JP2010109298A - Plating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plating apparatus that keeps height as desired in each pump produced by electroless plating, fixes the height, and improves adhesion with an electrode pad. <P>SOLUTION: The plating apparatus 60 includes a variable-angle chuck 9 which keeps a wafer carrier 11 in an inclined position so that a circuit forming surface 20 of a semiconductor wafer 1 faces upward than a horizontal direction and a transferring arm 10 to perform flotation, sinking, and transfer of the wafer carrier 11 held by the variable-angle chuck 9. The inclined angle θ of the wafer carrier 11 by the variable-angle chuck 9 is ≥20° and ≤40°. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a plating apparatus for forming bumps on an electrode pad of a circuit pattern formed on one side of a semiconductor wafer by an electroless plating method. Hereinafter, in the present specification, the one surface of the semiconductor wafer on which the circuit pattern is formed is referred to as “circuit formation surface of the semiconductor wafer” or simply “circuit formation surface”. Hereinafter, in the present specification, each processing step for forming a bump by an electroless plating method is referred to as an “electroless plating process”.

  2. Description of the Related Art In recent years, with the miniaturization of semiconductor devices, semiconductor wafers as semiconductor devices have high circuit patterns such as TCP (Tape Carrier Package), COF (Chip On Film), and COG (Chip On Glass). Various mounting methods capable of density mounting have been proposed.

  In each of the above mounting methods, a protruding electrode called a bump is formed on an electrode pad of a circuit pattern, and the circuit pattern is transferred to the film substrate via the bump by thermocompression bonding or ACF (Anisotropy Conductive Film). Alternatively, it is a method of mounting on a glass substrate.

  A plating method is widely applied as a method of forming bumps on the electrode pads of the circuit pattern. As plating methods, an electrolytic plating method and an electroless plating method are mainly known, and conventionally, an electrolytic plating method using Au (gold) plating has been generally used.

  On the other hand, the electroless plating method is indispensable when forming the pattern of the protruding electrode and the sputtering process, which is essential when forming the barrier metal and the electrode at the time of the plating process, compared with the electrolytic plating method. Cost reduction because it is possible to omit the photo process and the etching process that was essential when removing the photoresist used during pattern formation and the barrier metal used during the plating process. In addition, the manufacturing process can be simplified and the delivery time can be shortened accordingly. Therefore, in recent years, an electroless plating method has attracted attention in place of the electrolytic plating method.

As an example of the electroless plating method, in Patent Document 1, a nickel (Ni) plating bump is formed on an electrode pad by an electroless plating method, and then a metal thin film such as Au plating is formed on the surface of the Ni plating bump. Techniques to do this are disclosed.
JP 2001-237267 A (released on August 31, 2001) JP-A-6-140409 (published on May 20, 1994) Japanese Patent Laid-Open No. 5-160101 (released on June 25, 1993) JP-A-8-64570 (published March 8, 1996) JP 2003-77880 A (published March 14, 2003)

  In order to improve the quality (mounting quality) of the semiconductor wafer in which bumps formed by electroless plating are formed on the electrode pads of the circuit pattern, the height of each pump must be maintained at a desired height. It is important to make the height of each pump constant and to improve the adhesion between each bump and the electrode pad. In the present specification, the “bump height” means the length (height) in the vertical direction from the electrode pad portion where the bump is formed to the tip of the bump.

  Here, as a technique related to an electroless plating process for forming a bump made of Ni and Au, for example, by an electroless plating method, an etching process, a zincate (zinc replacement) process, an electroless Ni plating process, and There is a technique for sequentially performing electroless Au plating (see Patent Document 2).

  In general, the electroless plating process is performed by sequentially immersing a wafer carrier containing semiconductor wafers in liquids (chemical solution or running water) stored in a plurality of processing tanks. However, when performing the electroless plating process, particularly when the wafer carrier is transported between a plurality of processing tanks, due to the flow of liquid from the semiconductor wafer contained in the wafer carrier, etc. When the electrode pad of the circuit pattern is exposed to the air and dried, the bumps formed on the electrode pad have a problem that the height is lowered or the adhesion with the electrode pad is lowered. The cause of this problem is that the surface of the electrode pad is oxidized (an oxide film is formed) due to the electrode pad being exposed to the atmosphere, and the surface of the electrode pad surface is generated by the occurrence of a watermark. It is estimated that the degree of activity decreases.

  The present invention has been made in view of the above problems, and its purpose is to maintain the height at a desired height and to make the height constant in each pump formed by an electroless plating method. And it is providing the plating processing apparatus which can improve adhesiveness with an electrode pad.

  As a result of intensive studies in view of the above problems, the inventors of the present application formed a wafer carrier containing semiconductor wafers by sequentially immersing them in liquids stored in a plurality of processing tanks. A plating apparatus for forming bumps on an electrode pad of a circuit pattern formed by electroless plating, wherein the circuit formation surface of the semiconductor wafer on which the circuit pattern is formed is above the horizontal direction A carrier holding device that holds the wafer carrier in an inclined posture so that the wafer carrier faces the surface, and the wafer carrier floats from the liquid stored in the processing tank with respect to the wafer carrier held by the carrier holding device. And a transfer arm that sinks the wafer carrier into the liquid stored in the processing tank and transfers the wafer carrier between the plurality of processing tanks. The wafer holding device includes the wafer carrier so that an inclination angle of the circuit forming surface in a vertical plane perpendicular to the circuit forming surface is 20 ° or more and 40 ° or less with respect to the vertical direction. If the plating processing device is characterized in that it is held in an inclined position, the height is maintained at a desired height in each pump formed by the electroless plating method, and the length is made constant. And found out that the adhesiveness with the electrode pad can be improved and came up with the present invention.

  In order to maintain the height at a desired height, to make the length constant, and to improve the adhesion with the electrode pad in each pump formed by the electroless plating method, the present inventors have made an electroless plating process. It was considered effective to reduce the risk of the electrode pads coming into contact with the air when

  Then, the inventors of the present application inclined the wafer carrier so that the circuit formation surface faces upward from the horizontal direction in order to reduce the possibility that the electrode pad is exposed to the atmosphere when performing electroless plating. We thought that it was effective to convey. This can reduce the risk of liquid flowing down from the semiconductor wafer accommodated in the wafer carrier when transporting between a plurality of processing baths, and thus can suppress the possibility that the electrode pad is exposed to the atmosphere. it is conceivable that.

  Patent Document 3 discloses a technique in which a chemical treatment and transfer between a plurality of processing tanks are performed by inclining a wafer cassette at a predetermined angle so that a device formation surface of a semiconductor wafer is on top. Patent Document 4 discloses a technique in which a cassette is inclined by a predetermined angle so that a device formation surface of a semiconductor wafer is on top and settled in a cleaning liquid. Patent Document 5 discloses a technique in which a carrier holder is tilted forward, taken out from a cleaning tank, and conveyed.

  However, each technique disclosed in Patent Documents 3 to 5 may be applied to an electroless plating apparatus as it is for the following reasons, but the electrode pad may be exposed to the atmosphere when performing the electroless plating process. The purpose of reducing the amount could not be achieved.

  That is, in the technique disclosed in Patent Document 3, the angle at which the wafer cassette is inclined is set to 1 ° to 15 °. However, when the angle is set to 1 ° to 15 °, the angle cannot be achieved in order to reduce the possibility of the chemical liquid flowing down during transport, and thus the above-described object cannot be achieved. The technique disclosed in Patent Document 3 is an invention in which the angle is set to 1 ° to 15 ° from the viewpoint of reducing the adhesion of foreign matter to the device formation surface of a semiconductor chip. It is not an invention made from the viewpoint of reducing the possibility that the electrode pad is exposed to the atmosphere.

In the technique disclosed in Patent Document 4, the lower limit is π / 12rad inclination angle theta _w, i.e., is sufficient as long as about 15 °, is not necessary to consider the upper limit of the inclination angle theta _w. However, when the inclination angle theta _w is about 15 °, also, since the inclination angle theta _w is too small in order to reduce the possibility that the drug solution flows down when conveyed, can not achieve the above object. On the other hand, if the inclination angle theta _w is large enough to exceed 40 °, the amount of chemical liquid remaining on the semiconductor wafer becomes very large, thereby, unnecessarily various chemical reactions on the semiconductor wafer during transport As a result, there is a possibility that the height of each formed pump may vary. The technique disclosed in Patent Document 4 is an wafer is an arbitrary angle greater than 15 ° the inclination angle theta _w from the viewpoint of reducing the generation of dust挨due to rub against the retaining part of the wafer cassettes invention It is not an invention made from the viewpoint of reducing the possibility that the electrode pad is exposed to the atmosphere when performing the electroless plating process.

  In the technique disclosed in Patent Document 5, the angle for tilting the carrier holder forward is not specifically described. Here, in order to prevent the cleaning liquid from flowing down from the carrier grip, it is considered that the carrier holder needs to be tilted forward to an extent exceeding 40 °. In this case, the chemical liquid remaining on the semiconductor wafer This increases the amount, which unnecessarily promotes various chemical reactions on the semiconductor wafer during transport, and as a result, the height of each formed pump may vary. The technique disclosed in Patent Document 5 tilts the carrier holder forward from the viewpoint of enabling the operator to carry the carrier from the washing tank to the dryer without touching the carrier and eliminating the risk of contamination and dust generation. It is an invention and is not an invention made from the viewpoint of reducing the possibility that the electrode pad is exposed to the atmosphere when performing electroless plating.

  Therefore, according to the above configuration, the inclination angle of the circuit forming surface in the vertical plane perpendicular to the circuit forming surface is 20 ° or more and 40 ° or less with respect to the vertical direction.

  When the tilt angle is less than 20 °, the flow of the liquid adhering to the semiconductor wafer with respect to the unit time when the wafer carrier is transferred after the electroless plating process in the processing tank (after being immersed in the liquid) The degree becomes very large. At this time, the liquid adhering to the semiconductor wafer flows down in a short time and disappears from the surface. As a result, the surface of the semiconductor wafer is oxidized, which causes a phenomenon that the electrode pads of the circuit pattern of the semiconductor wafer are dried by being exposed to the atmosphere. On the other hand, when the tilt angle exceeds 40 °, the degree of flow is very small. At this time, the amount of the liquid adhering to the semiconductor wafer becomes very large, and accordingly, various chemical reactions are unnecessarily promoted on the semiconductor wafer during transportation. As a result, each of the formed pumps There is a risk of variations in length.

  In consideration of the above, in each pump formed by the electroless plating method, the electroless plating process is performed to maintain the height at a desired height, to make the length constant, and to improve the adhesion with the electrode pad. It can be seen that the inclination angle of the circuit formation surface should be 20 ° or more and 40 ° or less in order to reduce the risk of the electrode pads coming into contact with the air when

  In addition, as a result of intensive studies in view of the above problems, the inventors of the present application have sequentially immersed a wafer carrier in which a semiconductor wafer is accommodated in liquids stored in a plurality of processing tanks, and the semiconductor wafer. A plating apparatus for forming bumps on an electrode pad of a circuit pattern formed on the substrate by an electroless plating method, wherein the circuit formation surface of the semiconductor wafer on which the circuit pattern is formed is from a horizontal direction. A carrier holding device for holding the wafer carrier in an inclined posture so that the wafer carrier is also directed upward, and the wafer carrier from the liquid stored in the processing tank with respect to the wafer carrier held by the carrier holding device. The wafer carrier is floated, the wafer carrier is settled into the liquid stored in the processing tank, and the wafer carrier is transferred between the processing tanks. And the transfer arm performs at least one of floating and sinking of the wafer carrier at a speed of 100 millimeters / second or more and 200 millimeters / second or less. If present, each pump formed by the electroless plating method can maintain the height at a desired height, make the length constant, and improve the adhesion to the electrode pad. The headline and the present invention have been devised.

  According to the above configuration, the rising and / or sinking speed of the wafer carrier is 100 millimeters / second or more and 200 millimeters / second or less.

  If the speed of ascent and / or settling is less than 100 millimeters per second, after the electroless plating process in the processing tank (after being immersed in a liquid), the time required for transporting the wafer carrier becomes longer. Along with this, the flow amount of the liquid adhering to the semiconductor wafer surface increases and disappears from the semiconductor wafer surface. On the other hand, when the rising and / or sinking speed exceeds 200 millimeters per second, the liquid is shaken off due to the friction between the liquid and air, so that the liquid attached to the surface of the semiconductor wafer flows down. Therefore, the amount of the liquid adhering to the surface of the semiconductor wafer increases and disappears from the surface of the semiconductor wafer. In either case, the surface of the semiconductor wafer is oxidized, which causes a phenomenon that the electrode pads of the circuit pattern of the semiconductor wafer are dried by being exposed to the atmosphere.

  In consideration of the above, in each pump formed by the electroless plating method, the electroless plating process is performed to maintain the height at a desired height, to make the length constant, and to improve the adhesion with the electrode pad. It can be seen that in order to reduce the risk of the electrode pads coming into contact with the atmosphere when performing, the rising and / or sinking speed of the wafer carrier should be greater than or equal to 100 millimeters per second and less than or equal to 200 millimeters per second.

  Furthermore, the inventors of the present application have conducted intensive studies in view of the above problems, and as a result, the wafer carrier in which the semiconductor wafer is accommodated is sequentially immersed in the liquid stored in a plurality of processing tanks, and the semiconductor wafer is obtained. A plating apparatus for forming bumps on an electrode pad of a circuit pattern formed on the substrate by an electroless plating method, wherein the circuit formation surface of the semiconductor wafer on which the circuit pattern is formed is from a horizontal direction. A carrier holding device for holding the wafer carrier in an inclined posture so that the wafer carrier is also directed upward, and the wafer carrier from the liquid stored in the processing tank with respect to the wafer carrier held by the carrier holding device. The wafer carrier is floated, the wafer carrier is settled into the liquid stored in the processing tank, and the wafer carrier is transferred between the processing tanks. If the plating processing apparatus is characterized in that it transports the wafer carrier in a time of 4 seconds or more and 9 seconds or less, it is formed by an electroless plating method. In order to devise the present invention, the present invention uniquely finds that each of the pumps can maintain the height at a desired height, can make the height constant, and can improve the adhesion to the electrode pad. It came.

  According to said structure, the conveyance time of a wafer carrier between several process tanks will be 4 second or more and 9 seconds or less.

  When the transfer time of the wafer carrier is less than 4 seconds, it is expected that the transfer speed will be excessively increased as opposed to shortening the transfer time. When the transport speed is excessively increased, the liquid is shaken off due to friction between the liquid and air, so that the flow of the liquid attached to the surface of the semiconductor wafer is promoted. The amount of liquid that adheres to the surface of the semiconductor wafer increases and disappears from the surface of the semiconductor wafer. On the other hand, if the transfer time of the wafer carrier exceeds 9 seconds, the time required to transfer the wafer carrier becomes longer after the electroless plating process (after immersion in the liquid) in the processing tank. The flow amount of the liquid adhering to the semiconductor wafer surface increases and disappears from the semiconductor wafer surface. In either case, the surface of the semiconductor wafer is oxidized, which causes a phenomenon that the electrode pads of the circuit pattern of the semiconductor wafer are dried by being exposed to the atmosphere.

  In consideration of the above, in each pump formed by the electroless plating method, the electroless plating process is performed to maintain the height at a desired height, to make the length constant, and to improve the adhesion with the electrode pad. It can be seen that the wafer carrier transport time should be 4 seconds or more and 9 seconds or less in order to reduce the risk of the electrode pads coming into contact with the air when performing the process.

  Further, in the plating apparatus according to the present invention, the above-described configuration in which the inclination angle of the circuit forming surface in the vertical plane perpendicular to the circuit forming surface is 20 ° or more and 40 ° or less with respect to the vertical direction, and the wafer carrier The above-mentioned configuration in which the rising and / or sinking speed is 100 millimeters / second or more and 200 millimeters / second or less, and the wafer carrier transfer time between a plurality of processing tanks is 4 seconds or more and 9 seconds or less. The above configuration may be applied in any combination, and when a combination of each configuration is applied, it is formed by a larger electroless plating method than when only one of the configurations is applied. In addition, in each pump, the height can be maintained at a desired height, the height can be made constant, and the adhesion to the electrode pad can be improved.

  The plating apparatus according to the present invention includes a plurality of the treatment tanks, a degreasing treatment tank in which a degreasing agent is stored, a first washing treatment tank in which pure water is stored, an etching processing tank in which an etching solution is stored, The second water washing treatment tank in which pure water is stored, the first zinc replacement treatment tank in which zinc replacement liquid is stored, the third water washing treatment tank in which pure water is stored, the nitric acid treatment tank in which nitric acid is stored, and the pure water The stored fourth washing treatment tank, the second zinc replacement treatment tank in which the zinc replacement solution is stored, the fifth water washing treatment tank in which pure water is stored, and the first electroless plating in which the nickel-phosphorous plating solution is stored A plating tank having a treatment tank, a sixth washing treatment tank in which pure water is stored, a second electroless plating treatment tank in which gold plating solution is stored, and a seventh washing treatment tank in which pure water is stored; The processing apparatus includes a degreasing agent stored in the degreasing tank with the wafer carrier. Pure water stored in the first washing treatment tank, etching solution stored in the etching treatment tank, pure water stored in the second washing treatment tank, zinc replacement stored in the first zinc replacement treatment tank Liquid, pure water stored in the third washing treatment tank, nitric acid stored in the nitric acid treatment tank, pure water stored in the fourth washing treatment tank, zinc stored in the second zinc replacement treatment tank Replacement liquid, pure water stored in the fifth washing treatment tank, nickel-phosphorous plating solution stored in the first electroless plating treatment tank, pure water stored in the sixth washing treatment tank, the first (2) The bumps are formed on the electrode pads by the electroless plating method by sequentially immersing the gold plating solution stored in the electroless plating bath and the pure water stored in the seventh washing bath. It is characterized by being.

  According to the above configuration, the height is maintained at a desired height in each pump formed by the electroless plating method at the time of the electroless plating process, the height is made constant, and the adhesion with the electrode pad is improved. Therefore, the quality (mounting quality) of the semiconductor wafer in which the bumps formed by the electroless plating method are formed on the electrode pads of the circuit pattern can be improved.

  As described above, in the plating apparatus according to the present invention, the electrode of the circuit pattern formed on the semiconductor wafer by sequentially immersing the wafer carrier containing the semiconductor wafer in the liquid stored in each of the plurality of processing tanks. A plating apparatus for forming bumps on a pad by an electroless plating method, wherein the circuit forming surface of the semiconductor wafer on which the circuit pattern is formed faces upward from the horizontal direction. A carrier holding device that holds the wafer carrier in an inclined posture, and the wafer carrier held by the carrier holding device floats from the liquid stored in the processing tank, and the processing tank A transfer arm that performs sedimentation of the wafer carrier into the stored liquid and transfer of the wafer carrier between the plurality of processing tanks, The carrier holding device tilts the wafer carrier so that an inclination angle of the circuit forming surface in a vertical plane perpendicular to the circuit forming surface is 20 ° or more and 40 ° or less with respect to the vertical direction. Hold it in a posture.

  In addition, the plating apparatus according to the present invention sequentially immerses a wafer carrier in which a semiconductor wafer is accommodated in a liquid stored in each of a plurality of processing tanks, on the electrode pad of the circuit pattern formed on the semiconductor wafer. In addition, a plating apparatus for forming bumps by an electroless plating method, wherein the wafer carrier is arranged such that a circuit forming surface of the semiconductor wafer on which the circuit pattern is formed faces upward from a horizontal direction. A carrier holding device that holds the wafer in an inclined posture, and the wafer carrier that is held by the carrier holding device floats from the liquid stored in the processing tank and is stored in the processing tank. A transfer arm that performs the settling of the wafer carrier into the liquid and the transfer of the wafer carrier between the plurality of processing tanks. Over arm at a rate of less per 100 mm or more and per 200 mm, it is performed above the wafer carrier, at least one of the floating and settling.

  Furthermore, the plating apparatus according to the present invention is configured to sequentially immerse a wafer carrier in which a semiconductor wafer is accommodated in a liquid stored in a plurality of processing tanks, on the electrode pad of a circuit pattern formed on the semiconductor wafer. In addition, a plating apparatus for forming bumps by an electroless plating method, wherein the wafer carrier is arranged such that a circuit forming surface of the semiconductor wafer on which the circuit pattern is formed faces upward from a horizontal direction. A carrier holding device that holds the wafer in an inclined posture, and the wafer carrier that is held by the carrier holding device floats from the liquid stored in the processing tank and is stored in the processing tank. A transfer arm configured to sink the wafer carrier into a liquid and transfer the wafer carrier between the plurality of processing tanks. Arms, 4 seconds and 9 seconds in the following time, and performs the transfer of the wafer carrier.

  Therefore, in each pump formed by the electroless plating method, the height can be maintained at a desired height, the length can be made constant, and the adhesion with the electrode pad can be improved. .

  First, with reference to FIGS. 1-5, each process process (electroless plating process) until it forms a bump with an electroless plating method is demonstrated.

  In the processing step shown in FIG. 1, the circuit pattern 3 is formed on the circuit forming surface 20 of the semiconductor wafer 1. The circuit pattern 3 has an electrode pad 2 on the surface opposite to the circuit forming surface 20. The surface of the electrode pad 2 is formed of an Al (aluminum) alloy having a thickness of about 0.5 μm to 1.1 μm. Specific processing steps for forming the circuit pattern 3 on the circuit forming surface 20 are not particularly limited, and a well-known semiconductor wafer manufacturing process can be applied, and thus detailed description thereof is omitted here.

  In the processing step shown in FIG. 2, the surface of the electrode pad 2 is degreased (degreasing process), and the etching portion 21 on the surface of the electrode pad 2 is etched by about 0.2 μm (etching process). For example, the degreasing treatment is performed by immersing the semiconductor wafer 1 in an alkaline degreasing agent at 25 degrees Celsius containing about 5% by weight of sodium hydroxide for about 5 minutes. The etching process is, for example, a so-called dip type wet etching in which the semiconductor wafer 1 is immersed for about 5 minutes in an etching solution at 25 degrees Celsius containing about 10% by weight of phosphoric acid.

  In the processing step shown in FIG. 3, after forming a Zn (zinc) film 4 about 0.1 μm on the etched portion 21 on the surface of the electrode pad 2, the Zn film 4 is once peeled off, and then again etched on the etched portion 21. The film 4 is formed to have a thickness of about 0.1 μm (zinc replacement treatment, zincate treatment). The reason why the formation process of the Zn film 4 is performed twice is to form a denser Zn film 4 by forming the Zn film 4 a plurality of times. Each of the formation processes of the Zn film 4 is performed by immersing the semiconductor wafer 1 in, for example, a zincate solution (zinc replacement solution) at 25 degrees Celsius. The exfoliation process of the Zn film 4 is performed by immersing the semiconductor wafer 1 in nitric acid at 25 degrees Celsius, for example (nitric acid process).

  In the processing step shown in FIG. 4, Ni bumps 5 having a length of 2 μm to 15 μm are formed on the electrode pad 2 including the Zn film 4 by the electroless plating method (first electroless plating process). Note that the Zn film 4 formed in the processing step shown in FIG. 3 is replaced with Ni and disappears in the initial stage of the processing step shown in FIG. The Ni bump 5 is formed by immersing the semiconductor wafer 1 in a Ni—P (phosphorus) plating solution at 80 to 90 degrees Celsius.

  In the processing step shown in FIG. 5, an Au film 6 having a thickness of 0.05 μm to 1.0 μm is formed around the Ni bump 5 by an electroless plating method (second electroless plating process). The Au film 6 is formed by immersing the semiconductor wafer 1 in an Au plating solution at 80 to 90 degrees Celsius.

  Thus, the electroless plating process for forming bumps made of the Ni bumps 5 and the Au film 6 on the electrode pads 2 of the circuit pattern 3 formed on the semiconductor wafer 1 by the electroless plating method is completed. The above electroless plating process is referred to Patent Document 2.

  In all the processing steps shown in FIGS. 2 to 5, a water washing process in which the semiconductor wafer 1 is immersed in pure water is performed. The water washing treatment is performed for the purpose of preventing chemical solution contamination with respect to the chemical solution used for each treatment in the subsequent treatment step, while indicating the end of each treatment step.

  FIG. 6 is a cross-sectional view showing a schematic configuration of a plating apparatus for performing electroless plating.

  An electroless plating apparatus (plating treatment) 60 shown in FIG. 6 includes a casing 7, a plurality of treatment tanks 8, an angle variable chuck (carrier holding apparatus) 9, and a transfer arm 10.

  The housing 7 is a housing of the electroless plating apparatus 60 in which the plurality of processing tanks 8, the variable angle chuck 9, and the transfer arm 10 are accommodated.

  The plurality of treatment tanks 8 are a degreasing treatment tank 8a in which a degreasing agent is stored, a washing treatment tank (first washing treatment tank) 8b in which pure water is stored, an etching treatment tank 8c in which an etching solution is stored, and pure water Stored water treatment tank (second water wash treatment tank) 8d, zincate treatment tank (first zinc replacement treatment tank) 8e in which the zincate solution is stored, water wash treatment tank (third water wash treatment tank) in which pure water is stored 8f, nitric acid treatment tank 8g in which nitric acid is stored, washing process tank (fourth washing process tank) 8h in which pure water is stored, zincate treatment tank (second zinc replacement treatment tank) 8i in which zincate liquid is stored, pure Water washing treatment tank (fifth washing treatment tank) 8j in which water is stored, Ni plating treatment tank (first electroless plating treatment tank) 8k in which Ni-P plating solution is stored, and water washing treatment in which pure water is stored Tank (sixth washing treatment tank) 8l, gold plating solution was stored The u-plating tank (second electroless plating tank) 8m and the water-washing tank (seventh water-washing tank) 8n in which pure water is stored are arranged in this order, and each has a substantially equal interval (for example, 1000 mm). ). Each of the plurality of processing tanks 8 (each of the processing tanks 8a to 8n) is a container having a volume enough to accommodate all the wafer carriers 11 described later.

  In the electroless plating process shown in FIGS. 2 to 5, the semiconductor wafer 1 formed with the circuit pattern 3 having the electrode pad 2 obtained in the process shown in FIG. 1 is stored in the degreasing tank 8 a. The degreasing treatment (see the treatment step shown in FIG. 2) is performed by immersing in a degreasing agent, and the rinsing treatment is performed by immersing in the pure water stored in the rinsing processing tank 8b, and the etching solution stored in the etching processing tank 8c Dipping and performing the above-described etching process (see the processing step shown in FIG. 2), immersing in pure water stored in the rinsing tank 8d, performing the rinsing process, and immersing in the zincate liquid stored in the zincate tank 8e. The Zn film 4 is formed (see the processing step shown in FIG. 3), immersed in pure water stored in the water-washing treatment tank 8f to perform the water-washing process, and immersed in nitric acid stored in the nitric acid-treatment tank 8g. Stripping treatment of Zn film 4 (Fig. ), Soaked in pure water stored in the water-washing treatment tank 8h to perform the above-mentioned water-washing treatment, and immersed in the zincate liquid stored in the zincate-treatment tank 8i to form the Zn film 4 again (FIG. 3), soak in the pure water stored in the water washing tank 8j, perform the above water washing, and soak in the Ni-P-based plating solution stored in the Ni plating tank 8k. (See the processing step shown in FIG. 4), soaked in pure water stored in the water washing tank 8l to perform the above water washing process, immersed in an Au plating solution stored in the Au plating tank 8m, and Au film 6 (see the processing step shown in FIG. 5), and the above-mentioned water washing treatment is performed by immersing in pure water stored in the water washing treatment tank 8n. However, strictly speaking, the semiconductor wafer 1 is accommodated in a wafer carrier 11, and the wafer carrier 11 is immersed in a plurality of processing tanks 8 (each of the processing tanks 8 a to 8 n) in the order described above to perform electroless processing. Perform plating treatment.

  The variable angle chuck 9 can hold the wafer carrier 11 by sandwiching (holding) the wafer carrier 11. Further, the variable angle chuck 9 can be tilted with respect to the vertical direction (hereinafter referred to as “the tilt angle of the variable angle chuck 9”) by the tilt mechanism 61 (see FIG. 14) regardless of the holding of the wafer carrier 11. To be changed. That is, when the tilt angle of the variable angle chuck 9 is changed, the wafer carrier 11 held by the variable angle chuck 9 follows the tilt angle relative to the vertical direction (hereinafter referred to as “the tilt of the wafer carrier 11”). Will be changed by the same amount as the angle variable chuck 9.

  The transfer arm 10 is connected to the variable angle chuck 9, and the vertical position can be freely adjusted by the elevating mechanism 62 (see FIG. 14), and the horizontal position can be freely adjusted by the horizontal moving mechanism 63 (see FIG. 14). To be changed. In other words, the transfer arm 10 is moved up and down by the elevating mechanism 62 and moved horizontally by the horizontal moving mechanism 63. When the position of the transfer arm 10 in the vertical direction and / or the horizontal direction is changed, the angle variable chuck 9 connected to the transfer arm 10 and further, the angle variable chuck 9 is held. The position of the wafer carrier 11 in the vertical direction and / or the horizontal direction is changed by the same amount as that of the transfer arm 10. That is, the transfer arm 10 moves the angle variable chuck 9 up, down and horizontally regardless of the inclination angle of the angle variable chuck 9 described above.

  Here, the configuration of a control system for controlling the variable angle chuck 9 and the transfer arm 10 will be described with reference to FIG.

  FIG. 14 is a block diagram showing the configuration of the control system. The control system shown in FIG. 14 is a system for controlling the operations of the variable angle chuck 9 and the transfer arm 10, and includes an inclination mechanism 61, an elevating mechanism 62, a horizontal movement mechanism 63, a chuck operation control unit 64, and an arm operation control unit. 65 and a CPU (Central Processing Unit) 70. The chuck operation control unit 64 further includes an inclination control unit 64a and a holding control unit 64b. The arm operation control unit 65 further includes an elevation control unit 65a and a horizontal movement control unit 65b.

  The CPU 70 performs overall control of the electroless plating apparatus 60 (see FIG. 6) by executing a program stored in a storage element such as a RAM (Random Access Memory). Specifically, the CPU 70 follows the above program, and according to the progress of the electroless plating process by the electroless plating apparatus 60, the tilt information indicating the tilt angle of the angle variable chuck 9 and the wafer with respect to the angle variable chuck 9. The holding capability information indicating whether or not the carrier 11 can be held is transmitted to the chuck operation control unit 64. Further, according to the progress of the electroless plating process by the electroless plating apparatus 60, the CPU 70, according to the above program, shows the vertical position information indicating the vertical position of the transfer arm 10 and the horizontal position of the transfer arm 10. Is transmitted to the arm operation control unit 65. The holdability information may further include information indicating the strength with which the variable angle chuck 9 holds the wafer carrier 11.

  The tilt control unit 64 a controls the change of the tilt angle of the angle variable chuck 9 by the tilt mechanism 61 based on the tilt information from the CPU 70. Here, the tilt mechanism 61 is, for example, a roller that is formed in a connecting portion between the variable angle chuck 9 and the transfer arm 10 and gives a predetermined tilt angle to the variable angle chuck 9 according to the rotation direction and the rotation degree. In this case, the tilt control unit 64a controls the rotation direction and the degree of rotation of the tilt mechanism 61 based on the tilt information. . The tilt mechanism 61 set to the desired rotation direction and degree of rotation by the tilt control unit 64 a gives the desired tilt angle to the angle variable chuck 9.

  Based on the holdability information from the CPU 70, the holding control unit 64b sets the angle variable chuck 9 to a posture in which the wafer carrier 11 can be held or a posture in which the wafer carrier 11 cannot be held. Further, the holding control unit 64 b may control the strength with which the angle variable chuck 9 holds the wafer carrier 11 based on the holding availability information from the CPU 70.

  Based on the vertical position information from the CPU 70, the elevating control unit 65 a controls the vertical position change (up and down) of the transport arm 10 by the elevating mechanism 62. Here, although not shown, the elevating mechanism 62 is, for example, a columnar mechanism that is integrated with the transport arm 10 so that the elevating mechanism 62 can be raised and lowered. In this case, the elevating control unit 65a is a vertical mechanism. Based on the position information, the degree of ascent and descent of the elevating mechanism 62 is controlled. Then, the elevating mechanism 62 raised or lowered to the desired vertical position by the elevating control unit 65 a gives the transfer arm 10 a desired vertical position. In addition, the lifting mechanism 62 may be a mechanism that is integrated with the transfer arm 10 and that can freely expand and contract in the vertical direction. In this case, the lifting control unit 65 a Based on the position information, the degree of expansion / contraction of the elevating mechanism 62 is controlled. And the raising / lowering mechanism 62 set to the desired degree of expansion / contraction by the raising / lowering control part 65a will give the conveyance arm 10 the position of a desired perpendicular direction.

  The horizontal movement control unit 65 b controls the horizontal position change (horizontal movement) of the transfer arm 10 by the horizontal movement mechanism 63 based on the horizontal position information from the CPU 70. Here, although not shown in the figure, the horizontal movement mechanism 63 is, for example, in a horizontal direction along a rail that is integrated with the transfer arm 10 and attached to the ceiling of the electroless plating apparatus 60 (the upper surface inside the housing 7). In this case, the horizontal movement control unit 65b controls the horizontal position of the horizontal movement mechanism 63 based on the horizontal position information. Then, the horizontal movement mechanism 63 set at a desired horizontal position by the horizontal movement control unit 65 b gives the desired horizontal position to the transport arm 10.

  From here, in the electroless plating process shown in FIGS. 2 to 5, a plurality of treatment tanks are formed on the semiconductor wafer 1 formed with the circuit pattern 3 having the electrode pads 2 obtained in the treatment step shown in FIG. 1. A procedure for transporting the wafer carrier 11 between the plurality of processing tanks 8 using the variable angle chuck 9 and the transport arm 10 in the case of sequentially immersing in FIG. 8 will be described with reference to FIGS.

  Prior to the description of the transfer procedure, the wafer carrier 11 is, for example, a semiconductor wafer 1 on which a circuit pattern 3 having electrode pads 2 is formed. The semiconductor wafer 1 has a diameter of 6 inches and the semiconductor wafer 1 has a diameter of 8 inches. And a maximum of 25 semiconductor wafers 1 each having a diameter of 12 inches. It is assumed that all the semiconductor wafers 1 accommodated in the wafer carrier 11 have circuit formation surfaces 20 (see FIG. 1) facing substantially the same direction.

  In the present embodiment, a description will be given of an example in which the wafer carrier 11 is transferred from the degreasing treatment tank 8a to the water washing treatment tank 8b. However, the transfer procedure is not limited to this example. That is, the following transfer procedure is performed in the electroless plating process shown in FIGS. 2 to 5 on the semiconductor wafer 1 formed with the circuit pattern 3 having the electrode pads 2 obtained in the process step shown in FIG. The wafer carrier 11 can be similarly transported between a plurality of arbitrary processing tanks 8 using the variable angle chuck 9 and the transfer arm 10 when sequentially immersed in the plurality of processing tanks 8.

  First, in the procedure shown in FIG. 7, after the wafer carrier 11 is immersed in the degreasing liquid in the degreasing treatment tank 8a and the above degreasing process is performed, the transfer arm 10 is lowered and the variable angle chuck 9 is moved to the degreasing process tank 8a. Allow to settle inside. Further, in the procedure shown in FIG. 7, the wafer carrier 11 is held by sandwiching the wafer carrier 11 by the variable angle chuck 9 that has been settled inside the degreasing tank 8a. At this time, the wafer carrier 11 held by the variable angle chuck 9 has the circuit forming surface 20 of each semiconductor wafer 1 accommodated in the horizontal direction X. When the circuit forming surface 20 faces the horizontal direction X, the inclination angle of the circuit forming surface 20 in the vertical plane perpendicular to the circuit forming surface 20 is 0 ° with respect to the vertical direction Y. Here, the vertical plane perpendicular to the circuit forming surface 20 is a vertical plane extending in the horizontal direction X and the vertical direction Y, and is a plane parallel to the paper surface in the cross-sectional views shown in FIGS.

  Subsequently, in the procedure shown in FIG. 8, the angle variable chuck 9 holding the wafer carrier 11 is inclined by θ by a predetermined angle with respect to the posture shown in FIG. Accordingly, following the inclination of the variable angle chuck 9, the wafer carrier 11 held by the variable angle chuck 9 is inclined by the angle θ with respect to the posture shown in FIG. Is done. Specifically, the angle θ is an angle in a direction (see the straight line 81) parallel to the circuit forming surface 20 with respect to the vertical direction Y (see the straight line 80) in the vertical plane. Here, it should be noted that after the angle variable chuck 9 is inclined, the circuit forming surface 20 of each semiconductor wafer 1 is inclined so that the angle θ is directed upward from the horizontal direction X (see arrow Xt). It is a point.

  Subsequently, in the procedure shown in FIG. 9, the transfer arm 10 is raised by the raising distance lu while maintaining the tilted posture of the variable angle chuck 9 and the wafer carrier 11 according to the procedure shown in FIG. As a result, following the ascent of the transfer arm 10, the angle variable chuck 9 and the wafer carrier 11 are raised by the ascent distance lu similarly to the transfer arm 10. The wafer carrier 11 is lifted from the degreasing liquid stored in the degreasing tank 8a by being lifted by the rising distance lu, and is pulled up above the degreasing tank 8a.

  Subsequently, in the procedure shown in FIG. 10, the transfer arm 10 is moved horizontally by the transfer distance lc while maintaining the tilted posture of the variable angle chuck 9 and the wafer carrier 11 according to the procedure shown in FIG. As a result, following the horizontal movement of the transfer arm 10, the angle variable chuck 9 and the wafer carrier 11 are horizontally moved by the transfer distance lc similarly to the transfer arm 10. The wafer carrier 11 is transferred from above the degreasing treatment tank 8a to above the washing process tank 8b by being conveyed by a conveyance distance lc.

  Subsequently, in the procedure shown in FIG. 11, the transfer arm 10 is lowered while maintaining the tilted posture of the variable angle chuck 9 and the wafer carrier 11 according to the procedure shown in FIG. Is settled in the water washing treatment tank 8b. Although not shown, it goes without saying that the distance at which the wafer carrier 11 is lowered at this time is substantially equal to the rising distance lu according to the procedure shown in FIG.

  Subsequently, in the procedure shown in FIG. 12, the inclined posture according to the procedure shown in FIG. 8 is released with respect to the variable angle chuck 9 set in the washing treatment tank 8b. That is, in the procedure shown in FIG. 12, the circuit forming surface 20 of each semiconductor wafer 1 accommodated in the wafer carrier 11 held by the variable angle chuck 9 faces the horizontal direction X, and the circuit forming surface 20 in the vertical plane is The variable angle chuck 9 is inclined by a predetermined angle θ with respect to the posture shown in FIG. 8 so that the inclination angle becomes 0 ° with respect to the vertical direction Y. Note that, in the procedure illustrated in FIG. 8 and the procedure illustrated in FIG. 12, the direction in which the angle θ is inclined is naturally opposite to each other. Then, the said water washing process in the water washing tank 8b is performed.

  7 to 12 are sequentially performed, and the wafer carrier 11 is formed on the electrode pads of the circuit pattern 3 of the semiconductor wafer 1 by carrying the wafer carrier 11 between the plurality of processing tanks 8 while being inclined at an angle θ. In addition, the height of each bump (Ni bump 5 and Au film 6) can be maintained at a uniform and desired height, and it is possible to improve the adhesion between the bump and the electrode pad 2. Become.

  FIG. 13 is a table showing experimental results in which bumps are formed using the electroless plating apparatus 60. The wafer carrier inclination angle θ (predetermined angle θ described above), wafer carrier lifting conditions, wafer carrier transport conditions, and It is a table | surface which shows the relationship of bump performance.

  In the table shown in FIG. 13, the wafer carrier ascending / descending conditions are the distance lu (unit: mm) indicating the above-mentioned ascent distance lu, the time (unit: sec) required for the distance lu to rise, and the speed at which the distance lu is raised ( (Unit: mm / sec). In the present embodiment, as initial conditions in the wafer carrier ascending / descending conditions, the distance lu is 400 mm, the time required to increase the distance lu is 3.0 sec, and the speed at which the distance lu is increased is 133 mm / sec. Is set.

  In the table shown in FIG. 13, the wafer carrier transfer conditions are the distance lc (unit: mm) indicating the transfer distance lc described above, the time required for transfer of the distance lc (unit: sec), and the speed at which the distance lc is transferred ( (Unit: mm / sec). In the present embodiment, the initial conditions in the wafer carrier transfer conditions are the condition that the distance lc is 1000 mm, the time required to transfer the distance lc is 6.5 sec, and the speed for transferring the distance lc is 154 mm / sec. Is set.

  In the table shown in FIG. 13, the bump performance refers to the in-plane uniformity of the bump, which is an index indicating the uniformity of the height of each bump formed on the circuit pattern 3, and the decrease in the adhesion between the bump and the electrode pad 2. It defines the occurrence of weak bump strength, which is an index indicating presence or absence.

  For the bump in-plane uniformity, the standard shown in the following mathematical formula (1) is set for the height of each bump formed on the circuit pattern 3, and it is good (◯) when it is within this standard, and when it is outside this standard It is judged as no (×). Here, in the following formula (1), the parameter “MAX” is the height of the highest bump among the bumps, and the parameter “MIN” is the height of the lowest bump among the bumps.

−20 ≦ (MAX−MIN) / (MAX + MIN) × 100 ≦ 20 (1)
The occurrence of weak bump strength is judged as good (absent) when there is no bump having a shear strength per unit area of less than 0.003 g / μm ² , and not (present) when it exists.

  In the table shown in FIG. 13, as the semiconductor wafer accommodated in the wafer carrier, a semiconductor wafer having a diameter of 8 inches and a number of mounted circuit patterns of 1000 was used.

  First, the wafer carrier ascending / descending condition and the wafer carrier conveying condition were all set as the initial conditions described above, and the wafer carrier inclination angle θ was appropriately changed between 0 ° and 90 ° (the first to sixth rows in the table shown in FIG. 13). Reference) The case will be described. In this case, when the wafer carrier inclination angle θ is 20 ° to 40 ° (see the 2nd to 4th rows in the table shown in FIG. 13), the bump in-plane uniformity is good (◯) and the bump strength is weak. A result of good (none) was obtained. That is, it is appropriate that the wafer carrier inclination angle θ, that is, the predetermined inclination angle θ (see FIG. 8) of the wafer carrier 11 is 20 ° or more and 40 ° or less.

  In addition, when the wafer carrier inclination angle θ is less than 20 °, the following reasons are presumed as the reason why the in-plane bump uniformity is not (x) and the bump strength is weak (present). That is, in this case, the flow rate of the liquid adhering to the semiconductor wafer 1 with respect to the unit time when the wafer carrier 11 is transported after processing in a certain processing tank 8 (any one of the processing tanks 8a to 8n). However, it becomes very large. At this time, the liquid adhering to the semiconductor wafer 1 flows down in a short time and disappears from the surface. As a result, the surface of the semiconductor wafer 1 is oxidized, which causes a phenomenon that the electrode pads 2 of the circuit pattern 3 of the semiconductor wafer 1 are dried by being exposed to the atmosphere.

  In addition, when the wafer carrier inclination angle θ exceeds 40 °, the following reasons are presumed as the reason why the bump in-plane uniformity is not good (x) and the bump strength is weak (is not present). That is, in this case, the flow rate of the liquid adhering to the semiconductor wafer 1 per unit time when the wafer carrier 11 is transferred after the processing in a certain processing tank 8 becomes very small. At this time, the remaining amount of the liquid adhering to the semiconductor wafer 1 becomes very large, and accordingly, various chemical reactions are unnecessarily promoted on the semiconductor wafer 1 during the transfer. There is a risk of variations in pump length.

  Next, the wafer carrier tilt angle θ is set to 30 °, all the wafer carrier transport conditions are set to the above initial conditions, and the distance lu is set to the initial condition among the wafer carrier lift conditions, and the wafer carrier lift conditions are set. Among these, the case where the speed of increasing the distance lu is appropriately changed between 80 mm / sec and 400 mm / sec (see the seventh to tenth rows in the table shown in FIG. 13) will be described. In this case, in response to the change in speed, the time required to increase the distance lu is also changed between 5 sec and 1 sec as shown in the table of FIG. In this case, when the speed of increasing the distance lu is 100 mm / sec to 200 mm / sec (refer to the 8th and 9th rows in the table shown in FIG. 13), the uniformity in the bump surface is good (◯) and the bump strength is weak. The result was good (none). When the speed at which the distance lu is increased is 100 mm / sec to 200 mm / sec, the time required to increase the distance lu is 4 sec to 2 sec. That is, the time required for the rising of the rising distance lu (see FIG. 9), and the time required for the lowering of the distance (see the description relating to FIG. 11) where the wafer carrier 11 is lowered, which is substantially equal to the rising distance lu, is 100 mm. / Sec or more and 200 mm / sec or less is appropriate.

  The reason why the in-plane uniformity of the bump is no (x) and the occurrence of weak bump strength is not (exists) when the speed of increasing and / or decreasing the distance lu is less than 100 mm / sec is as follows. Guessed. That is, in this case, the transfer time of the wafer carrier 11 becomes longer, and accordingly, the amount of liquid attached to the surface of the semiconductor wafer 1 increases and disappears from the surface of the semiconductor wafer 1. This causes a phenomenon that the surface of the semiconductor wafer 1 is oxidized and the electrode pads 2 of the circuit pattern 3 of the semiconductor wafer 1 are dried by being exposed to the atmosphere.

  The reason why the uniformity in the bump surface is not (x) and the occurrence of weak bump strength is not (present) when the speed of increasing and / or decreasing the distance lu exceeds 200 mm / sec is as follows. Guessed. That is, in this case, the flow of the liquid adhering to the surface of the semiconductor wafer 1 is promoted (by the liquid being shaken off) due to the friction between the liquid and air, and therefore adhering to the surface of the semiconductor wafer 1. The amount of the liquid that flows down increases and disappears from the surface of the semiconductor wafer 1. This causes a phenomenon that the surface of the semiconductor wafer 1 is oxidized and the electrode pads 2 of the circuit pattern 3 of the semiconductor wafer 1 are dried by being exposed to the atmosphere.

  Finally, the wafer carrier inclination angle θ is set to 30 °, the wafer carrier lifting conditions are all the initial conditions described above, and the distance lc is set to the initial conditions among the wafer carrier transfer conditions, and the wafer carrier transfer conditions Among these, a case will be described in which the time required for transporting the distance lc is appropriately changed between 3 sec and 12 sec (see the 11th to 14th rows in the table shown in FIG. 13). In this case, the speed for transporting the distance lc is also changed between 333 mm / sec and 83 mm / sec as shown in the table of FIG. In this case, when the time required for transporting the distance lc is 4 sec to 9 sec (see the 12th and 13th rows in the table shown in FIG. 13), the uniformity in the bump surface is good (◯) and the bump strength is weak. A result of good (none) was obtained. When the time required for transporting the distance lc is 4 sec to 9 sec, the speed for transporting the distance lc is 250 mm / sec to 111 mm / sec. That is, it is appropriate that the time required for transporting the transport distance lc (see FIG. 10) is 4 sec or more and 9 sec or less.

  The following reasons are presumed as the reasons why the uniformity in the bump surface is negative (x) and the occurrence of weak bump strength is negative (present) when the time required for transporting the transport distance lc is less than 4 seconds. . That is, in this case, an excessive increase in the speed for carrying the distance lc is expected. When the speed is excessively increased, the flow of the liquid adhering to the semiconductor wafer 1 is promoted (by the liquid being shaken off) due to the friction between the liquid and air. The liquid disappears from the surface of the semiconductor wafer 1. This causes a phenomenon that the surface of the semiconductor wafer 1 is oxidized and the electrode pads 2 of the circuit pattern 3 of the semiconductor wafer 1 are dried by being exposed to the atmosphere.

  On the other hand, when the time required for the transfer of the transfer distance lc exceeds 9 sec, the time required for the transfer of the transfer distance lc becomes longer after the processing in the certain processing tank 8, and accordingly, the semiconductor wafer 1 The flow amount of the liquid adhering to the surface increases, and the liquid disappears from the surface of the semiconductor wafer 1. This causes a phenomenon that the surface of the semiconductor wafer 1 is oxidized and the electrode pads 2 of the circuit pattern 3 of the semiconductor wafer 1 are dried by being exposed to the atmosphere.

  The liquid adhering to the surface of the semiconductor wafer 1 gradually increases from the outer peripheral portion to the central portion of the semiconductor wafer 1 due to the relationship between surface tension and gravity when the semiconductor wafer 1 is pulled up from a certain processing tank 8. Since it flows down, the surface of the semiconductor wafer 1 is easily dried on the outer peripheral portion of the semiconductor wafer 1. That is, in order to prevent the surface of the semiconductor wafer 1 from being dried and to prevent the electrode pads 2 of the circuit pattern 3 from being dried, the entire surface of the semiconductor wafer 1 is transferred during the transfer of the wafer carrier 11 in which the semiconductor wafer 1 is accommodated. In addition, it is necessary to leave the adhered liquid. In view of the experimental results described above, by applying one or any combination of the appropriate wafer carrier tilt angle θ, wafer carrier lifting / lowering conditions, and wafer carrier transport conditions, It has been found that the plating apparatus 60 can form bumps that ensure uniformity in the bump surface and that there is no occurrence of weak bump strength.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

  In the plating apparatus, the present invention maintains the height at a desired height, makes the height constant, and improves the adhesion with the electrode pad in each pump formed by an electroless plating method. Therefore, the present invention can be applied to various plating apparatuses for forming bumps on an electrode pad of a circuit pattern formed on one surface of a semiconductor wafer by an electroless plating method.

It is a figure which shows an electroless-plating process process, and is sectional drawing which shows the process process which forms a circuit pattern in the one surface of a semiconductor wafer. It is a figure which shows an electroless-plating process process, and is sectional drawing which shows the process process which degreases the surface of an electrode pad, and also etches the surface of an electrode pad. It is a figure which shows an electroless-plating process process, and after forming a Zn film on the surface of an electrode pad, it is sectional drawing which shows a process process which once peels a Zn film and forms a Zn film again. It is a figure which shows an electroless-plating process process, and is sectional drawing which shows the process process which forms Ni bump by the electroless-plating method on the electrode pad containing on Zn film. It is a figure which shows an electroless-plating process process, and is sectional drawing which shows the process process which forms Au film | membrane by the electroless-plating method around Ni bump. It is sectional drawing which shows schematic structure of the plating processing apparatus which concerns on this invention. It is a figure which shows the conveyance procedure of the wafer carrier between several process tanks, and is sectional drawing which shows the procedure which descends a conveyance arm and sinks an angle variable chuck in the inside of a degreasing process tank. It is a figure which shows the conveyance procedure of the wafer carrier between several processing tanks, and is sectional drawing which shows the procedure which inclines a predetermined angle angle variable chuck | zipper holding the wafer carrier. It is a figure which shows the conveyance procedure of the wafer carrier between several process tanks, and is sectional drawing which shows the procedure which raises a conveyance arm. It is a figure which shows the conveyance procedure of the wafer carrier between several process tanks, and is sectional drawing which shows the procedure to move a conveyance arm horizontally. It is a figure which shows the conveyance procedure of the wafer carrier between several process tanks, and is sectional drawing which shows the procedure to which a conveyance arm is lowered | hung and an angle variable chuck and a wafer carrier are settled inside a washing process tank. It is a figure which shows the conveyance procedure of the wafer carrier between several processing tanks, and is sectional drawing which shows the procedure which cancels | releases the inclination of the variable angle chuck | zipper and wafer carrier which concern on the procedure shown in FIG. It is a table | surface which shows the experimental result which formed the bump using the said plating processing apparatus, and is a table | surface which shows the relationship between a wafer carrier inclination angle, wafer carrier raising / lowering conditions, wafer carrier conveyance conditions, and bump performance. It is a block diagram which shows the structure of a control system for controlling operation | movement of a variable angle chuck and a conveyance arm.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor wafer 2 Electrode pad 3 Circuit pattern 5 Ni bump 6 Au film 8 Treatment tank 8a Degreasing treatment tank 8b Water washing treatment tank (1st water washing treatment tank)
8c Etching tank 8d Water washing tank (second water washing tank)
8e Jincate treatment tank (first zinc replacement treatment tank)
8f Water washing tank (third water washing tank)
8g Nitric acid treatment tank 8h Water washing tank (4th water washing tank)
8i zincate treatment tank (second zinc replacement treatment tank)
8j Water washing tank (5th water washing tank)
8k Ni plating tank (first electroless plating tank)
8l water washing tank (6th water washing tank)
8m Au plating tank (second electroless plating tank)
8n water washing tank (7th water washing tank)
9 Variable angle chuck (carrier holding device)
DESCRIPTION OF SYMBOLS 10 Transfer arm 11 Wafer carrier 20 Circuit formation surface 60 Electroless plating apparatus (plating process treatment)
X Horizontal direction Y Vertical direction lc Transport distance lu Ascent distance θ Inclination angle of wafer carrier 11

Claims (6)

A wafer carrier containing a semiconductor wafer is sequentially immersed in liquids stored in a plurality of processing tanks, and bumps are formed on an electrode pad of a circuit pattern formed on the semiconductor wafer by an electroless plating method. A plating apparatus for
A carrier holding device that holds the wafer carrier in an inclined posture so that a circuit forming surface of the semiconductor wafer on which the circuit pattern is formed faces upward from a horizontal direction;
With respect to the wafer carrier held by the carrier holding device, the wafer carrier floats from the liquid stored in the processing tank, the wafer carrier settles into the liquid stored in the processing tank, and a plurality of A transfer arm for transferring the wafer carrier between the processing tanks,
The carrier holding device tilts the wafer carrier so that an inclination angle of the circuit forming surface in a vertical plane perpendicular to the circuit forming surface is 20 ° or more and 40 ° or less with respect to the vertical direction. A plating apparatus characterized by being held in a posture.   2. The plating apparatus according to claim 1, wherein the transfer arm performs at least one of floating and sinking of the wafer carrier at a speed of 100 millimeters / second or more and 200 millimeters / second or less.   3. The plating apparatus according to claim 1, wherein the transfer arm transfers the wafer carrier in a time of 4 seconds or more and 9 seconds or less. A wafer carrier containing a semiconductor wafer is sequentially immersed in liquids stored in a plurality of processing tanks, and bumps are formed on an electrode pad of a circuit pattern formed on the semiconductor wafer by an electroless plating method. A plating apparatus for
A carrier holding device that holds the wafer carrier in an inclined posture so that a circuit forming surface of the semiconductor wafer on which the circuit pattern is formed faces upward from a horizontal direction;
With respect to the wafer carrier held by the carrier holding device, the wafer carrier floats from the liquid stored in the processing tank, the wafer carrier settles into the liquid stored in the processing tank, and a plurality of A transfer arm for transferring the wafer carrier between the processing tanks,
The plating apparatus according to claim 1, wherein the transfer arm performs at least one of floating and sinking of the wafer carrier at a speed of 100 millimeters / second or more and 200 millimeters / second or less. A wafer carrier containing a semiconductor wafer is sequentially immersed in liquids stored in a plurality of processing tanks, and bumps are formed on an electrode pad of a circuit pattern formed on the semiconductor wafer by an electroless plating method. A plating apparatus for
A carrier holding device that holds the wafer carrier in an inclined posture so that a circuit forming surface of the semiconductor wafer on which the circuit pattern is formed faces upward from a horizontal direction;
With respect to the wafer carrier held by the carrier holding device, the wafer carrier floats from the liquid stored in the processing tank, the wafer carrier settles into the liquid stored in the processing tank, and a plurality of A transfer arm for transferring the wafer carrier between the processing tanks,
The plating apparatus according to claim 1, wherein the transfer arm transfers the wafer carrier in a time of 4 seconds or more and 9 seconds or less. The plurality of treatment tanks are
A degreasing treatment tank in which a degreasing agent is stored, a first washing process tank in which pure water is stored, an etching processing tank in which an etching solution is stored, a second washing process tank in which pure water is stored, and a zinc replacement solution are stored. The first zinc replacement treatment tank, the third water washing treatment tank in which the pure water is stored, the nitric acid treatment tank in which the nitric acid is stored, the fourth water washing treatment tank in which the pure water is stored, and the second in which the zinc replacement liquid is stored. A zinc replacement treatment tank, a fifth water washing treatment tank in which pure water is stored, a first electroless plating treatment tank in which nickel-phosphorous plating solution is stored, a sixth water washing treatment tank in which pure water is stored, and a gold plating solution A second electroless plating treatment tank stored, and a seventh washing treatment tank in which pure water is stored;
The plating apparatus includes the wafer carrier,
Degreasing agent stored in the degreasing tank, pure water stored in the first washing tank, etching liquid stored in the etching tank, pure water stored in the second washing tank, the first 1 zinc replacement solution stored in the zinc replacement treatment tank, pure water stored in the third water washing treatment tank, nitric acid stored in the nitric acid treatment tank, pure water stored in the fourth water washing processing tank, Zinc replacement liquid stored in the second zinc replacement processing tank, pure water stored in the fifth water washing processing tank, nickel-phosphorous plating liquid stored in the first electroless plating processing tank, the sixth water cleaning In the order of pure water stored in the processing tank, gold plating solution stored in the second electroless plating processing tank, pure water stored in the seventh water-washing processing tank, in order, on the electrode pad, The bump is formed by electroless plating. Plating apparatus according to any one of claims 1 to 5, symptoms.

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