JP2001316888A - Plating system for semiconductor substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plating system which can easily maintain each plating tank outside a clean room, preventing a spread of mist, particles and the like generated from a plating liquid and a cleaning liquid, and which can easily cope with needs of varying numbers of the plating tanks and cleaning/drying tanks. SOLUTION: The plating system 101 comprises a semiconductor substrate transportation means 205 and 213 for conveying a semiconductor substrate, a plating means 104 which is arranged in surroundings of the semiconductor substrate transportation means 213 and detachable/attachable to the plating system 101, and a cleaning/drying means 103 which is arranged in surroundings of the semiconductor substrate transportation means 213 and detachable/ attachable to the plating system 101.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plating apparatus and a plating method for forming a plating layer on a semiconductor substrate, and more particularly to a plating technique effective when forming fine wiring on a wafer by copper plating. About.

[0002]

2. Description of the Related Art In recent years, attention has been paid to copper instead of aluminum as a wiring material for semiconductor devices. This corresponds to the fact that the increase in capacitance between wirings cannot be ignored with the miniaturization. That is, if the capacitance between the wirings increases, the performance of the LSI deteriorates due to the wiring delay. To prevent this, either a low resistance wiring or a low dielectric constant interlayer film is required. Copper has attracted attention as a replacement for aluminum wiring because copper has lower resistivity than aluminum and higher electromigration resistance.

As a method for forming a copper wiring, a sputtering method,
There are a CVD method and an electrolytic plating method. Among these methods, a wiring technique using an electroplating method has attracted attention. In the method of forming an embedded wiring using the electrolytic plating method, first, a barrier metal layer is formed in a groove or a connection hole, and then copper is generally formed by a sputtering method or a CVD method. In this electrolytic plating method, copper can be embedded in grooves and connection holes having a high aspect ratio at room temperature.

As a plating apparatus for forming copper wiring on a wafer by an electrolytic plating method, for example, there is one disclosed in Japanese Patent Application Laid-Open No. H11-154653. The plating apparatus disclosed herein includes a loading / unloading area for transferring a cassette containing a substrate, a plating processing area for performing a plating process, and a cleaning / drying area for cleaning and drying the substrate after the plating process. The cleaning / drying area and the plating area are provided with independent supply / exhaust and pressure control.

The plating apparatus disclosed in Japanese Patent Application Laid-Open No. H11-307481 mainly includes a transfer chamber provided with a transfer robot for transferring a wafer, a load-side wafer storage unit, a pretreatment chamber, a plating chamber, The post-processing chamber and the unload-side wafer storage section are connected by, for example, a gate valve, which is a so-called multi-chamber configuration.

[0006]

However, in the plating apparatus described in Japanese Patent Application Laid-Open No. H11-154653, since the atmosphere is controlled for each area, particles and chemical mist between the areas are controlled. Although diffusion and the like can be prevented, diffusion of particles and chemical mist between the plating tanks installed in the plating area cannot be prevented. Therefore, in particular, in the case of performing a process using different conditions in each plating tank, for example, using a different plating solution, diffusion of particles and chemical mist between the plating tanks becomes a problem, but the above-described apparatus cannot prevent it.

Further, in a normal plating apparatus, mist is generated because the processing is performed using a plating solution or the like. Therefore, no matter how the atmosphere in the plating apparatus is controlled, mist may be present in the plating apparatus. Therefore, it is desirable that maintenance of the plating apparatus be performed outside the clean room where the plating apparatus is installed. However, since the plating tank and the cleaning / drying tank of the plating apparatus are not configured to be easily detachable and movable, it is not easy to move the plating tank out of the clean room and perform maintenance. Similarly, it is not easy to respond to the needs such as increase and decrease of the plating tank and the washing / drying tank.

In the plating apparatus disclosed in Japanese Patent Application Laid-Open No. H11-307481, the atmosphere inside the plating chamber having a plating tank therein is only a non-oxidizing atmosphere. Is not controlled. Therefore, in the above plating apparatus, when the sealed state of the plating chamber is released by opening the gate valve when transferring the wafer, the mist in the plating chamber diffuses out of the plating chamber.

The present invention has been made in view of the above problems, and aims to prevent mist and particles generated from a plating solution and a cleaning solution from being diffused, and to easily perform maintenance of each plating tank outside a clean room. It is an object of the present invention to provide a plating apparatus capable of easily responding to the needs of increasing and decreasing the number of plating tanks and washing / drying tanks.

[0010]

According to a first aspect of the present invention, there is provided a plating system, comprising: a semiconductor substrate transporting unit for transporting a semiconductor substrate; and a plating process disposed around the semiconductor substrate transporting unit. The present invention further includes a plating system comprising: a plating unit that is detachable from the system; and a cleaning / drying unit that is disposed around the semiconductor substrate transport unit and that is detachable from the plating system.

[0011] Further, a plating processing means detachably mountable to the plating processing system according to claim 2 is provided in the plating processing means for transferring a semiconductor substrate to and from the semiconductor substrate transfer section; At least one of atmosphere control means for cleaning the atmosphere and a plating tank portion disposed in the plating means for performing a plating process on the semiconductor substrate.

Further, the plating tank section disposed in the plating processing means according to the third aspect includes an exhaust means for exhausting mist generated from a plating solution in the plating tank section to dissolve in water.

The atmosphere control means for purifying the atmosphere in the semiconductor substrate transfer section according to claim 4 is:
It includes a pressure adjusting means for adjusting the pressure in the plating means.

The plating method according to claim 5, wherein the step of cleaning the atmosphere of the semiconductor substrate transport section, the step of exhausting the mist generated from the plating solution in the plating tank section and dissolving it in water, A step of cleaning the atmosphere of the transfer section and a step of loading the semiconductor substrate into the semiconductor substrate transfer section in the plating processing means after starting the step of exhausting mist generated from the plating solution in the plating tank section and dissolving it in water; Transporting the semiconductor substrate from the semiconductor substrate transport unit to a plating tank unit and performing a plating process in the plating tank unit;
The method includes a step of transporting the plated semiconductor substrate from the plating tank section to the semiconductor substrate transport section and carrying out the plating processing means.

Further, the plating method according to claim 6 includes a step of cleaning the atmosphere of the semiconductor substrate transport section, a step of exhausting mist generated from the plating solution in the plating tank section and dissolving it in water, A step of controlling the pressure inside the unit to be lower than a pressure outside the plating processing unit, a step of cleaning the atmosphere of the wafer transfer unit, a step of exhausting mist generated from a plating solution in the plating tank unit and dissolving it in water, Loading the semiconductor substrate into the semiconductor substrate transport section in the plating means after starting the step of controlling the pressure in the plating means to be lower than the pressure outside the plating means; and Transferring the semiconductor substrate from the semiconductor substrate transfer section to the plating tank section and performing plating, and transferring the plated semiconductor substrate from the plating tank section to the semiconductor substrate transfer section; Carrying out from the plating means.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a plating system 101 used to carry out the present invention, and FIG. 2 is a plan layout view of the plating system 101.

As shown in FIGS. 1 and 2, the plating system 101 includes a cassette station 102 and a process station 106. Cassette station 102
Has a cassette stage 20 for placing cassettes.
1. There is a transfer stage 215 on which a first wafer transfer device 205 for transferring a wafer is installed. The cassette stage 201 and the transfer stage 215 are arranged separated by a first partition wall 203.

As shown in FIGS. 1 and 2, the cassette stage 201 is provided with a cassette mounting table 201a for mounting a plurality of, for example, up to four cassettes 202. A plurality of wafers, for example, 25 wafers, can be placed and stored at equal pitches in the cassette 202 in multiple stages, and a lid 218 is attached to an opening for taking out and storing the wafers. The cassette mounting table 201a is provided with a detection unit (not shown) for detecting that the cassette 202 has been mounted.

The cassette mounting table 201a is configured to be movable in the direction of the first partition 203 by a cassette driving mechanism provided below the cassette mounting table 201a. The first partition 203 is provided with a first opening 105 having substantially the same area as the opening of the cassette 202 at a position facing the opening of the cassette 202. The first opening 105 is for taking out and storing a wafer from the cassette 202. When the cassette 202 is not mounted, the first opening 105 is used to shut off the atmosphere between the cassette stage 201 and the transfer stage 215. One shutter member 204
Is closed by This first shutter member 204
Is mounted so as to be able to move up and down by a shutter member driving mechanism (not shown).

As shown in FIG. 2, the transfer stage 215 is provided with a rail 217 provided in parallel with the cassette stage 201, and a first wafer transfer device 205 arranged on the rail 217. The first wafer transfer device 205 holds a transfer device main body 206, a transfer arm support 207 provided on the transfer device main body 206, a support shaft 208a that rotatably supports the transfer arm support 207, and a wafer. A transfer arm 209,
Transfer arm support shaft 2 that rotatably supports transfer arm 209
08 and.

The transport device main body 206 can be moved on the rail 217 by a drive mechanism. The transfer arm support table 207 is connected to the transfer device main body 206 via a support shaft 208a, and the support shaft 208
When a is rotated, it is turned around the support shaft 208a. The transfer arm 209 is connected to the support table 207 via the transfer arm support shaft 208, and is turned around the transfer arm support shaft 208 when the transfer arm support shaft 208 is rotated. That is, it is configured that the wafer can be turned upside down while holding the wafer on the transfer arm 209.

The support base support shaft 208a and the transfer arm support shaft 208 are configured to be able to protrude in the axial direction. When the support base support shaft 208a is protruded, the transfer arm support base 207 is raised, and the transfer arm support shaft 208 is raised. Extending the transfer arm 209
Protrudes. Therefore, the transfer arm 209 is
It can be moved back and forth, upside down, and turning.
By these movements, the wafer can be transferred to a predetermined position. The transfer arm 209 is provided with a suction mechanism (not shown), and the wafer is held by a so-called vacuum chuck method in which the wafer is suctioned by the suction mechanism.

As shown in FIG. 2, the process station 106 has a function (rail) equivalent to that of the first wafer transfer device 205.
Second wafer transfer device 2 having a moving function on 217)
13 is disposed at the center, a wafer is temporarily stored around the buffer, for example, a buffer 216, a plating processing means for plating the wafer, for example, a plating module 104, and a cleaning / drying means for cleaning and drying the wafer after the plating processing. For example, cleaning / drying modules 103 are respectively arranged. The plating module 104 and the cleaning / drying module 103 have a hermetically sealed structure, and are provided with gate valves 214 for carrying in and out the wafer.

Transfer stage 215 and process station 1
Between 06, a second partition 211 is provided. further,
The second partition 211 has a second opening 210, and the second opening 21
At 0, a second shutter member 212 that can be opened and closed is attached. When a wafer is not loaded or unloaded between the transfer stage 215 and the process station 106, the second shutter member 212 is closed and the transfer stage 215
And the atmosphere of the process station 106 is shut off.

Some of the walls of the process station 106
It can be opened and closed. Plating module 10
4 and the washing / drying module 103 are provided with moving means, for example, wheels 107 and rails 217, and can run on the rails 217. Further, the moving means may be configured to lift and move the plating module 104 and the washing / drying module 103 from above by a crane, or a transport jig to move the plating module 104 and the washing / drying module 103.
The drying module 103 may be fixed and moved. With these configurations, the plating module 104
And plating system 101 of washing and drying module 103
It is easy to set up.

Thus, it is possible to sufficiently meet the needs of the plating system 104 and the number of the cleaning / drying modules 103 in the plating system 101, and there is no problem even if mist flows out during maintenance. The modules 103 and 104 can be moved out of the clean room to perform maintenance. The maintenance time is, for example, a predetermined wafer processing time,
This may be a time when the value of a parameter such as the number of processed wafers changes from an initial value to a predetermined value.

It should be noted that some of the plating module 104 or the cleaning / drying module 103 requiring maintenance are
Even when the wafer is taken out of the plating system, the wafer can be plated by the remaining processing modules of the plating system. Further, in this embodiment, the entire plating module 104 and the cleaning / drying module 103 are detachable, but if the plating module 104 and a part of the cleaning / drying module 103 are separate, for example, the plating module 104, Only the wafer transfer unit 301 and the plating tank unit 302 shown in FIG. 3 may be made movable by moving means such as wheels, rails, cranes, and transfer jigs, similarly to the plating module 104.

Next, the configuration and operation of the plating module 104 will be described with reference to FIG. The plating processing module 104 includes a wafer transfer unit 301 that transfers a wafer,
The plating system includes a plating tank unit 302 for plating a wafer and an atmosphere control system for controlling the atmosphere in the plating module 104.

The plating bath 302a of the plating bath section 302 contains a plating solution L therein, and an anode electrode 321 is provided in the plating solution L. The anode electrode 321 is connected to the positive electrode of the power supply. A plating solution circulation system for circulating the plating solution is located below the plating tank 302a.
304 is provided. The plating solution is ejected upward from the third opening 322 by the plating solution circulation system 304.

The wafer transfer unit 301 includes a wafer holding unit 30
3. Atmosphere control system is provided. The wafer holding means 303 has a vertical drive mechanism 305 and can move up and down. The wafer holding means 303 is provided with a cathode electrode (not shown), and the cathode electrode is connected to the back surface of the plating surface of the wafer and to the negative electrode of the power supply.

Next, the atmosphere control system will be described. As shown in FIG. 3, an air supply port is provided above the wafer transfer unit 301.
A first exhaust port 315 is provided at the bottom thereof, and a circulation line is provided between the air supply port 306 and the first exhaust port 315.
311 is connected. In addition, the air inlet 306 and the circulation line 311
An air supply chamber 310 is provided at the connection portion.

In the air supply chamber 310, a blowing means 307 such as a blowing fan, an air cleaning means 308 such as a chemical filter having a function of removing organic contaminants, and a filter having a dustproof function such as a ULPA filter are arranged in order from the top to the bottom. Have been. A perforated plate 309 is provided on the upper surface of the first exhaust port 315, and the air supply port 306 and the first exhaust port in the circulation line 311 are provided.
An outside air inlet 314 is provided between the 315s. Inside the outside air inlet 314, an air volume adjusting means 312 such as a damper or a flow rate adjusting valve is attached.

A second exhaust port 317 is provided at a height at which mist or the like generated from the plating solution in the plating tank is exhausted and dissolved in water, for example, at a height near the level of the plating solution. An exhaust pipe 320 is connected to 317. Exhaust pipe
At 320, a pressure adjusting means 313 such as a slit damper and a pressure adjusting valve and a contaminant removing means 319 such as a mist catcher for removing mist in the air and a scrubber for washing and removing contaminants are provided. Here, the load on the factory utility can be significantly reduced by dissolving and collecting the mist in water.

According to the embodiment of the present invention, with the above-described configuration, contaminants such as mist contained in the atmosphere in the plating tank 302 can be discharged from the second exhaust port 317. Outflow to the transport unit 301 can be prevented. In addition, the atmosphere of the wafer transfer unit 301 supplies clean air into the transfer unit from the top, and circulates through the ULPA filter and the chemical filter.Thus, even if particles or impurity gas are mixed into the air for some reason,
It can be reliably removed.

Therefore, the cleanliness of the atmosphere of the wafer transfer section 301 is controlled to about class 1 to 10 (however, class 1 means cleanliness of less than 0.5 μm of dust in a 1-foot cube). Mist from the plating solution can be prevented. As a result, the atmosphere in the wafer transfer unit 301 and the plating tank unit 302 can be controlled to two atmospheres having substantially different cleanliness.

When the damper of the outside air inlet 314 shown in FIG. 3 is opened at a predetermined opening, the outside air, that is, the clean air in the clean room is circulated from the outside air inlet 314 to the circulation pipe.
311 and can be supplied into the plating module 104. Therefore, the plating module 10
(4) The amount of clean air supplied by the exhaust from the second exhaust port 317 is supplied from the outside exhaust port 314, and the amount of clean air supplied through the second exhaust port 317 is supplied from the outside air inlet 314. Can be maintained.

The air volume adjusting means 312 and the pressure adjusting means 313 of the outside air inlet 314 configured as described above are configured to be controlled by control signals from a control means 318, for example, a central processing unit (CPU). ing. That is, the signal detected by the pressure detecting unit 316 that detects the pressure inside the plating module 104, the external pressure, the pressure inside the plating module 104 and the external pressure, which is installed in the plating module 104, The detection signal is transmitted to the CPU, the detection signal is compared with the information stored in the CPU in advance, and the control signal is supplied to the outside air inlet 314, the air volume adjusting means 312,
By transmitting the pressure to the pressure adjusting means 313, the pressure in the plating module 104 is set lower than the outside by a predetermined value, and the amount of supplied clean air can be controlled to a predetermined value.

Therefore, when the gate valve 214 of the wafer transfer section 301 is opened and closed, the atmosphere of the wafer transfer section 301 can further prevent the outside of the plating module 104 from leaking.

Next, a processing operation of a wafer in the plating system 101 will be briefly described with reference to FIGS.
First, the cassette 202 is mounted on the cassette mounting table 201a.
The cassette mounting table 201a is moved by the cassette drive mechanism to the partition 20.
3 moves in the direction of the first opening 105. Thereafter, the lid 218 of the cassette 202 is removed by a lock mechanism (not shown) of the first shutter member 204 at the opening. While holding the lid 218, the first shutter member 204 is lowered by a shutter member lifting / lowering means (not shown) and waits. In this state, the wafer is taken out. Of transfer stage 215
The first wafer transfer device 205 is moved on the rail 217 to approach the cassette 202, and the transfer arm 209 is further moved to the cassette 202.
The wafer is inserted below the wafer in the cassette 202 by extending to the side, and the wafer is transferred onto the transfer arm 209.

Next, the first wafer transfer device 205 is
7 to approach the second opening 210 of the second partition 211. Further, the wafer is moved to the buffer 216 in the process station 106 with the second shutter member 204 of the second opening 210 opened, and the wafer is loaded into the buffer 216. After carrying in, the second shutter member 204 of the second opening 210 is closed.

The wafer loaded into the buffer 216 is loaded into the plating module 104 via the gate valve 214 by the second wafer transfer device 213 arranged at the center of the process station 106. The loaded wafer is held by the wafer holding means 303, descends, and penetrates into a plating solution containing copper sulfate or the like. Then, a negative potential is applied to the cathode, while a positive potential is applied to the anode to elute copper as copper ions from the anode and attach the copper ions to the wafer surface of the cathode, thereby plating the wafer. Done.

Next, the plated wafer is taken out of the plating module 104 via the gate valve 214 by the second wafer transfer device 213, and is carried into the cleaning / drying module 103 via the gate valve 214.・
A drying process is performed.

The wafer having been subjected to the cleaning / drying processing is transferred to the cassette 202 by the reverse operation of the transfer to the process station 106. Further, when the processing of all the wafers in the cassette 202 is completed, the first shutter member 204 holding the lid 218 is raised by the shutter member lifting / lowering means, moves to the opening of the cassette 202, and attaches the lid 218. The cassette mounting table 201a is
When the cassette is mounted, the cassette mounting table 201a is retracted by the drive mechanism to move the cassette 202 to the cassette pick-up position. A series of processing of the wafer is performed as described above.

When maintenance or replacement (including replacement of parts) of the plating module and the cleaning / drying module has been performed, a dummy wafer is flowed before processing to perform a step of stabilizing each processing condition. May be.

[0046]

As described above, according to the present invention,
With the configuration described above, the following effects can be obtained.

In other words, the plating module and the cleaning / drying module are movably arranged, and the plating module and the cleaning / drying module can be easily attached to and detached from the plating system. Performance can be improved.

Further, since the atmosphere of the wafer transfer section in the plating module is cleaned and the mist generated from the plating solution in the plating tank section is exhausted and dissolved in water, the processing capacity can be improved, and The yield is improved. Furthermore, since the mist is dissolved in water and collected, the load on the factory utility can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view of a plating system according to an embodiment of the present invention.

FIG. 2 is a plan layout view of a plating system according to an embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of the plating module shown in FIGS. 1 and 2;

[Explanation of symbols]

 101 Plating system 102 Cassette station 103 Cleaning / drying module 104 Plating module 105 First opening 106 Process station 107 Wheel 201 Cassette stage 202 Cassette 203 First partition 204 First shutter member 205 First wafer transfer device 206 Transfer device body 207 Transfer arm support base 208 Transfer arm support shaft 208a Support base support shaft 209 Transfer arm 210 Second opening 211 Second partition 212 Second shutter member 213 Second wafer transfer device 214 Gate valve 215 Transfer stage 216 Buffer 217 Rail 218 lid 301 Wafer transfer section 302 Plating tank section 302a Plating tank 303 Wafer holding means 304 Plating solution circulation system 305 Vertical drive mechanism 306 Air supply port 307 Blowing means 308 Air cleaning means 309 Perforated plate 310 Air supply chamber 311 Circulation line 312 Air volume adjustment Means 313 Pressure adjusting means 314 Outside air inlet 315 First exhaust port 316 Pressure detecting means 317 Second exhaust port 318 Control means 319 Contaminant removal means 320 Exhaust line 321 Anode electrode 322 Third opening

Claims (6)

[Claims] 1. A plating system for plating a semiconductor substrate, comprising: a semiconductor substrate transport unit for transporting the semiconductor substrate; and a plating system disposed around the semiconductor substrate transport unit and attached to and detached from the plating system. A plating system comprising: a possible plating unit; and a cleaning / drying unit disposed around the semiconductor substrate transfer unit and detachable from the plating system. 2. A semiconductor substrate transport unit, wherein the plating processing unit is disposed in the plating system and transfers a semiconductor substrate, an atmosphere control unit for cleaning an atmosphere in the semiconductor substrate transport unit, The plating system according to claim 1, further comprising: a plating tank disposed in the plating unit to perform a plating process on the semiconductor substrate. 3. The plating method according to claim 2, wherein the plating tank portion disposed in the plating processing means has an exhaust unit for exhausting mist generated from a plating solution in the plating tank unit and dissolving it in water. Processing system. 4. The plating system according to claim 2, wherein the atmosphere control unit includes a pressure adjusting unit that adjusts a pressure in the plating unit. 5. A step of cleaning an atmosphere of a semiconductor substrate transport section, a step of exhausting mist generated from a plating solution in a plating tank section and dissolving it in water, and a step of cleaning an atmosphere of the semiconductor substrate transport section. Transporting a semiconductor substrate into the semiconductor substrate transport unit in plating means after evacuation of a mist generated from the plating solution in the plating tank and dissolving in water; and transporting the semiconductor substrate to the semiconductor substrate transport unit. From the step of carrying the plating to the plating tank portion and performing plating treatment in the plating tank portion, and the step of carrying the plated semiconductor substrate from the plating tank portion to the semiconductor substrate carrying portion and unloading from the plating treatment means, Plating method. 6. A step of cleaning the atmosphere in the semiconductor substrate transport section, a step of exhausting mist generated from a plating solution in the plating tank section and dissolving it in water, and a step of increasing a pressure inside the plating section outside the plating section. A step of controlling the pressure to be lower than a pressure; a step of cleaning the atmosphere of the wafer transfer section; a step of exhausting mist generated from a plating solution in the plating tank section to dissolve in water; Transporting the semiconductor substrate to the semiconductor substrate transport section in the plating means after starting the step of controlling the pressure to be lower than the pressure outside the means, and transporting the semiconductor substrate from the semiconductor substrate transport section to the plating tank section Carrying out a plating process, and carrying out the plated semiconductor substrate from the plating tank to the semiconductor substrate carrying portion and carrying out the plating process means. , Consisting of a plating method.