WO2023032191A1

WO2023032191A1 - Plating method and plating apparatus

Info

Publication number: WO2023032191A1
Application number: PCT/JP2021/032624
Authority: WO
Inventors: 一仁辻
Original assignee: 株式会社荏原製作所
Priority date: 2021-09-06
Filing date: 2021-09-06
Publication date: 2023-03-09
Also published as: JPWO2023032191A1

Abstract

One purpose of the present invention is to reduce the time during which a substrate holder is lifted while also reducing the amount of excess plating solution which is taken from a plating tank.　A method for plating a substrate, said method including: a step for plating a substrate held by a substrate holder in a plating solution inside a plating tank; a step for angling the substrate holder in a manner such that the surface of the substrate is tilted at a prescribed angle from horizontal in the plating solution in the plating tank; a step for collecting the plating solution in the plating tank by raising the substrate holder at a first speed to a first height at which at least some of the substrate holder is exposed from the liquid surface of the plating solution in the plating tank while in a state in which the substrate holder is angled, and causing the plating solution adhered to the substrate holder and/or to the substrate to be absorbed by the liquid surface as a result of surface tension; and a step for increasing the substrate holder to a second height which is higher than the first height at a second speed which is faster than is the first speed.

Description

Plating method and plating equipment

This application relates to a plating method and a plating apparatus.

A cup-type electroplating device is known as an example of a plating device. A cup-type electroplating apparatus immerses a substrate (for example, a semiconductor wafer) held in a substrate holder with the surface to be plated facing downward in a plating solution, and applies a voltage between the substrate and the anode to A conductive film is deposited on the surface of the After plating, the substrate holder holding the substrate is pulled up from the plating solution and transferred to a subsequent processing module such as a cleaning module.

When pulling up the substrate holder after plating, if the substrate holder is pulled up in a horizontal position, a large amount of plating solution adhering to the substrate and the substrate holder is carried out from the plating bath or plating module (called drag-out). On the other hand, a method of tilting and pulling up the substrate holder is known. By pulling up the substrate holder in an inclined state, the plating solution can easily drop along the surfaces of the substrate and the substrate holder which are inclined by gravity. This makes it possible to reduce the amount of plating solution carried out (drag-out amount) compared to when the substrate holder is pulled up in a horizontal state. In the plating apparatus described in Japanese Patent No. 4719631 (Patent Document 1), a cleaning medium is jetted from a jet nozzle toward a wafer tilted above a plating processing cup to remove the liquid adhering to the wafer. collected in a cup.

Patent No. 4719631 specification

The slower the speed of pulling up the substrate holder, the smaller the dragout amount. One of the reasons for this is that the longer the pulling-up time is, the more the plating solution drops from the substrate holder into the plating bath. However, slowing down the lift speed of the substrate holder can take a long time and adversely affect throughput. Therefore, it is desirable to shorten the pull-up time while reducing the drag-out amount.

One of the purposes of the present invention is to reduce the amount of plating solution carried out from the plating bath while reducing the time required to pull up the substrate holder.

According to one embodiment, there is provided a method of plating a substrate, comprising: plating the substrate held by a substrate holder in a plating solution in a plating bath; a step of tilting the substrate holder so that the substrate holder is tilted at a predetermined angle from the horizontal; and with the substrate holder being tilted, at least part of the substrate holder is exposed from the liquid surface of the plating solution in the plating bath. a step of raising the substrate holder to a first height at a first speed, absorbing the plating solution adhering to the substrate holder and/or the substrate by surface tension to the liquid surface, and collecting the plating solution in the plating bath; and raising the substrate holder to a second height higher than the first height at a second speed higher than the first speed.

1 is a perspective view showing the overall configuration of a plating apparatus of this embodiment; FIG. 1 is a plan view showing the overall configuration of a plating apparatus of this embodiment; FIG. 1 is a longitudinal sectional view schematically showing the configuration of a plating module of this embodiment; FIG. It is an experimental result of measuring the relationship between the pulling-up time of the substrate holder and the amount of dragout. It is an experimental result of measuring the relationship between the pulling-up time of the substrate holder and the drag-out amount when the substrate holder is not rotated and when the substrate holder is rotated. FIG. 10 is a vertical cross-sectional view of the plating module showing a process of spraying pure water onto the substrate holder after being pulled up; It is an example of a flow chart of a plating method including a process of pulling up a substrate holder.

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

<Overall Configuration of Plating Equipment>
FIG. 1 is a perspective view showing the overall configuration of the plating apparatus of this embodiment. FIG. 2 is a plan view showing the overall configuration of the plating apparatus of this embodiment. As shown in FIGS. 1 and 2, the plating apparatus 1000 includes a load port 100, a transfer robot 110, an aligner 120, a pre-wet module 200, a pre-soak module 300, a plating module 400, a cleaning module 500, a spin rinse dryer 600, and a transfer device. 700 and a control module 800 .

The load port 100 is a module for loading substrates stored in cassettes such as FOUPs (not shown) into the plating apparatus 1000 and for unloading substrates from the plating apparatus 1000 to cassettes. Although four load ports 100 are arranged horizontally in this embodiment, the number and arrangement of the load ports 100 are arbitrary. The transport robot 110 is a robot for transporting substrates, and is configured to transfer substrates among the load port 100 , the aligner 120 and the transport device 700 . When transferring substrates between the transfer robot 110 and the transfer device 700, the transfer robot 110 and the transfer device 700 can transfer the substrates via a temporary placement table (not shown).

The aligner 120 is a module for aligning the positions of orientation flats, notches, etc. of the substrate in a predetermined direction. Although two aligners 120 are arranged horizontally in this embodiment, the number and arrangement of the aligners 120 are arbitrary. The pre-wet module 200 replaces the air inside the pattern formed on the substrate surface with the treatment liquid by wetting the surface to be plated of the substrate before the plating treatment with a treatment liquid such as pure water or degassed water. The pre-wet module 200 is configured to perform a pre-wet process that facilitates the supply of the plating solution to the inside of the pattern by replacing the treatment solution inside the pattern with the plating solution during plating. Although two pre-wet modules 200 are arranged vertically in this embodiment, the number and arrangement of the pre-wet modules 200 are arbitrary.

In the presoak module 300, for example, an oxide film having a large electric resistance existing on the surface of a seed layer formed on the surface to be plated of the substrate before plating is etched away with a processing liquid such as sulfuric acid or hydrochloric acid, and the surface of the plating substrate is cleaned. Alternatively, it is configured to perform a pre-soak process for activation. In this embodiment, two presoak modules 300 are arranged side by side in the vertical direction, but the number and arrangement of the presoak modules 300 are arbitrary. The plating module 400 applies plating to the substrate. In this embodiment, there are two sets of 12 plating modules 400 arranged vertically and four horizontally, and a total of 24 plating modules 400 are provided. The number and arrangement of are arbitrary.

The cleaning module 500 is configured to perform a cleaning process on the substrate in order to remove the plating solution and the like remaining on the substrate after the plating process. In this embodiment, two cleaning modules 500 are arranged side by side in the vertical direction, but the number and arrangement of the cleaning modules 500 are arbitrary. The spin rinse dryer 600 is a module for drying the substrate after cleaning by rotating it at high speed. Although two spin rinse dryers are arranged vertically in this embodiment, the number and arrangement of the spin rinse dryers are arbitrary. The transport device 700 is a device for transporting substrates between a plurality of modules within the plating apparatus 1000 . Control module 800 is configured to control a plurality of modules of plating apparatus 1000 and may comprise, for example, a general purpose or dedicated computer with input/output interfaces to an operator.

An example of a series of plating processes by the plating apparatus 1000 will be explained. First, a substrate stored in a cassette is loaded into the load port 100 . Subsequently, the transport robot 110 takes out the substrate from the cassette of the load port 100 and transports the substrate to the aligner 120 . The aligner 120 aligns orientation flats, notches, etc. of the substrate in a predetermined direction. The transport robot 110 transfers the substrate aligned by the aligner 120 to the transport device 700 .

The transport device 700 transports the substrate received from the transport robot 110 to the pre-wet module 200 . The pre-wet module 200 pre-wets the substrate. The transport device 700 transports the pre-wet processed substrate to the pre-soak module 300 . The presoak module 300 applies a presoak treatment to the substrate. The transport device 700 transports the presoaked substrate to the plating module 400 . The plating module 400 applies plating to the substrate.

The transport device 700 transports the plated substrate to the cleaning module 500 . The cleaning module 500 performs a cleaning process on the substrate. The transport device 700 transports the cleaned substrate to the spin rinse dryer 600 . A spin rinse dryer 600 performs a drying process on the substrate. The transport device 700 delivers the dried substrate to the transport robot 110 . The transport robot 110 transports the substrate received from the transport device 700 to the cassette of the load port 100 . Finally, the cassette containing the substrates is unloaded from the load port 100 .

<Configuration of plating module>
Next, the configuration of the plating module 400 will be described. Since the 24 plating modules 400 in this embodiment have the same configuration, only one plating module 400 will be described. FIG. 3 is a longitudinal sectional view schematically showing the configuration of the plating module 400 of this embodiment. As shown in FIG. 3, the plating module 400 includes a plating bath 410 for containing a plating solution and an overflow bath 412 arranged around the plating bath 410 . The overflow bath 412 collects the plating solution overflowing from the plating bath 410 . The plating solution recovered in the overflow bath 412 is returned to the plating bath 410 through a circulation path (not shown) and reused. The plating module 400 includes a membrane 420 that vertically separates the interior of the plating bath 410 . The interior of the plating bath 410 is partitioned into a cathode area 422 and an anode area 424 by a membrane 420 . Cathode region 422 and anode region 424 are each filled with a plating solution. An anode 430 is provided on the bottom surface of the plating bath 410 in the anode area 424 . A resistor 450 is disposed in the cathode region 422 so as to face the membrane 420 . The resistor 450 is a member for uniformizing the plating process on the surface to be plated of the substrate Wf, and is composed of a plate-like member having a large number of holes.

The plating module 400 also includes a substrate holder 440 for holding the substrate Wf with the surface to be plated facing downward. The substrate holder 440 includes power contacts for powering the substrate Wf from a power source (not shown). The plating module 400 includes an elevating mechanism 442 for elevating the substrate holder 440 . The lifting mechanism 442 can be implemented by a known mechanism such as a motor. The plating module 400 lowers the substrate holder 440 using the elevating mechanism 442 to immerse the substrate Wf in the plating solution in the cathode region 422, and applies a voltage between the anode 430 and the substrate Wf to lift the substrate Wf. It is configured to apply plating to the surface to be plated.

The plating module 400 also includes a tilting mechanism 444 for tilting the substrate holder 440 . The tilting mechanism 444 can be implemented by a known mechanism such as a mechanism called a tilting mechanism. Furthermore, the plating module 400 includes a rotation mechanism 446 for rotating the substrate holder 440 so that the substrate Wf rotates around a virtual rotation axis extending vertically through the center of the surface to be plated. The rotating mechanism 446 can be implemented by a known mechanism such as a motor.

In this embodiment, the elevating mechanism 442 is operated in a state in which the surface to be plated of the substrate Wf held by the substrate holder 440 by the tilting mechanism 444 is tilted several degrees (for example, 5°) with respect to the horizontal plane (liquid surface of the plating solution). It is configured to raise the substrate holder 440 to lift the substrate Wf out of the plating solution. Further, the elevating mechanism 442 lowers the substrate holder 440 in a state in which the surface to be plated of the substrate Wf held by the substrate holder 440 is tilted several degrees with respect to the surface of the plating solution by the tilting mechanism 444, and the substrate Wf is immersed. may be configured to allow A horizontal plane is a plane parallel to the ground and can be defined as a plane defined by the surface or liquid level of the plating solution in the plating bath (when the surface/liquid level is in a flat state).

<Control of lifting speed>
Experiments have shown that when the speed during lifting the substrate holder 440 from the surface of the plating solution (a state in which part of the substrate holder 440 is exposed from the surface of the solution and part of which is in the solution) is reduced, the amount of the plating solution taken out increases. (drag-out amount) was found to be effective. This is because the plating solution on the surfaces of the substrate holder 440 and the substrate Wf is absorbed by the plating solution in the plating bath 410 due to surface tension simultaneously with the lifting. Therefore, in the present embodiment, as shown in FIG. 3, when the substrate holder 440 is pulled up in an inclined state, the substrate holder 440 is pulled up from the plating solution at the first speed V1 so that the entire surface of the substrate holder 440 is exposed from the plating solution. A configuration is adopted in which the height (first height H1) at the time of the movement is raised to the second height H2 at a faster second speed V2 (>V1). As a result, a configuration is adopted in which the pulling-up time is shortened while suppressing the drying of the substrate surface while reducing the amount of dragout.

Here, the first height H1 is the height when the substrate holder 440 rises and the entire surface of the substrate holder 440 is just exposed from the plating solution ("height when the entire surface of the substrate holder 440 is exposed from the plating solution. ”). The second height H2 is an arbitrary height above the first height H1, for example, the height for loading/unloading the substrate Wf to/from the substrate holder 440 and/or the rinsing liquid for the substrate Wf. may be at a height for cleaning the substrate Wf by spraying. H0 in FIG. 3 indicates the height of the substrate holder 440 (referred to as plating height) when the substrate Wf is plated in the plating solution. In the present embodiment, the plating height H0 is set to H0=0 as a reference for the height of the substrate holder 440 . Also, the height of the substrate holder 440 is defined as the height of the center position of the substrate Wf, as shown in FIG. Note that the height of the substrate holder 440 may be the height of another portion of the substrate holder.

FIG. 4 shows experimental results of measuring the relationship between the substrate holder lifting time and the amount of dragout. This experimental result was obtained when a copper sulfate plating solution was used as the plating solution. In the graph of FIG. 4, the horizontal axis indicates the lifting time (s, seconds) required for lifting to the second height H2, and the vertical axis indicates the dragout amount (mL), which is the amount of the plating solution taken out.

A curve CA is a measurement result when the substrate holder 440 is lifted at a constant lifting speed. A numerical value attached to each point on the curve CA indicates a constant pulling speed. For example, the point 50 mm/s is the measurement result when the substrate holder 440 is pulled up at a constant pulling speed of 50 mm/s, indicating that the pulling up time is about 2 s and the dragout amount is about 17.5 mL. A point of 1 mm/s is a measurement result when the substrate holder 440 is pulled up at a constant pulling speed of 1 mm/s, and indicates that the pulling up time is about 108 s and the dragout amount is about 1.8 mL. In other words, when the substrate holder 440 is lifted at a constant lifting speed, if the lifting speed is increased, the amount of dragout cannot be sufficiently reduced. However, it can be seen that the pulling time is greatly increased.

Curve CB is measured when the substrate holder 440 is lifted to a first height H1 at a first speed V1 and then lifted to a second height at a second speed V2 (50 mm/s in this measurement). This is the result. A numerical value attached to each point on the curve CB indicates the value of the first speed V1. For example, the point 10 mm/s is the measurement result when the first speed V1 is pulled up to the first height H1 at 10 mm/s and then the second speed V2 is pulled up to the second height H2 at 50 mm/s. , indicating that the pull-up time is about 4 s and the dragout volume is about 9.5 mL. The point 1 mm/s is the measurement result when pulled up to the first height H1 at the first speed V1 = 1 mm/s and then pulled up to the second height H2 at the second speed V2 = 50 mm/s. The time is approximately 35 s and the dragout volume is approximately 1.8 mL. That is, the substrate holder 440 is lifted up at the first speed V1 to the height H1 when the entire substrate holder 440 is exposed from the liquid surface, and then lifted up to the second height H2 at the second speed V2 (>V1). It can be seen that the pull-up time can be shortened while reducing the

As indicated by curve CB in FIG. 4, the substrate holder 440 is pulled up at a low first speed V1 to a first height H1 when the entire surface of the substrate holder 440 is exposed from the surface of the plating solution (at the time of exposure). is accelerated to the second speed V2, it is possible to shorten the pull-up time while reducing the drag-out amount. In particular, it is effective when the first speed V1 is 10 mm/s or less. This is because if the first speed V1 is higher than 10 mm/s, the dragout amount cannot be sufficiently reduced, and the original pull-up time is short, so there is little need to further shorten the pull-up time. More preferably, the first speed V1 is 5 mm/s or less. When the substrate was pulled up at the first velocity V1=5 mm/s or less, no dripping of the plating solution from the substrate holder 440 was observed during the pulling up at the second velocity V2 (50 mm/s). That is, while the substrate holder 440 was pulled up at the first speed V1=5 mm/s or less, the plating solution on the surfaces of the substrate Wf and the substrate holder 440 was sufficiently removed by surface tension, and the second speed V2 was changed. However, it is expected that the amount of dragout will not change. Also, considering the throughput, the first speed V1 is preferably 1 mm/s or more.

FIG. 5 shows experimental results of measuring the relationship between the substrate holder pull-up time and the amount of drag-out when the substrate holder is not rotated and when it is rotated. This experimental result was obtained when a copper sulfate plating solution was used as the plating solution. In the graph of FIG. 4, the horizontal axis indicates the lifting time (s, seconds) required for lifting to the second height H2, and the vertical axis indicates the dragout amount (mL), which is the amount of the plating solution taken out.

The curve C0 is obtained by lifting the substrate holder 440 at a first speed V1 (numerical values attached to each point on the curve C0) and a second speed V2 (50 mm/s) without rotating the substrate holder 440 (rotational speed 0 rpm). The measurement results for the case are shown. Curve C5 is obtained when the substrate holder 440 is pulled up at the first speed V1 (numerical value attached to each point on the curve C5) and the second speed V2 (50 mm/s) while rotating the substrate holder 440 at a rotation speed of 5 rpm. shows the measurement results of From this experimental result, the amount of dragout is slightly larger when the substrate Wf is rotated. This is because when the substrate Wf and the substrate holder 440 are pulled up from the surface of the plating solution, the substrate holder 440 rotates and the plating solution is swirled up and adheres to the substrate Wf and/or the substrate holder 440 . Therefore, when pulling up the substrate holder 440 , it is preferable not to rotate the substrate Wf and the substrate holder 440 while the substrate holder 440 is in contact with the plating solution in the plating tank 410 .

In a state where the entire surface of the substrate holder 440 is exposed from the plating solution and the entire surface of the substrate holder 440 is separated from the liquid surface of the plating solution, the rotation of the substrate holder 440 causes the plating solution to be swirled up and attached to the substrate holder 440 . Therefore, it is preferable to rotate the substrate holder 440 to facilitate dropping the plating solution adhering to the substrate Wf and/or the substrate holder 440 into the plating bath 410 .

FIG. 6 is a vertical cross-sectional view of the plating module showing the process of spraying pure water onto the substrate holder after being pulled up. A sprayer 460 is provided in the plating module 400, and after the substrate holder 440 is raised to the second height H2 (see FIG. 3), the pure water 452 is sprayed onto the substrate Wf and/or the substrate holder 440, and the pure water 452 after spraying is applied. may be returned to the plating bath 410 in part or in whole. Since the pure water 452 after spraying contains the plating solution remaining on the substrate Wf and/or the substrate holder 440, by collecting this in the plating tank 410, the amount of dragout can be further reduced. On the other hand, since the pure water 452 mixed into the plating tank 410 dilutes the plating solution, the amount of the pure water 452 mixed is preferably less than the amount of water evaporated from the plating solution during operation of the apparatus. Of the pure water 452 sprayed onto the substrate Wf and/or the substrate holder 440, the portion that is not returned to the plating bath 410 may be drained to a drainage area (not shown) outside the plating bath 410 by rotating the substrate holder 440. , a movable tray (not shown) for receiving the sprayed pure water 452 may be prepared.

A liquid other than pure water and/or an inert gas such as nitrogen may be sprayed from the injector 460 onto the substrate Wf and/or the substrate holder 440 as a cleaning medium. Depending on the type of cleaning medium, the sprayed cleaning medium may or may not be mixed into the plating bath 410 .

FIG. 7 is an example of a flow chart of the plating method including the process of pulling up the substrate holder according to this embodiment. This process is executed by a program stored in a non-volatile memory (not shown) included in control device 800 . Note that the control device 800 may cooperate with another control device or sequencer to perform this process.

In step S<b>11 , the substrate holder 440 holding the substrate Wf is immersed in the plating solution of the plating tank 410 by the elevating mechanism 442 . In step S12, the substrate Wf is plated.

In step S13, after the plating process, the tilting mechanism 444 tilts the substrate Wf in the plating solution of the plating bath 410 such that the surface to be plated of the substrate Wf is tilted several degrees (for example, 5°) with respect to the liquid surface (horizontal) of the plating solution. Tilt the holder 440 .

In step S14, the elevating mechanism 442 raises the substrate holder 440 at a relatively low first speed V1 to the first height H1 when the entire surface of the substrate holder 440 is exposed from the liquid surface of the plating solution. At this time, the substrate holder 440 is not rotated.

In step S15, the elevating mechanism 442 elevates the substrate holder 440 to the second height H2 at a relatively high second speed V2. At this time, the substrate holder 440 may be rotated.

In step S16, the injector 460 sprays pure water onto the substrate Wf and/or the substrate holder 440 to clean the substrate Wf and/or the substrate holder 440. Note that the cleaning process in step S16 may be omitted.

In step S17, the substrate Wf is removed from the substrate holder 440.

(Evaluation of drag-out amount)
The evaluation as to whether or not the dragout amount, which is the amount of the plating solution carried out by the substrate Wf, has been reduced can be performed, for example, as follows. The surfaces of the substrate holder 440 and the substrate Wf pulled up from the plating solution are washed with a certain amount of pure water (for example, 1 L), and the electrical conductivity of the recovered washing solution (pure water) is measured. For example, a bat for recovery is arranged below the substrate holder 440 and the cleaning liquid is recovered by the bat. On the other hand, by measuring the electrical conductivity in advance when a given plating solution is mixed into a certain amount of pure water, a calibration curve can be created from the relationship between the amount of plating solution mixed and the electrical conductivity. . Using this calibration curve, the amount of dragout of the plating solution can be calculated from the electrical conductivity obtained by the measurement. When the substrate Wf is washed in the plating module 400 after being pulled up (step S16 in FIG. 7), the surface of the substrate Wf after washing in S16 is further washed with a certain amount of pure water (for example, 1 L). After washing, the electric conductivity of the washing liquid (pure water) collected in further washing is measured. According to this method, it is possible to easily evaluate whether or not the amount of dragout has been reduced with sufficient accuracy.

(Other embodiments)
(1) In the above embodiment, the first height H1 at the end point of pulling up at the first speed V1 (<V2) is the height when the entire surface of the substrate holder 440 is exposed from the plating solution. may be lower than the height when the entire surface of the substrate holder 440 is exposed from the plating solution, as long as at least a portion of the substrate holder 440 is exposed from the plating solution. That is, the pulling-up at the first speed may be finished while a part of the substrate holder 440 is in contact with the liquid surface of the plating solution. In this case also, the substrate holder 440 and/or substrate holder 440 and/or substrate holder 440 and/or substrate holder 440 and/or Alternatively, the plating solution on the surface of the substrate Wf is absorbed by the plating solution in the plating tank 410 due to surface tension, and the amount of dragout can be reduced.
(2) Also, the first height H1 may be higher than the height when the entire surface of the substrate holder 440 is exposed from the plating solution, as long as the length of the lifting time is within the allowable range. In this case, by pulling up the substrate holder 440 at the first speed to a position higher than the height at which the entire surface of the substrate holder 440 is exposed from the plating solution, the recovery of the plating solution due to surface tension can be fully utilized. can. Further, depending on the first height H1, the substrate holder 440 is pulled up at the first speed V1 (<V2) to a height where the entire surface of the substrate holder 440 is exposed from the plating solution, and the surfaces of the substrate holder 440 and the substrate Wf are lifted. of the plating solution is absorbed by the plating solution in the plating bath 410 due to surface tension, and then, while the substrate is being pulled up at the first speed V1, more of the plating solution is dropped from the substrate holder 440 and/or the substrate Wf into the plating bath 410. can also be expected.
(3) In the above embodiment, an example was described in which the substrate holder 440 was lifted at the second speed V2 after the period during which the substrate holder 440 was lifted at the first speed V1. A period during which the substrate holder 440 is pulled up at one or a plurality of speeds different from the first speed V1 and the second speed V2 may be provided between the period during which the substrate holder 440 is lifted at the two speeds V2. By further providing such a period between the period of pulling up at the first speed V1 and the period of pulling up at the second speed V2, it is possible to adjust the balance between the reduction of the amount of the plating solution taken out and the shortening of the pulling period. can.

At least the following embodiments can be grasped from the above embodiments.
According to one embodiment, there is provided a method of plating a substrate, comprising: plating the substrate held by a substrate holder in a plating solution in a plating bath; at least a portion of the substrate holder is exposed from the surface of the plating solution in the plating bath while the substrate holder is tilted at a predetermined angle from the horizontal. a step of raising the substrate holder to a first height at a first speed, absorbing the plating solution adhering to the substrate holder and/or the substrate by surface tension to the liquid surface, and collecting the plating solution in the plating bath; and elevating the substrate holder at a second speed that is greater than the first speed to a second height that is greater than the first height. Horizontal is a direction parallel to the ground and can be defined as the direction along which a plane defined by the surface or liquid level (when the surface/liquid level is in a flat state) of the plating solution in the plating bath extends. This plating method can be applied to, for example, a cup-type plating apparatus in which a substrate held by a substrate holder with the surface to be plated facing downward (substantially horizontal) is immersed in a plating solution and plated. .

According to this embodiment, the substrate holder and/or the substrate are adhered to by raising the substrate holder at a relatively slow first speed to a first height where at least a portion of the substrate holder is exposed from the plating solution. It is possible to ensure a long time for the plating solution to be absorbed by the surface of the plating solution due to the surface tension, and to collect a large amount of the plating solution in the plating tank. Note that this embodiment also includes a case where a part of the substrate holder is exposed from the liquid surface of the plating solution at the end of plating, and the substrate holder is raised from that position to a higher first height at the first speed. . Further, by raising the substrate holder at a relatively high second speed after raising it to the first height, it is possible to suppress an increase in the raising time required for the entire raising of the substrate holder. As a result, it is possible to shorten the time required to pull up the substrate holder while reducing the amount of plating solution carried out. That is, it is possible to reduce the amount of plating solution used and the cost, and suppress the influence on the throughput. In addition, drying of the substrate surface can be suppressed by suppressing an increase in the time required to pull up the substrate holder.

According to one embodiment, the first height is the height when the entire surface of the substrate holder is exposed from the plating solution.

According to this embodiment, the substrate holder can be raised at a relatively slow first speed until the entire surface of the substrate holder is exposed from the plating solution, maximizing the amount of plating solution recovered by surface tension. At the same time, it is possible to maximize the section to be pulled up at the second speed, which is relatively high, and to shorten the pulling up time.

According to one embodiment, the first height is lower than the height when the entire surface of the substrate holder is exposed from the plating solution.

According to this embodiment, when the plating solution can be recovered sufficiently by raising the substrate holder at a relatively low first speed to a height lower than the height at which the entire surface of the substrate holder is exposed from the plating solution, The pull-up speed can be set to the relatively high second speed at an earlier stage, and the pull-up time can be further shortened.

According to one embodiment, the first height is higher than the height when the entire surface of the substrate holder is exposed from the plating solution.

According to this embodiment, by pulling up the substrate holder at the first speed to a position higher than the height at which the entire surface of the substrate holder is exposed from the plating solution, recovery of the plating solution due to surface tension is fully utilized. be able to. Also, depending on the first height, the substrate holder is raised at a relatively slow first rate to a height where the entire surface of the substrate holder is exposed from the plating solution, thereby maximizing recovery of the plating solution due to surface tension, and The plating solution remaining on the substrate and/or substrate holder is dropped by continuing to rise at a relatively slow first speed for a certain time/height after the entire surface of the substrate holder is exposed from the plating solution. It can be expected that the time for the plating solution is secured and the recovery of the plating solution is further improved.

According to one embodiment, between the recovering step and the step of raising at the second speed, the step of raising the substrate holder at one or more speeds different from the first and second speeds is further included. . Raising at one or more velocities includes at least one of a period of raising the substrate holder at a constant rate, a period of raising with acceleration, and a period of raising with deceleration.

According to this embodiment, a further step added between the recovering step and the step of raising at the second speed adjusts the balance between reducing the amount of plating solution taken out and shortening the lifting period. can do.

According to one embodiment, the substrate holder is not rotated in the recovering step.

According to this embodiment, by not rotating the substrate holder while the substrate holder is in contact with the plating solution, the plating solution is swirled up in the plating tank by the rotation of the substrate holder, and the plating solution is applied to the substrate holder and/or the substrate. Adhesion can be suppressed.

According to one embodiment, in the step of raising the substrate holder at the second speed, the substrate holder is rotated.

According to this embodiment, after the entire surface of the substrate holder is exposed from the plating solution, that is, in a state in which the substrate holder is separated from the liquid surface of the plating solution, the substrate holder is rotated so that the plating bath is moved by the rotation of the substrate holder. The plating solution remaining on the substrate and/or the substrate holder can be efficiently dropped into the plating tank while suppressing or preventing the plating solution from being swirled up.

According to one embodiment, the method further includes the step of spraying pure water onto the surface of the substrate and/or the substrate holder, and allowing part or all of the sprayed pure water to drop into the plating bath.

According to this embodiment, after the substrate holder is lifted to a height above the plating solution, pure water is sprayed onto the substrate and/or the substrate holder to remove the plating solution remaining on the substrate and/or the substrate holder. can be further collected in the plating tank together with the

According to one embodiment, the first speed is 10 mm/s or less.

According to one embodiment, the first speed is 5 mm/s or less.

According to one embodiment, the plating solution is a copper sulfate plating solution.

According to one embodiment, a plating apparatus for plating a substrate is configured to include a substrate holder for holding a substrate, a plating solution and an anode during plating of the substrate, the A plating bath for plating the substrate held by the substrate holder in a plating solution, an elevating mechanism for elevating the substrate holder, a tilting mechanism for tilting the substrate holder, and at least the elevating mechanism and the tilting mechanism are controlled. a control device, wherein the control device controls the tilting mechanism to tilt the substrate holder so that the surface of the substrate is tilted at a predetermined angle from the horizontal in the plating solution of the plating bath; The elevating mechanism is controlled to elevate the substrate holder at a first speed to a first height where at least part of the substrate holder is exposed from the liquid surface of the plating solution in the plating bath while the substrate holder is tilted. and thereafter raising the substrate holder at a second speed that is higher than the first speed to a second height that is higher than the first height. This embodiment also includes a case where a part of the substrate holder is exposed from the liquid surface of the plating solution at the end of plating, and the substrate holder is raised from that position to a higher first height at the first speed. The plating apparatus is, for example, a cup-type plating apparatus that performs plating by immersing a substrate held in a substrate holder with the surface to be plated facing downward (substantially horizontal) in a plating solution. According to this embodiment, at least some of the effects described in the above embodiment are achieved.

Although several embodiments of the present invention have been described above, the above-described embodiments of the present invention are intended to facilitate understanding of the present invention, and do not limit the present invention. The present invention may be modified and improved without departing from its spirit, and the present invention includes equivalents thereof. In addition, any combination or omission of each component described in the claims and the specification is possible within the range that at least part of the above problems can be solved or at least part of the effect is achieved. is. The entire disclosure, including the specification, claims, drawings and abstract of US Pat. No. 4,719,631 (Patent Document 1) is incorporated herein by reference in its entirety.

400 plating module 410 plating bath 412 overflow bath 420 membrane 422 cathode region 424 anode region 430 anode 440 substrate holder 442 lifting mechanism 444 tilting mechanism 446 rotating mechanism 450 resistor 460 injector Wf substrate

Claims

A method of plating a substrate, comprising:
plating the substrate held by the substrate holder in a plating solution in a plating tank;
tilting the substrate holder so that the surface of the substrate is tilted at a predetermined angle from the horizontal in the plating solution in the plating tank;
With the substrate holder being inclined, the substrate holder is raised at a first speed to a first height at which at least part of the substrate holder is exposed from the surface of the plating solution in the plating tank, and the substrate holder and/or Alternatively, a step of absorbing the plating solution adhering to the substrate into the liquid surface by surface tension and recovering the plating solution in the plating tank;
raising the substrate holder at a second speed that is higher than the first speed to a second height that is higher than the first height;
plating methods including;
In the plating method according to claim 1,
The plating method, wherein the first height is a height when the entire surface of the substrate holder is exposed from the plating solution.
In the plating method according to claim 1,
The plating method, wherein the first height is lower than the height when the entire surface of the substrate holder is exposed from the plating solution.
In the plating method according to claim 1,
The plating method, wherein the first height is higher than the height when the entire surface of the substrate holder is exposed from the plating solution.
In the plating method according to any one of claims 1 to 4,
The plating method further comprising, between the recovering step and the step of raising at the second speed, raising the substrate holder at one or more speeds different from the first and second speeds.
In the plating method according to any one of claims 1 to 5,
A plating method, wherein the substrate holder is not rotated in the recovering step.
In the plating method according to any one of claims 1 to 6,
The plating method, wherein in the step of raising the substrate holder at the second speed, the substrate holder is rotated.
In the plating method according to any one of claims 1 to 7,
The plating method further includes the step of spraying pure water onto the surface of the substrate and/or the substrate holder, and allowing part or all of the sprayed pure water to drop into a plating tank.
In the plating method according to any one of claims 1 to 8,
The plating method, wherein the first speed is 10 mm/s or less.
In the plating method according to claim 9,
The plating method, wherein the first speed is 5 mm/s or less.
In the plating method according to any one of claims 1 to 10,
The plating method, wherein the plating solution is a copper sulfate plating solution.
A plating apparatus for plating a substrate,
a substrate holder for holding the substrate;
a plating bath configured to contain a plating solution and an anode for plating the substrate held by the substrate holder in the plating solution during plating of the substrate;
an elevating mechanism for elevating the substrate holder;
a tilting mechanism for tilting the substrate holder;
a control device that controls at least the lifting mechanism and the tilting mechanism;
with
The control device controls the tilting mechanism to tilt the substrate holder so that the surface of the substrate is tilted at a predetermined angle from the horizontal in the plating solution in the plating tank, and controls the lifting mechanism. and raising the substrate holder at a first speed to a first height where at least part of the substrate holder is exposed from the surface of the plating solution in the plating bath while the substrate holder is tilted, and then the substrate holder is at a second speed higher than the first speed to a second height higher than the first height;
Plating equipment.