JP5501671B2 - Processing apparatus and processing method - Google Patents

Description

  The present invention relates to a processing apparatus and a processing method for surface-treating an object to be processed using a processing liquid.

  Examples of the surface treatment applied to the object to be processed using a treatment liquid containing a chemical include electrolytic plating, electroless plating, and etching. Such surface treatment technology is also used in semiconductor manufacturing, and in particular, electroless plating that can be processed at low cost has been put into practical use in recent years.

  While electroless plating is low in cost, it is necessary to control the conditions of the treatment liquid such as component concentration and liquid temperature very finely as compared with electrolytic plating. Conventionally, many methods for automatically controlling the electroless plating solution have been proposed. For example, Patent Documents 1 and 2 describe a technique in which the concentration of a component contained in a processing liquid in a processing tank is measured and the replenishment amount of the processing liquid component is controlled online based on the measurement result.

  Further, in electroless plating, it is necessary to control the supply flow rate of the treatment liquid in order to maintain an appropriate concentration of the components contained in the treatment liquid. For example, Patent Document 3 describes a method of plating an inner wall surface of a hole provided in an object to be processed by defining a supply flow rate of a processing liquid.

JP 6-41764 A (published February 15, 1994) JP 2002-47575 A (published on February 15, 2002) Japanese Patent Laid-Open No. 9-13174 (published on January 14, 1997)

  A characteristic of electroless plating is that it can be processed without limiting the wafer size to be processed. However, the wafer size to be processed tends to increase in diameter, and particularly in the case of a multi-product mixed line, the area to be plated of the wafer varies greatly. Further, the area to be plated of a semiconductor wafer varies depending on the device to be mounted, and the area to be plated of the wafer tends to increase due to reduction in chip size, increase in the number of pads, and the like. Further, along with the downsizing and high density of packages, wafer mounting accuracy is also required, and it is necessary to perform plating processing with higher accuracy by reducing variations in plating film thickness.

  However, as described in Patent Documents 1 and 2, in the conventional processing liquid condition control method, the state of the processing liquid in the processing tank is based on the state of the processing liquid measured at one specific location in the processing tank. The processing solution conditions of the entire processing tank are not sufficiently controlled. Further, in the methods described in Patent Documents 1 and 2, the processing liquid conditions are controlled only by the replenishment amount of the processing liquid components, and the method is applied to increase in the area of the object to be processed and multi-mixed processing. Is insufficient.

  In electroless plating, as described in Patent Document 3, it is common to set the flow rate of the processing liquid as small as possible. However, as the wafer size increases, the volume of the processing tank increases. Therefore, if the flow rate is small, the response time of the component concentration meter with respect to the component replenishment becomes long, and the condition control of the treatment liquid becomes unstable.

  The present invention has been made in view of the above problems, and its purpose is to appropriately control the concentration of components contained in the treatment liquid in the treatment tank and to use the treatment liquid to achieve a uniform surface of the object to be treated. An object of the present invention is to provide a processing device and a processing method capable of realizing processing.

In order to solve the above problems, the processing apparatus according to the present invention is a processing apparatus for surface-treating an object to be processed using a processing liquid, wherein the processing object is introduced into the processing tank, and the processing tank First concentration detecting means for detecting, as a first component concentration, a concentration of a component contained in the processing liquid circulating in a circulation line connected to the processing liquid inlet and outlet of the processing liquid; In a position different from the first concentration detection means in the circulation line, a second concentration detection means for detecting the concentration of the component contained in the processing liquid as a second component concentration, and a first concentration detected by the first concentration detection means. The concentration difference between the first component concentration and the second component concentration is determined in advance so that the one component concentration and the second component concentration detected by the second concentration detecting means become a predetermined target concentration. Target concentration So that the flow control means for adjusting the flow rate of the processing solution in the processing tank and the circulation line in the flow rate of the treatment liquid is adjusted by the flow control means, a predetermined flow rate limit A treatment liquid replenishing means for replenishing the treatment liquid in the treatment tank or the circulation line, and the flow rate control means has a flow rate of the treatment liquid to be adjusted that exceeds the flow rate limit value. The flow rate of the processing liquid is adjusted so as to be the flow rate limit value .

The processing method according to the present invention is a processing method for surface-treating an object to be processed using a processing liquid in order to solve the above-described problem, and the inside of the processing tank into which the object to be processed is introduced and the processing tank A first concentration detecting step of detecting, as a first component concentration, a concentration of a component contained in the processing liquid circulating in a circulation line connected to the inlet and outlet of the processing liquid, and in the processing tank and the At a position different from the first concentration detection step in the circulation line, a second concentration detection step for detecting the concentration of the component contained in the processing liquid as a second component concentration, and the detection at the first concentration detection step. The first component concentration and the second component concentration detected in the second concentration detection step are set to a predetermined target concentration, or a concentration difference between the first component concentration and the second component concentration is predicted. Such that the target density difference defined, a flow rate control step of adjusting the flow rate of the processing solution in the processing tank and the circulation line in the flow rate of the treatment liquid is adjusted by the flow rate control step, advance A treatment liquid replenishment step of replenishing the treatment liquid in the treatment tank or the circulation line when a predetermined flow rate limit value is exceeded, and in the flow rate control step, the flow rate of the treatment liquid to be adjusted is When the flow rate limit value is exceeded, the flow rate of the processing liquid is adjusted so as to become the flow rate limit value .

According to said structure, the density | concentration of the component contained in the process liquid which circulates in the inside of a process tank and the circulation line connected to the process tank is made into a several different position by a 1st density | concentration detection means and a 2nd density | concentration detection means. Detect each. Then, the control unit is configured so that the component concentrations at different positions detected by the first concentration detection unit and the second concentration detection unit, or the concentration difference between the component concentrations become a predetermined target value set in advance. The flow rate of the processing liquid in the processing tank and the circulation line is adjusted. In addition, according to the above configuration, the component concentration of the treatment liquid in the treatment tank is appropriately adjusted by controlling the flow rate up to a predetermined flow rate limit value. When the flow rate limit value is exceeded, an amount corresponding to the excess flow rate is set. The processing liquid is replenished to the processing tank and the circulation line. Thereby, it is possible to control the component concentration of the processing liquid in the processing tank while maintaining the appropriate flow rate in the processing tank and the circulation line, and more appropriate concentration control becomes possible.

  In this way, the component concentration of the processing liquid in the processing tank is controlled by adjusting the flow rate of the circulating processing liquid. For example, even when the processing area of the object to be processed becomes large, it is appropriate regardless of the processing area. It is possible to control the component concentration. Thereby, since the component density | concentration of the process liquid in a processing tank can be maintained uniformly, the uniform surface treatment of a to-be-processed object can be implement | achieved with sufficient reproducibility. Therefore, for example, surface treatments such as electroless plating, electrolytic plating, and etching in which the treatment process is strongly influenced by the component concentration or flow rate of the treatment liquid can be suitably performed.

  The processing apparatus according to the present invention includes a plurality of the second concentration detection means, and the flow rate control means is a concentration with the first component concentration among the second component concentrations detected by the plurality of second concentration detection means. The second component concentration having the largest difference becomes the predetermined target concentration, or the concentration difference between the second component concentration and the first component concentration becomes the predetermined target concentration difference. It is preferable to adjust the flow rate of the treatment liquid in the treatment tank and the circulation line. Thereby, the density | concentration in a processing tank and a circulation line can be controlled more accurately.

  In the processing apparatus according to the present invention, the first concentration detecting means detects the first component concentration at a position closer to the inlet than the second concentration detecting means in the processing tank, and detects the second concentration detection. The means detects the second component concentration at a position closer to the outlet than the first concentration detection means in the processing tank, and the flow rate control means sets the second component concentration to a second predetermined value. A first target concentration of the first component concentration for obtaining a target concentration is calculated, and the treatment liquid in the treatment tank and the circulation line is adjusted so that the first component concentration becomes the first target concentration. It is preferable to adjust the flow rate.

  According to the above configuration, the flow rate is controlled so that the component concentration or the component concentration difference in the portion where the component concentration difference between the inlet and outlet of the processing liquid is large in the processing tank becomes a predetermined target value. The component concentration of the treatment liquid in the treatment tank is adjusted. Therefore, more appropriate concentration control is possible, and uniform surface treatment of the workpiece can be realized.

  In the processing apparatus according to the present invention, it is preferable that the first concentration detection means and the second concentration detection means detect the concentration of a component contained in the processing liquid based on the absorbance of the processing liquid. Thereby, the component density | concentration of the process liquid in a process tank can be controlled more accurately.

The processing apparatus according to the present invention is a processing apparatus for surface-treating an object to be processed using a processing liquid, and is connected to the inside of the processing tank into which the object to be processed is introduced, and the inlet and outlet of the processing tank. The first concentration detection means for detecting the concentration of the component contained in the treatment liquid circulating in the circulation line as the first component concentration, and the first concentration detection means in the treatment tank and the circulation line At different positions, second concentration detection means for detecting the concentration of the component contained in the processing liquid as the second component concentration, first component concentration detected by the first concentration detection means, and detection by the second concentration detection means In the treatment tank, the second component concentration is set to a predetermined target concentration, or the difference between the first component concentration and the second component concentration is set to a predetermined target concentration difference. And the above circulation line And flow control means for adjusting the flow rate of the treatment liquid in the inner, the flow rate of the treatment liquid is adjusted by the flow control means, when exceeding the flow rate limit value set in advance, the treatment tank or the circulation line in A processing liquid replenishing means for replenishing the processing liquid , and the flow rate control means is configured such that when the flow rate of the processing liquid to be adjusted exceeds the flow rate limit value, the flow rate of the processing liquid becomes the flow rate limit. Since the concentration is adjusted so as to be a value, it is possible to appropriately control the concentration of the component contained in the processing liquid, and to achieve a uniform surface treatment of the object to be processed using the processing liquid. be able to. In addition, the concentration of the processing liquid in the processing tank is appropriately adjusted by controlling the flow rate up to a predetermined flow rate limit value. When the flow rate limit value is exceeded, an amount of processing liquid corresponding to the excess flow rate is circulated in the processing tank and Since the line is replenished, it is possible to control the component concentration of the treatment liquid in the treatment tank while keeping the flow rate in the treatment tank and the circulation line at an appropriate flow rate, and more appropriate concentration control is possible. become.

It is the schematic which shows the electroless-plating apparatus which concerns on one Embodiment. It is a flowchart explaining the flow of the adjustment process of the flow volume in the electroless-plating apparatus which concerns on one Embodiment of this invention. It is the schematic which shows the electroless-plating apparatus which concerns on other embodiment. It is a flowchart explaining the flow of the adjustment process of the flow volume and replenishment amount in the electroless plating apparatus which concerns on other embodiment of this invention.

(First embodiment)
A first embodiment of a processing apparatus according to the present invention will be described below with reference to FIGS. In this embodiment, the processing apparatus according to the present invention will be described as an electroless plating apparatus that performs electroless plating using a nickel plating solution. However, the present invention is not limited to this, and the concentration and flow rate of the plating solution are not limited thereto. In addition, it can be applied to other surface treatments such as electroless plating, electrolytic plating, etching, etc., in which the treatment process is strongly influenced.

  FIG. 1 is a schematic view showing an embodiment of the electroless plating apparatus 100, and FIG. 2 is a flowchart for explaining the flow of flow rate adjustment processing in the electroless plating apparatus 100. FIG. As shown in FIG. 1, the electroless plating apparatus 100 includes a first concentration meter (first concentration detection means) 4, a second concentration meter (second concentration detection means) 5, and a control unit (flow rate control means) 14. I have. Further, the electroless plating apparatus 100 may include a treatment tank 1, a circulation pump 2, a circulation line 3, a filter 6, a flow meter 7, a heater 8, a nozzle 9, a pure water line 10, and an air operation valve 11. The electroless plating apparatus 100 is introduced into the processing tank 1 by electroless plating using a plating liquid (processing liquid) introduced into the processing tank 1 on the wafer (object to be processed) 13 held by the carrier 12. It is a device for surface treatment.

  A plating solution used for electroless plating of the wafer is supplied into the processing tank 1 from the nozzle 9 via the circulation line 3. Accordingly, the nozzle 9 functions as an inlet for introducing the plating solution into the treatment tank 1. The circulation line 3 is connected to a nozzle 9 provided in the processing tank 1, and is connected to a storage tank that stores a plating solution that has flowed out from an opening (outlet) at the top of the processing tank 1. The plating solution introduced into the tank 1 and flowing out of the processing tank 1 is circulated inside.

  The plating solution flowing out from the processing tank 1 is stored in a storage tank, and water is supplied from the pure water line 10 to supplement the evaporated water. The supply of water from the pure water line 10 to the plating solution is controlled by opening and closing an air operated valve, and moisture is supplied at a predetermined rate based on the evaporation rate of moisture.

  The circulation line 3 includes a circulation pump 2, a filter 6, a flow meter 7, and a heater 8 between a connection portion with the opening of the processing tank 1 and a connection portion with the nozzle 9. The circulation pump 2 gives power to the plating solution for circulating the plating solution in the circulation line 3 in the clockwise direction in FIG. 1, and a known pump such as a centrifugal pump can be used. The circulation pump 2 is driven based on a command from the control unit 14 to circulate the plating solution. The flow rate of the plating solution in the treatment tank 1 and the circulation line 3 is adjusted by the circulation pump 2.

  The filter 6 filters the plating solution circulating in the circulation line 3 to remove impurities in the plating solution. The flow meter 7 detects the flow rate of the plating solution in the circulation line 3 and is used for managing the flow rate per unit time of the plating solution supplied into the processing tank 1. The heater 8 heats the temperature of the plating solution supplied from the circulation line 3 to the treatment tank 1 to a predetermined appropriate temperature. The heating of the plating solution by the heater 8 is adjusted to a temperature set appropriately depending on the components contained in the plating solution, the type of wafer to be plated, the plating conditions, and the like.

  Each of the first densitometer 4 and the second densitometer 5 detects the ion concentration (component concentration) of the plating component in the plating solution in the treatment tank 1. In the present embodiment, the first densitometer 4 is provided closer to the nozzle 9 for supplying the plating solution to the treatment tank 1 than the second densitometer 5, and is near the nozzle 9, that is, near the plating solution inlet. The ion concentration (first component concentration) of the plating component is detected. The second densitometer 5 is provided closer to the outlet through which the plating solution flows out of the processing tank 1 than the first densitometer 4, and the ion concentration of the plating component in the vicinity of the outlet (second component concentration). Is detected. The second densitometer 5 may be installed at a plurality of locations in the treatment tank 1.

  The first ion concentration and the second ion concentration detected by the first concentration meter 4 and the second concentration meter 5 are respectively fed back to the control unit 14, and the control unit 14 supplies the flow rate of the plating solution to the circulation pump based on these values. To adjust. The installation position of the first concentration meter 4 and the second concentration meter 5 and the detection position of the ion concentration are not limited to this, and a plurality of different positions in the circulation path of the plating solution constituted by the treatment tank 1 and the circulation line 3. The number of densitometers is not limited to this.

  When three or more densitometers are used, the ion concentration detected by each is fed back to the control unit 14 and controlled based on, for example, the difference between the densitometer near the nozzle 9 and the densitometer showing the minimum ion concentration. May be. By providing a plurality of densitometers, the control by the control unit 14 can be performed with higher accuracy.

The first concentration meter 4 and the second concentration meter 5 are not particularly limited as long as the components in the plating solution can be accurately identified and quantified and the analysis time thereof is relatively fast. A spectrophotometer that is particularly useful for on-line measurement described in Patent Documents 1 and 2 can be suitably used. When using an absorptiometer as the first densitometer 4 and the second densitometer 5, the measurement wavelength is generally different between nickel ions (Ni ²⁺ ) and hypophosphite ions (H ₂ PO ₂ ⁻ ) described later, One of these components is measured as a representative and fed back to the control unit 14.

  As a plating solution used in the electroless plating apparatus 100, a conventionally known electroless plating solution can be used. In the present embodiment, an electroless nickel plating solution is used, which contains nickel sulfate as a metal source and hypophosphorous acid as a reducing agent added with a trace additive as active ingredients. In the electroless plating apparatus 100, nickel ions are precipitated by electrons released by oxidation of hypophosphorous acid in the plating solution introduced into the processing tank 1, and the wafer is immersed in the plating solution by the deposited nickel. The wafer 13 is surface-treated by coating the surface of 13.

  Here, the wafer 13 may be subjected to a predetermined pretreatment before the surface treatment by the electroless plating apparatus 100. As such pretreatment, a known syndicate treatment can be performed when plating on aluminum, and a known palladium activation treatment can be performed when plating on copper or semiconductor.

The electroless plating treatment using the electroless nickel plating solution proceeds according to the following reaction formulas (1) to (3);
(Main reaction)
Ni ²⁺ + H ₂ PO ₂ ⁻ + H ₂ O → Ni + H ₂ PO ₃ ⁻ + 2H ⁺ (1)
(Side reaction: generation of hydrogen)
H ₂ O + H ₂ PO ₂ ⁻ → H ₂ ↑ + H ₂ PO ₃ ⁻ (2)
(Side reaction: Phosphorus eutectoid)
H ₂ PO ₂ ⁻ + H → P + OH ⁻ + H ₂ O (3)
As the electroless plating process according to the reaction formulas (1) to (3) proceeds, nickel ions (Ni ²⁺ ) and hypophosphite ions (H ₂ PO ₂ ⁻ ) in the plating solution decrease. Therefore, in the processing tank 1, in the plating solution circulating from the nozzle 9 side toward the opening of the processing tank 1, the ion concentration on the nozzle 9 side is higher than the ion concentration on the opening side. That is, the first metal ion concentration detected by the first concentration meter 4 is higher than the second metal ion concentration detected by the second concentration meter 5.

  Such a gradient of the ion concentration in the processing tank 1 causes a variation in the thickness of the plating film formed on the wafer 13, which makes it difficult to perform the plating process with high accuracy. Such a problem is greatly affected when the plating area of the wafer 13 is large.

  In the electroless plating apparatus 100, the ion concentration of plating components such as nickel ions and hypophosphite ions is measured by the first densitometer 4 and the second densitometer 5 at a plurality of locations where the concentration difference becomes large. The control unit 14 controls the circulation pump 2 so that the ion concentration or ion concentration difference thus obtained becomes a predetermined target concentration or target concentration difference. That is, by adjusting the flow rate of the plating solution with the circulation pump 2, the flow rate of the plating solution supplied into the processing tank 1 is adjusted, and the ion concentration in the processing tank 1 is kept uniform. Thereby, it is possible to form a plating film having a uniform film thickness on the wafer 13.

  In the conventional electroless plating apparatus, in order to adjust the ion concentration of the plating solution in the processing tank, it is controlled by supplementing the components consumed by the plating process. However, the ion concentration management by replenishing the components cannot cope with the correction of the concentration difference caused by the increase of the plating area, and the consumption of the components increases. According to the electroless plating apparatus 100, since the inflow amount of the plating solution flowing into the processing tank 1 is adjusted by controlling the flow rate of the plating solution, such a problem does not occur.

  Next, a process for adjusting the flow rate of the plating solution by the control unit 14 of the electroless plating apparatus 100 will be described with reference to FIG. As shown in FIG. 2, first, in the second subtracter 20 provided in the control unit 14, a second target value (second target concentration) SV <b> 2 and a second concentration that are predetermined as target values of the second ion concentration. A concentration difference from the second ion concentration PV2 detected by the total 5 is calculated. A signal representing the concentration difference calculated in the second subtracter 20 is transmitted to the second PID controller 21, and based on the concentration difference, the second PID controller 21 sets the second ion concentration PV2 to the concentration of the second target value SV2. The target value of the first ion concentration such that becomes the first target value (first target concentration) SV1 is output to the first subtractor 22. The second target value SV2 and the difference between the second target value SV2 and the first target value SV1 are set in advance so that the variation in the plating film thickness falls within the standard range, and the second PID control The data is stored in a storage unit (not shown) in the container 41.

  Then, the first subtracter 22 calculates the concentration difference between the first target value SV1 and the first ion concentration PV1 detected by the first concentration meter 4. A signal representing the concentration difference calculated in the first subtracter 22 is transmitted to the first PID control unit 23, and the first PID control unit 23 sets the first ion concentration PV1 to the concentration of the first target value SV1 based on the concentration difference. Is output to the third subtractor 24 as the third target value SV3. In the third subtracter 24, the flow rate difference between the third target value SV3 and the flow rate PV3 detected by the flow meter 7 is calculated. A signal representing the flow rate difference calculated in the third subtractor 24 is transmitted to the third PID control unit 25, and the third PID control unit 25 determines the flow rate of the plating solution in the processing tank 1 and the circulation line 3 based on the flow rate difference. A signal for controlling the circulation pump 2 is transmitted to the circulation pump 2 so that PV3 becomes the third target value SV3.

  The circulation pump 2 adjusts the rotation speed and the like based on the signal, and sets the flow rate of the plating solution in the treatment tank 1 and the circulation line 3 to the third target value SV3.

  The adjustment of the flow rate by the circulation pump 2 can be performed by adjusting the rotation speed of the circulation pump 2. Further, the plating solution component consumed by the electroless plating process may be manually replenished as appropriate based on the detection results of the first concentration meter 4 and the second concentration meter 5.

(Second Embodiment)
Another embodiment of the electroless plating apparatus will be described below with reference to FIGS. FIG. 3 is a schematic view showing an embodiment of the electroless plating apparatus 101, and FIG. 4 is a flowchart for explaining the flow of flow rate adjustment processing in the electroless plating apparatus 101. As shown in FIG. 3, the electroless plating apparatus 101 according to the present embodiment includes an injector 15, an injection pump (treatment liquid replenishing means) 16, and a replenisher liquid tank 17. Different from the plating apparatus 100. Therefore, in this embodiment, only points different from the first embodiment will be described, and other detailed descriptions will be omitted.

  The injector 15 is connected to the opening side of the treatment tank 1 with respect to the circulation pump 2 in the circulation line 3, and is connected to the replenisher tank 17 through the injection pump 16. In the replenisher tank 17, a plating solution containing the same components as the plating solution circulating in the treatment tank 1 and the circulation line 3 is introduced. The plating solution in the replenishing solution tank 17 is sent out by the injection pump 16 and introduced into the circulation line 3 from the injector 15. In the electroless plating apparatus 101, the controller 14 controls the injection pump 16 to control the replenishment of the plating solution from the replenisher solution tank 17. The replenishment of the plating solution by the control unit 14 is PID controlled along with the flow rate control based on the first ion concentration and the second ion concentration measured by the first concentration meter 4 and the second concentration meter 5.

  The adjustment process of the flow rate and replenishment amount of the plating solution by the control unit 14 of the electroless plating apparatus 101 will be described with reference to FIG. As shown in FIG. 4, first, in the second subtracter 40 provided in the control unit 14, the second target value SV <b> 2 predetermined as the target value of the second ion concentration and the second densitometer 5 are detected. A concentration difference from the second ion concentration PV2 is calculated. A signal representing the concentration difference calculated in the second subtracter 40 is transmitted to the second PID controller 41, and the second PID controller 41 has a concentration at which the second ion concentration PV2 is the second target value SV2 based on the concentration difference. The target value of the first ion concentration such that becomes is output to the first subtractor 42 as the first target value SV1. The second target value SV2 and the difference between the second target value SV2 and the first target value SV1 are set in advance so that the variation in the plating film thickness falls within the standard range, and the second PID control The data is stored in a storage unit (not shown) in the container 41.

  Then, the first subtractor 42 calculates a concentration difference between the first target value SV1 and the first ion concentration PV1 detected by the first concentration meter 4. A signal representing the concentration difference calculated in the first subtracter 42 is transmitted to the first PID control unit 43, and the first PID control unit 43 sets the first ion concentration PV1 to the concentration of the first target value SV1 based on the concentration difference. Is output to the limiter circuit 44 as the third target value SV3.

  In the limiter circuit 44, a predetermined flow rate limit value (flow rate limit value) LV3 is compared with the third target value SV3 as an upper limit value of the flow rate of the plating solution, and the third target value SV3 is equal to or lower than the flow rate limit value LV3. In this case, the third target value SV3 is output to the third subtracter 45 as it is. When the third target value SV3 is larger than the flow rate limit value LV3, the flow rate limit value LV3 is output to the third subtractor 45 and the plating solution proportional to the flow rate difference between the third target value SV3 and the flow rate limit value LV3 is output. A replenishment value SV4 indicating the replenishment amount is output to the injection pump 16. A flow rate upper limit value suitable for the plating process is set in advance as the flow rate limit value LV3, and is stored in a storage unit (not shown) in the limiter circuit 44.

  Then, the third subtracter 45 calculates a flow rate difference between the third target value SV3 or the flow rate limit value LV3 and the flow rate PV3 detected by the flow meter 7. A signal representing the flow rate difference calculated in the third subtracter 45 is transmitted to the third PID control unit 46, and the third PID control unit 46 determines the flow rate of the plating solution in the processing tank 1 and the circulation line 3 based on the flow rate difference. A signal for controlling the circulation pump 2 is transmitted to the circulation pump 2 so that PV3 becomes the third target value SV3. The circulation pump 2 adjusts the rotation speed and the like based on the signal, and sets the flow rate of the plating solution in the treatment tank 1 and the circulation line 3 to the third target value SV3.

  The injection pump 16 that has received the signal representing the replenishment value SV4 output from the limiter circuit 44 is driven to supply an amount of plating solution corresponding to the replenishment value SV4 into the circulation line 3. That is, when the replenishment value SV4> 0, the injection pump 16 is driven to replenish the plating solution at a predetermined flow rate, and when the replenishment value SV4 = 0, the injection pump 16 is stopped and replenishment of the plating solution is performed. Absent.

  In the electroless plating apparatus 101, the second concentration meter 5 may be installed at a plurality of locations in the treatment tank 1. By providing a plurality of second densitometers 5, the accuracy of density control can be further increased. In this case, the second ion concentration PV2 measured by the second densitometer 5 is sent to the second subtracter 40 through the minimum value circuit. That is, the second ion concentration having the largest concentration difference from the first ion concentration PV1 is used as the second ion concentration PV2 for concentration control.

  The present invention can be used for surface treatments such as electroless plating, electrolytic plating, and etching in which the treatment process is strongly influenced by the component concentration and flow rate of the treatment liquid.

DESCRIPTION OF SYMBOLS 1 Processing tank 2 Circulation pump 3 Circulation line 4 1st concentration meter (1st concentration detection means)
5 Second densitometer (second concentration detector)
6 Filter 7 Flowmeter 8 Heater 9 Nozzle 10 Pure water line 11 Air operated valve 12 Carrier 13 Wafer (Processed object)
14 Control unit (control means)
15 Injector 16 Injection pump (Processing liquid replenishment means)
17 Replenisher tank

Claims (5)

A processing apparatus for surface-treating an object to be processed using a processing liquid,
The concentration of the component contained in the processing liquid circulating in the processing tank into which the workpiece is introduced and in the circulation line connected to the inlet and outlet of the processing liquid in the processing tank is the first component concentration. First concentration detecting means for detecting
Second concentration detection means for detecting the concentration of a component contained in the treatment liquid as a second component concentration at a position different from the first concentration detection means in the treatment tank and the circulation line;
The first component concentration detected by the first concentration detection means and the second component concentration detected by the second concentration detection means become a predetermined target concentration, or the first component concentration and the second component A flow rate control means for adjusting the flow rate of the treatment liquid in the treatment tank and the circulation line so that the difference in concentration from the concentration becomes a predetermined target concentration difference ;
A treatment liquid replenishing means for replenishing the treatment liquid in the treatment tank or the circulation line when the flow rate of the treatment liquid adjusted by the flow rate control means exceeds a predetermined flow rate limit value. ,
The said flow control means adjusts so that the flow volume of the said process liquid may become the said flow volume limit value, when the flow volume of the said process liquid to adjust exceeds the said flow volume limit value . A plurality of the second concentration detection means;
The flow rate control unit is configured such that a second component concentration having the largest difference from the first component concentration among the second component concentrations detected by the plurality of second concentration detection units becomes a predetermined target concentration. Or adjusting the flow rate of the processing liquid in the processing tank and the circulation line so that the concentration difference between the second component concentration and the first component concentration becomes a predetermined target concentration difference. The processing apparatus according to claim 1. The first concentration detecting means detects the first component concentration at a position closer to the inlet than the second concentration detecting means in the processing tank,
The second concentration detection means detects the second component concentration at a position closer to the outlet than the first concentration detection means in the processing tank,
The flow rate control means calculates a first target concentration of the first component concentration for setting the second component concentration to a predetermined second target concentration, and the first component concentration becomes the first target concentration. The processing apparatus according to claim 1 or 2, wherein the flow rate of the processing liquid in the processing tank and the circulation line is adjusted. The said 1st density | concentration detection means and the said 2nd density | concentration detection means detect the density | concentration of the component contained in the said process liquid based on the light absorbency of the said process liquid, The any one of Claims 1-3 characterized by the above-mentioned. The processing apparatus as described in. A processing method for surface-treating an object to be processed using a processing liquid,
The concentration of the component contained in the processing liquid circulating in the processing tank into which the workpiece is introduced and in the circulation line connected to the inlet and outlet of the processing liquid in the processing tank is the first component concentration. A first concentration detection step to detect as
A second concentration detection step of detecting a concentration of a component contained in the treatment liquid as a second component concentration at a position different from the first concentration detection step in the treatment tank and the circulation line;
The first component concentration detected in the first concentration detection step and the second component concentration detected in the second concentration detection step become a predetermined target concentration, or the first component concentration and the first concentration A flow rate control step of adjusting the flow rate of the treatment liquid in the treatment tank and the circulation line so that the concentration difference from the two component concentrations becomes a predetermined target concentration difference ;
A treatment liquid replenishment step of replenishing the treatment liquid in the treatment tank or the circulation line when the flow rate of the treatment liquid adjusted by the flow rate control step exceeds a predetermined flow rate limit value; > include,
In the flow rate control step, when the flow rate of the processing liquid to be adjusted exceeds the flow rate limit value, the processing method is adjusted so that the flow rate of the processing liquid becomes the flow rate limit value .

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