JP2001316867A - Equipment and method for liquid treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a uniform film of high quality. SOLUTION: A diapbragm 11 is provided in an eleetrolytic plating tank 100, for compartmentalizing an anodic reaction partition 1 including anodes 2 from a cathodic reaction partition 10, in which a wafer 17 to be treated which is connected to cathodes 13 is dipped. In the diaphragm 11, several supply ports are arranged in a circumferential direction, and plating liquid is supplied as primary stream 42 from a center and as secondary stream 43 from the surrounding supply ports to the cathodic reaction partition 10, to be circulated. The plating liquid is also supplied separately to an anodic reaction partition 1. A distributor may be arranged under a surface to be plated of wafer 17 placed on wafer support parts 104. Pores for circulating the plating liquid may be arranged in an anode 2. The anode 2 is impelled upward by a spring and the top face is controlled with a stopper so that a position of the top face of the anode may not fluctuate, even when the anode dissolves in the plating liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid processing apparatus and a liquid processing method using a processing tank having a jet plating tank and having a structure in which an anode electrode portion and a cathode electrode portion are separated by a diaphragm.

[0002]

2. Description of the Related Art In order to form a metal film on a semiconductor wafer, a technique of forming a seed layer on a semiconductor wafer by PVD or the like and forming a plating layer on the seed layer has been widely used.

As a plating apparatus for a semiconductor substrate, for example, as disclosed in Japanese Patent Application Laid-Open No. 11-209890, a semiconductor substrate is immersed in a plating solution in a plating bath while a surface to be plated is held downward. The mainstream is to supply the plating solution from the lower end of the plating tank in an upward flow. However, in the configuration disclosed in Japanese Patent Application Laid-Open No. H11-209890, impurities generated from the anode electrode are mixed into the plating solution, thereby deteriorating the quality of the plating layer.

To solve this problem, for example, as disclosed in Japanese Patent Application Laid-Open No. 11-350185, a plating tank is immersed by a diaphragm in which an anode electrode region and a substrate to be plated connected to a cathode electrode are immersed. There is also a technique for separating the target area from the target area.

In any type of plating apparatus,
The contact time between the substrate to be plated and the circulating plating solution varies depending on the location, and the electric field density on the surface to be plated is not uniform, so that it is difficult to form a uniform plating layer. there were.

In order to adjust the electric field density, as disclosed in Japanese Patent Application Laid-Open No. 8-158094, there is a device provided with a fin.
As a result, problems such as deposition of metal occur.

In any type of plating apparatus, when the anode electrode is made of a material that dissolves in a plating solution, the surface area of the anode electrode is plated with the progress of the processing. It dissolves in the liquid, and the anode electrode gradually becomes smaller. Therefore, as the processing time elapses (the number of processed sheets increases), the distance between the anode electrode and the substrate to be processed (cathode electrode) increases, and when the same voltage is applied between both electrodes, the electric field increases. Gradually weakens.

For this reason, there is a problem not only in the uniformity of the thickness of the plating film of each wafer (in-plane uniformity) but also in the uniformity of the thickness of the plating film between the wafers (uniformity between the surfaces).

In addition, there is a problem that convection of the plating solution is likely to occur near the anode electrode, and metal deposition is likely to occur. A similar problem is with other liquid treatment systems.
This also occurs in the liquid treatment method.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a liquid processing apparatus and a liquid processing method capable of forming a uniform and high-quality film. . Another object of the present invention is to provide a liquid processing apparatus and a liquid processing method that are unlikely to change over time.

[0011]

In order to achieve the above object, a liquid processing apparatus according to a first aspect of the present invention comprises a first electrode, a processing tank for storing a processing liquid, and a processing object. Holding means for holding and immersing the processing surface of the processing object in the processing liquid in the processing tank; a first region including the first electrode in the processing tank; and a second area in which the processing object is immersed. And a supply unit that supplies the processing liquid to the first region from the plurality of supply ports and supplies the processing liquid to the second region.

According to this configuration, the processing liquid is supplied from the plurality of supply ports of the separation unit. Therefore, the retention of the processing liquid in the first region can be prevented as compared with the case where the processing liquid is supplied from one supply port.

The liquid processing apparatus is, for example, a plating apparatus, wherein the processing liquid is composed of a plating liquid, the first electrode is an anode electrode, the processing body is a semiconductor wafer, The means includes a cathode electrode that is in contact with the surface to be processed of the semiconductor wafer, the surface to be processed is immersed in the processing tank with the surface to be processed facing down, and the separation unit includes:
The plating solution is supplied to the second region by the upward flow from the plurality of supply ports.

[0014] The separation section is formed, for example, at a central portion and has a main flow port for supplying a processing liquid to be a main flow, and a plurality of sub-flow ports arranged around the central port and supplying a sub-flow, respectively. Prepare.

[0015] The separating portion may include, for example, a shaft having an opening formed therein, a branch portion having one end fixed to the shaft, extending radially, and having a flow path connected to the sub-flow port therein; Supply means for supplying the main flow of the processing liquid to the second region through the substrate and supplying the processing liquid to the flow path formed in the branch, a film covering between the branch and the branch, Consists of

[0016] The supply means may include a nozzle which penetrates the opening and ejects a processing liquid.

[0017] A fin for adjusting the electric field in the processing tank may be further provided in the processing tank, provided with a flow path for circulating the processing liquid.

In order to achieve the above object, a liquid processing apparatus according to a second aspect of the present invention comprises a processing tank for storing a processing liquid,
A processing unit for holding a processing target and performing processing with a processing liquid on a processing surface of the processing target; a first region including a first electrode in the processing bath; and a second region in which the processing target is immersed. A separation unit that supplies the processing liquid to the second region, a supply unit that supplies the processing liquid to the first region, and a flow unit that is disposed in the processing tank and flows the processing liquid. And a fin for adjusting an electric field in the processing tank.

When fins are arranged in the processing tank for adjusting the electric field, the flow of the processing liquid tends to be hindered by the fins. However, in the present invention, since the flow path for flowing the processing liquid through the fins is formed, the electric field can be adjusted without obstructing the flow of the processing liquid so much.

The fin has, for example, a triangular cross section,
The flat surface has a donut-shaped outer shape, and a flow path for flowing the processing liquid is provided on the surface or inside thereof.

In order to achieve the above object, a liquid processing apparatus according to a third aspect of the present invention comprises a processing tank containing a processing liquid,
A processing unit for holding a processing target and performing processing with a processing liquid on a processing surface of the processing target; a first region including a first electrode in the processing bath; and a second region in which the processing target is immersed. A separation unit that supplies the processing liquid to the second area, a supply unit that supplies the processing liquid to the first area, and a rectifying plate that adjusts the flow of the processing liquid to the processing surface of the workpiece And the following.

According to this configuration, since the flow of the processing liquid on the processing surface of the object to be processed is adjusted by the rectifying plate, it is possible to perform uniform processing on the processing surface.

The current plate has, for example, a flat or conical outer shape, and has an opening through which the processing liquid flows.

The openings of the current plate are desirably formed such that the opening ratios become uniform. The current plate may be composed of a propeller that stirs the processing liquid.

In order to achieve the above object, a liquid processing apparatus according to a fourth aspect of the present invention comprises a processing tank containing a processing liquid,
A holding unit that holds the object to be processed and applies a voltage to the object to be processed, and immerses the object in a processing liquid, and an electrode that is arranged in the processing apparatus and forms an electric field between the object and the object. And supporting means for supporting the electrode so as to maintain the upper surface of the electrode at a predetermined position. According to this configuration, the distance between the target object and the electrode is kept constant, and the electric field is kept constant.

This is effective when the electrode is made of a material that dissolves in the processing solution.

In order to achieve the above object, in a liquid processing method according to a fifth aspect of the present invention, a processing tank for storing a processing liquid is divided into two upper and lower sections, and the object to be processed is processed into an upper section processing liquid. A voltage is applied at the same time as the immersion, and a voltage is applied to the electrode arranged in the lower section to generate an electric field between the electrode and the object to be processed. Do
It is characterized by the following.

In this case, it is desirable to supply the processing liquid which is the main flow to the upper section from the center thereof, and to supply the processing liquid which constitutes the sub-flow from a plurality of locations surrounding the central port.

In order to achieve the above object, in a liquid processing method according to a sixth aspect of the present invention, an object to be processed is immersed in a processing liquid contained in a processing tank, and a voltage is applied to the processing object. A voltage is applied to the electrodes arranged in the substrate to generate an electric field between the electrodes and the object to be processed, and fins are arranged in the processing tank to adjust the electric field between the electrodes and the object to be processed. And a process liquid is circulated through a passage formed in the fin.

In order to achieve the above object, in a liquid processing method according to a seventh aspect of the present invention, an object to be processed is immersed in a processing liquid contained in a processing tank, and a voltage is applied to the processing object. A voltage is applied to the electrodes arranged on the substrate to generate an electric field between the electrodes and the object to be processed, and a rectifying plate is arranged opposite to the processing surface of the object to be processed to process the object. Adjusting the flow of the processing liquid to the surface.

Further, in order to achieve the above object, in a liquid processing method according to an eighth aspect of the present invention, the object to be processed is immersed in a processing solution contained in a processing tank, and a voltage is applied thereto. A voltage is applied to the electrode disposed in the tank, an electric field is generated between the electrode and the object to be processed, and the electrode is applied to the processing liquid so that the upper surface of the electrode is maintained at a predetermined position. The position of the electrode is adjusted according to a degree of dissolution, or a change in the concentration of the processing solution or a change in the generated electric field.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A semiconductor wafer processing plating apparatus according to an embodiment of the present invention and a plating method using the same will be described below with reference to the drawings.

FIGS. 1 to 3 are views showing the entire configuration of a plating apparatus 111 including a semiconductor substrate plating apparatus and a cleaning apparatus according to an embodiment of the present invention. FIG. 2 is a plan view and FIG. 3 is a side view. As shown in the figure, the plating apparatus 111 includes a cassette station 121 and a processing station 122.

The cassette station 121 carries wafers supplied from the outside to the apparatus 111 in units of wafer cassettes from the cassette 123a into the plating apparatus 111,
Alternatively, the plated wafer is plated with a plating apparatus 111.
Out to the cassette 123b.

A cassette mounting table 124 is provided in the cassette station 121, and a wafer cassette 123a containing a wafer to be plated is supplied from outside. Further, in the mounting table 124, the plated wafer is stored in the unloading cassette 123b.

The transfer of the wafer on the mounting table 124 is performed by the first transfer mechanism 125. The first transfer mechanism 125 is movable in the x-axis direction and is movable up and down in the z-axis direction so as to access the plurality of wafer cassettes 123 mounted on the mounting table 124. Also,
The wafer can be rotated about the z-axis so that the wafer can be transferred from the processing station 122 to the mounting table 124.

The atmosphere inside the cassette station 121 and the processing station 122 is kept clean by the downflow of clean air.

The processing station 122 includes a plating unit 126 for plating a wafer one by one, and a cleaning / drying unit 12 for cleaning and drying after the plating.
7 are provided at predetermined positions.

In the plating unit 126, the wafer on which the seed layer is formed is subjected to plating, for example, a Cu thin film is formed on the wafer. Further, the cleaning and drying unit 127, as described below, high speed plating the treated surface of the wafer, is cleaned back surface and the peripheral drug solution, a washing solution such as pure water (etching), after washing, the wafer under N ₂ purge By rotating, the wafer is dried.

As shown in FIG. 2, a second transfer mechanism 129 is provided at the center of the processing station 122, and the processing units are arranged radially around the second transfer mechanism 129. Further, as shown in FIGS. 1 and 3, the processing station is composed of two upper and lower stages. The upper and lower stages of the processing station 122 each include four processing units radially arranged around the second transport mechanism 129, and the processing station 22 has eight units.

In the embodiment shown in FIG. 1 and FIG.
This shows an apparatus configuration in which one plating processing unit 126 and two cleaning / drying units 127 and two extra units 128 are arranged in the upper stage.

The transfer of the wafer in the processing station 122 is performed by the second transfer mechanism 129. The second transport mechanism 129 is loaded from the cassette station 121 by the first transport mechanism 125 and
The wafer placed on the placement unit 130 in the inside is received and transported to one of the lower plating units 126. After the completion of the plating process, it is further sent to the washing / drying unit 127. Finally, the second transport mechanism 129 sends the wafer that has passed through the plating unit 126 and the cleaning / drying unit 127 to the mounting unit 130, and the first transport mechanism 125 receives the wafer and stores it in the cassette 123. Here, the first transport mechanism 125 can directly receive the wafer from the cleaning / drying unit without going through the mounting unit 130. In this case, the cassette station 121 and the processing station 1
By providing a gate on the side wall between the gate and the gate 22, contamination by particles or the like can be prevented.

The second transport mechanism 129 is rotatable about the z-axis and is capable of moving up and down in the z-axis direction so that each processing unit in the processing station 122 having the two-stage configuration described above can be accessed. It is.

The second transport mechanism 129 has three arms, one of which is provided from the loading section 130 to the plating unit 1.
26, one of which is a plating unit 12
6 is transferred to the cleaning / drying unit 127, and one wafer is dedicated to the transfer from the cleaning / drying unit 127 to the mounting unit 130, thereby minimizing contamination by particles, chemicals, and the like.

In the above-described embodiment, four plating processing units 126 are provided in the lower stage, and two cleaning / drying units 1 are provided in the upper stage.
27 and two extra units 128 are arranged, but other device configurations utilizing the extra units 128 are also possible. For example, a configuration in which four plating processing units 126 are provided in the lower stage, and one plating processing unit 126 and three cleaning / drying units 127 are provided in the upper stage is also possible.

The extra unit 128 can be another processing unit that can be combined with the plating unit 126 and the cleaning / drying unit 127, for example, an annealing unit that performs annealing after plating.

The plating apparatus constituting the plating unit 126 will be described below. FIG. 4 shows a configuration of the plating apparatus of the present embodiment. (First Embodiment) As shown in FIG. 4, a semiconductor wafer plating apparatus includes a plating tank 100 containing a plating solution.
And a semiconductor wafer to be processed (hereinafter simply referred to as a wafer) 17
And a wafer supporting unit 101 for processing while holding. The plating tank 100 has a two-tank structure including an inner tank 4 and an outer tank 5. The inner tank 4 is separated by a diaphragm 11 into a lower anode reaction section 1 and an upper cathode reaction section 40. The details of the diaphragm 11 will be described later with reference to FIG. An anode electrode 2 is arranged in the anode reaction section 1.

At the bottom of the inner tank 4,
A first supply port 7 for supplying a plating solution containing copper and a first discharge port 3 for discharging the plating solution in the anode reaction section 1 are formed. The plating solution is supplied into the anode reaction section 1 through the first supply port 7 by the circulation pump 20. The plating solution in the anode reaction section 1 circulates in the anode reaction section 1 with convection flowing from below to above, and is discharged from the anode reaction section 1 through the first outlet 3. The plating solution discharged from the first discharge port 3 is supplied to a line connected to the circulation pump 20 via the plating solution storage unit 24. The plating storage section 24 includes a filter 28 for removing bubbles and impurities in the plating solution.

At the bottom of the inner tank 4, a second supply port 6 for supplying a plating solution into the cathode reaction section 10 is formed. The second supply port 6 is connected to a supply pipe 21 penetrating through the anode reaction section 1, and the supply pipe 21 is connected to the nozzle section 9 protruding above the diaphragm 11.

The nozzle section 9 has a jet port 9a for jetting the supplied plating solution directly into the cathode reaction section 10, and a discharge port 9b for supplying to the flow path 32 formed in the diaphragm 11. The plating solution discharged from the discharge port 9b passes through a flow path 32 in the diaphragm 11, and is supplied to a cathode reaction section 40 from a discharge port 33 (discussed below) formed in the flow path.

The plating solution supplied from the nozzle 9 and the discharge port of the diaphragm 11 involves convection from below to above.
It is discharged out of the plating tank 4 by overflow.

An outer tank 5 is provided outside the inner tank 4, and a groove space 19 exists between the plating tank 4 and the outer tank 5. In addition, a second outlet 8 for discharging the plating solution flowing into the groove space 19 is formed at the bottom of the outer tank 5. The plating solution discharged from the cathode reaction section 10 to the outside of the inner tank 4 flows into the groove space 19 and is discharged to the plating solution storage tank 27 through the second outlet 8.

The plating liquid discharged into the plating liquid storage section 27 has a higher degree of cleanliness than the plating liquid discharged into the plating liquid storage section 24. Therefore, the plating solution stored in the plating solution storage tank 27 is output to a line connected to the circulation pump 20.

The circulation pump 20 includes a plating solution replenishing tank 26.
Is supplied with fresh plating solution.

A flow control valve 23 is disposed in the line through which the plating solution flows to control the amount of circulation. Each flow control valve 23 is controlled by a control unit 25 to control its opening to control the flow rate. The control unit 25 adjusts the opening of the flow control valve 23 in accordance with a detection signal from a sensor (not shown) that measures an operation factor required for plating solution management, for example, temperature, pressure, plating solution concentration, or the like. Control.

The wafer support 101 is supported by the support main body 14.
And the cathode electrode portion 13 attached to the support portion main body 14
And a vacuum chuck 16 for loading and unloading the wafer 17.

The cathode electrode portion 13 is formed on the peripheral portion of the support portion main body 14 so that a plurality of hemispherical electrodes come into contact with the end of the surface to be plated (the surface on which the seed layer is formed) 22 of the wafer 17. They are arranged circumferentially. Rubber seal part 1
5 supports the wafer 17 from below and suppresses the plating solution from entering the cathode electrode portion 13. The vacuum chuck unit 16 moves up and down to load and unload the wafer 17 onto the cathode electrode unit. During the plating process, the vacuum chuck unit 16 presses the wafer 17 from above and prevents the wafer 17 from being displaced. A support shaft 18 that supports the support body 14 is connected to a rotation mechanism of a motor (not shown), and rotates the wafer 17 at a constant speed.

The inner tank 4 is divided into the anode reaction section 1 and the cathode reaction section 1
As shown in FIG. 5, the diaphragm 11 divided into 0 and has a hollow portion 31 in the center of which a jet nozzle 9 for supplying a plating solution to the cathode reaction compartment 10 is mounted, and from the hollow portion 31 to the peripheral portion. Plating solution flow path (branch) 3 that extends radially in the opposite direction
2 is provided. In the hollow portion between the flow passages 32 (branch portions) of the diaphragm 11, a film-like body through which the plating solution cannot pass but which can transmit an electric field is mounted integrally with the flow passage 32 (branch portion). Since there is no space communicating vertically, the anode reaction zone 1 and the cathode reaction zone 10 are separated by the diaphragm 11, thereby preventing the plating solutions in both zones from being mixed.

A plating liquid discharge port 33 is provided on the upper surface of the radial flow path 32. The plating solution supplied from the discharge port 9 b connected to the flow path 32 formed in the diaphragm 11 passes through the radial flow path 32, and is discharged from the discharge ports 33 provided at two places on each flow path 32 through the cathode reaction compartment. 10 is supplied as a side stream. In order to control the flow rate of the sub-flow of the plating solution ejected from the ejection port 33, the ejection port 33 has a shape, an arrangement, and a size in consideration of a pressure loss caused by the circulation of the plating solution inside the flow path 32. Well, the number etc. are designed.

Next, a plating process using the plating apparatus having the above configuration will be described. First, the pump 20 is driven to supply a clean plating solution from the first supply port 7 to the anode reaction section 1.
To supply. The plating solution in the anode reaction section 1 circulates in the anode reaction section 1 with convection flowing from below to above, and is discharged from the anode reaction section 1 through the first outlet 3. The plating liquid discharged from the first discharge port 3 is re-supplied to the circulation pump 20 in a clean state after bubbles and impurities are removed by the filter 28 of the plating liquid storage unit 24.

The plating solution supplied to the second supply port 6 by the circulation pump 20 is supplied to the nozzle section 9 via the supply pipe 21, and the plating solution is supplied from the jet port 9 a of the nozzle section 9 to the cathode reaction section 1.
The gas is injected into the cathode reaction compartment 10 and is supplied to the inside of the cathode reaction compartment 10 from the discharge ports 33 distributed through the flow passage 32 in the diaphragm 11.

The plating solution supplied into the cathode reaction section 10 is accompanied by convection upward from below, and is discharged out of the inner tank 4 by overflow, so that the groove space 19 is formed.
And supplied to the circulation pump 20 through the second discharge port 8 and further through the plating solution storage tank 27. Thus, the plating solution in the cathode compartment 10 is circulated.

On the other hand, the wafer 17 to be plated is housed in the cassette 123 and mounted on the
Is placed on the table 130 by the transport unit 125 and supplied to an arbitrary plating unit 126 by the second transport unit 129. The adsorption unit 16 of the plating apparatus adsorbs and transports the wafer 17, places the cathode electrode unit 13 in contact with the end of the wafer 17, and presses and presses this, as shown in FIG.

Further, the anode electrode 2 and the cathode electrode 1
3 is applied with a predetermined voltage. As a result, the wafer 17 in contact with the anode electrode 2 and the cathode electrode 13
And an electric field is generated between them. Next, the supporting portion 101 is gradually lowered while rotating, and the surface to be processed of the wafer 17 is immersed in the plating solution.

FIG. 6 is a schematic diagram showing the flow of a plating solution in the plating tank 100, particularly in the cathode reaction section 10, when the wafer 17 is being plated. The main flow 42 of the plating solution supplied from the plurality of ejection nozzles 9 a of the ejection nozzle portion 9 protruding above the diaphragm 11 by the supply pipe 21 penetrating the anode reaction section 1 rises toward the surface 22 to be plated of the wafer 17. Thus, the entire convection 44 of the cathode reaction section 10 is constituted.
On the other hand, the sub-flow 43 of the plating solution supplied from the discharge port 33 of the radial flow path 32 provided in the diaphragm 11 generates a secondary convection 45 in the peripheral portion (particularly on the wall surface side).

Therefore, the main flow 42 and two types of sub-flows 43 near the center and the side wall are formed in the cathode reaction section 10, and the uniformity of the flow field is improved.
Since the film itself rotates, a uniform plating layer can be formed. In addition, as compared with the vicinity of the center of the wafer 17, local segregation and stagnation are more likely to occur.
In addition, since the secondary convection 45 exists, local stagnation of the plating solution is prevented, and deposition of metal due to a decrease in the linear velocity of the flow in the plating tank is prevented.

Further, since the plating solution in the anode reaction section 1 and the plating solution in the cathode reaction section 10 are separated from each other, the plating surface 22 of the wafer 17 of impurities which may be generated from additives of the electrolytic solution or the like. Adhesion to the surface is prevented. Therefore,
A high quality plating layer can be formed.

The wafer support 101 immerses the mounted wafer 17 in a plating solution for a predetermined time, and when a plating layer having a predetermined thickness is formed, the wafer 17 is lifted together with the entire wafer support 101. The lifted wafer 17 is
The wafer is transported by the second transport mechanism and transferred to the cleaning device 127, and the operation proceeds to the subsequent cleaning (removing unnecessary plating) operation.

The structure of the diaphragm 11 is not limited to the structure shown in FIG. The material and shape of the diaphragm 11 are arbitrary as long as the plating solution in the anode reaction section 1 and the plating solution in the cathode reaction section 10 can be separated, an electric field can be passed, and a main stream and a sub stream can be formed. In addition, the arrangement position of the discharge ports 33 for forming the substream is also arbitrary. For example, the number or the size of the discharge ports is increased as approaching from the center to the peripheral portion, and the area of the discharge ports per unit area is increased. May be made substantially constant over the entire surface.

(Second Embodiment) In the first embodiment, the distribution of the electric field density between the anode 2 and the wafer 17 is generated, and the thickness of the formed plating film may be uneven. . Therefore, a plating apparatus having fins for making the electric field density uniform in the cathode reaction section 10 will be described.

FIG. 7A is a plan view of the fin 12 for electric field adjustment, and FIG. 7B is a cross-sectional view. As shown
The fin 12 has a donut-shaped planar shape having a plurality of recessed spaces 61 on an outer peripheral portion, and has a triangular cross-sectional shape as shown in FIG. 7B. This fin 1
2 is, for example, PVDF (polyvinylidene fluoride)
Consists of As shown in FIG. 8, the electric field adjusting fins 12 are installed on the side wall of the inner tank 4 of the plating tank 100, and adjust the electric field and the flow of the plating solution on the side wall of the cathode reaction section 10.

According to such a configuration, the fins 12 make the electric field density near the processing surface of the wafer 17 uniform. This is because the electric field has the property of being straight and biased toward the one with the smaller resistance. By interrupting this electric field, the wafer 1
The distance of the end of the wire 7 becomes longer and the resistance increases. for that reason,
The electric field density which tends to concentrate on the peripheral portion of the wafer 17 in contact with the cathode electrode 13 can be adjusted to be uniform. Further, since the concave space 61 is formed in the peripheral portion of the fin 12, the plating solution passes through this portion.
There is no retention of the plating solution. As shown in FIG. 7B, an example is shown in which the plating solution flow path is formed in the outer peripheral portion of the fin 12, but a plurality of fine holes may be arranged in the fin to allow the plating solution to flow.

The fins 12 can be integrated with the diaphragm 11. FIG. 9 shows an example of the structure of the diaphragm 11 and the fin 12 which are integrally formed. In this configuration, the channel 3 of the diaphragm 11
2 is connected to the concave space 61 of the fin 12.

FIG. 10 is a schematic diagram of a plating apparatus using the electric field adjusting fins 12 integrated with the diaphragm 11. In this configuration, the main flow 42 of the plating solution supplied from the ejection nozzle portion 9a rises toward the surface 22 to be plated of the wafer 17 and forms the entire convection 44 of the cathode reaction section 10 of the plating tank. On the other hand, the radial flow path 32 provided in the diaphragm 11
The sub-flow 43 of the plating solution supplied from the discharge port 33 of the above forms a local or secondary convection 45 in the periphery of the surface 22 to be plated. In the vicinity of the side wall, the fin 12
The sub flow 46 ejected through the flow channel 63 communicating with the concave portion 61 of the outer peripheral portion provided therein rises in contact with the side wall.

Therefore, in the cathode reaction section 10, the main stream 4
2 and two types of sub-streams 43 near the center and the side wall, and a third sub-stream 46 formed by the supply from the discharge port 63 of the fin 12 is formed. This improves the uniformity of the flow field. Further, local accumulation of the plating solution, particularly near the side wall of the plating tank, that is, at the end of the plating surface 22 of the wafer 17, is prevented, and deposition of metal due to a decrease in the linear velocity of the flow in the plating tank is prevented. You.

(Third Embodiment) Wafer Support 101
An embodiment of a plating apparatus provided with a means for making the flow uniform just below the surface to be plated 22 of the wafer 17 placed on the substrate 17 will be described. As shown in FIG. 11, rectifying plate support portions 52 arranged at appropriate intervals are formed on the peripheral edge of the lower end of the wafer supporting portion 14, and the rectifying plate 5 is fixed to the rectifying plate supporting portion 52, and A space 53 surrounded by the current plate 51 and the current plate support portion 52 is formed.

The plating solution that has passed through the opening 57 of the rectifying plate 51 provided immediately below the surface 22 to be plated of the wafer 17 becomes a uniform flow 54 and rises in the region 53,
Contacts the surface 22 to be plated. Then, the plating surface 22
Reaches the surface 22 to be plated and joins to form an overall convection 55. The overall convection 55 flows out of the region 53 through the space between the current plate support portions 52 while moving from the central portion to the peripheral portion of the surface 22 to be plated. The plating solution flowing out of the region 53 rides on the convection 44 from below to above of the entire cathode reaction section 10 shown in FIG.

The current plate 51 is connected to the wafer support 101.
It rotates with the rotation of. Therefore, the plating solution that has passed through the opening 57 changes to convection from bottom to top with a spiral flow due to rotation, and local stagnation in the region 53 is more unlikely to occur. On the other hand, the current plate 51 controls the reaction on the plating surface 22 by controlling the flow rate of the plating solution below the plating surface 22 of the wafer 17.

When the angle of the joint 58 between the rectifying plate 51 and the rectifying plate support plate 52 is close to a right angle, the rectifying plate support 5
2, the plating solution flowing out of the region 53 tends to stay. Therefore, a structure is used in which the rectifying plate 51 has a more conical shape than a flat plate, and the rectifying plate 51 and the rectifying plate support plate 52 have an obtuse angle to suppress the stagnation of the plating solution in the region 53. preferable.

FIG. 12 shows a configuration example of the current plate 51. In this example, the current plate 51 has a circular planar shape similar to the shape of the wafer 17 and includes a plurality of openings 71. In order to keep the area ratio of the openings 71 constant in a plane parallel to the wafer 17, openings 71 of the same size are formed at equal intervals on the circumference of the concentric circle as shown in FIG.

As shown in FIG. 13, on the concentric circle,
The same number of openings 72 may be arranged radially. However, the opening 72 is formed such that its size becomes larger toward the periphery. The shape of the opening is not limited to a rectangle or a circle, and any shape can be selected. Further, the size, number, density, or interval of the openings can be selected so as to obtain a desired flow below the plating surface 22 of the wafer 17.

FIG. 14 shows a rectifying plate 5 based on another design concept.
1 is shown. The current plate 51 has a hollow portion 73 at the center and a propeller 76 composed of four flat blades connecting the outer portion 75 to the center portion 74. There is a space between the blades.

In addition to the planar blade shown in the figure, a blade having three-dimensional torsion, such as a propeller used for a fan or the like, can be used. further,
The number of blades can also be appropriately selected, and by changing the shape and number of blades, the stirring effect of the plating solution can be changed to change the flow state below the surface 22 to be plated.

FIG. 15 is a schematic diagram showing the flow of the plating solution in the plating tank 100 when the propeller-shaped current plate 51 shown in FIG. The main flow 54 of the plating solution passing through the opening in the center of the disk rises toward the surface 22 to be plated of the wafer and contributes to the convection 55 of the entire cathode reaction section 10 of the plating tank. On the other hand, the plating solution that has passed through the space between the propellers forms a substream 56 while the flow is disturbed by the propellers. By this sub-flow 56, local stagnation can be prevented also in the peripheral part, especially in the wall surface side.

(Fourth Embodiment) In the first to third embodiments, the configuration of the cathodic reaction section 10 has been mainly described. Segregation of the metal inside occurs. Therefore, an embodiment having a configuration capable of preventing the stagnation of the plating solution in the anode reaction section will be described below.

FIG. 16 shows a cross-sectional shape of the anode electrode 2 in which pores are formed. In this configuration, the plating solution is supplied from the supply pipe 81 to the anodic reaction section 1, passes through the pores 82 of the anode electrode 2, reaches the upper portion of the anodic reaction section 1, and as a whole section, from the bottom to the top. While convection is occurring, it reaches the liquid reservoir below the plating tank.

According to the configuration of this embodiment, since the pores 82 are formed in the anode electrode 2, the plating solution
It becomes much easier to circulate than when there are no pores. Therefore, stagnation of the plating solution is prevented, segregation of metals in the plating solution is prevented, and stagnation of bubbles and impurities generated during the reaction is suppressed.

(Fifth Embodiment) The anode electrode 2 is
For example, when formed from copper, the surface area of the anode electrode dissolves in the plating solution with the progress of the plating process, and the distance between the anode electrode 2 and the wafer 17 increases with the elapse of the processing time. Even when the same voltage is applied between the electrode 2 and the cathode electrode 13, the electric field gradually weakens.

Hereinafter, a plating apparatus capable of solving such a problem with a relatively simple configuration will be described. FIG.
1 shows a configuration of an anode electrode 2 according to this embodiment. The anode electrode 2 includes a spring chamber 91 in which an coil spring 92 wound around a drive shaft 93 is housed at an end.
The spring 92 urges the anode electrode 2 upward. Also,
A stopper 94 that contacts the upper surface of the anode electrode 2 is disposed at the tip of the drive shaft 93.

When the anode electrode 2 is dissolved in the plating solution and becomes small, the anode electrode 2 is pushed up to a position where the upper surface thereof contacts the stopper 93 by the urging of the coil spring 92. For this reason, the upper surface of the anode electrode 2 is always adjusted to a fixed position, and the distance between the upper surface of the anode electrode 2 parallel to the surface 22 to be plated of the wafer 17 is kept constant irrespective of the number of wafers 17 to be plated. You. Therefore,
While the voltage between the anode electrode 2 and the cathode electrode 13 is kept constant, the electric field distribution in the plating tank can be kept constant, and the flow field of the plating solution can be kept almost constant. . Therefore, even when a large number of wafers 17 are processed, it is possible to form a plating layer having a uniform film thickness on both the single wafer 17 and the plating surface 22 between the multiple wafers 17. it can.

The structure for urging the anode electrode 2 upward and the structure for fixing the anode electrode 2 at a predetermined position on the upper surface of the anode electrode 2 are not limited to the structure shown in FIG.

The movement of the anode electrode 2 is determined based on the concentration in the plating solution by a concentration detector (not shown) or the like.
The configuration may be such that the position of the anode electrode 2 is moved via control means (not shown). Further, the driving may be performed after a lapse of a predetermined time during the plating process. further,
A configuration may be adopted in which one wafer 17 is moved by a predetermined amount after the processing is completed or after a predetermined number of wafers are processed. With such a configuration, the position between the electrodes can be more controlled, and the uniformity of plating is improved.

The present invention is not limited to the above embodiment, and various modifications and applications are possible. For example, the configurations of the first to fifth embodiments can be used in any combination. Further, in the above embodiment, a plating apparatus for performing copper plating on a semiconductor wafer has been described. However, the present invention is applicable to any apparatus that includes an anode electrode and a cathode electrode and performs a liquid treatment on a target object. It is possible. Further, the object to be processed is not limited to a semiconductor wafer, and can be applied to a glass substrate for an LCD.

[0094]

As described above, according to the present invention,
Uniform liquid processing can be efficiently performed.

[Brief description of the drawings]

FIG. 1 is a three-dimensional view of a plating apparatus including a semiconductor substrate plating apparatus and a cleaning apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view of a plating apparatus including a semiconductor substrate plating apparatus and a cleaning apparatus according to an embodiment of the present invention.

FIG. 3 is a side view of a plating apparatus including a semiconductor substrate plating apparatus and a cleaning apparatus according to the embodiment of the present invention.

FIG. 4 is an apparatus configuration diagram of a semiconductor wafer processing plating apparatus according to the first embodiment of the present invention.

FIG. 5 is a diagram showing the shape of the diaphragm shown in FIG. 4;

6 is a schematic diagram of a flow of a semiconductor wafer plating apparatus including the diaphragm shown in FIG.

FIG. 7A is a plan view of a fin of a plating apparatus for semiconductor wafer processing according to a second embodiment of the present invention, and FIG.
Is a sectional view.

FIG. 8 is a cross-sectional view of the semiconductor wafer plating apparatus with the fins shown in FIG. 7 mounted.

FIG. 9 is a diagram showing a configuration example of a fin integrated with a diaphragm.

FIG. 10 is a schematic diagram of a flow of a plating solution in a semiconductor wafer plating apparatus having the fins of FIG. 9;

FIG. 11 is a schematic diagram of an apparatus in which a current plate of a semiconductor wafer plating apparatus according to a third embodiment of the present invention is installed and a schematic diagram of a flow;

FIG. 12 is a diagram showing an example of the shape of the current plate shown in FIG.

FIG. 13 is a view showing another example of the shape of the current plate shown in FIG. 11;

FIG. 14 is a view showing still another example of the shape of the current plate shown in FIG. 11;

FIG. 15 is a schematic diagram of a flow of a plating solution in a semiconductor wafer plating apparatus including the rectifying plate of FIG.

FIG. 16 is an apparatus configuration diagram of a semiconductor wafer plating apparatus according to a fourth embodiment of the present invention.

FIG. 17 is an apparatus configuration diagram near an anode electrode of a semiconductor wafer plating apparatus according to a fifth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Anode reaction compartment 2 Anode electrode 3 Anode reaction plating solution outlet 4 Plating tank inner wall 5 Plating tank outer wall 6 Cathode compartment plating solution supply unit 7 Anode compartment plating solution supply unit 8 Cathode reaction plating solution outlet 9 Plating solution jet nozzle DESCRIPTION OF SYMBOLS 10 Cathode reaction section 11 Diaphragm 12 Fin 13 Cathode electrode 14 Wafer support part 15 Seal part 16 Vacuum chuck 17 Wafer 18 Wafer support part support shaft 19 Space between plating tank inner and outer walls 20 Circulation pump 21 Plating solution supply pipe 22 Wafer plating surface 23 Valve 24 Storage tank 25 Controller (for flow control valve) 26 Replenishment tank 27 Liquid storage tank 28 Filter 31 Hollow part of diaphragm 32 Diaphragm channel 33 Opening 41 Discharge nozzle 42 Main stream of plating solution 43 Substream of plating solution 44 Cathode reaction Total convection of the compartment 45 Secondary convection of the cathodic reaction compartment 46 Three sub-streams 51 Rectifier plate 52 Rectifier plate support 53 Main area of wafer near the wafer 54 Plating liquid in the area near the wafer 55 Total convection in the area near the wafer 56 Secondary convection in the area near the wafer 61 Space 71 Rectangular opening 72 Circular opening 73 Central hollow 74 Central edge 75 Peripheral edge 76 Blade 81 Plating solution supply pipe under anode electrode 82 Anode electrode pore 90 Anode electrode driving device 91 Spring chamber 92 Coil spring 93 Drive Shaft 94 Stopper 100 Plating tank 101 Support 111 Plating apparatus 121 Cassette station 122 Processing station 123 Cassette 124 Mounting table 125 First transport mechanism 126 Plating processing unit 127 Washing / drying unit 128 Extra unit 129 Second transport mechanism 130 Processing station 12 The stage of the internal

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Koichiro Kimura 1-2-141 Machiya, Shiroyama-cho, Tsukui-gun, Kanagawa Prefecture Tokyo Electron E.E. 4M104 BB04 CC01 DD33 DD52 DD53 HH20

Claims (20)

[Claims] 1. A processing tank having a first electrode and containing a processing liquid, holding means for holding a processing object, and immersing a processing surface of the processing object in the processing liquid in the processing tank; A separation unit configured to separate the processing tank into a first region including the first electrode and a second region in which the object is immersed, and to supply the processing liquid to the second region from the plurality of supply ports; A liquid supply apparatus for supplying a processing liquid to the first region. 2. The processing liquid is composed of a plating liquid, the first electrode is an anode electrode, the processing body is a semiconductor wafer, and the holding means is in contact with a surface to be processed of the semiconductor wafer. A cathode electrode to be provided, the surface to be processed is immersed in the processing tank with the surface to be processed facing down, and the separation unit supplies a plating solution to a second region by an ascending flow from the plurality of supply ports. The liquid processing apparatus according to claim 1, wherein: 3. The separation section includes a main flow port formed at a central portion for supplying a processing liquid as a main flow, and a plurality of sub-flow ports disposed around the central port and supplying respective sub-flows. The liquid processing apparatus according to claim 1, further comprising: 4. The separating section includes: a shaft having an opening; a branch fixed at one end to the shaft, extending radially, and internally having a flow path connected to the sub-flow port; Supply means for supplying the main flow of the processing liquid to the second region through the substrate and supplying the processing liquid to the flow path formed in the branch, a film covering between the branch and the branch, The liquid processing apparatus according to claim 3, further comprising: 5. The liquid processing apparatus according to claim 4, wherein said supply means includes a nozzle which penetrates said opening and ejects a processing liquid. 6. The processing tank according to claim 1, further comprising a flow path for circulating the processing liquid, and further comprising a fin in the processing tank for adjusting an electric field in the processing tank. The liquid processing apparatus according to any one of the preceding claims. 7. A processing tank for storing a processing liquid, processing means for holding an object to be processed, and processing the processing surface of the processing object with the processing liquid, wherein the processing tank includes a first electrode including a first electrode. And a second section in which the object to be processed is immersed, and a separation unit that supplies the processing liquid to the second area; a supply unit that supplies the processing liquid to the first area; A liquid processing apparatus, comprising: a fin disposed in a tank, for providing a flow path for flowing a processing liquid, and adjusting an electric field in the processing tank. 8. The fin according to claim 6, wherein the fin has a triangular cross section, a donut-shaped outer surface, and a flow path for flowing the processing liquid on its surface or inside. A liquid processing apparatus according to claim 1. 9. A processing tank for storing a processing liquid, processing means for holding an object to be processed, and processing the processing surface of the processing object with the processing liquid; A separation unit that separates the region into a second region into which the object to be processed is immersed, and supplies the processing solution to the second region; a supply unit that supplies the processing solution to the first region; A liquid processing apparatus, comprising: a rectifying plate for adjusting a flow of a processing liquid to a processing surface of a body. 10. The liquid processing apparatus according to claim 9, wherein the current plate has a flat or conical outer shape, and has an opening through which the processing liquid flows. 11. The liquid processing apparatus according to claim 9, wherein the openings of the current plate are formed so as to have an equal opening ratio. 12. The liquid processing apparatus according to claim 9, wherein the current plate includes a propeller for stirring the processing liquid. 13. A processing tank for storing a processing liquid; holding means for holding a processing object, applying a voltage to the processing object, and immersing the processing object in the processing liquid; A liquid processing apparatus, comprising: an electrode for forming an electric field between the electrode and the object; and a support unit for supporting the electrode so that an upper surface of the electrode is maintained at a predetermined position. 14. The processing solution is composed of a plating solution, and the electrode is an anode electrode to which a voltage higher than the voltage applied to the object is applied, and is made of a material that dissolves in the plating solution. 2. The method according to claim 1, wherein
4. The liquid processing apparatus according to 3. 15. A processing tank containing a processing solution is divided into upper and lower compartments, and an object is immersed in a processing solution in an upper compartment and a voltage is applied, and a voltage is applied to an electrode arranged in a lower compartment. And generating an electric field between the electrode and the object to be processed, and supplying the processing liquid dispersedly from a plurality of locations to the upper section. 16. A processing liquid as a main flow is supplied to the upper section from a central portion thereof, and a processing liquid constituting a sub-flow is supplied from a plurality of locations surrounding a central opening.
3. The liquid treatment method according to item 1. 17. An object to be processed is immersed in a processing solution contained in a processing tank, and a voltage is applied thereto. A voltage is applied to an electrode disposed in the processing tank, so that the electrode and the object are processed. An electric field is generated between the electrodes, and a fin is arranged in the processing tank to adjust the electric field between the electrode and the object to be processed, and to flow the processing liquid through a passage formed in the fin. A liquid processing method characterized by the above-mentioned. 18. An object to be processed is immersed in a processing solution accommodated in a processing tank and a voltage is applied thereto. A voltage is applied to an electrode disposed in the processing tank, and the electrode and the object are processed. A liquid processing method, comprising: generating an electric field between the processing surfaces; and arranging a rectifying plate so as to face a processing surface of the processing target to adjust a flow of the processing liquid to the processing surface of the processing target. 19. An object to be processed is immersed in a processing solution contained in a processing tank, and a voltage is applied thereto. A voltage is applied to an electrode disposed in the processing tank, and the electrode and the object are processed. An electric field is generated, and the position of the electrode is adjusted according to the degree of dissolution of the electrode in the treatment liquid, so as to maintain the upper surface of the electrode at a predetermined position. Processing method. 20. A predetermined position on the upper surface of the electrode, which is set and maintained at a predetermined electrode position which is variable for each liquid processing of the object to be processed, in accordance with a processing liquid condition and an electric field generated and applied. 20. The liquid treatment method according to claim 19, wherein