KR20050057334A - Electroless plating apparatus and electroless plating method - Google Patents

Abstract

A plate is placed near a substrate held by a substrate holding section. A treating liquid is ejected from a treating liquid ejecting section, thereby plating the substrate electrolessly. The treating liquid flows through the gap between the substrate and the plate. Therefore a flow of the treating liquid occurs on the substrate. As a result, a fresh treating liquid can be supplied onto the substrate. Thus, a plating film can be formed very uniformly on the substrate even if the amount of treating liquid is small.

Description

ELECTROLESS PLATING APPARATUS AND ELECTROLESS PLATING METHOD}

 The present invention relates to an electroless plating apparatus and an electroless plating method.

 In the formation of the semiconductor device, the formation of wiring on the semiconductor substrate is performed.

With the improvement in the degree of integration of semiconductor devices, the wiring has become finer, and correspondingly, the development of the wiring making technology has been implemented. For example, as a method of forming copper wiring, a dual damascene method of forming a copper seed layer by sputtering and filling a groove or the like by electroplating to form wiring and interlayer connection has been put into practical use. In this method, it is difficult to form electroplating on the surface to be plated on which the seed layer is not formed.

On the other hand, as a plating method which does not require a seed layer, there is an electroless plating method. Electroless plating forms a plated film by chemical reduction, and the plated film can be formed continuously by acting as a self-catalyst. Electroless plating does not require the creation of the seed layer in advance (or the formation of the seed layer on the entire surface to be plated), and the nonuniformity of the film thickness in the formation of the seed layer (especially in the concave and convex portions). Step coverage) does not have to be considered very much.

Moreover, the following techniques are disclosed regarding electroless plating (refer patent document 1, 2).

* Patent Document 1: Japanese Patent Laid-Open Publication, Japanese Patent Application Laid-Open No. 2001-73157 (4 pages, FIG. 1)

* Patent Document 2: Japanese Patent Laid-Open Publication, Japanese Patent Laid-Open No. 2001-342573 (4th to 5th pages, 2nd and 3rd degrees)

1 is a partial cross-sectional view showing an electroless plating apparatus according to the first embodiment.

2A and 2B are plan views showing an example of the lower surface of the upper plate of the electroless plating apparatus shown in FIG. 1.

3 is a partial cross-sectional view showing a state in which the wafer W and the like provided in the electroless plating apparatus shown in FIG. 1 are inclined.

4 is a flowchart showing an example of a procedure in the case of performing electroless plating using the electroless plating apparatus according to the first embodiment.

FIG. 5 is a partial cross-sectional view showing a state of the electroless plating apparatus in the case where electroless plating is performed in the order shown in FIG. 4.

FIG. 6 is a partial cross-sectional view showing the state of the electroless plating apparatus in the case where electroless plating is performed in the order shown in FIG. 4.

FIG. 7 is a partial sectional view showing a state of the electroless plating apparatus in the case where electroless plating is performed in the order shown in FIG. 4.

FIG. 8 is a partial cross-sectional view showing a state of the electroless plating apparatus in the case where electroless plating is performed in the procedure shown in FIG. 4.

FIG. 9 is a partial cross-sectional view showing a state of the electroless plating apparatus in the case where electroless plating is performed in the order shown in FIG. 4.

FIG. 10 is a partial sectional view showing a state of the electroless plating apparatus in the case where electroless plating is performed in the order shown in FIG. 4.

FIG. 11 is a partial cross-sectional view showing the state of the electroless plating apparatus in the case where electroless plating is performed in the procedure shown in FIG. 4.

In electroless plating, the plating liquid is composed of many chemicals, and since the composition change is likely to change, the plating liquid becomes unstable and its life is likely to be shortened. In electroless plating, the deposition rate of the plated film is generally slower than that of electrolytic plating, and the formation rate of the plated film and the characteristics of the plated film formed are easily changed depending on process conditions such as temperature, composition ratio, and flow rate of the plating liquid. In Patent Documents 1 and 2, electroless plating is carried out in a state where a plating solution is collected on a substrate, and the characteristics of the plating solution tend to change during film formation. As a result, in performing electroless plating on a substrate, it becomes difficult to secure uniformity of processing on the substrate. In addition, the amount of the plating liquid per unit precipitation amount is increased due to the instability of the plating liquid as described above, and the cost is likely to be high.

In view of the above, it is an object of the present invention to provide an electroless plating apparatus and an electroless plating method which are easy to secure uniformity of processing to a substrate even with a small amount of the processing liquid.

In order to achieve the above object, the electroless plating apparatus according to the present invention has a substrate holding portion for holding a substrate, a plate disposed to face the substrate held on the substrate holding portion, and a surface of the plate facing the substrate. And a processing liquid discharge portion for discharging the processing liquid and a gap adjusting portion for changing a distance between the plate and the substrate.

The gap adjusting unit allows the substrate held by the substrate holding unit to close the plate, and discharges the processing liquid from the processing liquid discharge unit, thereby performing electroless plating on the substrate.

As the processing liquid flows through the gap between the substrate and the plate, a flow of the processing liquid occurs on the substrate, thereby making it possible to reduce the concentration nonuniformity at the interface where the plating film is deposited. As a result, a plating film can be formed on a board | substrate with high uniformity. Moreover, by adjusting the space | interval of a board | substrate and a plate by a space | interval adjustment part, it becomes possible to control the volume of the plating liquid on a board | substrate, and by narrowing this space | interval, the usage-amount of a process liquid can be reduced.

The "treatment liquid" as used herein contains at least a chemical solution for electroless plating, and may optionally include a cleaning liquid used for pretreatment and post-treatment of electroless plating. That is, any of the apparatuses which perform only electroless plating using the electroless plating chemical liquid as the "treatment liquid" and the apparatus which also performs the pre-treatment or post-treatment of the electroless plating are included in the "electroless plating apparatus".

(1) The electroless plating apparatus may further include a heating unit for heating the plate.

Since the plate is heated, it becomes easy to ensure the uniformity of the temperature of the processing liquid between the gap between the substrate and the plate. As a result, the uniformity of the plating film formed on a board | substrate can be improved more, and the deposition rate of a plating film can be made larger.

(2) The electroless plating apparatus may further include an inclination adjustment unit for integrally changing the inclination of the substrate and the plate.

By tilting the substrate, the gas between the substrate and the plate can be promptly replaced with the treatment liquid, whereby the non-uniformity of the plated film due to the bubbles remaining on the substrate can be reduced. In addition, gas (e.g., hydrogen) generated during formation of the plating film can be quickly removed between the substrate and the plate. In this way, unevenness of the plated film due to bubbles in the processing liquid can be reduced.

(3) The electroless plating apparatus may further include a liquid supply mechanism for temperature-controlling and supplying a processing liquid to the plate.

The uniformity of the temperature of a process liquid can be improved further by heating a process liquid previously.

1) Here, the said liquid supply mechanism may switch and supply a process liquid. Various processes can be performed with respect to a board | substrate by switching a some process liquid. For example, a plurality of plated films can be formed on the substrate by switching the chemical solution for electroless plating. In addition, by using the electroless plating pretreatment or posttreatment liquid as the treatment liquid, the electroless plating treatment, its pretreatment and posttreatment can be carried out continuously. Specific examples of pretreatment and post-treatment include washing of the substrate, activation of the substrate, and the like.

2) The liquid supply mechanism may have a processing liquid generating unit for mixing a plurality of chemical liquids to generate a processing liquid. By the processing liquid generating unit, it is possible to generate the required amount of processing liquid immediately before the supply, and to stably supply the processing liquid. As a result, the uniformity of the plating film formed on the substrate is further improved.

(4) an electroless plating apparatus is formed on the second plate disposed opposite to the second surface different from the surface of the substrate, and on the surface of the second plate opposite to the second surface of the substrate; The liquid discharge part for discharging the temperature-controlled liquid and the second gap adjusting part for changing the distance between the second plate and the substrate may be further provided.

The substrate can be heated from the rear surface by bringing the second plate and the substrate into close proximity and supplying the liquid heated in the liquid discharge portion by the second gap adjusting portion. As a result, it becomes possible to heat a board | substrate in front and back by a plate and a 2nd plate, and the uniformity of the temperature of a board | substrate further improves.

Unlike the "treatment liquid", this "liquid" does not necessarily contain an electroless plating chemical. This is because it is sufficient that the "liquid" functions as a heat medium for heating the second plate. As the "liquid", pure water can be used, for example. When pure water is used, the processing liquid can be prevented from returning from the front surface side to the rear surface side of the substrate, thereby preventing the back surface of the substrate from being contaminated by the processing liquid (the components, for example, metal ions constituting the plating liquid). can do.

Here, the heating of the "liquid" may be performed by a heating means such as a heater provided in the second plate, but is performed by a liquid supply mechanism for supplying the liquid discharged from the liquid discharge part to the second plate by controlling the temperature. You may. The temperature uniformity of the substrate can be further improved by adjusting the temperature of the liquid in advance.

(5) The electroless plating apparatus may further include a movable nozzle for discharging the processing liquid to the substrate.

By the nozzle, the processing liquid can be supplied to a desired portion of the substrate, thereby improving the flexibility of supplying the processing liquid onto the substrate.

B. An electroless plating method according to the present invention includes a holding step of holding a substrate, an arranging step of placing a plate opposite to the substrate held in the holding step, and a substrate and a plate disposed to face each other in the placing step. And forming a plated film on the substrate by supplying the processing liquid therebetween.

The gap between the held substrate and the plate is brought close to each other, and the substrate is subjected to electroless plating by supplying a treatment liquid therebetween.

As the processing liquid flows through the gap between the substrate and the plate, a flow of the processing liquid occurs on the substrate, whereby a fresh processing liquid can be supplied onto the substrate. As a result, a highly uniform plated film can be formed at the reaction interface of the substrate.

(1) You may have the space | interval adjustment step which adjusts the space | interval of the said board | substrate and the said plate so that it may become narrower than the thickness of the process liquid at the time of holding | maintenance by surface tension on the said board | substrate.

By limiting the distance between the substrate and the plate, the amount of the processing liquid used can be reduced.

(2) The film forming step may have a processing liquid generating step of generating a processing liquid by mixing a plurality of chemical liquids.

It is possible to generate the required amount of processing liquid immediately before the supply, and to stably supply the processing liquid. As a result, the uniformity of the plating film formed on the substrate is further improved.

(3) The electroless plating method may further include an inclination step of tilting the substrate held in the holding step prior to the film forming step.

By tilting the substrate, the gas between the substrate and the plate can be quickly replaced with the treatment liquid, and the nonuniformity of the plated film due to the remaining of bubbles can be reduced. In addition, gas (e.g., hydrogen) generated during the formation of the plating film can be promptly removed from between the substrate and the plate. In this way, unevenness of the plated film due to bubbles in the processing liquid can be reduced.

(4) The electroless plating method may further include a heating step of heating the substrate held in the holding step before the film forming step.

 Since the plate is heated, it becomes easy to secure the stability and uniformity of the temperature of the processing liquid between the gaps. As a result, the uniformity of the plating film formed on a board | substrate can be improved further, and the precipitation rate of a plating film can be made further larger.

(First embodiment)

Hereinafter, an electroless plating apparatus according to a first embodiment of the present invention will be described in detail with reference to the drawings.

1 is a partial cross-sectional view showing the configuration of an electroless plating apparatus 10 according to a first embodiment of the present invention.

The electroless plating apparatus 10 can perform the electroless plating process to the wafer W which is a board | substrate, the preprocessing, the washing process after plating, and a drying process using a process liquid.

That is, the treatment liquid may include various liquids such as plating liquid pretreatment, post treatment chemical liquid, pure water, in addition to the electroless plating chemical liquid.

As a chemical liquid used for electroless plating, the following materials may be mixed and dissolved in pure water.

1) Metal salt: It is a material supplying metal ions constituting the plating film. The metal salt is, for example, copper sulfate, copper acetate or copper chloride when the plating film is copper.

2) Complexing agent: It is a material to improve the stability in liquid by complexing metal so that metal ions do not precipitate as hydroxide under strong alkalinity. As the complexing agent, for example, HEDTA, EDTA, ED as the amine material, citric acid, tartaric acid and gluconic acid can be used as the organic material.

3) Reducing agent: A material for catalytically reducing and depositing metal ions. Examples of the reducing agent include hypochlorous acid, glyoxylic acid, ditin tin chloride, boron hydride compounds and dicobalt acetate.

4) Stabilizer: It is a material that prevents natural decomposition of plating solution due to nonuniformity of oxide (copper oxide if copper plating film is copper). As the stabilizer, for example, bibirujiru, cyanide, thiourea, O-phenanthroline, neobroin, which preferentially forms a complex with monovalent copper, can be used.

5) pH buffer: It is a material for suppressing the change of pH when the reaction of the plating liquid proceeds. As the pH buffer, for example, boric acid, carbonic acid, oxycarboxylic acid can be used.

6) Additives: Additives include materials that promote and inhibit deposition of the plating film, and materials that modify the surface or the plating film.

As a material for suppressing the deposition rate of the plating film to stabilize the plating solution and to improve the properties of the plating film, for example, thiosulfate or 2-MBT can be used as the sulfur-based material.

As a material for lowering the surface tension of the plating liquid so that the plating liquid is uniformly disposed on the surface of the wafer W, for example, polyalkylene glycol and polyethylene glycol can be used as the nonionic material of the surfactant.

As shown in FIG. 1, the electroless plating apparatus 10 includes a base 11, a hollow motor 12, a wafer chuck 20 as a substrate holder, an upper plate 30, a lower plate 40, and a cup ( 50), nozzle arms 61 and 62, a substrate inclination mechanism 70 which is an inclination adjustment part, and a liquid supply mechanism 80. Here, the hollow motor 12, the wafer chuck 20, the upper plate 30, the lower plate 40, the cup 50, and the nozzle arms 61 and 62 are directly or indirectly connected to the base 11. And the base 11 are moved together, and the inclination by the substrate tilt mechanism 70 is performed.

The wafer chuck 20 holds and fixes the wafer W. The wafer chuck 20 includes a wafer holding claw 21, a wafer chuck bottom plate 23, and a wafer chuck support portion 24.

A plurality of wafer holding claws 21 are arranged on the outer circumference of the wafer chuck bottom plate 23 to hold and fix the wafer W. As shown in FIG.

The wafer chuck bottom plate 23 is a substantially circular flat plate connected to the upper surface of the wafer chuck support part 24, and is disposed on the bottom surface of the cup 50.

The wafer chuck support part 24 is substantially cylindrical shape, is connected to the circular opening part provided in the wafer chuck bottom plate 23, and comprises the rotating shaft of the hollow motor 12. As shown in FIG. As a result, by driving the hollow motor 12, the wafer chuck 20 can be rotated while the wafer W is held.

2A and 2B are plan views showing an example of the lower surface of the upper plate 30, respectively.

As shown in Figs. 1, 2A, and 2B, the upper plate 30 is a substantially circular flat plate shape disposed to face the upper surface of the wafer W, and the treatment of chemical liquid, pure water, and the like on the upper surface of the wafer W is performed. The liquid is supplied and the treatment liquid is heated. For this reason, in order to efficiently manufacture the semiconductor device using the wafer W, it is preferable that the size of the upper plate 30 is close to the size of the wafer W or is larger than the wafer W. Specifically, it is preferable that the size of the upper plate 30 is 80% or more, or 90% or more of the area of the wafer W.

Here, the size of the upper plate 30 is somewhat smaller than the wafer W in FIG. 1 in order to prevent the upper plate 30 from contacting the wafer holding claw 21. However, this is not necessarily an absolute condition, and for example, it is possible to avoid this condition by preventing the upper end of the wafer holding claw 21 from protruding from the upper surface of the wafer W.

The upper plate 30 has a heater H, a processing liquid discharge port 31, a processing liquid inlet 32, a temperature measuring mechanism 33, and is connected to a lifting mechanism 34.

The heater H is heating means, such as a heating wire, for heating the upper plate 30. The heater H corresponds to the temperature measurement result in the temperature measuring device 33 so that the upper plate 30, and thus the wafer W, is maintained at a desired temperature (for example, in the range of room temperature to about 60 ° C). The amount of heat generated is controlled by control means (not shown).

The treatment liquid discharge port 31 is formed in the singular or plural on the lower surface of the upper plate 30, and discharges the treatment liquid introduced from the treatment liquid inlet 32.

As shown in Figs. 2A and 2B, each of the heater H and the processing liquid discharge port 31 is distributed and disposed on the lower surface, so that the temperature of the upper plate 30 and the supply of the processing liquid can be equalized. . The processing liquid discharge port 31 is disposed radially from, for example, four directions (FIG. 2A) or three directions (FIG. 2B) from the center of the lower surface of the upper plate 30. However, these arrangements are only an example, and it is also possible to arrange | position the process liquid discharge port 31 other than radial, for example, vertically and horizontally aligned. That is, if the distribution of the temperature and the processing liquid supply amount on the upper plate 30 is achieved as a result, the number, shape, and arrangement of the heater H and the processing liquid discharge port 31 can be appropriately selected.

The processing liquid inlet 32 is on the upper surface side of the upper plate 30, and the processing liquid flows in, and the processing liquid flows into the processing liquid discharge port 31. The treatment liquid introduced into the treatment liquid inlet 32 may be used by switching between pure water (RT: room temperature) and heated chemical liquids 1 and 2 (for example, a range of about 60 ° C. from room temperature). In addition, it is also possible to introduce the chemical liquids 1 and 2 (in some cases, a plurality of chemical liquids containing different chemical liquids) mixed in the mixing box 85 to be described later into the treatment liquid inlet 32.

The temperature measuring mechanism 33 is a temperature measuring means such as a thermocouple embedded in the upper plate 30, and measures the temperature of the upper plate 30.

The elevating mechanism 34 is connected to the upper plate 30 to raise and lower the upper plate 30 in a state facing the wafer W so as to control the distance from the wafer W, for example, between 0.1 and 500 mm. can do. During the electroless plating, the wafer W and the upper plate 30 are brought close to each other (for example, the gap between the wafer W and the upper plate 30 is 2 mm or less), and the size of the gap space is limited to the wafer ( The processing liquid supplied on the surface of W) can be made uniform and the amount of use can be reduced.

As shown in FIG. 1, the lower plate 40 has a substantially circular flat plate shape disposed to face the lower surface of the wafer W, and is supplied with the pure water heated to the lower surface thereof in a state close to the wafer W. As shown in FIG. The wafer W can be appropriately heated.

In order to efficiently heat the wafer W, it is preferable that the size of the lower plate 40 approximate the size of the wafer W. FIG. Specifically, it is preferable that the size of the lower plate 40 is 80% or more, or 90% or more of the area of the wafer W.

The lower plate 40 has a processing liquid discharge port 41 formed at the center of the upper surface thereof, and is supported by the support portion 42.

The processing liquid discharge port 41 discharges the processing liquid that has passed through the support part 42. The treatment liquid can be used by switching pure water (RT: room temperature) and heated pure water (for example, in the range of room temperature to about 60 ° C).

The support part 42 penetrates the hollow motor 12, and is connected to the lifting mechanism (not shown) which is a space | interval adjustment part. By operating the lifting mechanism, the support portion 42, and further, the lower plate 40 can be lifted up and down.

The cup 50 holds the wafer chuck 20 therein, and collects and discharges the processing liquid used for the processing of the wafer W. The cup side 51, the cup bottom plate 52, and the waste pipe Has 53.

The cup side part 51 is a substantially cylindrical shape whose inner periphery is along the outer periphery of the wafer chuck 20, and the upper end part is located in the upper vicinity of the holding surface of the wafer chuck 20. As shown in FIG.

The cup bottom plate 52 is connected to the lower end part of the cup side part 51, has an opening part in the position corresponding to the hollow motor 12, and the wafer chuck 20 is arrange | positioned in the position corresponding to the opening part.

The waste liquid pipe 53 is connected to the cup bottom plate 52, and discharges the waste liquid (the processing liquid which processed the wafer W) from the cup 50 to the waste liquid line of a factory in which the electroless plating apparatus 10 is installed. Piping for

The cup 50 is connected to the lifting mechanism not shown, and can move up and down with respect to the base 11 and the wafer W. As shown in FIG.

The nozzle arms 61 and 62 are disposed in the vicinity of the upper surface of the wafer W, and discharge fluid such as processing liquid, air and the like from the opening of the tip portion thereof. The discharged fluid can appropriately select pure water, chemical liquid and nitrogen gas. A moving mechanism (not shown) for moving the nozzle arms 61, 62 in the direction toward the center of the wafer W is connected to the nozzle arms 61, 62, respectively. In the case of discharging fluid to the wafer W, the nozzle arms 61 and 62 are moved above the wafer W, and when the discharge is completed, the nozzle arms 61 and 62 are moved out of the outer circumference of the wafer W. The number of nozzle arms may be either singular or three or more depending on the amount and type of chemical liquid to be discharged.

The substrate inclination mechanism 70 is connected to the base 11, and the base 11, the wafer chuck 20, the wafer W, and the upper plate 30 connected to the base 11 by moving one end of the base 11 up and down. ), The bottom plate 40 and the cup 50 are inclined, for example, in the range of 0 to 10 degrees, or 0 to 5 degrees.

3 is a partial cross-sectional view showing a state in which the wafer W and the like are inclined by the substrate tilt mechanism 70. The base 11 is inclined by the substrate tilt mechanism 70, and the wafer W or the like directly or indirectly connected to the base 11 is inclined at an angle θ.

The liquid supply mechanism 80 supplies the processing liquid heated to the upper plate 30 and the lower plate 40, and the temperature adjusting mechanism 81, the processing liquid tanks 82, 83, 84, and the pumps P1 to P5), the valves V1 to V5, and the mixing box 85 are configured. In addition, although FIG. 1 shows the case where chemical | medical solution 1 and 2 and two types of chemical | medical solution are used, the number of a process tank, a pump, and a valve can be set suitably according to the number of chemical liquids mixed in the mixing box 85. FIG.

The temperature control mechanism 81 has hot water and processing liquid tanks 82 to 84 therein, and heats the processing liquid (pure water, chemical liquids 1 and 2) in the processing liquid tanks 82 to 84 with hot water. In the apparatus, the treatment liquid is appropriately heated to, for example, about 60 ° C from room temperature. For this temperature control, for example, a heater (for example, an input heater and a heater (external heater) provided outside the treatment liquid tanks 82 to 84) can be suitably used in the water tank and the treatment liquid tanks 82 to 84.

The treatment liquid tanks 82, 83, and 84 are tanks for holding pure water and chemical liquids 1, 2, respectively.

The pumps P1 to P3 suck the processing liquid from the processing liquid tanks 82 to 84. Moreover, you may transfer the liquid from the process liquid tanks 82-84 by pressurizing process liquid tanks 82-84, respectively.

The valves V1 to V3 open and close the pipe to supply and stop the supply of the processing liquid. The valves V4 and V5 are for supplying pure water at room temperature (not heated) to the upper plate 30 and the lower plate 40, respectively.

The mixing box 85 is a container for mixing the chemical liquids 1 and 2 transferred from the treatment liquid tanks 83 and 84.

The chemical liquids 1 and 2 can be mixed into the mixing box 85 and temperature-controlled by the upper plate 30. In addition, the lower plate 40 can be appropriately sent to the temperature controlled pure water.

(The details of the electroless plating process)

4 is a flowchart showing an example of a procedure of electroless plating the wafer W using the electroless plating apparatus 10. 5 to 11 are partial cross-sectional views showing the state of the electroless plating apparatus 10 in each step when electroless plating is performed in the order shown in FIG. 4. Hereinafter, this order will be described in detail with reference to FIGS. 4 to 11.

(1) Holding the Wafer W (Step S1 and Fig. 5)

The wafer W is held on the wafer chuck 20. For example, a suction arm (substrate transport mechanism) (not shown) that sucks the wafer W from its upper surface mounts the wafer W on the wafer chuck 20. Then, the wafer W is held by the wafer holding claw 21 of the wafer chuck 20. Further, by lowering the cup 50, the suction arm can be moved in the horizontal direction below the upper surface of the wafer W. As shown in FIG.

(2) Pretreatment of Wafer W (Step S2 and Fig. 6)

The pretreatment of the wafer W is performed by rotating the wafer W and supplying the processing liquid from the nozzle arm 61 or the nozzle arm 62 to the upper surface of the wafer W. FIG.

The rotation of the wafer W is performed by rotating the wafer chuck 20 by the hollow motor 12, and the rotation speed at this time can be 100 to 200 rpm as an example.

Either or both of the nozzle arms 61 and 62 move upward of the wafer W to discharge the processing liquid. The treatment liquids supplied from the nozzle arms 61 and 62 are sequentially supplied with, for example, pure water for cleaning the wafer W or chemical liquid for catalytic activation treatment of the wafer W, depending on the purpose of the pretreatment. The discharge amount at this time is sufficient to be sufficient to form a paddle (layer) of processing liquid on the wafer W, for example, about 100 mL. However, you may increase a discharge amount as needed. In addition, the discharged process liquid may be appropriately heated (for example, in a range of about 60 ° C. at room temperature).

(3) Heating the Wafer W (Step S3 and FIG. 7)

Heating of the wafer W is performed to maintain the wafer W at a temperature suitable for the reaction of the plating liquid.

The lower plate 40 is heated to approach the lower surface of the wafer W (for example, a distance between the lower surface of the wafer W and the upper surface of the lower plate 40: about 0.1 to 2 mm), and from the processing liquid discharge port 41. The pure water heated by the liquid supply mechanism 80 is supplied. The heated pure water is filled between the lower surface of the wafer W and the upper surface of the lower plate 40 to heat the wafer W.

Moreover, the uniformity of the heating of the wafer W can be improved by rotating the wafer W during the heating of this wafer W. FIG.

By heating the wafer W with a liquid such as pure water, it becomes easy to rotate or non-rotate the wafer W and the lower plate 40 separately, and contamination of the lower surface of the wafer W is prevented.

The above heating of the wafer W may be performed by other means. For example, the wafer W may be heated by radiant heat of a heater or a lamp. In some cases, the wafer W may be heated by bringing the heated lower plate 40 into contact with the wafer W.

(4) Supply of Plating Solution (Steps S4 and 8).

The upper plate 30 is heated to approach the upper surface of the wafer W (for example, the distance between the upper surface of the wafer W and the lower surface of the upper plate 30: about 0.1 to 2 mm), and from the processing liquid discharge port 31. The chemical liquid (plating liquid) for plating is supplied (30-100 mL / min as an example). The supplied plating liquid fills up between the upper surface of the wafer W and the lower surface of the upper plate 30 and flows out into the cup 50. At this time, the plating liquid is temperature-controlled by the upper plate 30 (for example, in the range of about 60 ° C. at room temperature). In addition, it is preferable that the plating liquid supplied is temperature-controlled by the liquid supply mechanism 80.

Here, the uniformity of the plating film formed in the wafer W can be improved by rotating the wafer W by the wafer chuck 20. As an example, the wafer W is rotated at 10 to 50 rpm.

In addition, the heating of the upper plate 30 can be performed beforehand somewhere in the previous steps S1 to S3. By carrying out the heating of the upper plate 30 in parallel with other processes, the processing time of the wafer W can be reduced.

As described above, the plating film is formed on the wafer W by supplying the plating liquid heated at a desired temperature to the upper surface of the wafer W. As shown in FIG. By rotating the wafer W while supplying this plating liquid, the uniformity of the formation of the plating film on the wafer W can be improved.

In supply of the above plating liquid, it is also possible to do the following.

1) The wafer chuck 20 and the upper plate 30 can be tilted by the substrate tilt mechanism 70 before the plating liquid is supplied.

By inclining the wafer W, the gas between the wafer W and the upper plate 30 can be promptly removed and replaced with a plating liquid. For example, if the removal of gas between the wafer W and the upper plate 30 is incomplete, bubbles remain between the wafer W and the upper plate 30, which may cause the uniformity of the formed plating film to be impaired. .

In addition, gas (for example, hydrogen) is generated by the formation of the plating film by the plating liquid, bubbles are formed by the generated gas, and uniformity of the plating film may be impaired.

By inclining the wafer W by the substrate inclination mechanism 70, it is possible to reduce the generation of bubbles and to promote the escape of generated bubbles, thereby improving the uniformity of the plated film.

2) The temperature of the plating liquid can be changed in time.

By doing in this way, the structure and composition can be changed in the layer direction of the plating film formed.

3) Supply of the plating liquid during the formation of the plating film may be performed intermittently rather than continuously. The plating liquid supplied on the wafer W can be consumed efficiently, and the amount of use thereof can be reduced.

(5) Cleaning the Wafer W (Step S5 and FIG. 9)

The wafer W is washed with pure water. This cleaning can be performed by switching the processing liquid discharged from the processing liquid discharge port 31 of the upper plate 30 from the plating liquid to pure water. At this time, pure water can be supplied from the processing liquid discharge port 41 of the lower plate 40.

The nozzle arms 61 and 62 can also be used for the cleaning of the wafer W. As shown in FIG. At this time, supply of the plating liquid from the process liquid discharge port 31 of the upper plate 30 is stopped, and the upper plate 30 is removed from the wafer W. As shown in FIG. Thereafter, the nozzle arms 61 and 62 are moved above the wafer W to supply pure water. Also at this time, it is preferable to supply pure water from the processing liquid discharge port 41 of the lower plate 40.

The uniformity of cleaning of the wafer W can be improved by rotating the wafer W during the cleaning of the above wafer W. FIG.

(6) Drying the wafer W (step S6 and FIG. 10).

The pure water on the wafer W is removed by stopping the supply of pure water to the wafer W and rotating the wafer W at a high speed. In some cases, nitrogen gas may be ejected from the nozzle arms 61 and 62 to accelerate the drying of the wafer W. FIG.

(7) Removal of wafer W (step S7 and FIG. 11).

After the drying of the wafer W is completed, the holding of the wafer W by the wafer chuck 20 is stopped. Thereafter, the wafer W is removed on the wafer chuck 20 by a suction arm (substrate transport mechanism) (not shown).

(Features of the electroless plating apparatus 10)

The electroless plating apparatus 10 has the following characteristics.

(1) The plating liquid is supplied from the upper plate 30 in a state in which the wafer W and the upper plate 30 are adjacent to each other, and fill the gap between the wafer W and the upper plate 30, so that the wafer W Is discharged from the outer periphery of). For this reason, the flow of a plating liquid is formed in the direction from the center to the outer periphery on the wafer W, and fresh plating liquid can be supplied to the wafer W. As shown in FIG.

(2) By making the gap between the wafer W and the upper plate 30 close to each other, the plating liquid can be efficiently used and the amount of the plating liquid can be reduced.

(3) By rotating the wafer W during the formation of the plating film, the plating liquid can be supplied to the wafer W surface, and further, the in-plane uniformity of the film thickness of the plating film can be achieved.

(4) By using the upper plate 30 and the lower plate 40, the wafer W can be uniformly heated from the top and the bottom. As a result, the homogenization of the characteristic of the plating film formed in the wafer W can be aimed at.

(5) Since it is necessary to have a size corresponding to the wafer W, the installation area of the apparatus is not required very much.

(Other Embodiments)

Embodiments of the present invention are not limited to the above-described embodiments, but can be expanded and changed. Extended and modified embodiments are also included in the technical scope of the present invention.

(1) For example, a glass plate etc. other than the wafer W can be used as a board | substrate.

(2) Supply of the processing liquid (including the plating liquid) to the substrate is not necessarily performed continuously, but may be performed intermittently to some extent. At least, while the processing liquid is supplied to the substrate, fresh processing liquid can be supplied onto the substrate to maintain homogeneity of processing of the substrate. In addition, even if the supply of the processing liquid is temporarily stopped, the homogeneity of the processing of the substrate is not significantly impaired unless the change of the processing liquid within the stopping time is very large.

(3) The heater arrange | positioned at the upper plate 30 may be divided into multiple numbers. By dividing the heater, it is possible to independently control the temperature of a plurality of regions of the upper plate 30, thereby improving the uniformity of the temperature distribution of the upper plate 30 and further improving the uniformity of the processing to the substrate.

In the electroless plating apparatus and the electroless plating method according to the present invention, it is possible to form a plated film on a substrate with high uniformity even with a small amount of processing liquid, and can be used and manufactured industrially.

Claims (14)

A substrate holding part for holding a substrate, A plate disposed opposite the substrate held by the substrate holding portion, a processing liquid discharge portion formed on a surface of the plate opposite to the substrate, and for discharging the processing liquid; A gap adjusting part for changing a gap between the plate and the substrate; Electroless plating device. The method of claim 1, Further provided with a heating unit for heating the plate Electroless plating device. The method of claim 1, Further provided with a heating unit for heating the plate Electroless plating device. The method of claim 1, Further provided with a liquid supply mechanism for supplying a temperature control processing liquid to the plate Electroless plating device. The method of claim 4, wherein The liquid supply mechanism to switch the processing liquid to supply Electroless plating device. The method of claim 4, wherein The liquid supply mechanism has a processing liquid generating unit for generating a processing liquid by mixing a plurality of chemical liquids. Electroless plating device. The method of claim 1, A second plate disposed opposite to a second surface different from a surface of said substrate, said surface facing; A liquid ejecting portion formed on a surface of the second plate opposite to the second surface of the substrate and discharging a temperature controlled liquid; Further comprising a second gap adjusting unit for changing the gap between the second plate and the substrate Electroless plating device. The method of claim 7, wherein Further comprising a liquid supply mechanism for supplying to the second plate by controlling the temperature of the liquid discharged from the liquid discharge portion Electroless plating device. The method of claim 1, Further comprising a movable nozzle for discharging the processing liquid to the substrate Electroless plating device. A holding step of holding the substrate, An arrangement step of placing the plate facing the substrate held in the holding step; And a film forming step of supplying a processing liquid between the substrate and the plate arranged opposite to each other in the placing step to form a plating film on the substrate. Electroless Plating Method. The method of claim 10, And a gap adjusting step of adjusting a gap between the substrate and the plate so that the arrangement step is narrower than a thickness of the processing liquid when the surface tension is maintained on the substrate. Electroless Plating Method. The method of claim 10, The film forming step includes a processing liquid generating step of generating a processing liquid by mixing a plurality of chemical liquids. Electroless Plating Method. The method of claim 10, Prior to the film forming step, further comprising an inclination step of tilting the substrate held in the holding step Electroless Plating Method. The method of claim 10, Prior to the film forming step, further comprising a heating step of heating the substrate held in the holding step Electroless Plating Method.