JP2008095157A - Plating device and plating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plating device and a plating method where, even in the case a seed layer is thin-filmed, thus the sheet resistance value of the seed layer reaches ≥10 Ω/sq., or plating is directly performed on the surface of a barrier layer whose electric resistance is extremely high, heat generation in a cathode contact as a power feed part to a substrate and the peripheral parts thereof can be prevented. <P>SOLUTION: The plating device comprises: a substrate holder 36 for holding a substrate W; a cathode part 38 provided with a cathode contact 44 contacted with the substrate W held by the substrate holder 36 and energizing the same, and rotating integrally with the substrate holder 36; an anode 66 arranged so as to face the surface of the substrate W; and a cooling mechanism 58 for cooling the cathode contact 44. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a plating apparatus and a plating method, and more particularly, to form a buried wiring by embedding a conductor (wiring material) such as copper or silver in a wiring recess provided on the surface of a substrate such as a semiconductor wafer. The present invention relates to a plating apparatus and a plating method used.

  In recent years, as a metal material for forming a wiring circuit on a semiconductor substrate, a movement of using copper (Cu) having a low electrical resistivity and a high electromigration resistance instead of aluminum or an aluminum alloy has become prominent. This type of copper wiring is generally formed by embedding copper in a fine wiring recess provided on the surface of the substrate. As a method of forming this copper wiring, there are methods such as CVD, sputtering, and plating. In any case, copper is formed on almost the entire surface of the substrate, and unnecessary copper is formed by chemical mechanical polishing (CMP). To be removed.

FIG. 1 shows a manufacturing example of this type of copper wiring board W in the order of steps. First, as shown in FIG. 1A, an insulating film 2 such as an oxide film made of SiO ₂ or a low-k material film is deposited on a conductive layer 1a on a semiconductor substrate 1 on which a semiconductor element is formed. Inside the insulating film 2, a contact hole 3 and a trench 4 are formed as wiring recesses by lithography and etching techniques. A barrier layer 5 made of Ta, TaN, TiN, WN, SiTiN, CoWP, CoWB, or the like is formed thereon, and a seed layer 7 is formed thereon as a power supply layer for electrolytic plating.

  Then, as shown in FIG. 1B, the surface of the seed layer 7 of the substrate W is plated with copper so that the contact holes 3 and the trenches 4 are filled with copper, and the copper film 6 is formed on the insulating film 2. To deposit. Thereafter, the copper film 6, the seed layer 7 and the barrier layer 5 on the insulating film 2 are removed by chemical mechanical polishing (CMP) to insulate the surface of the copper film 6 filled in the contact hole 3 and the trench 4 from each other. The surface of the film 2 is substantially flush with the surface. Thereby, as shown in FIG. 1C, a wiring made of the copper film 6 is formed inside the insulating film 2.

  As the electric circuit pattern of a semiconductor device is increasingly miniaturized, the seed layer used as a power feeding layer when the wiring is formed by plating is also becoming thinner. Furthermore, development of direct plating that directly performs plating on the surface of the barrier layer without forming a seed layer is also progressing. As the seed layer becomes thinner, the electrical resistance (sheet resistance) of the seed layer increases. Further, when direct plating is performed, the electrical resistance (sheet resistance) of the barrier layer becomes extremely large.

  Thus, when the electrical resistance of the seed layer increases, it becomes difficult for electricity to flow to the center of the substrate, and there is a problem with the so-called terminal effect that causes an extreme difference in the plating amount between the outer periphery and the center of the substrate. In addition to this, problems such as increased power consumption due to increased electrical resistance and increased heat generation occur. In particular, in the contact portion of the cathode contact that contacts the seed layer and supplies electricity, the contact area between the cathode contact and the seed layer is small, and the cathode contact itself is suppressed to a fairly compact shape. As a result, the resistance increases, and the cathode contact and its peripheral parts are deformed, melted, burnt, or burnt due to heat generated from the cathode contact and the contact portion of the cathode contact with the seed layer. There is a problem.

  In general, many plating mechanisms employ a mechanism in which the contact portion between the cathode contact and the seed layer and the vicinity thereof do not touch the plating solution. Therefore, no plating film is deposited on the surface of the seed layer in the contact portion with the cathode contact and the vicinity thereof, and the resistance of the seed layer in the contact portion with the cathode contact and the vicinity thereof remains high. For this reason, the heat generation from the seed layer (substrate) in the vicinity of the contact portion with the cathode contact also causes deformation and breakage of parts around the cathode contact including the cathode contact. Such a problem becomes particularly prominent when the resistance value (sheet resistance value) of the seed layer exceeds 10Ω / □.

  The present invention has been made in view of the above circumstances, and the seed layer is thinned, the sheet resistance value of the seed layer is 10 Ω / □ or more, or the surface of the barrier layer having an extremely large electric resistance is directly plated. It is an object of the present invention to provide a plating apparatus and a plating method capable of protecting a cathode contact serving as a power feeding portion to a substrate and its peripheral components from heat generation even when the operation is performed.

The invention according to claim 1 includes a substrate holder that holds a substrate, a cathode contact that contacts and energizes the substrate held by the substrate holder, and a cathode portion that rotates integrally with the substrate holder; and a surface of the substrate And a cooling mechanism for cooling the cathode contact. The plating apparatus is characterized in that:
In this way, the cathode contact for supplying electricity to the substrate surface such as the seed layer is cooled by the cooling mechanism, thereby suppressing the heat generation from the cathode contact, the contact portion between the cathode contact and the substrate and the vicinity thereof, and the cathode contact. In addition, it is possible to prevent damage such as deformation and melting due to heat of the peripheral components.

The invention according to claim 2 is the plating apparatus according to claim 1, wherein the cooling mechanism cools the cathode contact by bringing a fluid as a refrigerant into contact with the cathode contact.
Examples of the method for cooling the cathode contact by bringing the fluid as a refrigerant into contact with the cathode contact include a spray method and a heat exchange method.

The invention according to claim 3 is the plating apparatus according to claim 2, wherein the fluid is a conductive or insulating liquid.
When cooling a cathode contact by injecting a fluid as a coolant toward the cathode contact, a current path that flows from the cathode contact through the conductive liquid to the substrate is created by using a conductive liquid as the coolant. As a result, it is possible to supply the current to the substrate more uniformly as compared with the case where electricity flows in a concentrated manner at the contact portion between the normal cathode contact and the substrate. In another aspect, when an insulating liquid is used as the coolant, it prevents the leakage current path from being formed unintentionally by contacting the peripheral components of the cathode contact when the coolant flows down after cooling the cathode contact. be able to. An example of the insulating liquid is pure water.

The invention according to claim 4 is the plating apparatus according to claim 2, wherein the fluid is gas, air, or an inert gas.
When the cathode contact is cooled by injecting a fluid as a coolant toward the cathode contact, current leakage due to the coolant can be eliminated by using a gas as the coolant. In such a case, by using air as a refrigerant, the refrigerant can be supplied inexpensively and easily without giving a danger of suffocation to surrounding people during discharge (exhaust). By using an inert gas, it is possible to prevent corrosion of the cathode contact and its peripheral parts due to the refrigerant.

The invention according to claim 5 is characterized in that the cooling mechanism has a fluid channel through which the fluid flows, and the fluid channel is provided inside or around the cathode contact. The plating apparatus according to any one of 2 to 4.
As a result, the heat generating part such as the cathode contact can be efficiently cooled with the refrigerant while easily collecting the refrigerant after cooling or circulating the cooled refrigerant easily. When the refrigerant touches, there is a risk of current leakage, for example, it is possible to prevent the refrigerant from touching a metal part or the like.

The invention according to claim 6 is the plating apparatus according to any one of claims 1 to 5, wherein the cathode contact is in contact with the outer peripheral portion of the substrate over the entire circumference of the outer peripheral portion. is there.
As a result, the contact area between the cathode contact and the substrate is widened to reduce the electrical resistance of the contact portion, and even when a high current is passed through the substrate at a high voltage, heat generation at the cathode contact and its vicinity is suppressed. be able to. In particular, by using a cathode contact that is crushed like an O-ring, the contact area between the cathode contact and the substrate can be significantly increased, and abnormal heat generation can be prevented.

  The invention according to claim 7 is characterized in that the cathode contact is made of metal, conductive rubber, conductive resin, conductive polymer, or rubber or resin having a metal coating on the surface. It is a plating apparatus in any one of Claims 1 thru | or 6.

  By making the cathode contact made of metal, it is possible to reduce heat generation from the material itself even if the resistance is small and the size is small. Also, the cathode contact is made of conductive rubber, conductive resin, conductive polymer, or rubber or resin with a metal coating on the surface, so that the cathode contact is flexible and the cathode contact is made by the substrate. The contact area between the cathode contact and the substrate can be increased, and heat generation can be suppressed from the cathode contact and its vicinity.

  According to an eighth aspect of the present invention, a plating solution is filled between a substrate surface which is a cathode with a cathode contact brought into contact with an outer peripheral portion and an anode disposed so as to face the surface, and the cathode contact is cooled with a coolant. However, the plating method is characterized in that a voltage is applied between the substrate surface and the anode to perform plating on the substrate surface.

  According to the present invention, particularly when plating is directly performed on the surface of a seed layer having a sheet resistance value of 10 Ω / □ or more, or on the surface of a barrier layer having an extremely high sheet resistance, heat generation from the cathode contact and the vicinity thereof is suppressed. Thus, the cathode contact and its peripheral parts can be prevented from being damaged by heat.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, as shown in FIG. 1, the surface of a seed layer 7 as a conductive film formed on the surface of a substrate W is plated with copper, and a contact hole 3, a trench 4, etc. provided in the insulating film 2. An example is shown in which copper is buried in the wiring recess to form a wiring made of copper. In the present invention, when the seed layer 7 is thin and the resistance value (sheet resistance value) of the sheet layer 7 is 10Ω / □ or more, or without providing the seed layer 7, the surface of the barrier layer 5 is directly plated. It is especially effective at times.
In the following examples, the same or corresponding members are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 2 shows an overall layout of the substrate processing apparatus provided with the plating apparatus according to the embodiment of the present invention. As shown in FIG. 2, in this substrate processing apparatus, two load / unload units 10 that house a plurality of substrates W are located in the same facility, and a plating process and an accompanying process are performed. Two plating apparatuses 12, a transfer robot 14 for delivering the substrate W between the load / unload unit 10 and the plating apparatus 12, and a plating solution supply facility 18 having a plating solution tank 16 are provided.

  As shown in FIG. 3, the plating apparatus 12 includes a substrate processing unit 20 that performs a plating process and an incidental process thereof, and a plating solution tray 22 that stores a plating solution is disposed adjacent to the substrate processing unit 20. ing. Further, an electrode arm portion 30 having an electrode head 28 that is held at the tip of a swing arm 26 that swings about the rotation shaft 24 and swings between the substrate processing unit 20 and the plating solution tray 22 is provided. Yes. Further, a precoat / recovery arm 32 and a fixed nozzle 34 for injecting a chemical solution such as pure water or ionic water, gas, or the like toward the substrate are disposed on the side of the substrate processing unit 20. In this embodiment, three fixed nozzles 34 are provided, and one of them is used for supplying pure water.

  As shown in FIG. 4, the substrate processing unit 20 has a surface (to-be-plated surface) on which the seed layer 7 (see FIG. 1 (a)) is formed upward (face-up) so that the back surface of the substrate W is attracted or the like. A substrate holder 36 that is detachably held and is movable up and down, and a cathode portion 38 that is disposed so as to surround a peripheral portion of the substrate holder 36 are provided. The substrate holder 36 rotates integrally with the cathode portion 38 at an arbitrary acceleration and speed. A substrate carry-in / out port (not shown) is provided on the side of the frame of the plating apparatus 12 on the side of the transfer robot 14.

  The plating solution tray 22 is used to wet the following high-resistance structure 62 and the anode 66 of the electrode arm 30 with the plating solution when the plating process is not being performed, and can accommodate the high-resistance structure 62. It is set to a size and has a plating solution supply port and a plating solution drain port (not shown). In addition, a photo sensor is attached to the plating solution tray 22 so that the plating solution in the plating solution tray 22 is fully filled, that is, overflow and drainage can be detected.

  The electrode arm unit 30 moves up and down through a vertical movement motor and a ball screw, which are not shown, and rotates (swings) between the plating solution tray 22 and the substrate processing unit 20 through a turning motor. .

  The precoat / recovery arm 32 is connected to the upper end of a support shaft extending in the vertical direction, pivots (swings) via a rotary actuator (not shown), and moves up and down via an air cylinder (not shown). . The precoat / collection arm includes a precoat nozzle (not shown) for discharging a precoat liquid intermittently and a plating solution recovery nozzle (not shown) for sucking and collecting the plating liquid on the substrate. Are held respectively.

  As shown in FIGS. 6 and 7, the cathode portion 38 is attached to an upper portion of a column 42 erected on the peripheral portion of the support plate 40. In this example, the cathode contact 44 is divided into six parts, and the cathode contact 44 An annular frame 48 is interposed between the cathode contact 44 and the seal portion 46. The ring-shaped seal portion 46 is disposed so as to cover the upper portion. The seal portion 46 is configured such that an inner peripheral edge portion thereof is inclined downward inward and gradually becomes thin, and an inner peripheral end portion thereof hangs downward. The cathode contact 44 is formed in a comb shape in which a plurality of teeth having spring properties are integrally connected to the inner peripheral portion, and the tip of the comb-shaped teeth comes into pressure contact with the seed layer 7 of the substrate W. Yes.

  Thus, when the substrate W held by the substrate holder 36 is raised, the cathode contact 44 comes into contact with the outer peripheral portion of the seed layer 7 formed on the surface of the substrate W, and power is supplied so that the seed layer 7 becomes a cathode. It becomes possible. At the same time, the inner peripheral end of the seal portion 46 is pressed against the upper surface of the peripheral edge of the substrate W, and this is sealed in a watertight manner, so that the plating solution supplied to the upper surface (surface to be plated) of the substrate W is the end of the substrate W. , And prevents the plating solution from contaminating the cathode contact 44.

  A pure water (refrigerant) injection nozzle 52 is located near the cathode contact 44 and injects pure water 50 as a refrigerant toward the cathode contact 44 and cools the cathode contact 44 and its vicinity with pure water (refrigerant) 50. Has been placed. In this example, as shown in FIG. 5, a total of four pure water (refrigerant) injection nozzles 52 are arranged outside the cathode contact 44. The number of pure water (refrigerant) injection nozzles 52 is as follows. It is determined arbitrarily. As shown in FIG. 4, each of the pure water (refrigerant) injection nozzles 52 is connected to a pipe 56 extending from the chiller 54, thereby constituting a cooling mechanism 58 for the cathode contact 44.

  In this example, pure water 50, which is an insulating liquid, is used as the refrigerant. Thereby, when the pure water (refrigerant) 50 flows down after cooling the cathode contact 44, it is possible to prevent an unintended current leakage path from being created by contacting the peripheral components of the cathode contact 44. If there is no possibility that such an electric leakage path is created, a conductive liquid may be used as the refrigerant, whereby the cathode contact 44 passes through the refrigerant (conductive liquid) to the seed layer 7 of the substrate. A current path that flows can be created, and the current is supplied more uniformly to the seed layer 7 of the substrate as compared with the case where electricity is concentrated and flows at the contact portion between the normal cathode contact 44 and the seed layer 7 of the substrate. be able to.

  As the refrigerant, gas, air, or an inert gas may be used instead of the pure water 50. By using gas as the refrigerant, current leakage due to the refrigerant can be eliminated. By using air as the refrigerant, the refrigerant can be supplied cheaply and easily without risking suffocation to the surrounding people during discharge (exhaust), and an inert gas is used as the refrigerant. By doing so, it is possible to prevent the cathode contact and its peripheral parts from being corroded by the refrigerant.

  In this embodiment, the cathode portion 38 cannot move up and down and rotates integrally with the substrate holder 36. However, the cathode portion 44 and the seal portion 46 can be moved vertically when the cathode contact 38 is lowered. The substrate holder 36 may be rotated in contact with the surface (upper surface) of the substrate.

  As shown in FIG. 4, the electrode head 28 of the electrode arm 30 includes an anode holder 60 connected to the free end of the swing arm 26 via a ball bearing (not shown), and a lower end opening of the anode holder 60. The high-resistance structure 62 is disposed so as to close the surface. As a result, a hollow anode chamber 64 is defined in the anode holder 60.

  The high resistance structure 62 is made of, for example, a porous ceramic such as alumina, SiC, mullite, zirconia, titania, cordierite, or a hard porous body such as a sintered body of polypropylene or polyethylene, or a composite thereof, or a woven fabric. And composed of non-woven fabric. For example, in the case of alumina-based ceramics, the pore diameter is 30 to 200 μm, and in the case of SiC, the pore diameter is 30 μm or less, the porosity is 20 to 95%, the thickness is 1 to 20 mm, preferably 5 to 20 mm, and more preferably 8 to About 15 mm is used. In this example, for example, the porous ceramic plate is made of alumina with a porosity of 30% and an average pore diameter of 100 μm. And, by containing the plating solution inside this, that is, the porous ceramic plate itself is an insulator, by allowing the plating solution to enter inside intricately and by following a fairly long path in the thickness direction, It is comprised so that it may have an electrical conductivity smaller than the electrical conductivity of a plating solution.

  Thus, by arranging the high resistance structure 62 in the opening of the anode holder 60 and generating a large resistance by the high resistance structure 62, the influence of the resistance of the seed layer 7 can be ignored, and the substrate W The in-plane difference of the current density due to the electrical resistance of the surface can be reduced, and the in-plane uniformity of the plating film can be improved.

  In the anode chamber 64, an anode 66 having a large number of through-holes passing through up and down is disposed above the high resistance structure 62. The anode holder 60 is provided with a plating solution discharge port 68 that sucks and discharges the plating solution in the anode chamber 64. The plating solution discharge port 68 is provided from the plating solution supply facility 18 (see FIG. 2). It is connected to an extending plating solution discharge pipe (not shown). Further, a plating solution injection part 70 is provided on the side of the anode holder 60. In this example, the plating solution injection unit 70 is formed of a tube having a nozzle shape at the lower end, and is connected to a plating solution supply pipe (not shown) extending from the plating solution supply facility 18 (see FIG. 2).

The plating solution injection unit 70 lowers the electrode head 28 until the gap between the substrate W held by the substrate holder 36 and the high resistance structure 62 becomes, for example, about 0.5 to 3 mm. This is for injecting a plating solution into a region between the substrate W and the high resistance structure 62 from the side of the high resistance structure 62.
The anode 66 is composed of copper containing 0.03 to 0.05% phosphorus (phosphorous copper) in order to suppress the formation of slime, but an insoluble insoluble anode should be used. May be.

  The anode side of the plating power source 72 is electrically connected to the anode 66 via the anode side conductor 74, and the cathode side of the plating power source 72 is electrically connected to the cathode contact 44 via the cathode side conductor 76.

Next, the operation of the substrate processing apparatus provided with the plating apparatus 12 of this embodiment will be described.
First, the substrate W before plating treatment is taken out from the load / unload unit 10 by the transfer robot 14, and one surface is electroplated from the substrate loading / unloading port provided on the side surface of the frame with the surface (surface to be plated) facing upward. It is conveyed inside the device 12. The substrate holder 36 sucks and holds the substrate W on its back surface (upper surface), and then retreats the robot hand. Then, the substrate holder 36 is raised, and the cathode contact 44 is brought into contact with the seed layer 7 of the substrate W so that power can be supplied to the seed layer 7, and the outer peripheral end of the substrate W is brought into contact with the seal portion 46 to be watertight. Seal.

  On the other hand, the electrode head 28 of the electrode arm unit 30 is at a normal position on the plating solution tray 22 at this point, and the high resistance structure 62 or the anode 66 is located in the plating solution tray 22. Then, supply of the plating solution to the plating solution tray 22 and the electrode head 28 is started. Then, until the substrate plating process is started, a new plating solution is supplied, and suction through a plating solution discharge pipe (not shown) is performed to replace the plating solution contained in the high resistance structure 62 and remove bubbles. I do.

  Next, the pre-coating process is performed. That is, the substrate holder 36 that has received the substrate W is rotated, and the precoat / collection arm 32 that is in the retracted position is moved to a position facing the substrate. When the rotation speed of the substrate holder 36 reaches a set value, a precoat liquid made of a surfactant, for example, is applied from the precoat nozzle (not shown) provided at the tip of the precoat / collection arm 32 to the surface of the substrate (to be covered). Discharge intermittently on the plating surface. At this time, since the substrate holder 36 is rotating, the precoat liquid spreads over the entire surface of the substrate W. Next, the precoat / collection arm 32 is returned to the retracted position, the rotational speed of the substrate holder 36 is increased, and the precoat liquid on the surface to be plated of the substrate W is shaken off and dried by centrifugal force.

  After pre-coating is completed, the process proceeds to plating. First, the rotation speed of the substrate holder 36 is reduced to the rotation speed during plating. Then, based on the signal that the pre-coating process of the substrate W has been completed, the electrode arm portion 30 is swung horizontally from above the plating solution tray 22 so that the electrode head 28 is positioned above the position where the plating process is performed. Thereafter, the electrode head 28 is lowered toward the cathode portion 38 and stopped. At this time, the high resistance structure 62 is brought into a position close to about 0.5 mm to 3 mm without contacting the surface of the substrate W. When the lowering of the electrode head 28 is completed, a plating solution is supplied between the substrate W and the high resistance structure 62 so that the anode 66 and the seed layer 7 on the surface of the substrate W are brought into contact with the plating solution. At the same time, the anode side of the plating power source 72 is electrically connected to the anode 66, and the cathode side is connected to the cathode contact 44. Thus, the surface of the seed layer 7 is plated by applying a voltage between the anode 66 and the seed layer 7 of the substrate W via the plating power source 72.

  If the seed layer 7 is thin and the resistance value (sheet resistance value) exceeds, for example, 10Ω / □, it becomes difficult for current to flow through the seed layer 7. Therefore, in order to reliably perform plating on the surface of the seed layer 7, it is necessary to flow a high current through the seed layer 7 at a high voltage. When a high current is passed through the seed layer 7 at a high voltage, the cathode contact 44 and the cathode Heat is generated from the contact portion between the contact 44 and the seed layer 7 and in the vicinity thereof. This is almost the same when plating directly on the surface of the barrier layer 5 having extremely high sheet resistance. Therefore, in this example, pure water 50 as a coolant is sprayed from the pure water (refrigerant) spray nozzle 52 toward the cathode contact 44 during plating, thereby cooling the cathode contact 44 and the vicinity thereof with the pure water 50. To do. Thereby, heat generation from the cathode contact 44 and its vicinity can be suppressed, and damage such as deformation and melting due to heat of the cathode contact 44 and its peripheral parts can be prevented.

  When the plating process is completed, the plating power source 72 is disconnected and the supply of pure water (refrigerant) 50 is stopped. Then, the electrode arm portion 30 is raised and turned to return to the upper part of the plating solution tray 22 and lowered to the normal position. Next, the precoat / recovery arm 32 is moved from the retracted position to a position facing the substrate W and lowered, and the remaining plating solution on the substrate W is recovered from a plating solution recovery nozzle (not shown). After the collection of the residual liquid is completed, the precoat / collection arm 32 is returned to the retracted position, and pure water is discharged from the fixed nozzle 34 for pure water to the central portion of the substrate W in order to rinse the substrate plating surface. At the same time, the substrate holder 36 is rotated at an increased speed to replace the plating solution on the surface of the substrate W with pure water.

  Thus, the plating process and all the pre-processes and cleaning / drying processes incidental thereto are completed, and the transfer robot 14 inserts the hand from the substrate carry-in / out port below the substrate W and lifts the substrate as it is, whereby the substrate holder The processed substrate W is received from 36. Then, the transfer robot 14 returns the processed substrate W received from the substrate holder 36 to the load / unload unit 10.

  8 and 9 show a main part of a plating apparatus according to another embodiment of the present invention. In this example, a weir portion 80 projecting downward is integrally provided at a position slightly spaced from the inner peripheral end of the seal portion 46 and sandwiching the contact portion between the inner peripheral end of the cathode contact 44 and the seed layer 7. When the substrate W held by the substrate holder 36 is raised, the inner peripheral end of the seal portion 46 and the weir portion 80 simultaneously come into contact with the upper surface of the substrate W, and the coolant channel 82 is provided between the seal portion 46 and the substrate W. Is formed. A refrigerant supply port 84 and a refrigerant discharge port 86 are connected to the refrigerant channel 82.

  In this example, the substrate W held by the substrate holder 36 is raised, the inner peripheral end of the seal portion 46 and the weir portion 80 are simultaneously brought into contact with the upper surface of the substrate W, and the refrigerant flows between the seal portion 46 and the substrate W. A path 82 is formed, and a coolant such as pure water is supplied to the coolant channel 82 to cool the cathode contact 44 located in the coolant channel 82 and the vicinity thereof. As a result, the cooled refrigerant can be easily recovered, and the heat generating part such as the cathode contact 44 can be efficiently cooled with the refrigerant while circulating the refrigerant. Moreover, the refrigerant around the cathode contact 44 When touched, it is possible to prevent the refrigerant from touching, for example, metal parts that may cause current leakage. In addition, when there is no possibility that such a leakage path is created, a conductive liquid may be used as the refrigerant. In this case, it is possible to create a current path that flows from the cathode contact through the conductive liquid to the substrate, and as a result, electricity is concentrated on the contact portion between the normal cathode contact and the substrate. A current can be supplied to the substrate more uniformly.

  10 and 11 show another example of the cathode contact. The cathode contact 88 in this example has a circular shape with a circular cross section, and is configured to come into contact with the outer peripheral portion of the substrate W in a continuous linear shape over the entire circumference of the outer peripheral portion. When only the tips of the teeth are in point contact with the seed layer 7 as in the comb-shaped cathode contact 44 in the above-described example, the contact area becomes small, resulting in a large electric resistance, and this narrow area. If a high current is applied at a high voltage, a considerable amount of heat is generated. As in this example, by using the cathode contact 88 that linearly contacts the entire outer periphery of the substrate W, the contact area of the cathode contact 88 is increased. When a part is crushed like an O-ring, the contact area of the cathode contact 88 is remarkably increased, and abnormal heat generation in the cathode contact 88 and its vicinity can be prevented.

  12 and 13 show a plating apparatus according to still another embodiment of the present invention. In this example, the cathode contact 90 is formed by coating the surface of a hollow fluororubber with metal (gold) by gold vapor deposition and processing it into a ring shape. The hollow portion of the cathode contact 90 is used as the refrigerant flow path 92, and the refrigerant flow path 92 extends from the refrigerant tank 94 and includes the pump 96. The refrigerant discharge returns to the refrigerant tank 94. The cooling mechanism 104 is configured by connecting the pipe 100 and further cooling the refrigerant in the refrigerant tank 94 by the chiller 102.

  Thus, by using fluororubber as the base material of the cathode contact 90, the cathode contact 90 has sufficient flexibility, and when the cathode contact 90 is pressed against the seed layer 7 of the substrate W, the seed layer The contact area with 7 can be increased. Also, the resistance of the cathode contact 90 itself can be considerably reduced by coating the rubber surface with gold, which has a low resistance among metals. Since gold is also excellent in chemical resistance, it is difficult to deteriorate. Further, since gold is soft among metals and has good adhesion with the seed layer 7, the contact resistance between the cathode contact 90 and the seed layer 7 can be further reduced.

  According to this example, the refrigerant, for example, pure water, stored in the refrigerant tank 94 is maintained at a constant temperature by circulating through the circulation line with the chiller 102, and the refrigerant is supplied as the pump 96 is driven. The refrigerant is sent into the refrigerant flow path 92 through the pipe 98. Then, the refrigerant (pure water) sent into the refrigerant flow path 92 flows along the refrigerant flow path 92 to directly cool the cathode contact 90. Then, the refrigerant (pure water) whose temperature has risen by making the cathode contact 90 a refrigerant (pure water) is returned from the refrigerant discharge pipe 100 into the refrigerant tank 94, thereby efficiently cooling the cathode contact 90. However, it circulates between the refrigerant tank 94 and the refrigerant flow path 92.

The cathode contacts 44 and 88 described above may be formed by coating a metal (gold) on the surface of a hollow fluororubber by gold vapor deposition.
The cathode contacts 44, 88, 90 may be made of metal. By using metal, the resistance can be reduced, and the heat generation from the material itself can be reduced even if the size is small. In particular, a contact area can be increased by using a metal seal used in vacuum equipment or the like and pressing it against the substrate. Any metal material can be used as the type of metal, but a platinum-coated stainless steel substrate is excellent in chemical resistance, strength, workability and cost. Gold can be used instead of platinum for excellent performance, but it is slightly inferior to platinum in terms of strength.

  The cathode contacts 44, 88, 90 may be made of conductive rubber or conductive resin. Thus, while making the cathode contact conductive, it is possible to flexibly contact the substrate (seed layer) to increase the contact area with the substrate (seed layer), reduce the contact resistance, and suppress heat generation. As a shape, a general seal shape such as an O-ring is good, and a V seal shape or a flat seal (gasket) shape may be used.

  The cathode contacts 44, 88, 90 may be made of a conductive polymer. When the cathode contact is made of conductive rubber or conductive resin that is made conductive by kneading metal or carbon, there is a risk of metal contamination on the substrate, but in this case, the cathode contact is in the molecular structure itself. By using a conductive polymer having conductivity, metal contamination can be eliminated.

  Here, the conductive rubber, the conductive resin, or the conductive polymer generally has a higher resistance than the metal material. For this reason, as in the example shown in FIGS. 12 and 13, the cathode contact 90 having a metal coating such as gold on the surface of fluorine rubber or the like is used as a cathode contact, so that it is like rubber or resin. And a cathode contact having a low resistance equivalent to that of metal. As a metal coating material, in addition to gold, silver and platinum are excellent in electrical resistance, adhesion to a substrate, and chemical resistance.

It is a figure which shows one manufacture example of a copper wiring board in order of a process. It is a top view which shows the whole substrate processing apparatus provided with the plating apparatus of embodiment of this invention. It is a top view of the plating apparatus shown in FIG. It is a schematic longitudinal cross-sectional view which shows the principal part at the time of plating of the plating apparatus shown in FIG. It is the sectional view on the AA line of FIG. It is a top view of the cathode part of the plating apparatus shown in FIG. FIG. 6D is a sectional view taken along line D-D. It is a schematic longitudinal cross-sectional view which shows the principal part of the plating apparatus of other embodiment of this invention. It is the BB sectional drawing of FIG. It is a top view which shows the other example of a cathode contact. It is sectional drawing which shows the relationship between the cathode contact shown in FIG. 10, and a board | substrate. It is a schematic longitudinal cross-sectional view which shows the principal part of the plating apparatus of other embodiment of this invention. It is CC sectional view taken on the line of FIG.

Explanation of symbols

5 Barrier layer 6 Copper film 7 Seed layer 10 Load / unload unit 12 Plating apparatus 20 Substrate processing unit 22 Plating solution tray 28 Electrode head 30 Electrode arm unit 32 Precoat / recovery arm 36 Substrate holder 38 Cathode units 44, 88, 90 Cathode Contact 46 Seal 50 50 Pure water (refrigerant)
52 Pure water (refrigerant) injection nozzles 58 and 104 Cooling mechanism 60 Anode holder 62 High resistance structure 64 Anode chamber 66 Anode 68 Plating solution outlet 70 Plating solution injection part 72 Power supply 80 Weir part 82 and 92 Refrigerant flow path 84 Refrigerant supply Port 86 Refrigerant discharge port 94 Refrigerant tank 98 Refrigerant supply pipe 100 Refrigerant discharge pipe

Claims (8)

A substrate holder for holding the substrate;
A cathode part that includes a cathode contact that contacts and energizes the substrate held by the substrate holder and rotates integrally with the substrate holder;
An anode disposed to face the surface of the substrate;
A plating apparatus comprising a cooling mechanism for cooling the cathode contact.   The plating apparatus according to claim 1, wherein the cooling mechanism cools the cathode contact by bringing a fluid serving as a refrigerant into contact with the cathode contact.   The plating apparatus according to claim 2, wherein the fluid is a conductive or insulating liquid.   The plating apparatus according to claim 2, wherein the fluid is gas, air, or an inert gas.   The said cooling mechanism has a fluid flow path which flows the said fluid, and this fluid flow path is provided in the inside or circumference | surroundings of the said cathode contact, The Claim 2 thru | or 4 characterized by the above-mentioned. Plating equipment.   The plating apparatus according to claim 1, wherein the cathode contact is in contact with the outer peripheral portion of the substrate over the entire circumference of the outer peripheral portion.   7. The cathode contact according to claim 1, wherein the cathode contact is made of metal, conductive rubber, conductive resin, conductive polymer, or rubber or resin with a metal coating on the surface. The plating apparatus as described.   The substrate surface and the anode are filled with a plating solution between an anode disposed so as to be opposed to the surface of the substrate, the cathode contact being brought into contact with the outer periphery of the cathode, and the cathode contact being cooled with a coolant. A plating method characterized in that a voltage is applied between and the surface of the substrate is plated.

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