plating apparatus 40 having the above-described configuration, the substrates to be plated 13 housed in a cassette placed on the load unit 41 are taken out one by one by the first robot 48 and transferred to the load stage 44. The to-be-plated substrate 13 transferred to the load stage 44 is transferred to the pretreatment tank 47 by the second robot 49 and pretreated 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 the plating process. The to-be-plated board | substrate 13 which the plating process was complete | finished is transferred to the rough water washing tank 45 by the 2nd robot 49, and a rough water washing process is performed. The to-be-plated substrate 13 that has been subjected to the rough water cleaning process is further transferred to the cleaning / drying tank 43 by the first robot 48, cleaned and dried, and then transferred to the unloading unit 42.
[0061]
As described above, the plating tank 10 according to the present invention includes a plating solution chamber 20 formed between the plating plate 10 of the substrate to be plated 13 and the perforated plate 21 disposed to face each other at a predetermined interval. A flat plating solution introduction chamber 22 formed below the porous plate 21 is provided, and the plating solution Q is poured into the plating solution introduction chamber 22 from the horizontal direction, and the substrate 13 to be plated is passed through the numerous holes 21 a of the porous plate 21. Since the flow of the plating solution perpendicular to the plating surface is formed, the depth dimension can be reduced as compared with a face-down type plating tank in which a conventional 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 is reduced as a whole plating apparatus. If a conventional plating tank is used, as shown in FIG. 11, only one plating tank can be arranged on each plating stage 46, so the arrangement area of the plating stage 46 is double that in the case of FIG.
[0062]
In addition, as the plating solution Q, a plating solution for performing other metal plating can be used in addition to the copper sulfate plating solution for performing copper plating.
[0063]
【The invention's effect】
  As described above, according to the first aspect of the present invention, the plating solution chamber formed between the substrate to be plated and the perforated plate disposed below the substrate with a predetermined gap therebetween, A flat plating solution introduction chamber formed below the perforated plate is provided, the plating solution is poured into the plating solution introduction chamber from the horizontal direction, and the plating solution is perpendicular to the plating surface of the substrate to be plated through the perforations of the perforated plate. Therefore, by setting the distance between the perforated plate and the substrate to be plated appropriately, the rising distance of the plating solution is lengthened and there is no need for rectification, and the plating layer has a flat structure with a small depth dimension. It becomes possible to do.In addition, the plating solution inflow direction flowing from the plating solution nozzle is horizontal and decentered from the center of the plating solution introduction chamber, so that a rotating flow of the plating solution is formed in the plating solution introduction chamber. The flow is ejected through the perforated plate into the plating solution chamber, and a plating solution jet with a rotating component in the same direction as the plating solution rotation flow in the plating solution introduction chamber is generated in the plating solution chamber to plate the substrate to be plated. The relative speed between the surface and the plating solution is increased, and the concentration diffusion layer is thinned in the vicinity of the plating surface, so that a uniform plating film can be formed. Further, the distance in the depth direction can be shortened, the plating tank can be miniaturized, and the entire apparatus can be miniaturized and the cost can be reduced.
[0064]
  According to the invention of claim 2, an anode chamber is provided below the plating solution introduction chamber via an ion exchange membrane or a porous neutral diaphragm, and the plating solution or another conductive solution is placed in the anode chamber.IntroduceThis prevents oxidative decomposition of the additive in the plating solution on the anode electrode surface, prevents abnormal consumption of the additive in the plating solution, and prevents the generated oxygen gas from being blocked by the ion exchange membrane or the porous neutral diaphragm. Since it does not reach the plated substrate, plating defects can be prevented from forming in fine holes and grooves on the surface of the substrate to be plated.
[0065]
Further, according to the invention described in claim 3, by providing the plating substrate rotating mechanism and rotating the substrate to be plated with the plating surface facing downward during plating, the plating surface is uniformly made into the plating solution. A plating film having a uniform thickness can be formed. In addition, after plating is finished, the substrate to be plated is lifted from the surface of the plating solution and rotated at a high speed, so that the plating solution adhering in the plating bath can be shaken off, and the plating solution is less likely to be contaminated outside. Become.
[0066]
According to the invention described in claim 4, by providing one or a plurality of holes having a diameter larger than the diameter of the surrounding porous holes in the central portion of the porous plate, the vertical jet of the plating solution passing through the porous plate The central portion of the substrate is strengthened, and the vertical jet contacted with the plating surface of the substrate to be plated flows to the outer peripheral portion without being disturbed along the surface to be plated. When the substrate to be plated is carried into the plating tank, it is immersed from the center of the substrate to be plated, and the bubbles on the surface to be plated can be quickly released.
[0067]
  According to the invention as set forth in claim 5,By providing a spiral guide vane that collects the flow of plating solution flowing in from multiple plating solution nozzles in the central part of the plating solution introduction chamber, Since the liquid is collected in the central part below the perforated plate and the pressure of the plating solution in the central part can be increased, the vertical jet flow through the central part of the perforated plate can be increased, and the plating surface of the substrate to be plated can be uniformly plated. A film can be formed.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration example of a conventional face-down plating tank.
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 view showing a configuration example of a plating tank of a plating apparatus according to the present invention.
4 is an enlarged view of a portion B in FIG.
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 the shape of a porous plate used in the plating apparatus according to the present invention.
FIG. 7 is a view showing a configuration example of a plating tank of the plating apparatus according to the present invention.
8 is a cross-sectional view taken along the line AA in FIG.
FIG. 9 is a view showing a configuration example of a plating tank of the plating apparatus according to the present invention.
FIG. 10 is a diagram showing an example of the overall configuration of a plating apparatus according to the present invention, in which 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 planar configuration of a conventional plating apparatus.
FIG. 12 is a diagram showing a state of plating film distribution when plating is performed by a conventional plating apparatus.
FIG. 13 is a diagram showing a state of plating film distribution when plating is performed by the plating apparatus according to the present invention.
[Explanation of symbols]
10 Plating tank
11 Plating tank body
12 Substrate holder
13 Substrate to be plated
14 Guide member
15 Bearing
16 cylinders
17 Substrate holding member
18 Motor
19 cylinders
20 Plating solution chamber
21 perforated plate
22 Plating solution introduction room
23 Collection Trap
24 Plating solution tank
25 pump
26 brushes
27 Electrical contacts
28 Anode electrode
29 Loading / unloading slit
30 Ion exchange membrane or porous neutral membrane
31 Anode chamber
32 pumps
33 Liquid tank
34 Nozzle plate
35 Plating solution supply section
36 Plating solution inlet
38 guide vanes
40 Plating equipment
41 Road Department
42 Unloading section
43 Washing and drying tank
44 Road Stage
45 Rough water washing tank
46 Plating stage
47 Pretreatment tank
48 The first robot
49 Second Robot
50 Plating solution supply chamber
51 Nozzle hole
52 Electric field correction ring

Claims (5)

In a plating apparatus that includes a plating tank and performs metal plating by bringing a plating solution into contact with a plating surface of a substrate to be plated in the plating tank,
The plating tank includes a plating solution chamber formed between the substrate to be plated disposed with a plating surface facing downward and a perforated plate disposed at a predetermined interval below the substrate to be plated, and the perforated plate. A flat plating solution introduction chamber formed below and a plurality of plating solution nozzles for allowing the plating solution to flow into the plating solution introduction chamber, and inflow of the plating solution flowing into the plating solution introduction chamber from the plating solution nozzle The direction is horizontal and eccentric from the center of the plating solution introduction chamber, and the plating solution flowing into the plating solution introduction chamber forms a flow of plating solution perpendicular to the plating surface of the substrate to be plated through the perforations of the porous plate. And a plating apparatus characterized by being guided to the plating solution chamber. The plating apparatus according to claim 1,
The plating tank is provided with a flat anode chamber below the plating solution introduction chamber via an ion exchange membrane or a porous neutral diaphragm, and an anode electrode facing the substrate to be plated is disposed at the bottom of the anode chamber. plating apparatus characterized by being by Uni configured to introduce the plating solution or other conductive fluid to the anode chamber. In the plating apparatus according to claim 1 or 2,
The plating apparatus includes a plating substrate rotating mechanism for rotating the substrate to be plated in the plating tank with the plating surface facing downward. In the plating apparatus according to any one of claims 1 to 3,
The plating apparatus according to claim 1, wherein one or a plurality of holes having a diameter larger than a diameter of a surrounding porous hole are provided in a central portion of the porous plate. In the plating apparatus according to any one of claims 1 to 4,
A plating apparatus comprising a spiral guide vane for collecting a flow of a plating solution flowing into the plating solution introduction chamber from the plurality of plating solution nozzles at a central portion of the plating solution introduction chamber .

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