PLATING APPARATUS

An objective of the present invention is to provide a plating apparatus capable of improving uniformity of a plating film formed on a substrate. The plating apparatus includes a plating tank, a substrate holder that holds a substrate, an anode disposed, in the plating tank, facing the substrate held by the substrate holder, and a film thickness measuring module including a sensor that detects a parameter related to a plating film formed on a surface to be plated of the substrate, the film thickness measuring module measuring a film thickness of the plating film based on a detection value of the sensor during a plating treatment.

TECHNICAL FIELD

The present application relates to a plating apparatus.

BACKGROUND ART

As an example of a plating apparatus, a cup type electrolytically plating apparatus is known (see, for example, Patent Literature 1). In the cup type electrolytically plating apparatus, a substrate (for example, a semiconductor wafer) with a surface to be plated being oriented downward is held by a substrate holder, and immersed into a plating solution, and a voltage is applied between the substrate and an anode, thereby precipitating a conductive film on a substrate surface.

In the plating apparatus, generally, a user sets in advance parameters such as a plating current value, a plating time and the like as plating treatment recipes, based on a target plating film thickness and an actual plating area of a substrate to be subjected to a plating treatment, and the plating treatment is performed based on the set treatment recipes (see, for example, Patent Literature 2). Then, a plurality of wafers on the same carrier are subjected to the plating treatment with the same treatment recipe. Also, to measure the plating film thickness after the plating treatment, in general, after the plating treatment of all the wafers in the carrier ends, the carrier containing the wafers is transferred from the plating apparatus to a separate film thickness measuring device, and wafer film thicknesses and wafer in-plane profiles are individually measured.

CITATION LIST

Patent Literatures

SUMMARY OF INVENTION

Technical Problem

In a plating apparatus, when substrates in the same carrier are subjected to a plating treatment on the same process conditions, variations might be generated in film thickness of a plating film formed on each substrate, due to dimensional tolerance of the substrate, change in state of a plating solution in a plating tank, or the like. Further, when an average film thickness of a plurality of substrates is adjusted, variations might be generated in plating film thickness depending on a location in the same substrate.

In view of above-described situations, one object of the present application is to provide a plating apparatus capable of improving uniformity of a plating film formed on a substrate.

Solution to Problem

According to an embodiment, a plating apparatus is provided, the plating apparatus including a plating tank, a substrate holder that holds a substrate, an anode disposed, in the plating tank, facing the substrate held by the substrate holder, and a film thickness measuring module including a sensor that detects a parameter related to a plating film formed on a surface to be plated of the substrate, the film thickness measuring module measuring a film thickness of the plating film based on a detection value of the sensor during a plating treatment

DESCRIPTION OF EMBODIMENTS

Hereinafter, description will be made as to embodiments of the present invention with reference to the drawings. In the drawings illustrated below; the same or corresponding constituent component is denoted with the same reference sign, and redundant description will not be repeated.

First Embodiment

<Overall Configuration of Plating Apparatus>

FIG.1is a perspective view showing an overall configuration of a plating apparatus of the first embodiment.FIG.2is a plan view showing the overall configuration of the plating apparatus of the first embodiment. The plating apparatus of the present embodiment is for use in subjecting a substrate to a plating treatment. Examples of the substrate include a square substrate and a circular substrate. As shown inFIGS.1and2, a plating apparatus1000includes a loading/unloading module100, a transfer robot110, an aligner120, a prewetting module200, a presoaking module300, a plating module400, a washing module500, a spin rinse dryer module600, a transfer device700, and a control module800.

The loading/unloading module100is a module for loading a substrate such as a semiconductor wafer into the plating apparatus1000and unloading the substrate from the plating apparatus1000, and a cassette for housing the substrate is mounted on the module. In the present embodiment, four loading/unloading modules100are arranged in a horizontal direction, but the number and arrangement of the loading/unloading modules100are arbitrary. The transfer robot110is a robot for transferring the substrate, and configured to deliver the substrate among the loading/unloading module100, the aligner120, and the transfer device700. The transfer robot110and the transfer device700can deliver the substrate via an unshown temporary stand, when delivering the substrate between the transfer robot110and the transfer device700. The aligner120is a module for aligning positions of an orientation flat, a notch and the like of the substrate in a predetermined direction. In the present embodiment, two aligners120are arranged in the horizontal direction, but the number and arrangement of the aligners120are arbitrary.

The prewetting module200is a module for adhering a treatment liquid (prewetting liquid) such as pure water or de-aired water to a surface to be treated of the substrate prior to the plating treatment. In the present embodiment, two prewetting modules200are arranged in an up-down direction, but the number and arrangement of the prewetting modules200are arbitrary. The presoaking module300is a module for etching an oxide film on the surface to be plated of the substrate prior to the plating treatment. In the present embodiment, two presoaking modules300are arranged in the up-down direction, but the number and arrangement of the presoaking modules300are arbitrary.

The plating module400is a module for subjecting the substrate to the plating treatment. In the present embodiment, there are two sets of twelve plating modules400, each set including three plating modules arranged in the up-down direction and four plating modules arranged in the horizontal direction, and 24 plating modules400in total are provided. The number and arrangement of the plating modules400are arbitrary.

The washing module500is a module for washing the substrate subjected to the plating treatment. In the present embodiment, two washing modules500are arranged in the up-down direction, but the number and arrangement of the washing modules500are arbitrary. The spin rinse dryer module600is a module for rotating the substrate subjected to a washing treatment at a high speed to dry the substrate. In the present embodiment, two spin rinse dryer modules are arranged in the up-down direction, but the number and arrangement of the spin rinse dryer modules are arbitrary.

The transfer device700is a device for transferring the substrate among a plurality of modules in the plating apparatus1000. The control module800is a module for controlling the plurality of modules of the plating apparatus1000, and may include a general computer or a dedicated computer including, for example, an input/output interface between the computer and an operator.

An example of a series of plating treatments by the plating apparatus1000will be described. First, the substrate is loaded into the loading/unloading module100. Subsequently, the transfer robot110removes the substrate from the loading/unloading module100, and transfers the substrate to the aligner120. The aligner120aligns the positions of the orientation flat, notch and the like in the predetermined direction. The transfer robot110delivers, to the transfer device700, the substrate aligned in the direction by the aligner120.

The transfer device700transfers, to the prewetting module200, the substrate received from the transfer robot110. The prewetting module200subjects the substrate to a prewetting treatment. The transfer device700transfers, to the presoaking module300, the substrate subjected to the prewetting treatment. The presoaking module300subjects the substrate to a presoaking treatment. The transfer device700transfers, to the plating module400, the substrate subjected to the presoaking treatment. The plating module400subjects the substrate to the plating treatment.

The transfer device700transfers, to the washing module500, the substrate subjected to the plating treatment. The washing module500subjects the substrate to the washing treatment. The transfer device700transfers the substrate subjected to the washing treatment to the spin rinse dryer module600. The spin rinse dryer module600subjects the substrate to a drying treatment. The transfer device700delivers the substrate subjected to the drying treatment to the transfer robot110. The transfer robot110transfers the substrate received from the transfer device700to the loading/unloading module100. Finally, the substrate is unloaded from the loading/unloading module100.

Next, a configuration of the plating module400will be described. In the present embodiment, 24 plating modules400include the same configuration, and hence one plating module400will only be described.FIG.3is a longitudinal sectional view schematically showing the configuration of the plating module400of the first embodiment. As shown inFIG.3, the plating module400includes a plating tank410for containing a plating solution. The plating tank410includes a cylindrical inner tank412having an open upper surface, and an unshown outer tank provided around the inner tank412so that the plating solution overflowing from an upper edge of the inner tank412is accumulated.

The plating module400includes a substrate holder440for holding a substrate Wf with a surface to be plated Wf-a being oriented downward. The substrate holder440also includes a power supply contact point to supply power from an unshown power source to the substrate Wf. The plating module400includes an elevating/lowering mechanism442for elevating and lowering the substrate holder440. In the embodiment, the plating module400includes a rotation mechanism448that rotates the substrate holder440about a vertical axis. The elevating/lowering mechanism442and the rotation mechanism448can be achieved by a known mechanism such as a motor.

The plating module400includes a membrane420that separates an interior of the inner tank412in the up-down direction. The interior of the inner tank412is divided into a cathode region422and an anode region424by the membrane420. The cathode region422and the anode region424are each filled with the plating solution. In the present embodiment, an example in which the membrane420is provided is described, but the membrane420) does not have to be provided.

In the embodiment, an anode430) is provided on a bottom surface of the inner tank412of the anode region424. An anode mask426for adjusting electrolysis between the anode430) and the substrate Wf is disposed in the anode region424. The anode mask426is, for example, a substantially plate-shaped member made of a dielectric material and provided on a front surface of (above) the anode430. The anode mask426has an opening through which a current flowing between the anode430and the substrate Wf passes. In the present embodiment, the anode mask426is formed with a changeable opening dimension, and the opening dimension is adjusted by the control module800. Here, the opening dimension means a diameter when the opening is circular, and the opening dimension means a length of a side or the longest opening width side when the opening is polygonal. To change the opening dimension in the anode mask426, a known mechanism can be adopted. In the present embodiment, an example in which the anode mask426is provided is described, but the anode mask426does not have to be provided. Furthermore, the membrane420described above may be provided at the opening in the anode mask426.

In the cathode region422, a resistor450facing the membrane420is disposed. The resistor450is a member for uniformly performing the plating treatment in the surface to be plated Wf-a of the substrate Wf. In the present embodiment, the resistor450is configured to be movable in the up-down direction in the plating tank410by a drive mechanism452, and a position of the resistor450is adjusted by the control module800. However, the resistor is not limited to this example, and as an example, the resistor450may be fixed to the plating tank410so that the resistor cannot move in the plating tank410. The module400does not have to include the resistor450.

In the cathode region422, a sensor460is provided. The sensor460is supported on a sensor support468. The sensor460may be supported on a side wall of the inner tank412or the resistor450, in place of the sensor support468. The sensor support468may be a paddle for stirring the plating solution. Here, the paddle preferably moves in parallel with a plate surface of the substrate Wf to stir the plating solution but is not limited to this example. In the present embodiment, a plurality of sensors460are provided along a radial direction of the substrate Wf. However, the embodiment is not limited to this example, and at least one sensor460may only be provided in the plating module400. The detection signal by the sensor460is inputted into the control module800. In the present embodiment, the sensor460and the control module800correspond to an example of “a film thickness measuring module” for measuring the film thickness of the plating film formed on the surface to be plated Wf-a of the substrate Wf. The sensor460detects parameters related to the plating film formed on the surface to be plated Wf-a of the substrate Wf, and as an example, a distance sensor to measure a distance between the sensor460and the substrate Wf (plating film) or a displacement sensor to measure displacement of the surface to be plated Wf-a of the substrate Wf can be adopted. As the sensor460, a sensor for estimating a plating film formation rate may be adopted as a parameter related to the plating film. Specifically, as the sensor460, for example, an optical sensor such as a white confocal sensor, a potential sensor, a magnetic field sensor, or an eddy current sensor may be used.

FIG.4is a view showing an example of a white confocal sensor and a substrate cross section in the present embodiment, andFIGS.5and6are views each showing an example of a signal detection value by the white confocal sensor. As shown inFIG.4, a resist pattern is formed in advance on the substrate Wf to be subjected to the plating treatment. The white confocal sensor (sensor460) includes a light source462that generates irradiation light including a plurality of wavelength components, a light receiving unit464that receives reflected light from the substrate Wf, and a processing unit466that measures a distance to the substrate Wf based on the wavelength component of the light received by the light receiving unit464.

When a region Rp where resist is applied in the substrate Wf (hereinafter referred to also as the “resist region”) is irradiated with the irradiation light, a part of the irradiation light is reflected by a resist surface. Thereby, as the distance to the substrate Wf calculated by the processing unit466, a large signal strength (A1inFIG.5) indicating a distance to the resist is indicated. Further, another part of the irradiation light permeates the resist and is reflected by the surface of the substrate Wf on a back of the resist. Thereby, as the distance to the substrate Wf calculated by the processing unit466, a large signal strength indicating the distance (A2inFIG.5) to a substrate Wf surface on the back of the resist is indicated. Since plating is not formed in the resist region Rp, the detection result by the sensor460does not vary in the resist region Rp even if the plating treatment proceeds.

When a resist opening region (the region where the resist is not applied) Op on the substrate Wf is irradiated with the irradiation light, the irradiation light is mainly reflected by the surface of the substrate Wf. Thereby, as the distance to the substrate Wf calculated by the processing unit466, a large signal strength indicating the distance (A3inFIG.6) to the surface of the substrate Wf in the resist opening region Op is indicated. In the resist opening region Op, a plating film is formed by advancing the plating treatment, and the distance to the substrate Wf detected by the sensor460(processing unit466) varies.

Thus, in the white confocal sensor, a difference (th inFIG.6) between the distance to the substrate Wf surface on the back of the resist in the resist region Rp and the distance to the substrate Wf surface in the resist opening region Op corresponds to a plating film thickness. When using the white confocal sensor, the control module800preferably stores an average of detection signals of the resist region Rp in an initial process. As an example, the control module800preferably stores the average of the detection signals of the resist region Rp while the substrate Wf is first rotated once or several times by the rotation mechanism448of the substrate holder440). In addition, the control module800may not use the detection signal of a boundary region between the resist region Rp and the resist opening region Op by the sensor460or may use the detection signal as information such as for calibrating a detection position on the substrate Wf. However, light passing through the resist is different in refractive index from the atmosphere. Therefore, when estimating the plating film thickness th, it is necessary to convert the distance in the measurement signal into an actual distance based on optical principles.

<Potential Sensor and Magnetic Field Sensor>

When a potential sensor or a magnetic field sensor is adopted as the sensor460, the sensor460) can estimate a plating formation rate on the surface to be plated Wf-a instead of directly detecting a target of the surface to be plated Wf-a of the substrate Wf. The sensor460detects a potential or magnetic field at a location where the sensor460is disposed between the substrate Wf and the anode430, and the control module800or sensor460(film thickness measuring module) calculates the plating formation rate on the surface to be plated Wf-a based on the detection value. This is based on correlation between the plating current and the potential or magnetic field in the plating treatment. The current plating film thickness can be estimated based on change over time in plating formation rate calculated from start of plating. In the estimation of the plating film thickness based on the potential or magnetic field detected by the sensor460, a known technique can be adopted. As an example, the film thickness measuring module can estimate a distribution of the plating current in the substrate during the plating treatment based on the detection signal and estimate a distribution of the film thickness of the plating film in the substrate based on the estimated distribution of the plating current. In particular, in case of the potential, it is preferable to place a potential measuring sensor also in a position where there is comparatively no change in potential and to take a difference from the potential at the position. The change in measurement value of the potential difference is exceedingly small and is therefore susceptible to noise. To reduce noise, it is preferable to install an independent electrode in the plating solution and connect the electrode directly to ground. In that case, it is further preferable to place, in the plating tank, at least five electrodes for a plating substrate (cathode), an anode, two potential sensors (for measuring a potential difference between the two sensors), and grounding.

When an eddy current sensor is adopted as the sensor460, the sensor460detects an interlinkage magnetic flux formed by an eddy current of the substrate Wf and detects the plating film thickness of the substrate Wf based on the detected interlinkage magnetic flux. According to research of the present inventors, it has been found that when the eddy current sensor is adopted as the sensor460, detection accuracy is lower than when the other sensor is adopted. This is considered to be due to influence of the resist applied to the substrate Wf.

<End Point Detection and End Point Prediction>

Further, the control module800or the sensor460(film thickness measuring module) may detect an end point of the plating treatment or predict a time to the end point of the plating treatment, based on the detection value of the sensor460. As an example, the film thickness measuring module may end the plating treatment when the film thickness of the plating film reaches a desired thickness based on the detection value by the sensor460. As an example, the film thickness measuring module may calculate a film thickness increase rate of the plating film and predict a time until the desired thickness is reached, that is, the time to the end point of the plating treatment, based on the detection value by the sensor460.

Returning to the description of the configuration of the plating module400, in one embodiment, the cathode region422is provided with a shielding body470for shielding the current flowing from the anode430to the substrate Wf. The shielding body470is, for example, a substantially plate-shaped member made of a dielectric material.FIG.7is a schematic view of the shielding body470and the substrate Wf of the present embodiment seen from below. InFIG.7, the substrate holder440) that holds the substrate Wf is not shown. The shielding body470is configured to be movable to a shielding position (shown with a dashed line inFIGS.3and7) interposed between the surface to be plated Wf-a of the substrate Wf and the anode430and a retreated position (shown with a solid line inFIGS.3and4) retreated from between the surface to be plated Wf-a and the anode430. In other words, the shielding body470is configured to be movable to the shielding position below the surface to be plated Wf-a and the retreated position away from below the surface to be plated Wf-a. A position of the shielding body470is controlled through the control module800by the unshown drive mechanism. The movement of the shielding body470can be achieved by a known mechanism such as a motor or solenoid. In examples shown inFIGS.3and7, the shielding body470shields a part of an outer circumferential region of the surface to be plated Wf-a of the substrate Wf in a circumferential direction at the shielding position. In the example shown inFIG.7, the shielding body470is formed in a tapered shape that becomes thinner toward a center of the substrate Wf. However, without being limited to such examples, the shielding body470can be used in any shape predetermined by experiments or the like.

Next, the plating treatment in the plating module400of the present embodiment will be described in more detail. The substrate Wf is immersed into the plating solution of the cathode region422by use of the elevating/lowering mechanism442, and the substrate Wf is exposed to the plating solution. The plating module400can subject the surface to be plated Wf-a of the substrate Wf to the plating treatment by applying a voltage between the anode430) and the substrate Wf in this state. Also, in one embodiment, the plating treatment is performed while rotating the substrate holder440by use of the rotation mechanism448. By the plating treatment, a conductive film (plating film) is precipitated on the surface to be plated Wf-a of the substrate Wf. In the present embodiment, real-time detection by the sensor460is performed during the plating treatment. The control module800then measures the film thickness of the plating film based on the detection value by the sensor460. Thereby, the change in film thickness of the plating film formed on the surface to be plated Wf-a of the substrate Wf can be measured in real time in the plating treatment.

In the example shown inFIG.3, the plating module400includes a plurality of sensors460for measuring the film thickness of the plating film, and can measure a film thickness of the plating film at a plurality of locations on the surface to be plated Wf-a. Further, when the detection by the sensor460is performed with the rotation of the substrate holder440) (substrate Wf), the detection position by the sensor460can be changed, and the film thickness can be measured at a plurality of points in the circumferential direction of the substrate Wf, or in the whole circumferential direction.

Alternatively, the plating module400may change a rotation speed of the substrate Wf by the rotation mechanism448during the plating treatment. As an example, the plating module400may slowly rotate the substrate Wf for the estimation of the plating film thickness by a film thickness estimation module. As another example, the plating module400may rotate the substrate Wf at a first rotation speed Rs1during the plating treatment and may rotate the substrate Wf at a second rotation speed Rs2slower than the first rotation speed Rs1while the substrate Wf rotates once or several times every predetermined period (for example, every few seconds). Thus, the plating film thickness of the substrate Wf can be estimated with high accuracy, even when a sampling period by the sensor460is small with respect to the rotation speed of the substrate Wf. Here, the second rotation speed Rs2may be one-tenth of the first rotation speed Rs1.

Thus, according to the plating apparatus1000of the present embodiment, it is possible to measure the change in film thickness of the plating film during the plating treatment. Referring to the change in film thickness of the plating film that is thus measured, it is possible to adjust plating conditions including at least one of the plating current value, plating time, position of the resistor450, opening dimension of the anode mask426and position of the shielding body470at or after the next plating treatment. The plating conditions may be adjusted by a user of the plating apparatus1000or by the control module800. In the present embodiment, the control module800corresponds to an example of a “plating condition adjustment module”. As an example, the adjustment of the plating conditions by the control module800may be performed based on a conditional expression or a program predetermined by an experiment or the like.

The adjustment of the plating conditions may be performed when plating another substrate Wf, or the plating conditions in the current plating treatment may be adjusted in real time. As an example, the control module800may adjust the position of the shielding body470.FIG.8shows an example of the adjustment of the position of the shielding body470during the plating treatment, as an example of the adjustment of the plating conditions by the control module800. In the example shown inFIG.8, a predetermined detection point Sp (seeFIG.7) near an outer circumference of the substrate Wf is detected by the sensor460with the rotation of the substrate Wf, thereby measuring the change in film thickness in the circumferential direction of the substrate Wf (see an alternate long and short dash line inFIG.7).FIG.8shows, in an upper stage, the change in film thickness along a horizontal axis indicating a circumferential position θ and a vertical axis indicating the film thickness th. In the example shown inFIG.8, the film thickness th of the plating film formed in a region of θ1to θ2is smaller than that in another region. In such a case, the control module800may adjust the position of the shielding body470with the rotation of the substrate Wf so that the shielding body470moves to the retreated position in the region of01to02in which the film thickness th is small (“OFF” inFIG.8), and the shielding body470moves to the shielding position in the other region (“ON” inFIG.8). In this way, an amount of plating formed in the region of θ1to θ2can be increased to improve uniformity of the plating film formed on the substrate Wf.

Alternatively, the control module800may adjust a distance between the substrate Wf and the resistor450as real-time adjustment of the plating conditions. According to the research of the present inventors, it is found that the distance between the substrate Wf and the resistor450has a comparatively large influence on an amount of plating formed near the outer circumference of the substrate Wf and comparatively does not affect the amount of plating formed in a central region of the substrate Wf. For this reason, as an example, the control module800may decrease the distance between the substrate Wf and the resistor450when the film thickness of the plating film near the outer circumference is larger than a target and may increase the distance between the substrate Wf and the resistor450when the film thickness of the plating film near the outer circumference is smaller than the target. Alternatively, the control module800may increase the distance between the substrate Wf and the resistor450as the shielding body470is at the shielding position longer and may decrease the distance between the substrate Wf and the resistor450as the shielding body470is at the shielding position shorter. In this way, the uniformity of the plating film formed on the substrate Wf can be improved by adjusting the amount of the plating formed near the outer circumference of the substrate Wf. As an example, the control module800may adjust the distance between the substrate Wf and the resistor450by driving the elevating/lowering mechanism442. However, the control module800is not limited to this example and may adjust the distance between the substrate Wf and the resistor450by moving the resistor450with the drive mechanism452.

Further, the control module800may adjust the opening dimension of the anode mask426as the real-time adjustment of the plating conditions. As an example, the control module800may decrease the opening dimension of the anode mask426when the film thickness of the plating film near the outer circumference is larger than a target and may increase the opening dimension of the anode mask426when the film thickness of the plating film near the outer circumference is smaller than the target.

FIG.9is a longitudinal sectional view schematically showing a configuration of a plating module according to a modification of the first embodiment. Description of a part of a plating module400of the modification that overlaps with the plating module400of the first embodiment will not be repeated. In the plating module400of the modification, a sensor support468for supporting a sensor460is configured to be movable by a drive mechanism468a. Thereby, the sensor460supported on the sensor support468can be moved, and a detection position by the sensor460can be changed. Although not limited, the drive mechanism468amay be configured to move the sensor460along a radial direction of a substrate Wf. Also, in an example shown inFIG.9, a single sensor460is mounted on the sensor support468, but is not limited to this example, and a plurality of sensors460may be supported on the sensor support468and may be configured to be movable the drive mechanism468a.

Second Embodiment

FIG.10is a longitudinal sectional view schematically showing a configuration of a plating module400A of a second embodiment. In the second embodiment, a substrate Wf is held to extend in a vertical direction, that is, with a plate surface being oriented in a horizontal direction. As shown inFIG.10, the plating module400A includes a plating tank410A that holds a plating solution inside, an anode430A disposed in the plating tank410A, and a substrate holder440A. In the second embodiment, a square substrate will be described as an example of the substrate Wf, but as in the first embodiment, examples of the substrate Wf include the square substrate and a circular substrate.

The anode430A is disposed facing a plate surface of the substrate Wf in the plating tank. The anode430A is connected to a positive electrode of a power supply90, and the substrate Wf is connected to a negative electrode of the power supply90via the substrate holder440A. When a voltage is applied between the anode430A and the substrate Wf, a current flows through the substrate Wf, and a metal film is formed on the surface of the substrate Wf in the presence of the plating solution.

The plating tank410A includes an inner tank412A in which the substrate Wf and the anode430A are arranged, and an overflow tank414A adjacent to the inner tank412A. The plating solution in the inner tank412A overflows a side wall of the inner tank412A and flows into the overflow tank414A.

One end of a plating solution circulation line58ais connected to a bottom of the overflow tank414A, and the other end of the plating solution circulation line58ais connected to a bottom of the inner tank412A. A circulation pump58b, a constant temperature unit58cand a filter58dare attached to the plating solution circulation line58a. The plating solution overflows the side wall of the inner tank412A to flow into the overflow tank414A and is further returned to a plating solution storage tank52through the plating solution circulation line58afrom the overflow tank414A. Thus, the plating solution circulates between the inner tank412A and the overflow tank414A through the plating solution circulation line58a.

The plating module400A further includes a regulation plate454that regulates a potential distribution on the substrate Wf, and a paddle416that stirs the plating solution in the inner tank412A. The regulation plate454is disposed between the paddle416and the anode430A and includes an opening454afor limiting an electric field in the plating solution. The paddle416is disposed in the vicinity of the surface of the substrate Wf held by the substrate holder440A in the inner tank412A. The paddle416is made of, for example, titanium (Ti) or resin. The paddle416reciprocally moves in parallel with the surface of the substrate Wf, to stir the plating solution so that sufficient metal ions are uniformly supplied to the surface of the substrate Wf during the plating of the substrate Wf.

The plating module400A also includes a sensor460A for measuring a plating film thickness of the substrate Wf.FIG.11is a schematic view showing the substrate Wf and the sensor460A in the plating tank according to the present embodiment from a direction perpendicular to the plate surface of the substrate Wf. In examples shown inFIGS.10and11, the sensor460A is attached to the paddle416. Although not limited, in the example shown inFIG.11, two paddles416are arranged in the vicinity of a surface to be plated of the substrate Wf, and two sensors460A are attached to each of the two paddles416. In the examples shown inFIGS.10and11, the paddle416reciprocally moves in parallel with the surface of the substrate Wf, to stir the plating solution and to change a detection position by the sensor460A. The sensor460A is not limited to such examples and may be attached to the inner tank412A or may be supported on an unshown sensor support468, separate from the paddle416. As the sensor460A, the same sensor as the sensor460of the first embodiment may be adopted. A detection signal by the sensor460A is inputted into a control module800A.

In the plating module400A in the second embodiment, real-time detection by the sensor460A can be performed during a plating treatment in the same manner as in the plating module400of the first embodiment. The control module800A then measures the film thickness of the plating film based on a detection value by the sensor460A. Thereby, change in film thickness of the plating film formed on the surface to be plated of the substrate Wf can be measured in real time in the plating treatment. The control module800A can also adjust plating conditions based on the film thickness of the plating film in the same manner as described in the first embodiment.

FIG.12is a schematic view showing a substrate Wf and a sensor460A in a plating tank in a modification. In an example shown inFIG.12, four sensors460A are arranged at positions close to four corners, respectively, of a surface to be plated and are configured to be movable inward from the four corners by an unshown drive mechanism. In particular, in a square substrate, a film thickness distribution near a corner of the substrate Wf tends to noticeably affect in-plane uniformity, and therefore the arrangement of the sensors460A allows measurement of a film thickness at a suitable position on the substrate Wf. In the example shown inFIG.12, four sensors460A are provided, but one to three or five or more sensors460A may be provided. The sensors460A may also be configured to move symmetrically in synchronization with one another.

FIG.13is a schematic view showing a substrate Wf and a sensor460A in a plating tank in another modification. In an example shown inFIG.13, two sensors460A are arranged at positions close to long sides, respectively, of a surface to be plated and are configured to be movable along the long sides by an unshown drive mechanism. In particular, in a square substrate, a film thickness distribution near an edge portion of the substrate Wf tends to noticeably affect in-plane uniformity, and therefore the arrangement of the sensors460A allows measurement of a film thickness at a suitable position on the substrate Wf. In the example shown inFIG.13, two sensors460A are provided, but one or three or more sensors460A may be provided. The sensors460A may also be configured to move symmetrically in synchronization with each other.

The present invention can be described in aspects as follows.

According to Aspect 1, a plating apparatus is provided, the plating apparatus including a plating tank, a substrate holder that holds a substrate, an anode disposed, in the plating tank, facing the substrate held by the substrate holder, and a film thickness measuring module including a sensor that detects a parameter related to a plating film formed on a surface to be plated of the substrate, the film thickness measuring module measuring a film thickness of the plating film based on a detection value of the sensor during a plating treatment.

According to Aspect 1, the film thickness of the plating film can be measured during the plating treatment. This can improve uniformity of the plating film formed on the substrate.

According to Aspect 2, in Aspect 1, the plating apparatus further includes a plating condition adjustment module that adjusts plating conditions based on the film thickness of the plating film that is measured by the film thickness measuring module during the plating treatment.

According to Aspect 2, the uniformity of the plating film formed on the substrate can be improved.

According to Aspect 3, in Aspect 2, the plating apparatus further includes a shielding body that is movable to a shielding position interposed between the surface to be plated of the substrate and the anode, and a retreated position retreated from between the surface to be plated of the substrate and the anode, and the plating condition adjustment module adjusts a position of the shielding body as the adjustment of the plating conditions.

According to Aspect 3, the uniformity of the plating film formed on the substrate can be improved by using the shielding body.

According to Aspect 4, in Aspect 2 or 3, the plating apparatus further includes a resistor disposed between the anode and the substrate, and a drive mechanism to change a distance between the substrate and the resistor, and the plating condition adjustment module changes the distance between the substrate and the resistor as the adjustment of the plating conditions.

According to Aspect 4, the uniformity of the plating film formed on the substrate can be improved by adjusting the distance between the substrate and the resistor.

According to Aspect 5, in Aspects 2 to 4, the plating apparatus further includes an anode mask disposed above the anode, the anode mask having an opening dimension that is changeable, and the plating condition adjustment module changes the opening dimension of the anode mask as the adjustment of the plating conditions.

According to Aspect 5, the uniformity of the plating film formed on the substrate can be improved by adjusting the opening dimension of the anode mask.

According to Aspect 6, in Aspects 1 to 5, the sensor is a white confocal sensor or an eddy current sensor.

According to Aspect 6, the sensor can detect the surface to be plated of the substrate.

According to Aspect 7, in Aspects 1 to 5, the sensor is a magnetic field sensor or a potential sensor.

According to Aspect 7, the sensor can detect a magnetic field or a potential in the plating tank.

According to Aspect 8, in Aspect 7, the film thickness measuring module is configured to estimate a distribution of a plating current in the substrate during the plating treatment based on a detection signal by the sensor.

According to Aspect 9, in Aspect 8, the film thickness measuring module is configured to estimate a film thickness distribution of the plating film in the substrate based on the estimated distribution of the plating current in the substrate.

According to Aspect 10, in Aspects 1 to 9, the plating apparatus further includes a rotation mechanism that rotates the substrate holder, and the film thickness measuring module is configured to measure the film thickness of the plating film, with the rotation of the substrate by the rotation mechanism.

According to Aspect 10, a detection position of the substrate by the sensor can be changed by rotating the substrate, and the plating film formed on the substrate during the plating treatment can be more suitably detected.

According to Aspect 11, in Aspects 1 to 10, a plurality of sensors are provided from an outer circumference to an inner circumference of the substrate.

According to Aspect 11, a film thickness of the plating film can be measured at a plurality of positions on the substrate.

According to Aspect 12, in Aspects 1 to 10, a plurality of sensors are provided along an outer edge of the substrate.

According to Aspect 12, the film thickness of the plating film can be measured at the plurality of positions on the substrate.

According to Aspect 13, in Aspects 1 to 10, the film thickness measuring module is configured to move the sensor along a plate surface of the substrate during the plating treatment.

According to Aspect 13, the film thickness of the plating film can be measured at the plurality of positions on the substrate.

According to Aspect 14, in Aspects 1 to 13, the substrate holder is configured to hold the substrate with the surface to be plated being oriented downward in the plating tank.

According to Aspect 15, in Aspects 1 to 13, the substrate holder is configured to hold the substrate with the surface to be plated being oriented to a side in the plating tank.

The embodiments of the present invention have been described above, but the above embodiments of the present invention are described to facilitate understanding of the present invention and are not intended to limit the present invention. Needless to say, the present invention may be changed or modified without departing from the spirit, and the present invention includes equivalents to the invention. Also, in a range in which at least some of the above-described problems can be solved or a range in which at least some of effects are exhibited, any arbitrary combination of the embodiments and the modification is possible, and arbitrary combination or omission of respective constituent components described in claims and description is possible.

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