Substrate holder, plating device, and plating method of substrate

A substrate holder capable of being used in both single-side plating and double-side plating is required. Disclosed is a substrate holder for holding a substrate to be plated. The substrate holder includes a first frame having a first opening for exposing one surface of the substrate and a second frame having a second opening for exposing the other surface of the substrate, and the substrate is sandwiched between the first frame and the second frame. The substrate holder further includes a dummy substrate which is detachably disposed between the first frame and the substrate and formed of a material that at least direct current does not substantially flow therein. At least a part of the dummy substrate is in contact with at least a part of the one surface of the substrate, and the dummy substrate protects the one surface of the substrate from a plating solution.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the priority benefit of Japanese Patent Application No. 2018-214402, filed on Nov. 15, 2018. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND OF THE DISCLOSURE

Technical Field

The disclosure relates to a substrate holder, a plating device, and a plating method of substrate.

Related Art

In a plating device for plating a substrate such as a silicon wafer or the like, a substrate holder for holding the substrate is used. Known art may be found in Patent document 1 (Japanese Patent Application Laid-Open No. 2018-40045) and Patent document 2 (Japanese Patent Application Laid-Open No. 2004-277815).

SUMMARY

Plating processing can be generally divided into single-side plating for plating only one surface of a substrate and double-side plating for plating both surfaces of the substrate. In recent years, a substrate holder that can be used in both the single-side plating and the double-side plating is required.

In one embodiment, the disclosure provides a substrate holder for holding a substrate to be plated. The substrate holder includes a first frame having a first opening for exposing one surface of a substrate and a second frame having a second opening for exposing the other surface of the substrate, and the substrate is sandwiched between the first frame and the second frame. The substrate holder further includes a dummy substrate detachably disposed between the first frame and the substrate and formed of a material that at least a direct current does not substantially flow therein. At least a part of the dummy substrate is in contact with at least a part of the one surface of the substrate, and the dummy substrate protects the one surface of the substrate from a plating solution.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1is a schematic diagram of a plating device100of an embodiment.FIG. 1Ais a top view of the plating device100.FIG. 1Bis a side view of the plating device100. The plating device100of the embodiment includes a load port110, a substrate transfer robot120, a dryer130, a substrate attachment and detachment device140, a plating treatment portion150, a transporter160, and a stocker170. Furthermore, the plating device100may include a control portion180for controlling each portion of the plating device100. Besides, in the description below, the substrate to be plated is in a square shape. However, a substrate having a shape other than the square shape may also be used.

The load port110is arranged to load a substrate to the plating device100and unload the substrate from the device100. The load port110may be configured to be capable of mounting a mechanism such as a FOUP (Front Opening Universal Pod) or capable of transferring the substrate between the load port110and a mechanism such as a FOUP. The substrate loaded by the load port110is transferred to the substrate attachment and detachment device140by the substrate transfer robot120.

The substrate attachment and detachment device140is a device for attaching the substrate to a substrate holder or detaching the substrate from the substrate holder. It is necessary to transfer both the substrate and the substrate holder into the substrate attachment and detachment device140. Therefore, the substrate attachment and detachment device140is located at a position that is accessible by both the substrate transfer robot120and the transporter160.

The plating treatment portion150is arranged to perform plating on the substrate. The plating treatment portion150includes one treatment tank or a plurality of treatment tanks. At least one of the one treatment tank or the plurality of treatment tanks is a plating tank. As an example, the treatment portion150ofFIGS. 1A-1Bincludes eight treatment tanks, that is, a pre-water washing tank151, a pretreatment tank152, a first rinse tank153, a first plating tank154, a second rinse tank155, a second plating tank156, a third rinse tank157and a blow tank158. The plating device100can perform predetermined treatments in order in each treatment tank.

The transporter160is configured to transport the substrate holder between the substrate attachment and detachment device140, the plating treatment portion150, and the stocker170. The transporter160includes a transporter arm161for suspending the substrate holder, an arm vertical movement mechanism162for vertically moving the transporter arm161, and a horizontal movement mechanism163for horizontally moving the arm vertical movement mechanism162along the arrangement of the treatment tanks. It should be noted that the configuration of the transporter160is only an example.

The stocker170is configured to be capable of storing at least one substrate holder, or a plurality of substrate holders. By the transporter160, the substrate holder not holding a substrate is transported from the stocker170to the substrate attachment and detachment device140. The substrate holder transferred into the substrate attachment and detachment device140holds the substrate which is transported into the substrate attachment and detachment device140by the substrate transfer robot120. When the plating is completed, the substrate holder holding the substrate is transported into the substrate attachment and detachment device140. After that, the substrate attachment and detachment device140detaches the substrate from the substrate holder. At least one substrate holder200including a dummy substrate900(described later) and at least one substrate holder from which the dummy substrate900is detached are accommodated in the stocker170. Furthermore, when the substrate holder200includes a clamper290SL (described later), the substrate holder200may be accommodated in the stocker170in a semi-locking state.

Furthermore, the plating device100may optionally include a holder/dummy substrate cleaning portion190for cleaning the substrate holder200and/or the dummy substrate900described later. Details of the holder/dummy substrate cleaning portion190are described later.

Next, the substrate holder (added with a symbol “200” hereinafter) used in the plating device100is described.FIGS. 2A-2Care schematic diagrams of the substrate holder200.FIG. 2Ais a front view of the substrate holder200.FIG. 2Bis a cross-sectional view of the substrate holder200.FIG. 2Cis an enlarged exploded view of a section marked by “A” inFIG. 2B.

The substrate holder200is a member for holding the substrate by sandwiching the substrate between frames. The substrate holder200includes a front frame200aand a rear frame200bfor holding the substrate. It should be noted that the terms “front” and “rear” are for convenience only, and either the side on which the front frame200ais located or the side on which the rear frame200bis located may be referred to as a front surface. The front frame200aand the rear frame200bare clamped by at least one clamper290, or may be clamped by a plurality of clampers290(details of the clamper290are described later). The substrate (added with a symbol “W” hereinafter) is shown by an imaginary line inFIG. 2B.

The front frame200ahas a holder arm210a. A shoulder electrode220may be arranged on the shoulder of the holder arm210a. In the example ofFIGS. 2A-2C, two shoulder electrodes220are arranged on both shoulders of the holder arm210a. The shoulder electrodes220are electrically connected to substrate electrodes320described later by an unillustrated conductive path (wiring, bus bar or the like). The substrate electrodes320are electrically connected to the substrate W, and thus the shoulder electrodes220are electrically connected to the substrate W. A holder arm210bis arranged on the rear frame200b. The configuration of the holder arm210bis the same as the configuration of the holder arm210a. The front frame200amay include a wiring storage portion230a. The rear frame200bmay include a wiring storage portion230b.

In the respective central parts of the front frame200aand the rear frame200b, an opening260aand an opening260bfor exposing the substrate W are respectively formed. In the example ofFIGS. 2A-2C, the opening260aand the opening260bhave a square shape. The shapes of the opening260aand the opening260bmay also be appropriately changed if necessary.

When the substrate holder200holds the substrate W only, one surface of the substrate W is exposed to the outside via the opening260a, and the other surface of the substrate W is exposed to the outside via the opening260b. Accordingly, the substrate holder200can be used for double-side plating. On the other hand, when the substrate holder200holds both the substrate W and the dummy substrate900described later (seeFIG. 9), only one surface of the substrate W is exposed. Accordingly, the substrate holder200of an embodiment can be used for not only double-side plating but also single-side plating.

The substrate holder200includes one clamper290or a plurality of clampers290. The clamper290has a hook portion250attached to the front frame200aand a plate270attached to the rear frame200b. Alternatively, the hook portion250may be attached to the rear frame200b, and the plate270may be attached to the front frame200a. In the example ofFIGS. 2A-2C, totally, four clampers290are arranged around the opening260aand the opening260b.

The hook portion250includes a hook base251attached to the front frame200a, a hook body252, and a shaft253which pivotally supports the hook body252with respect to the hook base251. The hook portion250may further include a lever254for making the hook body252pivot about the shaft253. The hook body252extends toward the rear frame200b. The shaft253expands within a plane parallel to the surface of the substrate W to be held. The hook portion250may further include a pressing member, which is a pressing member (not shown) for maintaining the hooking between the hook body252and a claw271(described later) and which energizes the hook body252to a counterclockwise direction ofFIG. 2BorFIG. 2Cabout the shaft253. The pressing member may be, for example, a torsion spring.

A port241a(seeFIG. 2C) is arranged on the front frame200a. The hook portion250is attached to the port241a. A port241b(seeFIG. 2C) is arranged on the rear frame200b. The position and the number of the port241bcorrespond to the position and the number of the port241a. The plate270is attached to the port241b. The claw271to which the hook body252is hooked is arranged on the plate270. The claw271extends toward the front frame200a.

In the embodiment shown inFIGS. 2A-2C, the hooking between the hook body252and the claw271is released by pressing the lever254toward the rear frame200b. Instead, the lever254and the like may be configured so that the hooking is released by pulling the lever254.

<Details of Substrate Holding Portion>

Next,FIG. 3is used to describe details of a part of the substrate holder200holding the substrate W. The substrate electrodes320are respectively arranged on the front frame200aand the rear frame200bofFIG. 3. Each of the substrate electrodes320is electrically connected to each surface of the substrate W. Because the substrate electrodes320are electrically connected to the shoulder electrodes220, the shoulder electrodes220are electrically connected to the respective surfaces of the substrate W.

The substrate holder200includes an outer seal300and inner seals310for sealing a space where the substrate electrodes320exist from a plating solution. The outer seal300is in contact with the front frame200aand the rear frame200b. The outer seal300is configured to seal a gap between the front frame200aand the rear frame200bat the outside of the substrate W. The outer seal300may be arranged on the front frame200aor be arranged on the rear frame200b. The inner seals310are respectively arranged on the front frame200aand the rear frame200b. The inner seals310are in contact with the substrate W. However, when the dummy substrate900described later is attached to the substrate holder200, one of the inner seals310is in contact with the dummy substrate900. The outer seal300and the inner seals310can elastically deform in the thickness direction of the substrate W. The substrate W is held between the front frame200aand the rear frame200bby a contact pressure between the inner seals310and the substrate W.

The substrate holder200may include a clamper having a “semi-locking function”. The semi-locking function refers to “a function for holding the front frame200aand the rear frame200bin a state that the front frame200aand the rear frame200bare spaced apart”. Basically, the semi-locking function is a function for combining the front frame200aand the rear frame200bof the substrate holder not holding a substrate. In the semi-locking state, the seals and contact points of the front frame200aand the rear frame200bare not in contact with each other. The semi-locking of the substrate holder200is advantageous in terms of component life, transport easiness of the substrate holder, cleaning easiness of the substrate holder, and the like.

FIG. 4is a perspective view of a plate of the clamper290having the semi-locking function. In the following, the plate shown inFIG. 4is referred to as a “plate270SL”. “SL” is the initial of “Semi-Lock”.FIG. 5is a perspective view of a hook portion paired with the plate270SL ofFIG. 4. In the following, the hook portion shown inFIG. 5is referred to as a “hook portion2505L”.FIG. 6is a cross-sectional view of a clamper290SL including the plate270SL and the hook portion250SL.

The plate270SL has two claws271. Specifically, the plate270SL has a locking claw271aand a semi-locking claw271b. The locking claw271ais configured so that the substrate holder200can hold the substrate W when the hook body252is hooked to the locking claw271a. The semi-locking claw271bis configured so that a distance between the front frame200aand the rear frame200bwhen the hook body252is hooked to the semi-locking claw271bis larger than the distance between the front frame200aand the rear frame200bwhen the hook body252is hooked to the locking claw271a.

The hook portion250SL includes the hook body252which is extended in a longitudinal direction of the shaft253. Along with the extension of the hook body252, the hook body252is supported by two shafts253. However, inFIG. 5, one of the shafts253is hidden in other components and is not shown. The respectively shafts253are disposed coaxially. One extended shaft253can also be used instead of two shafts253.

The extended hook body252is selectively hooked to the locking claw271aand the semi-locking claw271b. The clamper290is locked when the hook body252is hooked to the locking claw271a. The clamper290is semi-locked (also referred to as “the substrate holder200is semi-locked”) when the hook body252is hooked to the semi-locking claw271b. When the substrate holder200is semi-locked, the outer seal300and the inner seals310are not substantially compressed.

Besides, as long as there is no contradiction, in the following, the “clamper290” may include the “clamper290SL”, the “plate270” may include the “plate270SL”, and the “hook portion250” may include the “hook portion250SL”.

<Substrate Attachment and Detachment Device>

In order to sandwich the substrate W between the front frame200aand the rear frame200b, it is necessary to hook the hook body252to the claw271(the locking claw271awhen the clamper290SL is used). When the hook body252is hooked to the claw271, the front frame200aand the rear frame200bare restrained from being separated from each other, and the outer seal300and the inner seals310elastically deform in the thickness direction of the substrate W and a seal pressure is generated. In order to hook the hook body252to the claw271, it is necessary to temporarily locate the hook body252closer to the rear side (in the right direction ofFIG. 2C) than the claw271. Accordingly, in order to hold the substrate W by the substrate holder200, it is necessary to press the front frame200atoward the rear frame200bor press the rear frame200btoward the front frame200a.

As described above, the outer seal300and the inner seals310exist between the front frame200aand the rear frame200b. Accordingly, when the front frame200aand/or the rear frame200bare/is pushed, a reaction force from the outer seal300and the inner seals310is generated. The substrate attachment and detachment device140of an embodiment is configured to be capable of pushing the front frame200aand/or the rear frame200bagainst the reaction force from the outer seal300and the inner seals310. The substrate attachment and detachment device140is further configured to be capable of hooking the hook body252to the claw271(pivoting the hook body252) in a state that the front frame200aand/or the rear frame200bare/is pushed. The substrate attachment and detachment device140can attach the substrate W to the substrate holder200by these operations.

Details of the substrate attachment and detachment device140are described below.FIGS. 7A-7Bare schematic diagrams of the substrate attachment and detachment device140of an embodiment.FIG. 7Ais a top view of the substrate attachment and detachment device140.FIG. 7Bis a side view of the substrate attachment and detachment device140. InFIG. 7A, the substrate transfer robot120and the transporter160are also illustrated in combination. The substrate attachment and detachment device140includes a holder reception portion700, a holder tilting portion710, a holder transfer portion720, and a pressing portion730. The transporter160is configured to be capable of accessing the holder reception portion700. The substrate W is loaded on the substrate attachment and detachment device140, more specifically on the pressing portion730by the substrate transfer robot120.

The holder reception portion700includes a holder reception body701and a holder reception linear movement mechanism702for moving the holder reception body701. The holder reception body701receives the substrate holder200from the transporter160. After that, the holder reception body701can be moved close to the holder tilting portion710by the holder reception linear movement mechanism702.

The holder tilting portion710includes a holder tilting portion arm711. The holder tilting portion arm711receives the substrate holder200from the holder reception body701. Due to the tilting of the holder tilting portion arm711, the substrate holder200is tilted until being horizontal (the vertically directed substrate holder200becomes horizontally directed).

The holder transfer portion720includes a holder carrier721, a carrier vertical movement mechanism722for vertically moving the holder carrier721, and a transfer portion linear movement mechanism723for moving the carrier vertical movement mechanism722toward the pressing portion730. The holder carrier721receives the substrate holder200from the holder tilting portion arm711and transfers the substrate holder200toward the pressing portion730.

The pressing portion730includes a stage731on which the substrate holder200is placed horizontally and a pressing unit732. The pressing unit732may have a pressing unit opening732opfor passing an upper substrate supporter803described later. The stage731is configured to receive the substrate holder200from the holder transfer portion720. The stage731is further configured to deliver the substrate holder200to the holder transfer portion720. The pressing unit732is disposed above the stage731. The pressing unit732is configured to be capable of moving vertically. The pressing unit732can press the substrate holder200on the stage731downward. The substrate holder200is pressed by the pressing unit732, and thereby the hook body252and the claw271are located at a position where the hook body252can be hooked to the claw271or the hooking between the hook body252and the claw271can be released.

It should be noted that the configuration of the substrate attachment and detachment device140that is shown is only an illustration. For example, the holder tilting portion710is not required as long as the substrate holder200can be made horizontal by the transporter160. For example, elements other than the pressing portion730are not required as long as the transporter160can directly transport the substrate holder200to the pressing portion730. The specific configuration of the substrate attachment and detachment device140may be determined appropriately. A so-called vertical pressing portion different from the pressing portion730ofFIGS. 7A-7Band pressing the substrate holder200perpendicular to the ground may be used.

FIGS. 8A-8Fare used to describe operations of the pressing portion730when the substrate W is attached to the substrate holder200. It should be noted thatFIGS. 8A-8Fmerely indicates the basic principle of the operations of the pressing portion730, and dimensions, shapes, arrangement and the like of the elements shown inFIGS. 8A-8Fare not accurate.FIGS. 8A-8Fare described in chronological order. Besides, when the substrate W is detached from the substrate holder200, operations in an order reverse to the illustrated order are performed. InFIG. 8A, all components that are illustrated are added with symbols. On the other hand, only major components at that time are added with symbols inFIGS. 8B-8F. In addition, in the following description, the substrate holder200is placed on the stage731in the manner that the front frame200afaces downward. However, the substrate holder200may also be placed on the stage731in the manner that the rear frame200bfaces downward.

As shown inFIGS. 8A-8F, the pressing portion730has a lower substrate supporter801and an upper substrate supporter803for sandwiching the substrate W between the front frame200aand the rear frame200b. The lower substrate supporter801can pass through the opening260ato support the substrate W. The lower substrate supporter801is configured to be capable of moving vertically by a lower substrate supporter vertical movement mechanism802. The upper substrate supporter803is configured to be capable of passing through the pressing unit opening732op. The upper substrate supporter803can pass through the opening260bto access the substrate W. The upper substrate supporter803is configured to be capable of moving vertically by the upper substrate supporter vertical movement mechanism804. The substrate W is sandwiched and supported by the lower substrate supporter801and the upper substrate supporter803.

The lower substrate supporter801and the upper substrate supporter803are directly in contact with the substrate W. Therefore, the lower substrate supporter801and the upper substrate supporter803are formed to only touch a contactable region of the substrate W. The contactable region of the substrate W is a region which is set in advance, for example, a region of the substrate W where wiring is not formed. Besides, the contactable region of the substrate W may be different depending on the substrate surface. The shape of the lower substrate supporter801may be the same as the shape of the upper substrate supporter803, or the shape of the lower substrate supporter801and the shape of the upper substrate supporter803may be different. For example, the shape of the lower substrate supporter801may be a cross shape when viewed from above. For example, the shape of the upper substrate supporter803may be a reverse U-shape (a shape of two contact points with the substrate W) when viewed from the side.

<FIG. 8A> It is a diagram showing the pressing portion730at the time point when the substrate holder200not holding the substrate W is transferred into the stocker170. In order not to inhibit the transferring of the substrate holder200, the lower substrate supporter801is lowered, and the pressing unit732and the upper substrate supporter803are raised. When the clamper290SL is used as the clamper290, the substrate holder200may be semi-locked.

<FIG. 8B> Locking of the clamper290or semi-locking of the clamper290SL is released. The release of the semi-locking of the clamper290SL may be performed by any actuator (not shown) pushing the lever254. The release of the locking of the clamper290may have a stage at which the pressing unit732or any actuator included in the pressing unit732presses the rear frame200btoward the front frame200abefore a stage at which the lever254is pushed. After the locking or semi-locking is released, the pressing unit732lifts the rear frame200b. The pressing unit732may have a hook or claw or the like (not shown) for lifting the rear frame200b. The lower substrate supporter801is raised by the lower substrate supporter vertical movement mechanism802so that the lower substrate supporter801can receive the substrate W at the time point ofFIG. 8C. However, when the substrate W is directly placed on the front frame200aat the time point ofFIG. 8C, raising of the lower substrate supporter801is not required.

<FIG. 8C> The substrate W is placed at a prescribed position of the lower substrate supporter801by the substrate transfer robot120. The substrate transfer robot120is configured not to interfere with the lower substrate supporter801and the upper substrate supporter803at the time point ofFIG. 8DandFIG. 8Edescribed later. At the time point ofFIG. 8C, the substrate W may be directly placed on the front frame200a.

<FIG. 8D> The upper substrate supporter803is lowered by the upper substrate supporter vertical movement mechanism804, and the substrate W is sandwiched by the lower substrate supporter801and the upper substrate supporter803. After that, the substrate transfer robot120releases the substrate W, and the substrate transfer robot120is detached to the outside of the pressing portion730.

<FIG. 8E> In a state that the substrate W is sandwiched, the lower substrate supporter801and the upper substrate supporter803are lowered by the lower substrate supporter vertical movement mechanism802and the upper substrate supporter vertical movement mechanism804. At the same time or after that, the pressing unit732is lowered, and the substrate W is sandwiched by the front frame200aand the rear frame200b. At the time point ofFIG. 8E, the rear frame200bis pressed toward the front frame200aby any actuator and the like; furthermore, the clamper290is locked by another actuator and the like. At the time point ofFIG. 8E, the front frame200amay be pressed toward the rear frame200b.

<FIG. 8F> An engagement between the pressing unit732and the rear frame200bis released, and the pressing unit732is raised. At the same time, after that or before that, the lower substrate supporter801is lowered by the lower substrate supporter vertical movement mechanism802, and the upper substrate supporter803is raised by the upper substrate supporter vertical movement mechanism804. The substrate W is attached to the substrate holder200by the above operations. AfterFIG. 8F, the substrate holder200is unloaded from the pressing portion730, and then from the substrate attachment and detachment device140. As shown inFIG. 8F, when the dummy substrate900(seeFIG. 9) is not held by the substrate holder200, both surfaces of the substrate W held on the substrate holder200are exposed. Accordingly, when the dummy substrate900is not held, the substrate holder200becomes a holder for double-sided plating. Plating conditions of each surface of the substrate W can be changed by controlling the electric power supplied from each of the substrate electrodes320.

Next, a structure and a method in a case of using the substrate holder200for single-side plating are described.FIG. 9is a cross-sectional view of the substrate holder200including the dummy substrate900. The substrate holder200ofFIG. 9is approximately the same as the substrate holder200ofFIG. 3except that the dummy substrate900is included. At least a part of the dummy substrate900is in contact with at least a part of any surface of the substrate W, for example, the surface facing the front frame200a. The dummy substrate900is detachably arranged on the substrate holder200.

One surface of the substrate W is covered by the dummy substrate900. In other words, the dummy substrate900protects one surface of the substrate W from the plating solution. “Protecting the member from the plating solution” may be paraphrased as “shielding/separating/isolating the member from the plating solution” and the like. By attaching the dummy substrate900to the substrate holder200, the substrate holder200can be used as a holder for single-side plating. The dummy substrate900is formed of a material that at least a direct current does not substantially flow therein, for example, an insulator or a dielectric material. When a direct current does not flow in the dummy substrate900, the electric power supply from the substrate electrodes320touching the dummy substrate900may be continued or may be stopped. The dummy substrate900may be formed of polyvinyl chloride for example. By the dummy substrate900blocking the direct current from the substrate electrodes320, formation of a plating layer on the dummy substrate900and disturbance of electrical conditions for the surface to be plated of the substrate W can be prevented. Basically, one surface of the substrate W covered by the dummy substrate900is not in contact with the plating solution. Accordingly, this surface of the substrate W can be prevented from being polluted by the plating solution.

The typical dummy substrate900has a first part901located in a region which is sealed by the outer seal300and the inner seals310, a second part902in contact with the inner seals310, and a third part903which is a part exposed via the opening260a. The outermost edge portion of the dummy substrate900is the first part901, the part disposed at the inner side of the first part901is the second part902, and the part disposed at further inner side than the second part902is the third part903. The first part901, the second part902, and the third part903are respectively different in thickness. However, the dummy substrate900(the dummy substrate900with uniform thickness) which is not divided into parts can also cover one surface of the substrate W. Accordingly, the shape of the dummy substrate900is not limited to the shape shown inFIG. 9.

The thickness of the second part902is thinner than the thickness of the first part901and the thickness of the third part903. When the dummy substrate900is viewed from the direction of the front frame200a, the dummy substrate900is configured so that a concave is formed in the part of the second part902. The inner seal310is in contact with this concave part. A deformation amount of the inner seal310has a limit, and thus there is a possibility that a thick substrate W cannot be held when the second part902is thick. The thickness of the second part902may be thin so as to correspond to substrates W of various thicknesses. In one example, the thickness of the second part902is, for example, 0.1 mm or more and 2 mm or less. In another example, the thickness of the second part902is, for example, 0.2 mm or more and 1 mm or less. In still another example, the thickness of the second part902may be 0.5 mm. Strength of the second part902may be taken into account when determining the thickness of the second part902.

The third part903prevents the dummy substrate900from falling off the substrate holder200when the substrate W is not held on the substrate holder200, particularly when the substrate holder200is semi-locked. Furthermore, the third part903defines a position relationship between the substrate holder200and the dummy substrate900. The size of the third part903in a plan view is slightly smaller than the size of the opening260ain a plan view. The thickness of the third part903is determined so that at least a part of the third part903is inserted into the opening260a. As one example, the third part903may be configured, for example, in a manner that a gap length between the third part903and the opening260ais 0.5 mm. For example, the thickness of the third part903may be about 7 mm. The thickness of the third part903may be determined so that the third part903does not protrude from the front frame200a. However, it should be noted that the specific size and thickness of the third part903may be different depending on various conditions.

Besides, when the substrate holder200holds the dummy substrate900in a semi-locking state, the distance between two inner seals is larger than the thickness of the second part902of the dummy substrate900. In other words, when the substrate holder200is in the semi-locking state, the dummy substrate900presses neither of the inner seals310(however, the dummy substrate900may press one of the inner seals310due to gravity depending on the orientation of the substrate holder200). In addition, the contact points (the substrate electrodes) of the substrate holder200are not in contact with the dummy substrate900.

<Operations of Pressing Portion when Dummy Substrate is Used>

FIG. 10is used to describe operations of the pressing portion730when the dummy substrate900is used.FIG. 8Ashould be referred to for the components not added with symbols.FIGS. 10A-10Care described in chronological order. The dummy substrate900is held on the substrate holder200at the time point ofFIG. 10A. The dummy substrate900may be held on the substrate holder200in a way similar toFIGS. 8A-8Fif necessary. The dummy substrate900may also be held on the substrate holder200in advance manually or by other devices or the like. For example, the substrate holder200on which the dummy substrate900is held and the substrate holder200on which the dummy substrate900is not held may be respectively accommodated in the stocker170, and each substrate holder200is used separately if necessary. Specifically, the substrate holder200including the dummy substrate900may be selected when single-side plating is performed, and the substrate holder200not including the dummy substrate900may be selected when double-side plating is performed. The substrate W is attached to the selected substrate holder200. After that, the substrate held by this substrate holder200is subjected to plating.

Holding the dummy substrate900on several substrate holders200accommodated in the stocker170is advantageous in that a station for accommodating the dummy substrate900, a transfer device for the dummy substrate900or an operation of transferring the dummy substrate900is not required. The substrate holder200on which the dummy substrate900is held is placed on the stage731. When the clamper290SL is used, the substrate holder200may be semi-locked at the time point ofFIG. 10A.

From the time point ofFIG. 10Ato the time point ofFIG. 10B, the following operations are performed. (1) The locking of the clamper290or the semi-locking of the clamper290SL is released. If necessary, the semi-locking is released after the pressing unit732presses the rear frame200btoward the front frame200a. (2) The rear frame200bis lifted up by the pressing unit732. (3) The dummy substrate900is lifted up by the lower substrate supporter801. (4) The substrate W is located above the dummy substrate900by the substrate transfer robot120.

From the time point ofFIG. 10Bto the time point ofFIG. 10C, the following operations are performed. (1) The upper substrate supporter803is lowered, and the substrate W and the dummy substrate900are sandwiched by the lower substrate supporter801and the upper substrate supporter803. (2) The substrate transfer robot120is detached from the pressing portion730. (3) The lower substrate supporter801, the upper substrate supporter803, and the pressing unit732are lowered, and both the substrate W and the dummy substrate900are sandwiched by the front frame200aand the rear frame200b. (4) The rear frame200bis pressed toward the front frame200a. (5) The clamper290is locked. (6) The engagement between the pressing unit732and the rear frame200bis released, and the pressing unit732is raised.

After the time point ofFIG. 10C, the lower substrate supporter801is lowered and the upper substrate supporter803is raised. After that, the substrate holder200on which both the substrate W and the dummy substrate900are held is unloaded from the pressing portion730. When the substrate W is detached from the substrate holder200on which both the substrate W and the dummy substrate900are held, operations in an order reverse to the above-described order are performed. The dummy substrate900may be detached from the substrate holder200after the substrate W is detached. The substrate holder200on which the dummy substrate900is held may be returned to the stocker170.

According to the above-described embodiments, a single substrate holder200can be used for both the single-side plating and the double-side plating only by selecting presence or absence of the dummy substrate900. The shape of the substrate holder200is not significantly changed according to the presence or absence of the dummy substrate900. Accordingly, it is unnecessary to significantly change the design of structural elements of the plating device100including the pressing portion730even when the substrate holder200of the embodiment is used.

In addition, the plating device100may have a substrate holder cleaning tank which cleans the substrate holder200in the semi-locking state. The substrate holder cleaning tank can store a cleaning solution (for example, pure water) inside. During cleaning of the substrate holder200, the substrate holder200in the semi-locking state is immersed in the cleaning solution. The substrate holder does not hold the substrate W in the semi-locking state, and thus the seals (for example, the outer seal300and/or the inner seals310), the contact points (for example, the substrate electrodes320) and the like are in contact with the cleaning solution and are cleaned. The cleaning solution in the substrate holder cleaning tank may be stirred by bubbling to improve the cleaning efficiency of the substrate holder200. The substrate holder200may be cleaned by showering the cleaning solution toward a section to be washed of the substrate holder200instead of immersing the substrate holder200in the cleaning solution.

Ideally, the plating solution does not adhere to the surface of the dummy substrate900facing the substrate W. However, actually, due to various reasons such as liquid splashes during attachment or detachment of the dummy substrate900or the substrate W, scratches, vibrations, design errors, assembly errors, time-related deteriorations of each component, and the like, liquids such as the plating solution and the like may adhere to the surface of the dummy substrate900facing the substrate W. The substrate holder200in the semi-locking state on which the dummy substrate900is held may also be cleaned. Even when the plating solution adheres to the surface of the dummy substrate900facing the substrate W, the dummy substrate900can also be cleaned by cleaning the substrate holder200along with the dummy substrate900. Besides, it may be that only the dummy substrate900held on the substrate holder200is cleaned. In the specification, the mechanism described above which cleans the substrate holder200and/or the dummy substrate900is referred to as a “holder/dummy substrate cleaning portion190”. Drying of the cleaned substrate holder200may be performed by pulling the substrate holder200up from the cleaning solution, or be performed by a blow tank which is arranged only for the drying of the substrate holder200, or be performed by the blow tank158.

<Surface of Dummy Substrate not Facing Substrate>

As is clear fromFIGS. 10A-10C, a part of the surface of the dummy substrate900not facing the substrate W is in contact with the lower substrate supporter801. Therefore, a concave portion1100corresponding to the shape of the lower substrate supporter801may be arranged on the surface of the dummy substrate900not facing the substrate W.FIG. 11Ais a diagram in which the dummy substrate900is viewed from the surface not facing the substrate W.FIG. 11Bis a cross-sectional view of a position marked with “A-A” inFIG. 11A. As described above, the lower substrate supporter801has a cross shape for example, and thus a cross-shaped concave portion1100is arranged inFIGS. 11A-11B. The concave portion1100is formed into a tapered groove shape. An inclination portion of the concave portion1100guides the lower substrate supporter801and thereby the lower substrate supporter801is reliably received by the concave portion1100. Besides, the lower substrate supporter801can only move vertically; in contrast, the dummy substrate900can move horizontally in the range of not colliding with the opening260a. Accordingly, to be accurate, it is the dummy substrate900itself that moves by the guidance of the concave portion1100.

In addition, the thickness of the dummy substrate900at the bottom of the concave portion1100may coincide with the thickness of the second part902. The thickness of the dummy substrate900at the bottom of the concave portion1100is made coincident with the second part902, and thereby the height of a surface of the dummy substrate900touching the inner seals310and the height of a surface of the dummy substrate900touching the lower substrate supporter801can be made coincident.

<Surface of Dummy Substrate Facing Substrate>

The dummy substrate900ofFIG. 9is in surface contact with the substrate W. Accordingly, when a liquid (typically, the plating solution) enters the space between the dummy substrate900and the substrate W, the dummy substrate900may stick to the substrate W. The detachment of the substrate W may be difficult when the dummy substrate900sticks to the substrate W. In order to prevent the sticking between the dummy substrate900and the substrate W, it may reduce a contact area between the dummy substrate900and the substrate W as much as possible, and/or to secure a path for supplying gas (for example, the air) between the dummy substrate900and the substrate W during detachment of the substrate W. In addition, the contactable region of a non-plating surface of the substrate W may also be limited. Therefore, a protrusion portion1200may be arranged on the surface of the dummy substrate900facing the substrate W.FIG. 12is a diagram in which the dummy substrate900is viewed from the surface facing the substrate W. The substrate W is in contact with the protrusion portion1200only instead of with the whole surface of the dummy substrate900. In the example ofFIG. 12, the protrusion portion1200has a cross shape. In addition, in the example ofFIG. 12, an edge part of the dummy substrate900is also the protrusion portion1200. By constituting the dummy substrate900as described above, the contact area between the dummy substrate900and the substrate W can be reduced and the supply path of gas can be secured, and the dummy substrate900can be prevented from sticking to the substrate W. In addition, by setting the shape of the protrusion portion1200to a shape similar to the contactable region of the substrate W, the contact between the dummy substrate900and the substrate W in parts other than the contactable region can be prevented.

When the dummy substrate900ofFIG. 12is used to plate a thin substrate W, the substrate W may deform due to water pressure of the plating solution. Therefore, the protrusion portions1200which are uniformly in contact with the substrate W over the whole surface of the dummy substrate900may be required.FIG. 13is a diagram in which the dummy substrate900is viewed from the surface facing the substrate W. A plurality of protrusion portions1200, 100 or more protrusion portions1200may be lined up on the surface of the dummy substrate900facing the substrate W inFIG. 13. In addition, the edge part of the dummy substrate900may also be the protrusion portion1200. By constituting the dummy substrate900as shown inFIG. 13, the contact area between the dummy substrate900and the substrate W can also be reduced and the supply path of gas can also be secured, and the dummy substrate900can also be prevented from sticking to the substrate W. A distance between the protrusion portions1200ofFIG. 13is short, and thus the deformation amount of the substrate W caused by the water pressure can be reduced when the dummy substrate900ofFIG. 13is used. The specific number and size of the protrusion portions1200and the distance between the protrusion portions1200and the like may be determined appropriately. Besides, each of the protrusion portions1200is in contact with the substrate W on a plane, and thus the respective protrusion portions1200are the same in the height which is measured from the same reference plane. Whether to configure the protrusion portion1200as shown inFIG. 12or as shown inFIG. 13may be determined by the specific processes of plating, the size, thickness and material of the substrate W, the presence or absence of contactable region on the non-plating surface of the substrate W, and the like.

In order to take out the substrate from the substrate holder holding the substrate W and the dummy substrate900being in an overlapping state, it is considered to configure the substrate transfer robot120so that the substrate transfer robot120holds the substrate W from above by vacuum suction, or claws arranged on the substrate transfer robot120scoop up the outer peripheral portion of the substrate W from below. In the latter case, it is difficult to scoop up only the substrate W from below and lift up the substrate W as long as the substrate W and the dummy substrate900have the same shape. The reason is that the claws of the substrate transfer robot120may interfere with the dummy substrate900. Therefore, cut-outs1400may be arranged on the outer peripheral portion of the dummy substrate900. InFIG. 14, the dummy substrate900including ten cut-outs1400is shown. Three cut-outs1400are arranged on each long edge of the dummy substrate900ofFIG. 14, and two cut-outs1400are arranged on each short edge. Besides, the “cut-out” is a term referring to a shape. In other words, an approach for forming the cut-outs1400is not limited to cutting. The cut-outs1400are arranged outside the position in contact with the inner seals310. When the dummy substrate900is divided into the first part901, the second part902, and the third part903(seeFIG. 9for the division), the cut-outs1400are arranged in the first part901. The cut-outs1400let the claws of the substrate transfer robot120pass through. Accordingly, the dummy substrate900is not scooped up with the substrate W.

FIG. 18is used to further describe the cut-outs1400.FIG. 18is a perspective view showing the substrate transfer robot120(to be accurate, a robot hand which is a part of the substrate transfer robot120), the substrate W, and the dummy substrate900. The substrate W ofFIG. 18has a rectangular shape having long edges and short edges. The shapes of the substrate transfer robot120and the dummy substrate900are optimized for the rectangular substrate W. The substrate transfer robot120ofFIG. 18includes claws1800and substrate holding members1810. The substrate holding members1810may be, for example, Bernoulli chucks for the suction of the substrate W. On the substrate transfer robot120, two claws1800are arranged along one short edge of the substrate W and three claws1800are arranged along one long edge of the substrate W.FIG. 19is a perspective view of the claw1800. The claw1800may include an attachment portion1900for attaching the claw1800to the substrate transfer robot120, a lever1910having a hook-shaped (claw-shaped) leading end, and a pin1920. The lever1910is configured to be capable of pivoting. The pivoting of the lever1910may be electromagnetically controlled by a motor and the like, or be controlled by a combination of mechanical components such as a pin, a spring and the like. The lever1910is “open” in an initial state. In other words, in the initial state, the lever1910is made to pivot so that the leading end of the lever1910is located outside the substrate W. The leading end of the lever1910can support the lower surface of the substrate W due to the pivoting of the lever1910.

The cut-outs1400are arranged on the dummy substrate900in a manner of corresponding to the position and number of the claw1800, more specifically, corresponding to the position and number of the lever1910. However, the “corresponding” here does not necessarily mean “the same”. The specific shape of the cut-out1400is determined according to the shape of the lever1910, particularly the shape of the leading end of the lever1910. The leading end of the lever1910can access the substrate W due to the cut-out1400, and the dummy substrate900is not scooped up with the substrate W.

Besides, the robot hand of the substrate transfer robot120is configured not to cause interference with the upper substrate supporter803and the like. For example, (the robot hand of) the substrate transfer robot120may have a groove and the like (not shown inFIG. 18) for passing the upper substrate supporter803.

As described above, there is a possibility that the dummy substrate900sticks to the substrate W when the dummy substrate900is used. In this case, if no force is applied to the dummy substrate900to fix the dummy substrate900, it is difficult to separate the dummy substrate900and the substrate W. Therefore, the dummy substrate900may be fixed by a fixture1500when the substrate W is taken out.FIG. 15is a diagram showing a fixation of the dummy substrate900using the fixture1500.FIG. 8should be referred to for the components not added with symbols inFIG. 15. The fixture1500is a vacuum chuck for example. One end of the fixture1500attracts the surface of the dummy substrate900not in contact with the substrate W to fix the dummy substrate900. The other end of the fixture1500is coupled to another component, for example, the stage731. The fixture1500fixes the dummy substrate900and thereby the substrate W is easily detached. The fixture1500may be an electromagnetic clamper, a mechanical fixture or the like besides the vacuum chuck. The fixture1500may be an element of the substrate holder200or an element of the pressing portion730.

<Pressing Down Dummy Substrate by Actuator of Substrate Transfer Robot>

In place of the fixture1500or in addition to the fixture1500, (the arm of) the substrate transfer robot120may have an actuator2100for pressing down the dummy substrate900.FIG. 20is a perspective view of the substrate transfer robot120having the actuator2100and the dummy substrate900having an extension portion2000. The position and number of the extension portion2000correspond to the position and number of the actuator2100. The “corresponding” here does not necessarily mean “the same”. The extension portion2000and the actuator2100may be arranged near at least one of the corner portions of the substrate W. Moreover, the extension portion2000and the actuator2100may be arranged near all the corner portions of the substrate W (four corners of the substrate W if the substrate W is rectangular). The actuator2100is capable of moving vertically. The actuator2100may be a pneumatic mechanism or a mechanism that operates electromagnetically. The extension portion2000is configured to protrude from the substrate W. Accordingly, the actuator2100can also access the extension portion2000even when the substrate W is placed on the dummy substrate900. In this example, the actuator2100presses the extension portion2000downward, and the substrate transfer robot120lifts the substrate W up at the same time. By this operation, the substrate W is easily detached even when the dummy substrate900sticks to the substrate W. Besides, although not shown inFIG. 20, it should be noted that the dummy substrate900is supported from below by the lower substrate supporter801for example.

<Selection of Double-Side Plating and Single-Side Plating Using Frame Replacement>

Different from the approaches described above, the substrate holder capable of both the double-side plating and the single-side plating can also be realized by replacing one of the front frame200aand the rear frame200bby a frame without opening. InFIG. 16, the rear frame200bofFIG. 2Bis replaced by a rear frame200b′ without the opening260b. In this case, the opening260bdoes not exist and thus one surface of the substrate W is not exposed. When the double-side plating is performed, the rear frame200b′ is replaced by the rear frame200bagain. Besides, in the specification, identity of the substrate holder200is not lost due to the replacement of the rear frame200b. In addition, the frame for replacement may also be a front frame200a′.

In the example ofFIG. 9, the dummy substrate900in the semi-locking state is prevented from falling off the substrate holder200by the third part903. However, the shape of the dummy substrate900is not limited to the example shown inFIG. 9.FIG. 17is a cross-sectional view of the substrate holder200including a dummy substrate900of another example. The dummy substrate900ofFIG. 17has a T-shaped cross section. A part corresponding to the “horizontal bar” of the T-shape, that is, a protrusion portion extending in a direction perpendicular to the surface of the dummy substrate900is disposed inside a region to be sealed by the outer seal300and the inner seals310. The protrusion portion is caught on any member (for example, a hook-shaped member) inside the region to be sealed, and thereby the dummy substrate900in the semi-locking state is prevented from falling off. However, it should be noted thatFIG. 17is only an illustration and the shape of the dummy substrate900and/or the fall prevention method of the dummy substrate900may be determined appropriately.

Some embodiments of the disclosure are described above. However, the above embodiments are intended to facilitate the understanding of the disclosure and do not limit the disclosure. The disclosure can be altered and improved without departing from the gist, and the disclosure includes the equivalents thereof. In addition, in a scope where at least some of the above-described problems can be solved or a scope where at least some of the effects are exhibited, any combination or omission of constituent elements described in the claims and the specification can be made.

The application discloses, as an embodiment, a substrate holder for holding a substrate to be plated. The substrate holder includes a first frame having a first opening for exposing one surface of the substrate and a second frame having a second opening for exposing the other surface of the substrate, and the substrate is sandwiched between the first frame and the second frame. The substrate holder further includes a dummy substrate which is detachably disposed between the first frame and the substrate and is formed of a material that at least a direct current does not substantially flow therein. At least a part of the dummy substrate is in contact with at least a part of the one surface of the substrate. The dummy substrate protects the one surface of the substrate from a plating solution.

As an example, the substrate holder exhibits an effect that it can be used in both double-side plating and single-side plating by attachment and detachment of the dummy substrate.

The application further discloses, as an embodiment, a substrate holder in which each of the first frame and the second frame includes an inner seal in contact with the substrate or the dummy substrate. At least one of the first frame and the second frame includes an outer seal in contact with the other frame. The dummy substrate includes a first part which is an outer edge portion of the dummy substrate, a second part which is closer to an inner side of the dummy substrate than the first part and in contact with the inner seals, and a third part which is closer to the inner side than the second part. A thickness of the second part is thinner than the thickness of the first part or the thickness of the third part. In certain embodiment, the thickness of the second part is 0.1 mm or more and 2 mm or less.

As an example, the substrate holder exhibits an effect of holding substrates of various thicknesses.

The application further discloses, as an embodiment, a substrate holder in which cut-outs for passing claws of a transfer device for transferring the substrate are arranged in the first part.

As an example, the substrate holder exhibits an effect of preventing interference between the transfer device and the dummy substrate.

The application further discloses, as an embodiment, a substrate holder in which the third part is configured so that at least a part of the third part is inserted into the first opening.

As an example, the substrate holder exhibits an effect of preventing falling of the dummy substrate when the substrate is not held on the substrate holder, particularly when the substrate holder is semi-locked.

The application further discloses, as an embodiment, a substrate holder in which a protrusion portion is arranged on a surface of the dummy substrate facing the substrate, and the protrusion portion is in contact with the substrate. In certain embodiment, the protrusion portion is configured to be in contact with only a contactable region of the substrate.

As an example, the substrate holder exhibits an effect of preventing the dummy substrate from sticking to the substrate.

The application further discloses, as an embodiment, a plating device which includes substrate holders of any embodiment, a substrate attachment and detachment device for attaching the substrate to the substrate holder and detaching the substrate from the substrate holder, a treatment portion including at least one plating tank, a transporter for transporting the substrate holder, and a stocker for accommodating the substrate holder. In certain embodiment, at least one substrate holder including the dummy substrate and at least one substrate holder from which the dummy substrate is detached are accommodated in the stocker. In certain embodiment, the substrate holder includes a clamper capable of semi-locking the substrate holder, and at least one of the substrate holders is accommodated in the stocker in the state of being semi-locked.

As an example, the substrate holder exhibits an effect that both single-side plating and double-side plating can be performed by selecting the substrate holder to be used.

The application further discloses, as an embodiment, a substrate plating method for plating a substrate using a substrate holder. The substrate holder includes a first frame having a first opening for exposing one surface of the substrate, and a second frame having a second opening for exposing the other surface of the substrate. The substrate is sandwiched between the first frame and the second frame. The substrate holder is accommodated in a stocker of a plating device. At least one of the substrate holders accommodated in the stocker includes a dummy substrate which is disposed between the first frame and the substrate and formed of a material that at least a direct current does not substantially flow therein. At least a part of the dummy substrate is in contact with at least a part of the one surface of the substrate, and the dummy substrate protects the one surface of the substrate from a plating solution. At least another one of the substrate holders accommodated in the stocker does not include the dummy substrate. The method includes a selection step for selecting the substrate holder to be used, and in which the substrate holder including the dummy substrate is selected when single-side plating is performed and the substrate holder not including the dummy substrate is selected when double-side plating is performed; a step for attaching a substrate to the substrate holder selected in the selection step; and a step for performing plating on the substrate held by the substrate holder selected in the selection step.

As an example, the method exhibits an effect that both single-side plating and double-side plating can be performed by selecting the substrate holder to be used.