Substrate processing unit and substrate processing apparatus

The present invention relates to a substrate holding device and a substrate holding method suitable for use when treating the surface (surface to be treated) of a substrate with a plating solution or other treatment liquid.

As a wiring forming process for semiconductor devices, a process in which a metal (conductor) is embedded in a trench and a contact hole (so-called damascene process) is being used. This is a process of embedding metals such as aluminum, and more recently copper and silver, in trenches and contact holes pre-formed in the interlayer insulating film, and then removing excess metals by chemical mechanical polishing (CMP) to flatten them. It is a technology.

In this kind of wiring, for example, in a copper wiring using copper as a wiring material, the surface of the wiring made of copper is exposed to the outside after flattening, so that thermal diffusion of the wiring (copper) can be prevented. For example, in the case of laminating an insulating film (oxide film) having an oxidizing atmosphere thereafter to make a semiconductor device having a multi-layer wiring structure, it is made of Co alloy, Ni alloy, etc. in order to prevent oxidation of the wiring (copper). It has been studied to selectively cover the surface of exposed wiring with a protective layer (cover material) to prevent thermal diffusion and oxidation of wiring. The Co alloy, Ni alloy and the like can be obtained by, for example, electroless plating.

For example, as shown in FIG. 1, SiO deposited on the surface of a substrate W such as a semiconductor wafer.₂After forming a trench 4 as a fine wiring recess inside an insulating film (interlayer insulating film) 2 made of a low-k material film or the like and forming a barrier layer 6 made of TaN or the like on the surface, for example, copper. Plating is performed to form a copper film on the surface of the substrate W, and copper is embedded inside the trench 4. After that, the surface of the substrate W is flattened by applying CMP (chemical mechanical polishing) to form a wiring 8 made of copper inside the insulating film 2. Then, a protective film (lid material) 9 made of a CoWP alloy film obtained by, for example, electroless plating is selectively formed on the surface of the wiring (copper) 8 to protect the wiring 8.

A process of selectively forming a protective film (lid material) 9 made of such a CoWP alloy film on the surface of the wiring 8 by general electroless plating will be described. First, a substrate W such as a semiconductor wafer subjected to CMP processing is subjected to, for example, H at a liquid temperature of 25 ° C and 0.5 M.₂SO₄By immersing it in an acid solution such as, for example, for about 1 minute to remove CMP residues such as copper remaining on the surface of the insulating film 2. Then, after cleaning (rinsing) the surface of the substrate W with a cleaning solution such as pure water, for example, PdCl.₂/ H₂SO₄The substrate W is immersed in the mixed solution for about 1 minute, whereby Pd as a catalyst is attached to the surface of the wiring 8 to activate the exposed surface of the wiring 8.

Next, after cleaning (rinsing) the surface of the substrate W with a cleaning liquid such as pure water, for example, at a liquid temperature of 25 ° C, 20 g / L of Na₃C₆H₅O₇ 2H₂The substrate W is immersed in a solution such as O (sodium citrate) to neutralize the surface of the wiring 8. Then, after cleaning (rinsing) the surface of the substrate W with pure water or the like, the substrate W is immersed in a CoWP plating solution having a liquid temperature of, for example, 80 ° C. for about 120 seconds to activate the wiring 8. Selective electroless plating (electroless CoWP lid plating) is applied to the surface, and then the surface of the substrate W is cleaned with a cleaning solution such as ultrapure water. As a result, a protective film 9 made of a CoWP alloy film is selectively formed on the surface of the wiring 8 to protect the wiring 8.

When forming a protective film (lid material) made of CoWP alloy by electroless plating, as described above, a catalyst applying treatment for applying a catalyst such as Pd is applied to the surface of the wiring. Further, in order to prevent the protective film from being formed on the insulating film, it is necessary to remove the CMP residue made of copper or the like remaining on the insulating film, which is generally H.₂SO₄And using inorganic acids such as HCl. On the other hand, the electroless plating solution is generally composed of an alkaline solution, and therefore, it is necessary to insert a neutralization step immediately before the plating process to stabilize the plating process, and the number of steps increases, so that each step The number of processing tanks in the above will also increase. As a result, not only the throughput is lowered, but also the process management of each process becomes complicated, and the device becomes large, which occupies a large installation space in the clean room and leads to an increase in the cost of the clean room.

This can lead to reduction of space in the entire substrate processing process and reduction of energy required for substrate transfer by performing processing using different processing liquids in one substrate processing unit, but different processing liquids can be used. This is because if the treatment used is performed in one treatment unit, it becomes difficult to avoid mixing and diluting the treatment liquid.

On the other hand, as a method of performing stable and uniform plating of a substrate (for example, electroless plating), or stable and uniform plating pretreatment and cleaning treatment of a substrate, the substrate is immersed in a treatment liquid and its surface (subject). A dip treatment method in which the treatment liquid is brought into contact with the treatment surface) is generally used. A substrate processing unit that employs this dip processing method is generally provided with a substrate holding device that seals the peripheral edge of the surface to hold the substrate, whereby the substrate is held by the substrate holding device and immersed in the processing liquid. When the treatment is carried out, the treatment liquid is prevented from wrapping around to the peripheral edge of the substrate surface and further to the back surface side.

Further, it is provided with a suction seal (annular seal) composed of an elastic body such as rubber and continuously extending in a ring shape, and the suction seal is pressed toward the substrate so that the end face of the suction seal is completely on the back peripheral edge of the substrate. A so-called vacuum suction method is used in which the substrate is held in close contact over the circumference, and the inside of the suction seal is vacuum-sucked to hold the substrate while sealing the peripheral edge of the back surface of the substrate in a ring shape with the suction seal. The adopted substrate holding device has been developed.

For substrate holding devices, it is important to be able to completely release the substrate from the head after processing without load. Conventionally, for example, in a substrate holding device adopting the above-mentioned vacuum suction method, N is formed inside the suction seal (annular seal).₂It has been widely practiced to release a substrate by introducing clean air such as gas and injecting it toward the substrate. But N₂In some cases, it was not possible to release a substrate firmly attached to an adsorption seal made of rubber or the like simply by introducing clean air such as gas. For this reason, by introducing pure water together with clean air into the suction seal and injecting it toward the substrate at the same time, even if the substrate is firmly attached to the adsorption seal made of rubber or the like, the substrate can be reliably attached. Is being released to.

However, when pure water is injected together with clean air in this way, for example, in a substrate holding device that employs a vacuum adsorption method, clean air and pure water are introduced in addition to the circuit that performs evacuation. Two circuits are required separately, which not only complicates the internal circuit configuration but also leads to an increase in the size of the device.

In addition, when the substrate is held by the substrate holding device and processing such as electroless plating is performed, the substrate is held with as weak a force as possible and more evenly over the entire surface so that the substrate is not deformed, and the processing accuracy is high. It is desirable to keep. However, in order to reliably prevent the substrate from coming off or coming off, the substrate may come off or come off even when the processing is generally performed while rotating at the maximum rotation speed, such as when draining (spin drying). A series of processes are performed by being adsorbed or mechanically held by the substrate holding device with no constant holding force. For this reason, not only the substrate is deformed by applying a local load to the substrate, but also the substrate is firmly attached to the suction seal or the like, which may make it difficult to release the substrate.

<p> The present invention has been made in view of the above circumstances, and has made it possible to hold and process a substrate while reliably preventing the substrate from coming off or falling off without strengthening the adsorption or mechanical holding force on the substrate. An object of the present invention is to provide a substrate holding device and a substrate holding method.</p>

<p> The substrate holding device of the present invention has a rotatable holding head provided with an annular seal that holds the substrate while sealing the back surface peripheral portion of the substrate, and the holding head is the holding head in a state of holding the substrate. A drawing mechanism for generating a negative pressure on the back surface side of the substrate sealed with the annular seal is provided as the substrate rotates.</p><p> In this way, as the holding head rotates, a negative pressure is generated on the back surface side of the substrate sealed with the annular seal via the drawing mechanism, and the negative pressure generated on the back surface side of the substrate causes the substrate. It is possible to obtain a holding force against. The number of diaphragm mechanisms provided on the holding head is arbitrarily set according to the required holding force.</p><p> The aperture mechanism<u style="single">,Before</u>It has an air vent hole provided in the covering body that integrally covers the back surface of the substrate held by the holding head, and a throat portion that communicates with the air vent hole, and air generated in the throat portion as the holding head rotates. The inside of the air vent hole is made negative pressure by utilizing the Venturi effect due to the flow of.</p><p> As a result, the speed of the air flow generated in the throat of the throttle mechanism is increased in proportion to the rotation speed of the holding head, and the pressure (negative pressure) inside the air vent hole is lowered, so that the substrate by the throttle mechanism is used. The holding force against the force can be increased in proportion to the rotation speed of the holding head.</p><p> It is preferable that the holding head evacuates the inside of the annular seal to attract and hold the substrate. The holding head preferably further has a pusher that presses the substrate held by the annular seal in a direction away from the holding head. As a result, even if the substrate is firmly attached to the annular seal, the substrate can be reliably released from the annular seal by utilizing the pressing force of the pusher.</p><p> In the substrate holding method of the present invention, the substrate is held by the holding head while sealing the peripheral edge of the back surface of the substrate with a ring-shaped annular seal, and the back surface of the substrate is rotated as the holding head is held. And a negative pressure is generated on the back surface side of the substrate partitioned by the annular seal.<u style="single">It is a substrate holding method, and has an air vent hole provided in a covering body covering the back surface of the substrate held by the holding head, and a throat portion communicating with the air vent hole. The inside of the air vent hole is made negative pressure by utilizing the Venturi effect due to the flow of air generated in the part.</u>。 </p>

<figref num="1">FIG. 1 is a cross-sectional view showing a state in which a protective film is formed by electroless plating.</figref><figref num="2">FIG. 2 is a plan layout of a substrate processing apparatus (electroless plating apparatus).</figref><figref num="3">FIG. 3 is a perspective view of the substrate transfer robot.</figref><figref num="4">FIG. 4 is a front view of the substrate transfer robot in a state where the substrate is held.</figref><figref num="5">FIG. 5 (a) is a cross-sectional view showing a state in which the body of the board transfer robot is extended, and FIG. 5 (b) is a cross-sectional view of the state in which the body of the board transfer robot is contracted.</figref><figref num="6">FIG. 6 is a plan view of the temporary stand.</figref><figref num="7">FIG. 7 is a front view of the temporary stand.</figref><figref num="8">FIG. 8 is a schematic view of a plating pretreatment unit (board treatment unit) in a state where the substrate is treated while closing the upper end opening of the inner tank with a spray treatment cup.</figref><figref num="9">FIG. 9 is a schematic view of a plating pretreatment unit (board treatment unit) in a state where the spray treatment cup is retracted and the substrate is treated in the inner tank.</figref><figref num="10">FIG. 10 is a schematic view of an electroless plating unit (board processing unit) in a state where the substrate is processed while closing the upper end opening of the inner tank with a spray processing cup.</figref><figref num="11">FIG. 11 is a schematic view of an electroless plating unit (board processing unit) in a state where the spray processing cup is retracted and the substrate is processed in the inner tank.</figref><figref num="12">FIG. 12 is a front view of the supply box.</figref><figref num="13">FIG. 13 is a side sectional view of the supply box.</figref><figref num="14">FIG. 14 is a perspective view showing the supply box and the container.</figref><figref num="15">FIG. 15 is a system diagram of the supply box.</figref><figref num="16">FIG. 16 is a vertical sectional front view showing a substrate holding device according to an embodiment of the present invention.</figref><figref num="17">FIG. 17 is an enlarged cross-sectional view of a main part showing the annular head of the substrate holding device shown in FIG.</figref><figref num="18">FIG. 18 is an enlarged cross-sectional view of a main part showing a pusher of the substrate holding device shown in FIG.</figref><figref num="19">FIG. 19 is a bottom view of the holding head.</figref><figref num="20">FIG. 20 is a perspective view of the holding head.</figref><figref num="21">FIG. 21 is a plan view of the holding head.</figref><figref num="22">FIG. 22 is a sectional view taken along line AA of FIG.</figref>

Hereinafter, embodiments of the present invention will be described with reference to the drawings. This embodiment shows an example of application to an electroless plating apparatus capable of efficiently forming, for example, a protective film 9 (see FIG. 1) by electroless plating on the surface of wiring formed on a substrate. Of course, it can be applied to other substrate processing devices such as electrolytic plating devices and CVD.

FIG. 2 shows a plan layout of a substrate processing apparatus (electroless plating apparatus). As shown in FIG. 2, this substrate processing apparatus includes a rectangular apparatus frame 12 to which a transport box 10 containing a large number of substrates such as semiconductor wafers can be attached and detached inside, for example, a smiff box or the like. Inside the device frame 12, a first substrate transfer robot 14, a temporary stand 16, and a second substrate transfer robot 18 are arranged in series at a central portion. A pair of cleaning / drying units 20, a post-plating unit 22, a pre-plating unit 24, and an electroless plating unit 26 are arranged on both sides. Further, a first treatment liquid supply unit 28 that supplies the treatment liquid to the plating pretreatment unit 24 and a second treatment liquid supply unit that supplies the treatment liquid to the electroless plating unit 26 are located on the opposite side of the transport box 10. 30 is provided.

This substrate processing device (electroless plating device) is installed in a clean room, and the pressure in the device frame 12 is set higher than the pressure in the clean room. As a result, air is prevented from flowing out from the device frame 12 into the clean room. Further, a downward flow (downflow) of fresh air is formed inside the device frame 12.

3 to 5 show the first substrate transfer robot 14. The second substrate transfer robot 18 also has the same configuration as the first substrate transfer robot 14. The first substrate transfer robot 14 is a so-called fixed robot, and has a body portion 32 that can be expanded and contracted in the vertical direction, a rotation drive unit 34 attached to the upper end of the body portion 32, and a horizontal portion attached to the rotation drive unit 34. It has a robot arm 36 that can be expanded and contracted in the direction. A reversing mechanism 40 that rotates a rotating shaft 38 extending in the horizontal direction is attached to the tip of the robot arm 36, and the back surface of the substrate W is attracted to the rotating shaft 38 of the reversing mechanism 40 to attract and hold the substrate W. A hand 44 having a suction portion 42 at the tip thereof is connected.

The substrate transfer robots 14 and 18 are in the middle of transfer, for example, in the case of the first substrate transfer robot 14, the substrate W is transferred from the transfer box 10 to the temporary stand 16 via the reversing mechanism 40. Is reversed from face-up to face-down, and for this reason, the back surface suction type hand 44 is adopted. By providing the reversing mechanism 40 in the substrate transfer robots 14 and 18 themselves, it is not necessary to separately equip the reversing device, and the device can be simplified.

As shown in FIG. 5, the body portion 32 has a hollow inner body 32a and an outer body 32b, and is configured to be expandable and contractible by a so-called nesting type. An exhaust duct (exhaust unit) 46 communicating with the inside of the outer body 32b is connected, and the air inside the first substrate transfer robot 14 is exhausted to the outside through the exhaust duct 46 and collected.

As a result, for example, the air exhausted from the inside of the board transfer robot 14 passes between the inner body 32a and the outer body 32b as the body 32 of the first board transfer robot moves up and down due to expansion and contraction. It is possible to prevent leakage to the outside of the substrate transfer robot 14 and keep the air flow in the vicinity of the substrate transfer robot 14 constant to prevent the substrate W from being contaminated by particles.

6 and 7 show the temporary stand 16. The temporary stand 16 is arranged between the first board transfer robot 14 and the second board transfer robot 18, and the board W is taken in and out from one direction on the side of the first board transfer robot 14 and the second board transfer robot 18. It has become like. Of course, the substrate may be taken in and out from any direction. In this way, by arranging the temporary stand 16 for temporarily placing the board between the board transfer robots 14 and 18, the board W can be efficiently transferred in the device frame 12 and the board transfer robots 14 and 18 are placed. As a result, the fixed robot can be used, and the cost of the entire device can be reduced.

On the temporary stand 16, an upper dry substrate temporary storage portion 50 and a lower wet substrate temporary storage portion 52 are partitioned by a partition plate 54 and are provided above and below. The temporary substrate mounting portion 50 for drying includes a plurality of support pins 56 erected on the partition plate 54 at positions along the peripheral edge portion of the substrate W, and the substrate W is provided via a tapered portion provided on the upper portion of the support pins 56. Hold while positioning. Similarly, the wet substrate temporary mounting portion 52 is provided with a plurality of support pins 60 erected on the base plate 58 at positions along the peripheral edge portion of the substrate W, via a tapered portion provided on the upper portion of the support pins 60. Hold the board W while positioning it.

As a drying prevention mechanism that prevents the substrate W from drying by spraying pure water toward the surface (upper surface) of the substrate W held by the support pin 60 of the wet substrate temporary placement portion 52 on the lower surface of the partition plate 54. Pure water spray nozzle 62 is installed. Further, between the partition plate 54 and the base plate 58, a shutter 63 that prevents the pure water sprayed from the pure water spray nozzle 62 toward the substrate W from leaking to the outside is provided so as to be openable and closable.

As a result, the substrate W held and conveyed by the first substrate transfer robot 14 is inverted and then positioned and held by the support pin 56 of the upper dry substrate temporary placement portion 50. After a series of processes, the substrate W held and conveyed by the second substrate transfer robot 18 is positioned and held by the support pin 60 of the lower wet substrate temporary placement portion 52. Then, whether or not the substrate W is held by the dry substrate temporary storage portion 50 or the wet substrate temporary storage portion 52 is detected by a sensor (not shown). Although the substrate W is inverted by the first substrate transfer robot 14 here, the second substrate transfer robot may invert it.

8 and 9 show the plating pretreatment unit 24. The plating pretreatment unit 24 is located inside the outer tank 70, which has a bottomed cylindrical shape and extends vertically, a substrate holding portion 72 which is vertically arranged inside the outer tank 70, and the outer tank 70. It has an inner tank 74 arranged below the substrate holding portion 72, and a spray processing cup 76 located inside the outer tank 70 that can close the upper end opening of the inner tank 74.

The substrate holding portion 72 moves up and down via the drive mechanism and rotates via the substrate rotation motor of the drive portion as described below. Further, the substrate holding portion 72 is provided with a ring-shaped annular seal 190 (see FIG. 16) on the lower surface side, and the annular seal 190 is pressed against the peripheral edge portion of the substrate W to seal the peripheral edge portion with the annular seal 190 while sealing the substrate. It is designed to hold W. As a result, the processing liquid is prevented from sneaking around to the back surface side of the substrate W held by the substrate holding portion 72.

At the lower part of the outer tank 70, a drain port 80 connected to a drainage line 78 for discharging the treatment liquid flowing into the outer tank 70 to the outside is provided. Further, on the lower side surface of the outer tub 70, it is connected to an exhaust duct 82 provided with a damper inside, whereby an air flow adjusting unit for adjusting the air flow of the outer tub 70 is configured. That is, the amount of clean air sent into the outer tub 70 and the amount of exhaust from the outer tub 70 are controlled (controlled) to manage the air flow in the outer tub 70. In this example, by controlling the airflow inside the outer tank 70 as a downflow, the leakage of the chemical atmosphere to the outside of the outer tank 70 is prevented, and the stagnation of the airflow is locally caused by the turbulent flow inside the outer tank 70. It is configured to prevent this from affecting other treatments in the outer tank 70.

Inside the inner tank 74, in this example, a chemical solution treatment unit 84 that performs chemical solution treatment of the substrate by spray treatment is provided. That is, the chemical solution processing unit 84 has a nozzle board 88 having a plurality of chemical solution spray nozzles 86 for spraying the chemical solution upward on the upper surface, and a chemical solution supply line 90 for supplying the chemical solution to the nozzle board 88. As a result, the substrate W is processed by spraying the chemical solution from the chemical solution spray nozzle 86 toward the lower surface (front surface) of the substrate W held by the substrate holding portion 72.

At the bottom of the inner tank 74, a drain port 94 connected to a drainage line 92 for discharging the chemical liquid flowing into the inner tank 74 to the outside is provided. In this example, the drainage line 92 is connected to the chemical liquid tank 100 with a filter 96 and a liquid feed pump 98 interposed therein. Further, the chemical solution supply line 90 is connected to the chemical solution tank 100 by interposing a liquid feed pump 102 and a filter 104 inside the chemical solution supply line 90. As a result, the chemical solution circulation line 106 for circulating and using the chemical solution is configured.

Further, in this example, the chemical solution temperature control unit 108 that constantly controls the temperature of the chemical solution in the chemical solution tank 100, the chemical solution in the chemical solution tank 100 is sampled and analyzed, and the insufficient components are replenished to supply the chemical solution tank 100. It is provided with a chemical solution analysis and replenishment unit 109 that keeps the composition of the chemical solution inside constant. As a result, the temperature and composition of the chemical solution in the chemical solution tank 100 can be kept constant, and the chemical solution can be circulated and used while supplying the chemical solution having a constant temperature and composition from the chemical solution supply line 90. The flow rate of the chemical solution sprayed from the chemical solution spray nozzle 86 is controlled via the liquid feed pump 102.

A nozzle board 110 is attached to the upper surface of the spray treatment cup 76 that freely covers the upper end opening of the inner tank 74, and in this example, the nozzle board 110 is a chemical solution that supplies a chemical solution (first treatment solution). The supply line 112 and the pure water supply line 114 that supplies pure water (second treatment liquid) are connected, and inside, a chemical liquid spray nozzle 116 that communicates with the chemical liquid supply line 112 and sprays the chemical liquid, and pure water supply. Two types of spray nozzles 118, which are pure water spray nozzles 118 that communicate with the line 114 and spray pure water, are arranged alternately in a straight line.

As a result, the substrate treated with the treatment liquid such as the chemical solution supplied from the chemical solution supply line 112 and sprayed from the chemical solution spray nozzle 116 is supplied from the pure water supply line 114 and sprayed from the pure water spray nozzle 118 immediately after the treatment. It can be washed (rinsed) with pure water. Moreover, even if pure water is generally mixed with other treatment liquids, treatment or the like does not generally cause a problem. In this example, the chemical solution sprayed from the chemical solution spray nozzle 116 is disposable without being collected, but the chemical solution is collected in the same manner as the chemical solution treatment unit 84 provided in the inner tank 74 described above. However, it may be circulated and reused.

Next, a usage example of the plating pretreatment unit 24 will be described. First, as shown in FIG. 8, in a state where the upper end opening of the inner tank 74 is covered with the spray processing cup 76, the substrate holding portion 72 holding the substrate W is placed at a predetermined position above the spray processing cup 76 (the first position). 1) Lower to the processing position). And in this example, as the chemical solution (first treatment solution), H₂SO₄Using a pre-cleaning solution consisting of an acid solution such as, the chemical solution (H) from the chemical solution spray nozzle 116 of the spray processing cup 76.₂SO₄Etc.) is sprayed toward the substrate W, and then pure water is sprayed from the pure water spray nozzle 118 of the spray processing cup 76 toward the substrate W to clean (rinse) the substrate W.

Then, as shown in FIG. 9, the spray processing cup 76 is retracted to the lateral shelter position of the inner tank 74 to open the upper end opening of the inner tank 74, and the substrate holding portion 72 holding the substrate W is used as a chemical solution. It is lowered to a predetermined position (second processing position) above the processing unit 84. And in this example, as a chemical solution, PdCl₂And H₂SO₄Using a catalyst-imparting solution such as a mixed solution with, a chemical solution (PdCl) is used from the chemical solution spray nozzle 86 of the chemical solution treatment unit 84.₂And H₂SO₄(Catalyst-imparting liquid such as a mixed liquid with) is sprayed toward the substrate W.

Next, after raising the substrate holding portion 72 holding the substrate W to a predetermined position (first processing position), the upper end opening of the inner tank 74 is covered with the spray processing cup 76, and the spray processing cup 76 Pure water is sprayed from the pure water spray nozzle 118 toward the substrate W to clean (rinse) the substrate W. As described above, the pretreated substrate is conveyed to the next process.

During these processes, as shown in FIGS. 8 and 9, a laminar downflow air flow is generated inside the outer tank 70, and most of this air is exhausted to the outside through the exhaust duct 82. .. This prevents the chemical atmosphere from leaking to the outside of the outer tank 70, and turbulence causes local airflow stagnation in the outer tank 70, which affects other treatments in the outer tank 70. It is possible to prevent it from happening.

Moreover, while the substrate W is held by the substrate holding portion 72, the chemical solution treatment of the substrate W in the inner tank 74 and the substrate W by at least two kinds of treatment solutions sprayed from the spray nozzles 116 and 118 of the spray processing cup 76. Can be processed individually. The upper end opening of the inner tank 74 is closed by the spray treatment cup 76, and the treatment liquid is sprayed from the spray nozzles 116 and 118 of the spray treatment cup 76 to treat the substrate W with the treatment liquid. The treatment liquid sprayed from 116,118 is discharged from the outer tank 70 through the drainage line 78 without flowing into the inner tank 74. As a result, the treatment liquid containing the chemical solution sprayed from the spray nozzles 116 and 118 of the spray treatment cup 76 is prevented from being mixed with the chemical solution used in the chemical solution treatment section 84 of the inner tank 74.

10 and 11 show the electroless plating unit 26. The differences between the electroless plating unit 26 and the plating pretreatment unit 24 are as follows.

That is, inside the inner tank 74 of the electroless plating unit 26, a chemical solution treatment unit 120 that performs a chemical solution treatment of the substrate by an immersion treatment is provided. The chemical solution treatment unit 120 has a bathtub 122 in which a chemical solution such as a plating solution is stored and the substrate W held by the substrate holding unit 72 is immersed in the chemical solution. The chemical supply line 90 extending from the chemical solution tank 100 for holding the chemical solution such as the plating solution is connected to the chemical solution supply unit 124 provided at the bottom of the bathtub 122, and the drainage line 92 is provided around the bathtub 122. The peripheral wall of the bathtub 122 is communicated with the chemical solution collection groove 126 for collecting the overflowing chemical solution, thereby forming a chemical solution circulation line 106 for circulating and using the chemical solution.

Further, in this example, the pure water supplied to the pure water supply line 127 is located slightly above the liquid level of the chemical solution stored in the bathtub 122 of the inner tank 74, and the pure water supplied through the pure water supply line 127 is slightly. A pure water spray nozzle 128 for spraying upward is provided.

Next, a usage example of the electroless plating unit 26 will be described. First, as shown in FIG. 10, with the upper end opening of the inner tank 74 covered with the spray processing cup 76, the substrate holding portion 72 holding the substrate W is placed at a predetermined position above the spray processing cup 76 (the first position). 1) Lower to the processing position). Then, in this example, as the chemical solution (first treatment solution), a catalyst-added post-treatment solution composed of a solution of sodium citrate or the like is used, and the chemical solution (sodium citrate or the like) is used from the chemical solution spray nozzle 116 of the spray treatment cup 76. A catalyst-imparted post-treatment liquid consisting of a solution) is sprayed onto the substrate W, and then pure water is sprayed from the pure water spray nozzle 118 of the spray treatment cup 76 toward the substrate W to clean the substrate W ( Rinse).

Next, while filling the inside of the bathtub 122 with a chemical solution (plating solution), the chemical solution is adjusted to a constant temperature and composition and circulated, and as shown in FIG. 11, the spray treatment cup 76 is placed in the inner tank 74. The upper end opening of the inner tank 74 is opened, the substrate holding portion 72 holding the substrate W is lowered, and the substrate W is immersed in the chemical solution (plating solution) in the bathtub 122. .. As a result, electroless plating (electroless CoWP lid plating) is applied to the surface of the substrate W. The composition of this chemical solution (plating solution) is as follows, for example.

Composition of plating solution CoSO₄ 7H₂O: 23g / L Na₃C₆H₅O₇ 2H₂O: 145g / L (NH₄)₂SO₄: 31g / L NaH₂PO₂ H₂O: 18g / L Na₂WO₄ 2H₂O: 10g / L PH: 8.8 (adjusted with NaOH aqueous solution)

Then, after the substrate W is pulled up from the liquid level of the chemical solution, pure water is sprayed from the pure water spray nozzle 128 toward the substrate W, whereby the chemical solution (plating solution) adhering to the surface of the substrate W is converted into pure water. Substitute to stop the electroless plating reaction. Thus, the substrate W electroless plating reaction immediately after pulling from the chemical solution (plating solution) quickly stops the response, plating unevenness to the plating film is prevented from occurring. Moreover, by using, for example, 10 to 20 cc of pure water, the evaporated water can be replenished with this pure water to keep the concentration of the chemical solution constant.

Next, after raising the substrate holding portion 72 holding the substrate W to a predetermined position (first processing position), the upper end opening of the inner tank 74 is covered with the spray processing cup 76, and the spray processing cup 76 Pure water is sprayed from the pure water spray nozzle 118 toward the substrate W to clean (rinse) the substrate W. As described above, the electroless plated substrate is transported to the next process.

During these processes, as shown in FIGS. 10 and 11, a laminar downflow air flow is generated inside the outer tank 70, and this air is exhausted to the outside through the exhaust duct 82. Further, at least two or more kinds of treatment liquids sprayed from the spray nozzles 116 and 118 of the spray treatment cup 76 are prevented from being mixed with the chemical liquid (plating liquid).

As shown in FIG. 2, the first treatment liquid supply unit 28 and the second treatment liquid supply unit 30 of the substrate processing apparatus are provided with supply boxes 130 and 132 for detachably holding a container containing a stock solution or an additive. There is. The supply box 130 of the first treatment liquid supply unit 28 is, for example, H used in the plating pretreatment unit 24.₂SO₄The supply box 132 of the second treatment liquid supply unit 30 is for preparing a chemical solution (first treatment liquid) composed of an acid solution such as sodium citrate, which is used in the electroless plating unit 26. This is for preparing a chemical solution (second treatment solution) consisting of a solution. Since these have the same configuration, one supply box 130 will be described here.

12 to 14 show the supply box 130. In this example, the supply box 130 has a cover 134 that can be opened and closed via the handle 133, and the container 136 made of a bottle or the like that stores the undiluted solution or the like inside and can be carried by hand has the cover 134. After opening, it is placed on the mounting table 138 and housed in the supply box 130. The mounting table 138 is equipped with a weight measuring device such as a load cell that detects the presence or absence of the container 136 and the volume of the undiluted solution or the like in the container 136, and an alarm is issued when the undiluted solution or the like in the container 136 is insufficient.

A pump 140, a back pressure valve 142 (see FIG. 15) and a flow meter 144 (see FIG. 15) are installed inside the supply box 130, and as the pump 140 is driven, a predetermined pressure is applied from the inside of the container 136. Raw materials and the like are supplied through the supply pipe 146 by a predetermined flow rate. Then, in this example, as shown in FIG. 15, the raw materials and the like supplied from the container 136 of the supply box 130 are supplied to the chemical solution tank 148 through the supply pipe 146, and the valve 150 and the flow meter 152 are supplied to the chemical solution tank 148. A chemical solution (first treatment solution) having a predetermined concentration is prepared by diluting with pure water supplied through.

In this way, by managing the components of the chemical solution (first treatment solution) supplied to the plating pretreatment unit 24 in the apparatus, the processing performance of the plating pretreatment unit 24 can be kept constant. Moreover, by using a portable bottle as the container 136, the container (bottle) can be easily and easily attached and detached. This also applies to the electroless plating unit 26.

FIG. 16 shows a substrate holding device 180 according to an embodiment of the invention, which has a substrate holding portion 72 provided in the plating pretreatment unit 24 and the electroless plating unit 26. As shown in FIG. 16, the substrate holding device 180 includes a substrate holding unit 72 and a driving unit 220. The substrate holding portion 72 has a substantially cylindrical substrate supporting portion 182 having an open lower surface and a substantially circular holding head 184 housed inside the substrate supporting portion 182 so as to be vertically movable. The drive unit 220 includes a board rotation motor 221 that rotationally drives the holding head 184, and an elevating cylinder 222 that raises and lowers the board support unit 182 to a predetermined position up and down. The holding head 184 is rotationally driven by the board rotation motor 221 and the board support portion 182 is moved up and down by the elevating cylinder 222. That is, the holding head 184 rotates only by rotation and does not move up and down, and the substrate support portion 182 rotates integrally with the holding head 184 and moves up and down relative to the holding head 184.

The substrate support portion 182 has a substrate temporary placement portion 185 protruding inward in a ring shape and temporarily placing the substrate W at the lower end portion thereof, and a substrate support portion 182 is provided on the peripheral wall of the substrate support portion 182. A board insertion port 186 for inserting the board W is provided inside.

The holding head 184 has a disk-shaped covering body 188 provided with a vacuum and pure water supply path 188a extending in the radial direction inside, and a ring-shaped lower surface is provided on the lower peripheral portion of the lower surface of the covering body 188. An annular seal 190 with a circumferential groove 190a (see FIG. 17) that extends continuously in the circumferential direction is attached. Then, the vacuum and pure water supply path 188a is selectively connected to one of the vacuum line 196 extending from the vacuum source 194 and the pure water supply line 200 extending from the pure water supply source 198 through the joint 192 provided in the covering body 188. , It communicates with the circumferential groove 190a through the through hole 190b provided inside the annular seal 190. As a result, a substrate holding mechanism 202 that attracts and holds the substrate W with the annular seal 190 and a substrate release mechanism 204 that releases the substrate W that is attracted and held by the annular seal 190 are configured.

That is, the lower surface of the annular seal 190 is pressed against the outer peripheral edge of the back surface (upper surface) of the substrate W, and the inside of the circumferential groove 190a of the annular seal 190 is evacuated via the vacuum line 200 constituting the substrate holding mechanism 202. Then, the substrate W is attracted and held by the annular seal 190, and pure water is introduced into the circumferential groove 190a of the annular seal 190 via the pure water supply line 200 constituting the substrate release mechanism 204 toward the substrate W. By ejecting, the substrate W that is attracted and held by the annular seal 190 is released.

In this way, by releasing the substrate W that is attracted and held by the annular seal 190 of the holding head 184 using water pressure, even if the substrate W is firmly attached to the annular seal 190 made of rubber or the like. The substrate W can be reliably released from the annular seal 190. Moreover, by releasing the substrate W using only water pressure, it is possible to eliminate the need for a circuit for introducing clean air. In this example, pure water is used, but it goes without saying that a liquid other than pure water may be used.

Further, by configuring the substrate release mechanism 204 so as to introduce the pressurized water inside the annular seal 190 to release the substrate W, it is not necessary to separately provide an area for introducing the pressurized water, and the structure is further simplified. Can be planned.

The annular seal 190 is made of an elastic body made of, for example, rubber, and as shown in FIG. 17, the lower end portion thereof is projected downward from the lower surface of the covering body 188 and attached to the lower surface of the covering body 188. As described above, when the substrate W is sucked and held, it serves as a seal that prevents the treatment liquid (plating liquid) from entering the back surface of the substrate W (the inner portion sealed in a ring shape by the annular seal 190). .. Of course, the shape of the annular seal 190 is not limited to the shape shown in the figure, and any shape and structure may be used as long as it is adsorbed in a ring shape with a predetermined circumferential width.

A plurality of vacuum and gas supply paths 188b extending in the radial direction are further provided inside the covering body 188, and the region surrounded by the annular seal 190 on the lower surface of the covering body 188 is shown in FIG. As shown above, a plurality of pushers 206 (six in the figure) are arranged along the circumferential direction. Each of the vacuum and gas supply units 188b is selectively connected to one of the vacuum line 210 extending from the vacuum source 194 and the gas supply line 214 extending from the gas supply source 212 through a joint 208 provided in the covering body 188. It communicates with the back of the pusher 206. As a result, the auxiliary substrate release mechanism 216 that releases the substrate W that is attracted and held by the annular seal 190 is configured.

That is, as shown in detail in FIG. 18, the pusher 206 is formed of a stretchable elastic material such as a synthetic rubber material made of fluororesin, and is hollow and has a stretchable bellows portion 206a and a columnar shape opened on the back side. It has a tip (lower end) pressing portion 206b, and is airtightly attached to the lower surface of the covering body 188 via the flange portion 206c. The lower surface of the pressing portion 206b is located slightly below the flat surface formed by the lower surface of the annular seal 190. As a result, when the substrate W is held by the annular seal 190, the inside of the vacuum and gas supply path 188b is evacuated through the vacuum line 210, the bellows portion 206a is contracted, and the pressing portion 206b is pressed against the substrate W. Lift to an upper position that does not interfere with retention. Then, when the substrate W held by the annular seal 190 is released, gas is introduced into the vacuum / gas supply path 188b via the gas supply line 214, the bellows portion 206a is extended, and the pressing portion 206b is pushed downward. Push down to push the substrate W downward.

In this way, by providing the auxiliary substrate release mechanism 216 as necessary, even if the substrate W is firmly attached to the lower surface of the annular seal 190, the substrate W is annularly formed by utilizing the pressing force of the pusher 206. It can be reliably released from the seal 190.

Further, in this example, as shown in FIGS. 20 to 22, the holding head 184 is provided with a plurality of (three in the drawing) diaphragm mechanisms 260. As the holding head 184 holding the substrate W rotates, the drawing mechanism 260 is sandwiched between the back surface side of the substrate W sealed by the annular seal 190, that is, the back surface of the substrate W and the covering body 188, and is sandwiched by the annular seal 190. Negative pressure is generated in the enclosed space.

The drawing mechanism 260 is provided in the covering body 188, and is sandwiched between the back surface of the substrate W held by the annular seal 190 and the covering body 188, and has an air vent hole 188c that allows air to escape in the space surrounded by the annular seal 190. It has a lid 262 that covers the upper part of the air vent hole 188c, and an operating plate 264 that is concentrically fixed to the holding head 184. Then, as shown in FIGS. 21 and 22, a throat portion 266 is provided between each lid body 262 and the operating plate 264 so that they are close to each other and the flow path cross-sectional area is minimized. As a result, as the holding head 184 rotates, an air flow is generated through the throat portion 266 as shown by an arrow in FIG. 21, and the speed of this air flow becomes the rotational speed of the holding head 184. It increases proportionally.

On the other hand, the lid 262 that covers the upper surface of the air vent hole 188c is provided with an air flow path 262a that communicates with the inside of the air vent hole 188c and opens at a position facing the throat portion 266. As a result, the throttle mechanism 260 utilizes the Venturi effect to create a negative pressure on the back surface side of the substrate W from the inside of the air vent hole 188c.

That is, as described above, when an air flow that passes through the throat portion 266 is generated as the holding head 184 rotates, the air inside the air vent hole 188c passes through the air flow path 262a to the outside due to this air flow. A negative pressure is generated from the inside of the air vent hole 188c to the back surface side of the substrate W, and the magnitude of this negative pressure is proportional to the rotation speed of the holding head 184.

In this way, as the holding head 184 rotates, it is sandwiched between the back surface side of the substrate sealed by the annular seal 190, that is, the back surface of the substrate W and the covering body 188 via the drawing mechanism 260, and is surrounded by the annular seal 190. By generating a negative pressure in the space, a holding force with respect to the substrate W can be obtained by the negative pressure generated on the back surface side of the substrate W. As a result, it is possible to secure a sufficient holding force for the substrate without strengthening the suction or mechanical holding force for the substrate. The number of diaphragm mechanisms 260 provided on the holding head 184 is arbitrarily set according to the required holding force.

Moreover, the speed of the air flow generated in the throat portion 266 of the throttle mechanism 260 is increased in proportion to the rotation speed of the holding head 184, and the inside of the air vent hole 188c is negatively pressured by utilizing the venturi effect of this air flow. By doing so, the holding force of the drawing mechanism 260 with respect to the substrate W can be increased in proportion to the rotation speed of the holding head 184.

Next, the operation of the substrate holding device 180 will be described. First, as shown in FIG. 16, the board support portion 182 is moved to the lowest position (board delivery position) without rotating the holding head 184, and the board W sucked by the robot hand (not shown) is moved. Insert it inside the board holding portion 72. Then, by releasing the suction of the robot hand, the substrate W is placed on the substrate temporary placement portion 185 of the substrate support portion 182. At this time, the surface (surface to be processed) of the substrate W faces downward. Then, the robot hand is pulled out from the board holding portion 72. Next, the substrate support portion 182 is raised so that the lower end surface of the annular seal 190 is brought into contact with the peripheral surface portion of the back surface (upper surface) of the substrate W, and further raised to bring them into close contact with each other. At this time, the pusher 206 of the auxiliary board release mechanism 216 is lifted upward so that the pusher 206 does not hinder the holding of the board W.

In this state, by evacuating the inside of the circumferential groove 190a of the annular seal 190 via the substrate holding mechanism 202, the peripheral edge of the back surface of the substrate W is attracted to the annular seal 190 to hold the substrate W. At this time, the suction force is generated only in the circumferential groove 190a inside the portion of the annular seal 190 in contact with the substrate W. As a result, the portion of the back surface of the substrate W surrounded by the annular seal 190 is blocked from the surface (surface to be processed) of the substrate W by the seal by the annular seal 190.

According to this example, by adsorbing the outer periphery of the substrate W with a ring-shaped small width (diameter) annular seal 190, the adsorption width is suppressed as small as possible and the influence on the substrate W (deflection, etc.) is eliminated. be able to. Specifically, the width of the annular seal 190 is very narrow, and the portion where the annular seal 190 contacts the substrate W is, for example, a portion between the outer circumference of the substrate W and 5 mm inside the annular seal 190. Since only the outer peripheral portion of the back surface of the substrate W comes into contact with the annular seal 190, there is no possibility that the temperature of the processing liquid during substrate processing is unnecessarily transmitted to the contact surface with the annular seal 190 and escapes.

Then, for example, when the substrate W held by the substrate holding portion 72 is immersed in the treatment liquid, such as the substrate holding portion 72 provided in the electroless plating unit 26 described above, the substrate supporting portion 182 is slightly moved. Lower the substrate W (for example, several mm) to separate the substrate W from the temporary substrate placement portion 185. In this state, the entire substrate holding device 180 is lowered, immersed in a treatment liquid such as a plating solution (not shown), and if necessary, the holding head 184 is rotated together with the substrate W to process the substrate. At this time, since the substrate W is only adsorbed and held on the back surface thereof, it is possible to dip the entire surface surface and the edge portion of the substrate W into the treatment liquid to perform the treatment.

Further, since the substrate support portion 182 is lowered and separated from the substrate W, and only the back surface of the substrate W is attracted and held, the flow of the treatment liquid with respect to the substrate W even if the substrate W is immersed in the treatment liquid. Is not hindered, and a uniform flow of the treatment liquid is formed over the entire surface of the substrate. Further, along with the flow of the treatment liquid, air bubbles caught on the surface of the substrate W and air bubbles generated by the treatment can be discharged upward from the surface of the substrate W. This makes it possible to solve the non-uniform flow of the treatment liquid and the influence of air bubbles, which adversely affect the treatment such as plating, and to perform the treatment such as uniform plating over the entire surface of the substrate including the edge. Further, since the inside of the ring-shaped vacuum-adsorbed portion on the back surface of the substrate W is blocked from the front surface by the seal by the annular seal 190, it is possible to prevent the treatment liquid from entering the inside of the annular seal 190 on the back surface of the substrate W. Can be done.

Then, for example, when rinsing (cleaning) with pure water and draining (spin drying) after rinsing are continuously performed, the entire substrate holding device 180 is raised to pull up the substrate W from the processing liquid, and the holding head 184 is moved to the substrate W. Pure water is injected toward the substrate W while rotating with the substrate W, and then the holding head 184 is rotated at a high speed together with the substrate W to drain (spin dry) the pure water adhering to the substrate.

At this time, the substrate W is held by the holding force generated by the drawing mechanism 260 using the negative pressure on the back surface side of the substrate W, in addition to the suction force generated by sucking the inside of the circumferential groove 190a of the annular seal 190. Moreover, the holding force is proportional to the rotation speed of the holding head 184 by the drawing mechanism 260. Therefore, even if the suction force by sucking the inside of the circumferential groove 190a of the annular seal 190 is weakened, a sufficient holding force of the substrate can be secured and the substrate can be prevented from falling off.

That is, conventionally, the suction force by sucking the inside of the circumferential groove 190a of the annular seal 190 is generally set to a size that can surely prevent the substrate from falling off even if the substrate is rotated at high speed. According to an example, even if this suction force is weakened, by utilizing the holding force by the drawing mechanism 260, it is possible to obtain a sufficient holding force for the substrate without strengthening the suction force or the mechanical holding force for the substrate. it can.

After a series of processing of the substrate W is completed, the substrate support portion 182 is raised to place the substrate W on the substrate temporary placement portion 185, and the circumferential groove 190a of the annular seal 190 is placed via the substrate release mechanism 204. Pure water is introduced into the inside of the pusher 206 and ejected toward the substrate W, and gas is introduced into the back side of the pusher 206 via the auxiliary substrate release mechanism 216 to pressurize the inside of the pusher 206 and lower the pressing portion 206b. The substrate W is pressed from the back surface thereof. At the same time, by lowering the substrate support portion 182, the substrate W is separated from the annular seal 190, and the substrate support portion 182 is further lowered to the position shown in FIG. Then, the robot hand is inserted into the board holding portion 72 and the board W is pulled out to the outside.

In this way, the liquid is ejected from the circumferential groove 190a of the annular seal 190 toward the substrate W, and if necessary, the back surface of the substrate W is pressed by the pressing portion 206b of the pusher 206. Even if the substrate W is firmly attached to the annular seal 190 formed of the body, the pressing force of pure water introduced into the circumferential groove 190a of the annular seal 190 and the pressing portion of the pusher 206 as required. By pressing the back surface of the substrate W by 206b, the substrate W can be easily and surely released from the annular seal 190.

According to this substrate holding device, by releasing the substrate held by the holding head using water pressure, even if the substrate is firmly attached to the annular seal made of rubber or the like, the substrate is released from the annular seal. It can be released reliably and the substrate can be attached and detached smoothly. Moreover, by releasing the substrate using only water pressure, a circuit for introducing clean air is not required, which makes it possible to simplify the circuit configuration and reduce the size of the device.

Further, the substrate is locally deformed by obtaining the holding force for the substrate through the drawing mechanism provided in the substrate holding head for holding the substrate without strengthening the suction or mechanical holding force for the substrate. Alternatively, it is possible to prevent the substrate from being firmly attached to the suction seal or the like, making it difficult to release the substrate.

Next, a series of electroless plating treatments by this electroless plating apparatus (board processing apparatus) will be described. In this example, as shown in FIG. 1, a case where a protective film (lid material) 9 made of a CoWP alloy film is selectively formed to protect the wiring 8 will be described.

First, from the transfer box 10 in which the substrate W (see FIG. 1, the same applies hereinafter) in which the wiring 8 is formed on the surface is housed with the surface of the substrate W facing upward (face-up), one substrate W is transferred to the first transfer robot 14 It is taken out in the above and conveyed to the dry substrate temporary storage portion 50 of the temporary storage table 16 and held by the dry substrate temporary storage portion 50. The substrate W held by the dry substrate temporary storage portion 50 of the temporary storage base 16 is transferred to the plating pretreatment unit 24 by the second transfer robot 18. The substrate is inverted from face-up to face-down by the first transfer robot 14 or the second transfer robot 18.

In the plating pretreatment unit 24, the substrate W is held face-down by the substrate holding portion 72, and the surface of the substrate W is first pre-cleaned. That is, as shown in FIG. 8, with the upper end opening of the inner tank 74 covered with the spray processing cup 76, the substrate holding portion 72 holding the substrate W is placed at a predetermined position above the spray processing cup 76 (the first position). 1) Lower to the processing position) and H₂SO₄A pre-cleaning solution consisting of an acid solution such as the above is sprayed from the chemical spray nozzle 116 of the spray treatment cup 76 toward the substrate W to remove CMP residues such as copper remaining on the surface of the insulating film 2 (see FIG. 1). After that, pure water is sprayed from the pure water spray nozzle 118 of the spray processing cup 76 toward the substrate W to clean (rinse) the substrate W.

Next, as shown in FIG. 9, the spray processing cup 76 is retracted to the lateral shelter position of the inner tank 74 to open the upper end opening of the inner tank 74, and the substrate holding portion 72 holding the substrate W is moved. After lowering to a predetermined position (second treatment position) above the chemical treatment unit 84, PdCl₂And H₂SO₄A catalyst-imparting solution such as a mixed solution with the above is sprayed from the chemical solution spray nozzle 86 of the chemical solution treatment unit 84 toward the substrate W. As a result, Pd as a catalyst is attached to the surface of the wiring 8, that is, a Pd nucleus as a catalyst nucleus (seed) is formed on the surface of the wiring 8 to activate the exposed surface of the surface wiring of the wiring 8.

Next, after raising the substrate holding portion 72 holding the substrate W to a predetermined position (first processing position), the upper end opening of the inner tank 74 is covered with the spray processing cup 76, and the spray processing cup 76 Pure water is sprayed from the pure water spray nozzle 118 toward the substrate W to clean (rinse) the substrate W. The second substrate transfer robot 18 receives the substrate after the pre-plating treatment from the substrate holding portion 72 of the pre-plating unit 24 and delivers it to the substrate holding portion 72 of the electrolytic plating unit 26.

The electroless plating unit 26 holds the substrate W face-down by the substrate holding portion 72, and first performs a chemical treatment on the surface of the substrate W. That is, as shown in FIG. 10, with the upper end opening of the inner tank 74 covered with the spray processing cup 76, the substrate holding portion 72 holding the substrate W is placed at a predetermined position above the spray processing cup 76 (the first position). 1) Lower to the treatment position), and spray the catalyst-added post-treatment liquid consisting of a solution of sodium citrate or the like from the chemical spray nozzle 116 of the spray treatment cup 76 toward the substrate W to neutralize the surface of the wiring 8. After that, pure water is sprayed from the pure water spray nozzle 118 of the spray treatment cup 76 toward the substrate W to clean (rinse) the substrate W.

Next, as shown in FIG. 11, the spray processing cup 76 is retracted to a side retreat position of the inner tank 74 to open the upper end opening of the inner tank 74, and the substrate holding portion 72 holding the substrate W is moved. By lowering the substrate W, the substrate W is immersed in a chemical solution (plating solution) in the bathtub 122, whereby electroless plating (electroless CoWP lid plating) is performed. That is, for example, the substrate W is immersed in a CoWP plating solution having a liquid temperature of 80 ° C for about 120 seconds, and the surface of the activated wiring 8 is subjected to selective electroless plating (electroless CoWP lid plating). ).

Then, after the substrate W is pulled up from the liquid level of the chemical solution, pure water is sprayed from the pure water spray nozzle 128 toward the substrate W, whereby the chemical solution on the surface of the substrate W is replaced with pure water for electroless plating. To stop.

Next, after raising the substrate holding portion 72 holding the substrate W to a predetermined position (first processing position), the upper end opening of the inner tank 74 is covered with the spray processing cup 76, and the spray processing cup 76 Pure water is sprayed from the pure water spray nozzle 118 toward the substrate W to clean (rinse) the substrate W. As a result, a protective film 9 made of a CoWP alloy film (see FIG. 1, the same applies hereinafter) is selectively formed on the surface of the wiring 8 to protect the wiring 8.

Next, the substrate W after electroless plating is transported by the second substrate transfer robot 18 to, for example, the post-plating unit 22 composed of a roll cleaning unit, where particles and unnecessary substances adhering to the surface of the substrate W are removed. Perform post-plating treatment to remove by rubbing with a roll-shaped brush. In the process of this transfer, the substrate is inverted from face-down to face-up. After that, the substrate W is conveyed by the second substrate transfer robot 18 to the wet substrate temporary storage portion 52 of the temporary placement table 16 and held by the wet substrate temporary storage portion 52. During this holding, pure water is sprayed from the spray nozzle 62 toward the substrate W to prevent the substrate W from drying out.

The first substrate transfer robot 14 takes out the substrate W from the wet substrate temporary storage portion 52 of the temporary placement table 16 and conveys it to, for example, a cleaning / drying unit 20 composed of a spin dry unit, where chemical cleaning and chemical cleaning of the surface of the substrate W are performed. Clean with pure water and spin dry. The substrate W after spin drying is returned to the inside of the transfer box 10 by the first transfer robot 14.

In this example, a CoWB alloy is used as the protective film 9, but a protective film made of CoB, NiB or NiWB may be formed as the protective film 9. Further, although an example in which copper is used as the wiring material is shown, a copper alloy, silver, silver alloy, gold, a gold alloy, or the like may be used in addition to copper.