JP2013104119A - Electroless plating apparatus and electroless plating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electroless plating apparatus which reduces carrying of moisture used in a previous processing as much as possible, using a high-productivity batch processing method, thereby more uniformly and stably performing a series of continuous processing.SOLUTION: There is provided the electroless plating apparatus which includes a substrate holder for holding and conveying a plurality of substrates in parallel in a vertical direction and simultaneously immersing the plurality of substrates in a treatment liquid in a treatment tank different between before and after the conveyance. The substrate holder includes: a support bar 94a having a plurality of support grooves 130 for supporting the substrate by positioning an outer peripheral part thereof; and a moisture removing mechanism 136a for removing the moisture stored from the inside of the support grooves 130 to the periphery thereof.

Description

  The present invention relates to an electroless plating apparatus and an electroless plating method, so that uniform processing can be stably performed on the surface of a substrate such as a semiconductor wafer while adopting a batch processing method with particularly high productivity. The present invention relates to an electroless plating apparatus and an electroless plating method.

  For example, as shown in FIG. 1, for example, as shown in FIG. 1, the micro bump 12 provided at a predetermined position of the CPU 10 and the micro bump 16 provided at a predetermined position of the memory 14 are both electrodes as the three-dimensional mounting for electrically connecting the semiconductor chips. It is proposed that the microbumps (electrodes) 12 and 16 are joined to each other.

  The micro bumps 16 provided in the memory 14 are made of, for example, Cu—Sn. For example, the microbump 12 provided in the CPU 10 has a Ni plating film 20 of 2 to 10 μm formed on the surface of the bump pad 18 made of, for example, Al or Cu, and the surface of the Ni plating film 20 has a thickness of 50 to 200 nm, for example. An Au plating film 22 is formed. The Au plating film 22 diffuses into the micro bumps 16 made of, for example, Cu—Sn when the micro bumps 12 and 16 are joined. Therefore, the Au plating film 22 itself does not affect the bonding, but has a role of preventing the oxidation of the surface of the Ni plating film 20 and maintaining the bonding strength.

  Here, the reason why the micro bumps 16 provided in the memory 14 and the bump pads 18 made of Cu, for example, are not directly connected is that Cu alone damages the underlying Low-K material. For this reason, the Ni plating film 20 and the Au plating film 22 are employed as buffer materials.

  Also in TSV (Through Silicon Via) wiring connection, as shown in FIG. 2, the surface bump 36 formed by sequentially laminating the Ni plating film 32 and the Au plating film 34 on the surface side of the TSV 30, and the back surface of the TSV 30 It has been proposed to join the back bumps 38 formed on the side.

  As a technique for forming the Ni plating films 20 and 32 and the Au plating films 22 and 34 as described above, the use of electroless plating instead of electrolytic plating has been studied. Further, in addition to Ni and Au, in the case of plating films made of simple materials and composite materials such as Co, Pd, Pt, Cu, Sn, Ag, Rh, and Ru that can be electrolessly plated, instead of electrolytic plating. Adoption of electroless plating has been studied.

  As the base metal (bump pad 18) of the micro bump 12 shown in FIG. Al and Cu are not catalytic metals such as Fe, Co, Ni, Pd, Pt and the like. For this reason, as a pretreatment for plating, a zincate process is generally performed when the base metal is Al, and a Pd catalyst application process (or initial energization) is performed when the base metal is Cu. In the zincate treatment on the Al surface, zinc is generally applied to the Al surface by displacement plating. Since zinc itself becomes a catalyst poison and interferes with the catalytic action, it is necessary to make the amount of zinc replacement plating appropriate when performing zincate treatment. In the electroless plating, zinc is replaced with a catalyst metal that can be electrolessly plated.

  As described above, the pretreatment (activation treatment) of the Al surface or Cu surface is displacement plating of a catalytic metal or zinc, for example, Pd catalyst application treatment is performed by immersing the substrate in a sulfuric acid-based palladium sulfate-containing solution. The zincate treatment is performed by immersing the substrate in a sodium hydroxide-based zinc oxide-containing solution. For this reason, the pre-plating treatment (activation treatment) is generally pre-cleaned with nitric acid or citrate to remove the oxide film or contaminants on the substrate surface, washed with water, and then dried. Without being carried out continuously. And electroless plating is continuously performed without drying the substrate surface after washing the substrate surface after the plating pretreatment. That is, a series of electroless plating processes are continuously performed without drying the substrate surface. This is because when the substrate surface is dried after pre-cleaning or pre-plating treatment, an oxide film is formed on the substrate surface, resulting in poor plating treatment.

  Here, depending on the pretreatment method for plating, for example, in a patterned wafer, there are problems such as damage to the base, deterioration of the denseness of the displacement plating film with the base metal, and an increase in the roughness of the plating film. In addition, in the case of a solid wafer, there arises a problem that the uniformity of the surface morphology of the substrate is deteriorated and the appearance is deteriorated.

  In the electroless plating pretreatment (activation treatment), it is important to perform substitution plating of Zn, Pd, etc. densely and uniformly. Here, the amount of displacement plating and surface etching during displacement plating is the concentration of the etching agent contained in the treatment liquid, for example, when the surface of Al is pre-plated (zincate treatment) with a sodium hydroxide-based zinc oxide-containing solution. When the plating pretreatment (Pd catalyst application treatment) is performed on the surface of Cu with a sulfuric acid-based palladium sulfate-containing solution, the concentration of NaOH is strongly influenced by the concentration of sulfuric acid and may be determined within a few seconds.

  Electroless plating equipment is generally classified into electroless plating equipment that employs a single wafer processing system that processes substrates one by one and electroless plating equipment that employs a batch processing system that holds and processes multiple substrates simultaneously. Broadly divided. The plating rate of electroless plating is generally 1 to 20 μm / s, which is much slower than the plating rate of electrolytic plating. For this reason, when applying electroless plating to a process that requires a great amount of time such as bump formation, it is common to consider a batch processing method rather than a single wafer processing method.

  The batch processing type electroless plating apparatus has an advantage that the throughput in the same footprint is very high as compared with the single wafer processing type. However, batch processing type electroless plating equipment treats multiple substrates held side by side in the vertical direction by simultaneously immersing them in a processing solution such as a plating pretreatment solution or a plating solution. Process performance (film thickness and film quality uniformity) due to the time required to completely immerse the substrate from the bottom to the top in the processing liquid, the direction of the processing liquid flow, the uniformity of the temperature distribution of the processing liquid, etc. ) Is inferior to the sheet processing method.

  As a substrate processing apparatus adopting a batch processing method, the applicant applies a substrate holder for holding a plurality of substrates and immersing them in a processing solution in the processing tank, and a processing liquid in the processing tank while holding the plurality of substrates. The thing which was made to rotate in is proposed (refer patent document 1). Moreover, as a substrate processing apparatus adopting a batch processing method, a carrier mounting unit, a horizontal transfer robot, a posture changing mechanism, a pusher, a transport mechanism, and a substrate processing unit are provided so that a plurality of substrates can be processed while being transported simultaneously. What has been proposed has been proposed (see Patent Document 2).

JP 2009-57593 A Japanese Patent No. 3974985

  In an electroless plating apparatus that employs a batch processing method, a plurality of substrates are processed in each processing tank before and after the movement while moving a substrate holder that holds a plurality of substrates such as semiconductor wafers in the vertical direction. In general, the treatment is carried out by immersing in the same process. In that case, for example, when the substrate held by the substrate holder is moved from the washing tank to the zincate treatment tank, the substrate is held in the vertical direction by the substrate holder, so that moisture easily collects in the lower portion of the substrate. In addition, the moisture adhering to the previous lot process tends to remain in the substrate holder.

  As described above, when the zincate treatment is performed in a state where moisture remains unevenly on the substrate surface, uneven concentration of the zincate solution occurs when the moisture and the zincate solution are mixed, and the solid wafer is affected by the uneven concentration of the zincate solution. In the pattern wafer, the appearance defect occurs, and in the pattern wafer, the plating film thickness variation in the substrate surface becomes large.

FIG. 3 shows the relationship between the amount of zinc substitution and the treatment time (seconds) when there is residual moisture on the surface (A ₁ ) and when there is no residual moisture (B ₁ ) when the zincate treatment is performed on the Al surface. FIG. 4 shows the amount of Al etching and the processing time (seconds) when there is residual moisture on the surface (A ₂ ) and when there is no residual moisture (B ₂ ). Show the relationship.

  As shown in FIG. 3 and FIG. 4, in particular, in the zincate treatment of the Al surface where the Al etching and zinc substitution plating rate are fast, the Al etching amount and the zinc substitution amount are determined in the initial few seconds (2 to 5 seconds), In addition, the etching amount and the displacement plating amount are increased at locations where there is a large amount of moisture. For this reason, zinc is unevenly substituted on the Al surface to form a rough plating film, and damage the base.

  Moreover, the amount of zinc that dissolves in the electroless plating solution increases at locations where there is a large amount of zinc adhered, which results in locations where the zinc concentration increases locally, and zinc dissolves and becomes a catalyst poison. Depending on the level of zinc concentration, a difference occurs in the plating film thickness. In addition, when multiple substrates are installed parallel to the vertical direction and immersed in the processing liquid, the processing time in the vertical direction of the substrate will differ, so the film thickness distribution of the plating film will be above and below the substrate. The difference is easy to come out. In particular, the difference becomes significant in a process with a short processing time such as a zincate process.

  Note that if the substrate is left in the atmosphere for a long time to remove moisture, the substrate surface is dried, and an oxide film is formed on the metal surface, which causes defective replacement plating. Further, if a large amount of moisture remains on the substrate or the substrate holder when the substrate is pulled up from the processing liquid, a difference occurs in the etching amount or the degree of water washing.

  In addition, the zincate processing liquid generally has a high viscosity, and when the substrate is lifted from the processing liquid, the amount of the zincate processing liquid attached to the substrate or the substrate holder tends to increase. Further, the Au plating solution is generally expensive, and similarly, it is desired to reduce the amount of the processing solution taken out.

  The present invention was made in view of the above circumstances, adopting a highly productive batch processing method, and further reducing the amount of moisture used in the previous processing etc. as much as possible, An object of the present invention is to provide an electroless plating apparatus and an electroless plating method which can be performed more uniformly and stably.

  The invention described in claim 1 has a substrate holder that transports a plurality of substrates while being held parallel to the vertical direction, and simultaneously immerses the plurality of substrates in a treatment liquid in different treatment tanks before and after the transportation. In the electroless plating apparatus, the substrate holder includes a support rod having a plurality of support grooves for supporting the substrate by positioning an outer peripheral portion of the substrate, and a moisture removing mechanism for removing moisture accumulated in or around the support grooves. It is an electroless-plating apparatus characterized by having.

  For example, after the substrate held by the substrate holder is pulled up from the processing liquid, the water (processing liquid) accumulated in or around the support groove for supporting the substrate is removed by the water removing mechanism by positioning the outer peripheral portion of the substrate. In this way, it is possible to reduce the amount of moisture brought into the continuous next process as much as possible, and to perform this continuous next process more uniformly and stably.

  According to a second aspect of the present invention, the moisture removing mechanism includes a pressurized gas supply line that is selectively connected to an opening end of a central hole that is closed inside the support rod, and a liquid intrusion prevention mechanism. 2. The electroless plating apparatus according to claim 1, further comprising a line, wherein the center hole and the inside of the support groove communicate with each other through a communication hole.

  As a result, pressurized gas such as pressurized air is supplied to the central hole and the communication hole of the support rod through the pressurized gas supply line, and is ejected toward the inside of the support groove, so that the inside or the periphery of the support groove. Moisture (treatment liquid) accumulated in can be removed by blowing off with pressurized gas. The liquid intrusion prevention line prevents the processing liquid from entering the center hole and the communication hole of the support rod during the processing.

  According to a third aspect of the present invention, the moisture removal mechanism includes a moisture suction line and a liquid intrusion prevention line that are selectively connected to an opening end of a central hole that is closed at one end provided in the support rod. 2. The electroless plating apparatus according to claim 1, wherein the center hole and the inside of the support groove communicate with each other through a communication hole.

  Thus, the moisture (treatment liquid) accumulated in or around the support groove is sucked and removed by sucking the inside of the support groove with a vacuum or the like from the center hole and the communication hole of the support rod through the moisture suction line. Can do. In addition, the amount of moisture (treatment liquid) taken out can be reduced by collecting the moisture (treatment liquid) removed by suction.

  The invention according to claim 4 is the electroless plating apparatus according to claim 1, further comprising a liquid circulation line for circulating the treatment liquid in the treatment tank in which the substrate held by the substrate holder is immersed. is there.

  The invention according to claim 5 is characterized in that the liquid intrusion prevention line comprises a pressurized fluid supply line for supplying a pressurized fluid into the central hole. It is.

The invention according to claim 6 is characterized in that the communication hole is opened toward the surface to be plated of the substrate held by the substrate holder. An electroless plating apparatus.
Thereby, the water | moisture content which remains on the to-be-plated surface side of the board | substrate in a support groove | channel can be mainly removed.

  The invention according to claim 7 further includes a control unit that adjusts a dipping speed for dipping the substrate held by the substrate holder in the processing liquid in the processing tank and a pulling speed for lifting the substrate from the processing liquid in the processing tank. The electroless plating apparatus according to claim 1, wherein the electroless plating apparatus is characterized in that

  In this way, the time required to completely immerse the substrate from the lower end to the upper end in the processing liquid is reduced by controlling the immersion speed of the substrate into the processing liquid and the pulling speed from the processing liquid by the control unit. Or a large amount of moisture can be prevented from remaining on the substrate pulled up from the processing liquid.

  The invention according to claim 8 is the electroless plating apparatus according to claim 7, wherein the immersion speed is 100 mm / s or more and the pulling speed is 50 mm / s or less.

The invention according to claim 9 further includes a moving mechanism that vibrates, vertically swings, or horizontally swings the substrate holder when the substrate held by the substrate holder is immersed in the processing liquid in the processing tank. The electroless plating apparatus according to claim 1, wherein the electroless plating apparatus is characterized in that
Diffusion of the processing liquid on the substrate surface can be promoted by immersing the substrate held by the substrate holder in the processing liquid while vibrating, swinging up and down, or swinging left and right.

The invention according to claim 10 includes a pure water injection mechanism that injects pure water toward the substrate after the substrate held by the substrate holder is immersed in the treatment liquid in the treatment tank and pulled up from the treatment liquid. Furthermore, it is an electroless-plating apparatus as described in any one of Claim 1 thru | or 9 characterized by the above-mentioned.
Thereby, it is possible to further reduce the amount of the processing liquid brought out to the outside by adhering to the substrate.

  According to the eleventh aspect of the present invention, a plurality of substrates are held in parallel in the vertical direction by the substrate holder by positioning the outer peripheral portion of the substrate in the plurality of support grooves provided in the support rod, and the substrate held by the substrate holder Is immersed in the first treatment liquid in the first treatment tank and pulled up from the first treatment liquid, the substrate holder holding the substrate is conveyed directly above the second treatment tank, and the substrate held by the substrate holder is An electroless plating method of immersing in a second treatment liquid in a second treatment tank and pulling up from the second treatment liquid, wherein moisture accumulated in or around the support groove is collected before or after the treatment or It is an electroless plating method characterized by removing in the middle.

  According to a twelfth aspect of the present invention, before the plurality of substrates are held parallel to the vertical direction by the substrate holder, moisture accumulated in or around the support groove is removed. The electroless plating method.

  According to a thirteenth aspect of the present invention, after the substrate is pulled up from the first processing liquid or the second processing liquid, moisture accumulated in or around the support groove is removed. 12. The electroless plating method according to 12.

  In the invention described in claim 14, the substrate is immersed in the first treatment liquid or the second treatment liquid at a dipping speed of 100 mm / second or more, and the substrate is pulled up from the first treatment liquid or the second treatment liquid. The electroless plating method according to any one of claims 11 to 13, wherein the speed is 50 mm / sec or less.

  The invention according to claim 15 is characterized in that the substrate held by the substrate holder is immersed in the first processing liquid or the second processing liquid while the substrate holder is vibrated, vertically swung or horizontally swung. The electroless plating method according to any one of claims 11 to 14.

  According to the present invention, a highly productive batch processing method is adopted, and the amount of moisture used in the previous processing or the like is reduced as much as possible, and a series of continuous processing is performed more uniformly and stably. Can do.

It is sectional drawing which shows the example of joining of a micro bump. It is sectional drawing which shows the example of a connection of TSV wiring. It is a graph which shows the relationship between the zinc substitution amount when performing a zincate process on Al surface, and processing time (second). It is a graph which shows the relationship between the aluminum etching amount when a zincate process is performed on Al surface, and processing time (second). It is sectional drawing which shows the example which forms Ni plating film and Au plating film on the surface of a bump pad by electroless plating in order of a process. It is a vertical front view which shows the outline | summary of the state when the board | substrate of the electroless-plating apparatus of embodiment of this invention is immersed in the process liquid (nitric acid) of a pre-cleaning tank. It is a vertical front view which shows the outline | summary of the state when processing the board | substrate of the electroless-plating apparatus of embodiment of this invention with a pre-cleaning module. It is a vertical front view which shows the outline | summary of the state at the time of delivering the board | substrate holder of a pre-cleaning module to the board | substrate holder of a zincate process module for the board | substrate of the electroless-plating apparatus of embodiment of this invention. It is a vertical front view which shows the outline | summary of the state when the board | substrate of the electroless-plating apparatus of embodiment of this invention is immersed in the zincate liquid of a zincate processing tank. It is a vertical front view which shows the outline | summary of the state at the time of pulling up from the zincate liquid, after immersing the board | substrate of the electroless-plating apparatus of embodiment of this invention in the zincate liquid of a zincate processing tank. It is a vertical front view which shows the outline | summary when the board | substrate of the electroless-plating apparatus of embodiment of this invention is immersed in the plating solution of Au plating tank. It is a vertical front view which shows the outline | summary when the board | substrate of the electroless-plating apparatus of embodiment of this invention is pulled up from the plating solution of Au plating tank. It is a schematic longitudinal front view which shows the pre-cleaning tank and substrate holder of a pre-cleaning module. It is a schematic sectional side view which shows the pre-cleaning tank and substrate holder of a pre-cleaning module. It is a schematic longitudinal front view which shows the water-washing tank and substrate holder of a pre-cleaning module. It is the schematic which shows the cross section which expanded a part of support rod with which the substrate holder of the pre-cleaning module was equipped with a moisture removal mechanism. (A) is the sectional view on the AA line of FIG. 16, (b) is the modification. It is the schematic which shows the cross section which expanded a part of support rod with which the substrate holder of the zincate processing module was equipped with the moisture removal mechanism. It is a block diagram which shows a series of processes by the electroless-plating apparatus. It is a principal part expanded sectional view which shows the other example of the support rod of a substrate holder. It is a principal part expanded sectional view which shows the further another example of the support rod of a substrate holder. It is a principal part expanded sectional view which shows the further another example of the support rod of a substrate holder. (A) is an external view when a series of electroless plating of the present invention is performed to sequentially form a Ni plating film and an Au plating film, and (b) to (d) are external views showing reference examples. . (A) shows an in-plane film thickness distribution diagram when a series of electroless plating of the present invention is performed on the surface of a patterned wafer having Al as a base metal to sequentially form a Ni plating film and an Au plating film. , (B) shows an external view and a cross-sectional view after the zincate treatment and after the plating treatment. (A) shows an in-plane film thickness distribution diagram when a conventional general electroless plating is performed on the surface of a patterned wafer using Al as a base metal, and a Ni plating film and an Au plating film are sequentially formed. , (B) shows an external view and a cross-sectional view after the zincate treatment and after the plating treatment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following examples, the same or corresponding members are denoted by the same reference numerals, and redundant description is omitted.

  In the following example, as shown in FIG. 5A, for example, a substrate W such as a semiconductor wafer provided with a bump pad 40 made of Al having a diameter D of several μm is prepared. Then, as shown in FIG. 5B, the surface of the substrate W is subjected to a zincate treatment as a pretreatment for plating, and a zinc plating film 42 is formed on the surface of the bump pad 40 by displacement plating. An Ni plating film 44 of 1.6 μm, for example, is formed on the surface of the film 42 by electroless plating, and an Au plating film of 0.1 μm, for example, is formed on the surface of the Ni plating film 44 by electroless plating (substitution plating). 46 is formed.

  6 to 12 are longitudinal front views showing the outline of the entire electroless plating apparatus according to the embodiment of the present invention in the order of steps. 6 to 12, this electroless plating apparatus includes a pre-cleaning module 54 having a pre-cleaning tank 50 and a water-washing tank 52, a zincate processing module 60 having a zincate processing tank 56 and a water-washing tank 58, and a Ni plating tank. 62, a Ni plating module 66 having a water rinsing tank 64, an Au plating module 72 having an Au plating tank 68 and a water rinsing tank 70, and a drying module 76 having a drying unit 74.

  The pre-cleaning module 54 is provided with a substrate holder 80 a that is movable up and down and left and right and that transports a plurality of substrates between the pre-cleaning tank 50 and the water-washing tank 52. Similarly, the zincate processing module 60 includes a substrate holder 80b, the Ni plating module 66 includes a substrate holder 80c, the Au plating module 72 includes a substrate holder 80d, and the drying module 76 includes a substrate holder 80e.

  Further, in parallel with these substrate holders 80a to 80e, a substrate holder 88 that can run along the guide 86 is provided, and a plurality of substrates are conveyed between the in-module substrate conveyance devices 84a to 84e. An inter-module substrate transfer device 90 that transfers a plurality of substrates is disposed.

  The substrate holder 80a has a dipping speed for dipping a plurality of substrates W held by the substrate holder 80a in the processing liquid in the processing tank to, for example, 100 mm / s or higher, and a pulling speed for pulling up from the processing liquid in the processing tank, for example Each of the control units is adjusted to 50 mm / s or less. Further, the substrate holder 80a further includes a moving mechanism that vibrates, vertically swings, or horizontally swings the substrate holder 80a when the substrate W held by the substrate holder 80a is immersed in the processing liquid in the processing tank. Yes. Thus, having the control unit and the moving mechanism is the same in the other substrate holders 80b, 80c, and 80d.

  The substrate holder 80a has a pair of side plates 92a disposed opposite to each other at a predetermined distance and a plurality of support bars 94a extending between the side plates 92a and supporting the outer peripheral portion of the substrate W. Similarly, the substrate holder 80b has a pair of side plates 92b and a plurality of support rods 94b, the substrate holder 80c has a pair of side plates 92c and a plurality of support rods 94c, and the substrate holder 80d has a pair of side plates 92d and a plurality of support rods. The rod 94d and the substrate holder 80e each have a pair of side plates 92e and a plurality of support rods 94e.

  In this example, it is located above the Au plating tank 68, held by the substrate holder 80d of the in-module substrate transfer device 84d, and pure toward the substrate W lifted from the processing solution (Au plating solution) of the Au plating tank 68. A pure water injection nozzle (not shown) for injecting water is disposed.

  FIG. 13 is a schematic longitudinal sectional front view showing the pre-cleaning tank 50 and the substrate holder 80a of the pre-cleaning module 54, and FIG. 14 is a schematic sectional side view. The pre-cleaning tank 50 of this example removes the oxide film on the surface of the substrate W, and further, the surface of the zinc plating film formed by displacement plating on the surface of the bump pad 40 (see FIG. 4) at the time of double zincate treatment. In order to remove it, nitric acid is used as the treatment liquid. The pre-cleaning tank 50 includes an inner tank 100 and an outer tank 102, and an overflow tank 104 is formed between the inner tank 100 and the outer tank 102. One end of a processing liquid circulation line 112 including a pump 106, a temperature regulator 108, and a filter 110 is connected to the bottom of the overflow tank 104 of the pre-cleaning tank 50. It is connected to the bottom of the tank 100. Furthermore, a rectifying plate 114 that arranges the flow of the processing liquid is disposed at the bottom of the inner tank 100.

  As a result, the processing liquid (nitric acid) in the pre-cleaning tank 50 is filtered by the filter 110 as the pump 106 is driven, and the temperature of the inner tank 100 is adjusted by the temperature regulator 108 as necessary. It circulates between the inside and the overflow tank 104. Note that the temperature of the treatment liquid (nitric acid) in the pre-cleaning tank 50 generally does not need to be adjusted (used at room temperature), so the temperature regulator 108 may be omitted.

  The zincate treatment tank 56, the Ni plating tank 62, and the Au plating tank 68 have the same configuration as that of the pre-cleaning tank 50 except for the treatment liquid. That is, in the zincate treatment tank 56, as the treatment liquid, for example, a zincate liquid having a liquid temperature of 50 ° C., for example, a sodium hydroxide-based zinc oxide-containing liquid is used. In the Ni plating tank 62, for example, a Ni plating solution having a liquid temperature of 80 ° C. is used as the processing solution. In the Au plating tank 68, for example, an Au plating solution with a liquid temperature of 75 ° C. is used as the processing solution.

  FIG. 15 is a schematic longitudinal sectional front view showing the rinsing tank 52 and the substrate holder 80 a of the pre-cleaning module 54. The washing tank 52 uses pure water as a treatment liquid. The flush tank 52 has an inner tank 120 and an outer tank 122, and an overflow tank 124 is formed between the inner tank 120 and the outer tank 122. A pure water supply line 126 is connected to the bottom of the inner tank 120, and a drainage line 128 is connected to the bottom of the overflow tank 124. As a result, the pure water supplied to the inner tank 120 through the pure water supply line 126 fills the inside of the inner tank 120, and then overflows into the overflow tank 124 and is discharged from the drain line 128. It has become. The other rinsing tanks 58, 64, and 70 have the same configuration as the rinsing tank 52.

  FIG. 16 is a schematic view showing an enlarged cross section of a part of the support bar 94a provided in the substrate holder 80a of the pre-cleaning module 54 together with a moisture removing mechanism. FIG. FIG.

  As shown in FIG. 16 and FIG. 17A, the support bar 94a has a plurality of support grooves 130 for positioning the outer periphery of the substrate W and supporting the substrate W in the vertical direction. At a predetermined pitch, for example, 5 mm pitch. Further, a central hole 132 whose one end is closed is provided inside the support rod 94a, and the central hole 132 and each support groove 130 communicate with each other through a communication hole 134a formed of a plurality of holes. A moisture removing mechanism 136 a that removes moisture accumulated in or around the support groove 130 is connected to the opening end of the central hole 132.

  The moisture removing mechanism 136a includes a pressurized gas supply line 138 that is alternatively selected at the opening end of the central hole 132 of the support rod 94a, and a liquid circulation line 140a that circulates the processing liquid through the central hole 132 in this example. have. The pressurized gas supply line 138 is connected to, for example, a pressurized gas supply source 142 that supplies high-pressure air, and an opening / closing valve 144a is interposed before joining the liquid circulation line 140a. The liquid circulation line 140a has a pump 146 and, as schematically shown, opens to the inside of a treatment tank such as the water washing tank 52, and opens and closes before joining the pressurized gas supply line 138. A valve 144b is interposed.

  As a result, the on-off valve 144b of the liquid circulation line 140a is closed and the on-off valve 144a of the pressurized gas supply line 138 is opened, whereby high-pressure gas such as air is guided into the center hole 132 of the support rod 94a, and the communication hole 134a. The moisture accumulated in and around the support groove 130 is blown off with a high-pressure gas to be removed. The removal of moisture can be performed in a state where the outer periphery of the substrate W is positioned in the support groove 130 to support the substrate W or in a state where the substrate W is not supported.

  For example, when the substrate W held by the substrate holder 80a is immersed in the processing liquid (pure water) in the rinsing tank 52 and the substrate W is subjected to the rinsing process, the on-off valve 144b of the liquid circulation line 140a is opened, The on-off valve 144a of the pressurized gas supply line 138 is closed. Thereby, the processing liquid (pure water) in the washing tank 52 is returned to the washing tank 52 through the central hole 132 of the support rod 94a and circulated. Thereby, the processing liquid (pure water) in the water rinsing tank 52 circulates through the communication hole 134a through the central hole 132, and the communication hole 134a and the central hole 132 can be cleaned.

  In the above example, as shown in FIG. 17A, the central hole 132 and the support groove 130 of the support rod 94a of the substrate holder 80a are communicated with each other through the communication hole 134a formed of a plurality of holes. As shown in FIG. 17B, the central hole 132 of the support rod 94a and the support groove 130 may be communicated with each other through a slit-shaped communication hole 134b that expands in a fan shape. The same applies to the support rods 94b to 94d of the other substrate holders 80b to 80d. The communication hole 134a may be omitted so that the support groove 130 communicates directly with the central hole 132.

  FIG. 18 is a schematic diagram showing an enlarged cross section of a part of the support bar 94b provided in the substrate holder 80b of the zincate processing module 60 together with the moisture removing mechanism. As shown in FIG. 18, the support rod 94b is provided with a plurality of support grooves 130 for supporting the substrate W in the vertical direction by positioning the outer peripheral portion of the substrate W, similar to the support rod 94a described above. The support groove 130 communicates with each other through a central hole 132 provided at one end and a communication hole 134a including a plurality of holes provided inside the support rod 94b. A moisture removal mechanism 136b that removes moisture accumulated in or around the support groove 130 is connected to the opening end of the central hole 132.

The moisture removal mechanism 136b has a moisture suction line 150 that is alternatively selected at the opening end of the central hole 132 of the support rod 94b, and in this example, a liquid intrusion prevention line 140b including a pressurized fluid supply line. ing. The moisture suction line 150 is connected to a moisture suction source 152 such as a vacuum pump, for example, and an opening / closing valve 144c is interposed before joining the liquid intrusion prevention line (pressurized fluid supply line) 140b. The liquid intrusion prevention line 140 _b is connected to a fluid supply source 154 that pressurizes and supplies a gas such as N ₂ gas or air, or a liquid such as pure water, and the opening and closing valve 144 d is connected to the moisture suction line 150. It is intervened.

  As a result, the on / off valve 144d of the liquid intrusion prevention line 140b is closed and the on / off valve 144c of the moisture suction line 150 is opened to pass through the central hole 132 and the communication hole 134a of the support rod 94b to the inside or the periphery of the support groove 130. Remove the accumulated water by suction. Note that the moisture removal is performed in the state where the outer periphery of the substrate W is positioned in the support groove 130 to support the substrate W, or in the state where the substrate W is not supported, as described above. Can do. Moisture (zincate treatment liquid) sucked through the moisture suction line 150 is configured to return to the zincate treatment tank 56.

For example, when the substrate W held by the substrate holder 80b is immersed in the processing solution (zincate solution) in the zincate processing tank 56 to perform the zincate processing of the substrate W, the opening / closing valve 144d of the liquid intrusion prevention line 140b is opened. The on-off valve 144b of the moisture suction line 150 is closed. As a result, a gas such as N ₂ gas or air is ejected toward the support groove 130 through the central hole 132 and the communication hole 134a of the support rod 94b. Thereby, it can prevent that the process liquid (zincate liquid) in the zincate processing tank 56 permeates into the center hole 132 from the communication hole 134a. Since the communication hole 134a and the central hole 132 are thin pipes, it is desirable to prevent the treatment liquid from entering as little as possible in order to prevent deposition of the treatment liquid inside the pipe.

  The support rod 94c of the substrate holder 80c of the Ni plating module 66 and the support rod 94d of the substrate holder 80d of the Au plating module 72 are also provided with a plurality of support grooves 130, similar to the support rod 94a. The support groove 130 is communicated with each other by a central hole 132 provided at one end and a communication hole 134a including a plurality of holes provided inside the support rod 94a. The opening end of the central hole 132 is connected to a moisture removal mechanism 136b having the same configuration as described above, which has a moisture suction line 150 and a liquid intrusion prevention line 140b composed of a pressurized fluid supply line.

  Next, a series of processes by the electroless plating apparatus of this example will be described with reference to FIGS. 6 to 12 and FIG.

  First, as shown in FIG. 6, the substrate holder 80 a of the pre-cleaning module 54 simultaneously receives a plurality of substrates W from the substrate holder 88 of the inter-module substrate transport apparatus 90 and holds them in the vertical direction. At this time, the substrate holder 80a is positioned immediately above the pre-cleaning tank 50, and the outer peripheral portion of each substrate W is positioned inside the support groove 130 of the support rod 94a, whereby the substrate W is arranged at a predetermined pitch. Aligned and held by the substrate holder 80a.

  Then, the substrate holder 80a is lowered, and the plurality of substrates W held by the substrate holder 80a are immersed in the processing liquid (nitric acid) in the pre-cleaning tank 50 for, for example, 1 minute, whereby the surface of the substrate W is The oxide film is removed. In this way, when the substrate W is immersed in the processing liquid (nitric acid), the liquid circulation line 140a is opened by opening the on-off valve 144b of the liquid circulation line 140a and closing the on-off valve 144a of the pressurized gas supply line 138. The treatment liquid (nitric acid) may be sucked from the communication hole 134 a and returned to the pre-cleaning tank 50. The same applies to the following.

  Next, as shown in FIG. 7, the plurality of substrates W held by the substrate holder 80 a are pulled up from the treatment liquid (nitric acid) in the pre-cleaning tank 50 and moved directly above the washing tank 52. Then, the substrate holder 80a is lowered, and the plurality of substrates W held by the substrate holder 80a are immersed in the treatment liquid (pure water) in the washing tank 52, for example, for 5 minutes. Wash with water. As described above, while the surface of the substrate W is washed with water, the processing liquid (pure water) in the washing tank 52 is circulated from the communication hole 134a through the central hole 132, and the communication hole 134a and the central hole 132 are circulated. The inside may be washed. Thereafter, the plurality of substrates W held by the substrate holder 80a are pulled up from the processing liquid (pure water) in the washing tank 52 at a pulling speed adjusted to, for example, 50 mm / s or less. Thus, by adjusting the pulling speed to, for example, 50 mm / s or less, it is possible to prevent a large amount of processing liquid (pure water) from remaining on the surface of the substrate W.

  In this way, after the substrate W is lifted from the processing liquid (pure water), the on-off valve 144b of the liquid circulation line 140a is closed and the on-off valve 144a of the pressurized gas supply line 138 is opened, so that high-pressure gas such as air is supplied. It guide | induces to the inside of the center hole 132 of the support rod 94a, it is made to eject toward the support groove 130 through the communicating hole 134a, and, thereby, the water collected in the support groove 130 thru | or its periphery is blown off with a high pressure gas and removed. Since the blown-off water mainly returns into the washing tank 52, the amount of water taken out is reduced as a result. In addition, since the water accumulated at the lower end of the substrate can be removed appropriately, adverse effects caused by mixing the water and the zincate liquid in the next zincate treatment can be reduced.

  Next, as shown in FIG. 8, the plurality of substrates W held in the vertical direction by the substrate holder 80 a of the pre-cleaning module 54 are passed through the substrate holder 88 of the inter-module substrate transfer device 90, and then the zincate processing module. 60 to the substrate holder 80b. The substrate holder 80 b is located immediately above the zincate processing tank 56. Further, before holding the plurality of substrates W, the on / off valve 144d of the liquid intrusion prevention line 140b is closed and the on / off valve 144c of the moisture suction line 150 is opened, so that the through hole 132a and the communication hole 134a of the support rod 94b are opened. The water accumulated in or around the support groove 130 is previously removed by suction.

  Next, as shown in FIG. 9, the substrate holder 80 b is lowered, and a plurality of substrates W held by the substrate holder 80 b are immersed in the processing liquid (zincate liquid) in the zincate processing tank 56 for 30 seconds, for example. Thus, the first zincate process is performed on the surface of the bump pad 40 made of Al (see FIG. 5). Thus, when the substrate W is immersed in the processing liquid (zincate liquid), the on-off valve 144d of the liquid intrusion prevention line 140b is opened, and the on-off valve 144c of the moisture suction line 150 is closed. As a result, the treatment liquid in the zincate treatment tank 56 is prevented from entering the central hole 132 from the communication hole 134a. The same applies to the following.

  The immersion speed when the substrate W held by the substrate holder 80b is immersed in the processing liquid (zincate liquid) in the zincate processing tank 56 is adjusted to 100 mm / s or more, for example. Thus, by adjusting the immersion speed to, for example, 100 mm / s or more, the time required to completely immerse the substrate W from the lower end to the upper end in the processing liquid (zincate processing liquid) can be reduced. . When the substrate W is immersed in the processing liquid (zincate liquid), it is preferable that the substrate holder 80b is vibrated, vertically oscillated, or horizontally oscillated via a moving mechanism. By these, diffusion of the processing liquid on the substrate surface can be promoted.

  Next, as shown in FIG. 10, the plurality of substrates W held by the substrate holder 80b are pulled up from the processing solution (zincate solution) in the zincate processing tank 56 at a pulling speed adjusted to, for example, 50 mm / s or less. . In this way, by adjusting the pulling speed to, for example, 50 mm / s or less, a large amount of processing liquid (zincate liquid) remains on the surface of the substrate W, the processing becomes uneven, or the processing liquid is taken out to the outside. It is possible to prevent the amount from increasing.

  As described above, after the substrate W is lifted from the processing liquid (zincate liquid), the on-off valve 144c of the liquid intrusion prevention line 140b is closed, and the on-off valve 144c of the moisture suction line 150 is opened, whereby the center hole 132 of the support rod 94b is opened. Then, water (zincate liquid) accumulated in or around the support groove 130 is removed by suction through the communication hole 134a. Thus, the amount of moisture (zincate solution) taken out to the outside can be minimized by sucking and removing the moisture (zincate solution) and reusing it.

  Next, almost in the same manner as described above, the plurality of substrates W held by the substrate holder 80 b are moved directly above the washing tank 58. Then, the substrate holder 80b is lowered, and the plurality of substrates W held by the substrate holder 80b are immersed in the processing liquid (pure water) in the washing bath 58 for, for example, 1 minute, thereby making the surface of the substrate W Wash with water. At this time, the processing liquid (pure water) may be ejected through the liquid intrusion prevention line 140b to clean the inside of the pipe. Thereafter, the plurality of substrates W held by the substrate holder 80b are pulled up from the processing liquid (pure water) in the washing tank 56.

  This cycle is repeated twice, with the substrate immersed in nitric acid and then washed with water, and immersed in the zincate solution and then washed with water, whereby a so-called double zincate treatment is performed. In this way, by performing the double zincate treatment, the zinc (zinc plating film) roughly applied to the surface of the bump pad 40 made of Al (see FIG. 5) by the first zincate treatment is removed with nitric acid. Thereafter, the surface of the bump pad 40 can be finely replaced with zinc by the second zincate treatment. Thereby, a galvanized film 42 shown in FIG. 5B is formed.

  Next, the substrate after the double zincate treatment is transferred to the substrate holder 80 c of the Ni plating module 66 via the substrate holder 88 of the inter-module substrate transfer device 90. Then, in substantially the same manner as the above-described zincate treatment, the plurality of substrates held in the vertical direction by the substrate holder 80c are placed in a treatment liquid (Ni plating liquid) having a liquid temperature of 80 ° C. in the Ni plating tank 62, for example. For example, the substrate is immersed for 50 minutes, and then the Ni-plated substrate is immersed in a treatment solution (pure water) in the washing bath 64 for 5 minutes, for example, and washed. Thereby, the Ni plating film 44 shown in FIG. 5B is formed.

  Next, the substrate after Ni plating is transferred to the substrate holder 80 d of the Au plating module 72 via the substrate holder 88 of the inter-module substrate transfer device 90. As in the above-described zincate process, as shown in FIG. 11, the plurality of substrates held in the vertical direction by lowering the substrate holder 80d and holding the substrate holder 80d in the vertical direction in the Au plating tank 68, for example, For example, the substrate is immersed in a treatment solution (Au plating solution) having a temperature of 75 ° C. for 10 minutes. Thereby, an Au plating film 46 shown in FIG. 5B is formed.

  Then, as in the above-described zincate process, as shown in FIG. 12, the plurality of substrates W held by the substrate holder 80d are placed in the Au plating tank 68 at a pulling speed adjusted to, for example, 50 mm / s or less. After pulling up from the processing solution (Au plating solution), the water ((Au plating solution) accumulated in or around the support groove 130 is removed by suction, and then directed toward the plurality of substrates W held by the substrate holder 80d. Then, pure water is jetted from the pure water jet nozzle, whereby the water (Au plating solution) adhering to the substrate W or the like is washed away with pure water and returned to the Au plating tank 68. The amount of pure water jetted at this time Is an amount commensurate with the amount of pure water reduced by, for example, processing the substrate, thereby further reducing the amount of generally taken-out Au plating solution to the outside.

  A pure water spray nozzle is disposed above the Ni plating tank 62 so that the Ni plating solution adhering to the substrate after Ni plating is washed away with pure water sprayed from the pure water spray nozzle and returned to the Ni plating tank 62. Anyway.

  And the board | substrate after Au plating is immersed in the process liquid (pure water) in the water-washing tank 80 for 5 minutes, for example, like the above-mentioned zincate process, and is washed with water.

  Next, the substrate after Au plating is delivered to the substrate holder 80e of the drying module 76 via the substrate holder 88 of the inter-module substrate transfer apparatus 90. Then, the plurality of substrates W held in the vertical direction by the substrate holder 80e are dried by the drying module 84 by, for example, a drying method using air blow or IPA (isopropyl alcohol) vapor.

  The substrate holder 88 of the inter-module substrate transport apparatus 90 receives the dried substrate W from the substrate holder 80e and transports it to the next process. This completes a series of electroless plating processes.

  As shown in FIG. 20, when supporting a plurality of substrates W in the same direction with the support rod 94 a of the substrate holder 80 a so that the surface Wa to be plated faces in a certain direction, The central hole 132 and the support groove 130 may communicate with each other through a communication hole 134c opened in one direction so as to face the surface Wa to be plated.

  In addition, as shown in FIG. 21, when a plurality of substrates W are supported by the support rod 94a of the substrate holder 80a in different directions so that the surfaces to be plated Wa face each other, The central hole 132 and the support groove 130 may communicate with each other through a communication hole 134d opened in a Y shape so as to face the plating surface Wa. In this case, as shown in FIG. 22, another communication hole 134e opened in a Y shape so as to face the back surface of the substrate W may be provided.

  The same applies to the support rods 94b to 94e of the other substrate holders 80b to 80e.

  Next, the above-described series of electroless plating is performed on the surface of the solid wafer using 1 μm Al as the base metal, and the 6 μm Ni plating film and the 0.1 μm Au plating film are sequentially formed. An external view when formed is shown in FIG.

  FIG. 23B shows a case where a 6 μm Ni plating film and a 0.1 μm Au plating film are sequentially formed on the surface of a solid wafer using 1 μm Al as a base metal by conventional general electroless plating. The external view is shown for reference. Further, FIG. 23 (c) shows that after a substrate washed with pure water is pulled up from pure water at a speed of 50 mm / s or less, it is immersed in a zincate solution at a soaking speed of 100 mm / s or more to perform a zincate treatment. 23 (d), when the substrate is immersed in the zincate solution, the substrate is further vibrated or swung. Otherwise, the conventional general electroless plating is used to form a 6 μm Ni plating film as described above. The external view when 0.1 micrometer Au plating film is formed in order is shown.

  From FIG. 23, a substrate washed with pure water is pulled up from pure water at a speed of 50 mm / s or less, and then immersed in a zincate solution at a soaking speed of 100 mm / s or more to perform a zincate treatment, whereby a spotty appearance is obtained. Further, the substrate is immersed in a zincate solution while vibrating or swinging, and further, the water is collected in or around the support groove for supporting the substrate by positioning the outer peripheral portion. It can be seen that the appearance is improved.

  FIG. 24A shows a 6 μm Ni plating film obtained by performing the above series of electroless plating using the above electroless plating apparatus on the surface of a patterned wafer using 1 μm Al as a base metal (bump pad). FIG. 24B shows an in-plane distribution diagram of the film thickness when the 0.1 μm Au plating film is sequentially formed, and FIG. 24B shows an external view and a cross-sectional view after the zincate treatment and after the plating treatment.

  In FIG. 25A, a conventional general electroless plating is performed on the surface of a patterned wafer using 1 μm of Al as a base metal (bump pad) to obtain a 6 μm Ni plating film and a 0.1 μm Au film. FIG. 25B shows an external view and a cross-sectional view after the zincate treatment and after the plating treatment.

  From FIG. 24 and FIG. 25, it can be seen that the variation in the in-plane distribution of the film thickness is reduced in the pattern wafer. This is considered to be due to the optimization and homogenization of the zinc substitution amount. At the same time, it can be seen that the roughness on the bump pad is reduced and the damage of the bump pad itself is reduced.

  In the above example, the moisture removal mechanism 136a having the pressurized gas supply line 138 and the liquid circulation line 140a for circulating the processing liquid through the central hole 132 is used as the moisture removal mechanism 136b. Although an example using a liquid intrusion prevention line 140b composed of a pressurized fluid supply line is shown, one of a pressurized gas supply line and a moisture suction line, one of a liquid circulation line and a pressurized fluid supply line The water removal mechanism may be configured by arbitrarily combining the above.

  Although one embodiment of the present invention has been described so far, it is needless to say that the present invention is not limited to the above-described embodiment, and may be implemented in various forms within the scope of the technical idea.

40 Bump pad 42 Zinc plating film 44 Ni plating film 46 Au plating film 50 Pre-cleaning tank 52, 58, 64, 70 Water-washing tank 54 Pre-cleaning module 56 Zincate processing tank 60 Zincate processing module 62 Ni plating tank 66 Ni plating module 68 Au Plating tank 72 Au plating module 74 Drying unit 76 Drying modules 80a to 80e Substrate holder 88 Substrate holder 90 Inter-module substrate transfer device 92a to 92e Side plates 94a to 94e Support rod 108 Temperature controller 110 Filter 112 Treatment liquid circulation line 130 Support groove 132 Central holes 134a to 134e Communication holes 136a and 136b Moisture removal mechanism 138 Pressurized gas supply line 140a Liquid circulation line 140b Liquid intrusion prevention line 142 Pressurized gas supply sources 144a to 144d Open / close valve 150 Water Suction line 152 water suction source 154 fluid source

Claims (15)

In an electroless plating apparatus having a substrate holder that holds a plurality of substrates in parallel in the vertical direction and has a substrate holder that simultaneously immerses the plurality of substrates in a processing solution in different processing tanks before and after the transfer
The substrate holder has a support rod having a plurality of support grooves for supporting the substrate by positioning an outer peripheral portion of the substrate, and a moisture removing mechanism for removing moisture accumulated in or around the support groove. Electroless plating equipment.   The moisture removal mechanism has a pressurized gas supply line and a liquid intrusion prevention line that are selectively connected to an opening end of a central hole that is closed at one end provided inside the support rod, The electroless plating apparatus according to claim 1, wherein the inside of the support groove communicates with each other through a communication hole.   The moisture removal mechanism has a moisture suction line and a liquid intrusion prevention line that are selectively connected to an open end of a central hole that is closed at one end provided in the support rod, and the central hole and the support 2. An electroless plating apparatus according to claim 1, wherein the inside of the groove communicates with each other through a communication hole.   The electroless plating apparatus according to claim 1, further comprising a liquid circulation line for circulating a treatment liquid in the treatment tank in which the substrate held by the substrate holder is immersed.   4. The electroless plating apparatus according to claim 2, wherein the liquid intrusion prevention line is a pressurized fluid supply line that supplies a pressurized fluid into the central hole.   The electroless plating apparatus according to any one of claims 1 to 5, wherein the communication hole is opened toward a surface to be plated of a substrate held by a substrate holder.   2. The apparatus according to claim 1, further comprising a control unit that adjusts an immersion speed for immersing the substrate held by the substrate holder in a processing liquid in the processing tank and a pulling speed for lifting the substrate from the processing liquid in the processing tank. The electroless plating apparatus according to claim 6.   The electroless plating apparatus according to claim 7, wherein the immersion speed is 100 mm / s or more and the pulling speed is 50 mm / s or less.   2. The apparatus according to claim 1, further comprising a moving mechanism that vibrates, vertically swings, or swings left and right when the substrate held by the substrate holder is immersed in a processing solution in the processing tank. The electroless plating apparatus according to claim 7.   The apparatus further comprises a pure water injection mechanism for injecting pure water toward the substrate after the substrate held by the substrate holder is dipped in the treatment liquid in the treatment tank and pulled up from the treatment liquid. The electroless plating apparatus according to any one of 1 to 9. A plurality of substrates are held in parallel in the vertical direction with a substrate holder by positioning the outer periphery of the substrate in a plurality of support grooves provided on the support rod,
The substrate held by the substrate holder is immersed in the first treatment liquid in the first treatment tank and pulled up from the first treatment liquid,
Transport the substrate holder holding the substrate directly above the second processing tank,
An electroless plating method in which a substrate held by a substrate holder is immersed in a second processing solution in a second processing tank and pulled up from the second processing solution,
An electroless plating method characterized by removing moisture accumulated in or around the support groove before or after the treatment or during the treatment.   12. The electroless plating method according to claim 11, wherein moisture accumulated in or around the support groove is removed before the plurality of substrates are held parallel to the vertical direction by the substrate holder.   13. The electroless plating method according to claim 11, wherein after the substrate is pulled up from the first treatment liquid or the second treatment liquid, moisture accumulated in or around the support groove is removed.   The immersion speed for immersing the substrate in the first treatment liquid or the second treatment liquid is 100 mm / second or more, and the pulling speed for lifting the substrate from the first treatment liquid or the second treatment liquid is 50 mm / second or less. The electroless plating method according to claim 11, wherein:   The substrate held by the substrate holder is immersed in the first processing liquid or the second processing liquid while the substrate holder is vibrated, vertically swung or horizontally swung. The electroless plating method according to claim 1.

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