Patent Application
20140356539
The embodiments described herein pertain generally to a plating apparatus and a plating method for performing a plating process by supplying a plating liquid to a surface of a substrate, and a storage medium therefor.
In general, on a substrate such as a semiconductor wafer or a liquid crystal substrate, there is formed a wiring for forming a circuit on a surface thereof. Such a wiring has been made of copper having a low electrical resistance and a high reliability instead of aluminum. However, as compared with aluminum, copper is easily oxidized. As a result, it is required to perform a plating process thereto with a metal having a high electromigration tolerance in order to suppress a surface of a copper wiring from being oxidized.
By way of example, a plating process is performed by supplying an electroless plating liquid to a surface of a substrate on which a copper wiring is formed. Such an electroless plating process is typically performed by a single-substrate processing apparatus (see, for example, Japanese Patent Laid-open Publication No. 2009-249679).
However, during a plating process, a temperature of a substrate needs to be controlled. In order to control the temperature of the substrate, a plating liquid heated to a high temperature is supplied to the substrate, and also, rear-surface temperature-controlling water is supplied to a rear surface of the substrate. However, if the rear-surface temperature-controlling water is used, the plating liquid and the rear-surface temperature-controlling water are mixed with each other in a waste liquid generated during and after the plating process. In general, a plating liquid is expensive, so that it is required to separate the plating liquid from the waste liquid and reuse the plating liquid. However, if the plating liquid and the rear-surface temperature-controlling water are mixed with each other in the waste liquid, it may be difficult to separate the plating liquid from the waste liquid and reuse the plating liquid.
In view of the foregoing problems, example embodiments provide a plating apparatus and a plating method capable of efficiently heating a substrate and reusing a plating liquid by suppressing temperature-controlling water from being mixed with the plating liquid to be drained out, and a storage medium therefor.
In one example embodiment, a plating apparatus that performs a plating process by supplying a plating liquid to a substrate includes a substrate holding device configured to hold the substrate; a discharging device configured to discharge the plating liquid toward the substrate held by the substrate holding device; a plating liquid supplying device connected to the discharging device and configured to supply the plating liquid to the discharging device; a gas supplying device configured to heat a heating gas having a higher specific heat capacity than air and supply the heated heating gas toward the substrate held by the substrate holding device; and a controller configured to control at least the discharging device, the plating liquid supplying device, and the gas supplying device.
In another example embodiment, a plating method of performing a plating process by supplying a plating liquid to a substrate includes holding the substrate by a substrate holding device; and plating the substrate by discharging the plating liquid from a discharging device toward the substrate held by the substrate holding device. Further, in the plating of the substrate, a heating gas having a higher specific heat capacity than air is heated and supplied toward the substrate held by the substrate holding device.
In yet another example embodiment, a computer-readable storage medium has stored thereon computer-executable instructions that, in response to execution, cause a plating apparatus to perform a plating method. Further, the plating method includes holding the substrate by a substrate holding device; and plating the substrate by discharging the plating liquid from a discharging device toward the substrate held by the substrate holding device. Furthermore, in the plating of the substrate, a heating gas having a higher specific heat capacity than air is heated and supplied toward the substrate held by the substrate holding device.
In accordance with the example embodiments, since a heating gas having a higher specific heat capacity than air is heated and supplied toward a substrate held by a substrate holding device, it is possible to efficiently heat the substrate. Further, temperature-controlling water or the like is suppressed from being mixed with a plating liquid to be drained, so that it is possible to easily reuse the plating liquid.
Hereinafter, referring to
<Plating System>
As depicted in
(Substrate Loading/Unloading Section)
The substrate loading/unloading section 92 includes a carrier mounting unit 94, a transfer chamber 96 configured to accommodate therein a transfer device 95, and a substrate transit chamber 98 configured to accommodate a substrate transit table 97. In the substrate loading/unloading section 92, the transfer chamber 96 and the substrate transit chamber 98 are connected to and communicate with each other via a transit opening 99. In the carrier mounting unit 94, multiple carriers 91 configured to accommodate the multiple substrates W in a horizontal posture are mounted. In the transfer chamber 96, the substrates W are transferred, and in the substrate transit chamber 98, the substrates W are transited with respect to the substrate processing section 93.
In the substrate loading/unloading section 92, a preset number of the substrates W are transferred each time by the transfer device 95 between one of the carriers 91 mounted on the carrier mounting unit 94 and the substrate transit table 97.
(Substrate Processing Section)
Further, the substrate processing section 93 includes a substrate transfer unit 87 extended in a forward/backward direction (a left/right direction in
The substrate transfer unit 87 includes a substrate transfer device 88 configured to be movable in the forward/backward direction. Further, the substrate transfer unit 87 communicates with the substrate transit table 97 in the substrate transit chamber 98 via a substrate loading/unloading opening 89.
In the substrate processing section 93, the substrates W are transferred into each of the plating apparatuses 20 one by one with the substrate transfer device 88 of the substrate transfer unit 87 in the horizontal posture. Further, in each of the plating apparatuses 20, a cleaning process and a plating process are performed on the substrates W one by one.
The respective plating apparatuses 20 have substantially the same configuration except that the respective plating apparatuses 20 use different kinds of plating liquids. Therefore, hereinafter, a configuration of one of the multiple plating apparatuses 20 will be explained.
(Plating Apparatus)
Hereinafter, referring to
As depicted in
Around the substrate holding device 110, there is provided a liquid draining device 140 configured to drain out the plating liquid dispersed from the substrate W. Further, the substrate holding device 110 is connected to a gas supplying device 170 configured to heat a heating gas G and supply the heated heating gas G toward the substrate W held by the substrate holding device 110. Furthermore, there is provided a controller 160 configured to control the substrate holding device 110, the discharging device 21, the plating liquid supplying device 30, the liquid draining device 140, and the gas supplying device 170.
(Substrate Holding Device)
As depicted in
The rotating device 162 is controlled by the controller 160 and configured to rotate the rotation shaft 111. Thus, the substrate W supported by the wafer chuck 113 is rotated. In this case, the controller 160 is configured to control the rotating device 162, so that the rotation shaft 111 and the wafer chuck 113 can be rotated or stopped. Further, the controller 160 can increase or decrease a rotation number of the rotation shaft 111 and the wafer chuck 113, or can maintain the rotation number thereof at a certain value.
Further, on the turntable 112 as a rear side of the substrate W, there is provided a back plate 171 with a space 5 from the substrate W. The back plate 171 faces the rear surface of the substrate W held by the wafer chuck 113 and is provided between the substrate W held by the wafer chuck 113 and the turntable 112. The back plate 171 is connected and fixed to a shaft 172 penetrating the central portion of the rotation shaft 111. Further, the back plate 171 may include therein a heater. Furthermore, a lower end of the shaft 172 is connected to an elevating device 179 such as an air cylinder. That is, the back plate 171 is configured to be moved up and down between the substrate W held by the wafer chuck 113 and the turntable 112 through the elevating device 179 and the shaft 172.
Within the back plate 171, there is formed a first flow path 174 that communicates with multiple openings 173 formed on a surface of the back plate 171, and the first flow path 174 communicates with a fluid supply path 175 passing through the central portion of the shaft 172. The fluid supply path 175 is connected via a valve 146 to a rear-surface processing liquid supplying device 145 configured to supply a processing liquid to the rear surface of the substrate W.
Further, the back plate 171 includes an opening (supply unit) 176 formed on the surface thereof and a second flow path 177 formed within the back plate 171. The second flow path 177 communicates with the opening 176 and also communicates with a gas supply path 178 vertically passing through the shaft 172. The gas supply path 178 is connected via a valve 188 to the gas supplying device 170 to be described later. That is, the back plate 171 has a function of supplying the heated heating gas G toward the rear surface of the substrate W.
Furthermore, in
(Discharging Device)
Hereinafter, the discharging device 21 configured to discharge a plating liquid to the substrate W will be explained. The discharging device 21 includes a first discharge nozzle 45 configured to discharge a plating liquid for chemical reduction plating, such as a CoP plating liquid, toward the substrate W. The plating liquid for the chemical reduction plating is supplied from the plating liquid supplying device 30 to the first discharge nozzle 45. Further, although only the first discharge nozzle 45 is illustrated in
Further, as depicted in
The discharge opening 71 of the second discharge nozzle 70 is connected via a valve 76a to a plating liquid supplying device 76 configured to supply a plating liquid for displacement plating, for example, a Pd plating liquid. Further, the discharge opening 72 is connected via a valve 77a to a cleaning liquid supplying device 77 configured to supply a cleaning liquid. Since the second discharge nozzle 70 configured as such is provided, it is possible to perform not only a plating process with the plating liquid for the chemical reduction plating but also a plating process with the plating liquid for the displacement plating, and also possible to perform a cleaning process within the single plating apparatus 20.
Further, as depicted in
Hereinafter, the first discharge nozzle 45 will be explained. As depicted in
(Plating Liquid Supplying Device)
Hereinafter, the plating liquid supplying device 30 configured to supply the plating liquid for the chemical reduction plating, such as a CoP plating liquid, to the first discharge nozzle 45 of the discharging device 21 will be explained.
As depicted in
Further, as depicted in
Various kinds of chemical liquids are supplied into the plating liquid supply tank 31 from multiple chemical liquid supplying sources (not illustrated) in which various kinds of components of the plating liquid 35 are stored. By way of example, chemical liquids such as a CoSO4 metal salt containing Co ions, a reducing agent (for example, hypophosphorous acid or the like), ammonia, and additives are supplied. In this case, flow rates of the various kinds of the chemical liquids are controlled such that the components of the plating liquid 35 to be stored within the plating liquid supply tank 31 are appropriately adjusted.
Furthermore, as depicted in
(Gas Supplying Device)
As described above, the gas supplying device 170 is configured to heat the heating gas G having a higher specific heat capacity than air and supply the heated heating gas G toward the substrate W held by the substrate holding device 110. As depicted in
The heating gas G has a higher specific heat capacity than air (specific heat capacity: 1.0 (J/g·K)), and specifically, includes, for example, steam (specific heat capacity: 2.1 (J/g·K)) and helium (specific heat capacity: 5.2 (J/g·K)). It is desirable to use the steam in terms of cost.
If the steam is used as the heating gas G, the heating gas G to be supplied to the gas supply path 178 is not necessarily limited to being supplied from the gas supply tank 181. As depicted in
Further, as depicted in
(Liquid Draining Device)
Hereinafter, the liquid draining device 140 configured to drain out a plating liquid or a cleaning liquid dispersed from the substrate W will be explained with reference to
The liquid draining device 140 includes a cup 105, which is provided around the substrate holding device 110 and has draining openings 124, 129, and 134; an elevating device 164 connected to the cup 105 and configured to vertically move up and down the cup 105; and liquid draining paths 120, 125, and 130 connected to the cup 105 and configured to collect and drain out a plating liquid dispersed from the substrate W at each of the draining openings 124, 129, and 134.
In this case, processing liquids dispersed from the substrate W are drained out from the liquid draining paths 120, 125, and 130 through the draining openings 124, 129, and 134 depending on kinds of the processing liquids. By way of example, a CoP plating liquid dispersed from the substrate W is drained out from the plating liquid draining path 120, a Pd plating liquid dispersed from the substrate W is drained out from the plating liquid draining path 125, and a cleaning liquid and a rinse liquid dispersed from the substrate W are drained out from the processing liquid draining path 130. The CoP plating liquid and the Pd plating liquid drained out as described above may be separately collected and reused.
An operation of the plating system 90 including the multiple plating apparatuses 20 configured as described above is controlled by the controller 160 according to various programs recorded in a storage medium 161 provided in the controller 160. Thus, various processes are performed on the substrate W. Herein, the storage medium 161 is configured to store various setting data or various programs such as a plating program to be described later. As the storage medium 161, a well-known storage medium such as a computer-readable memory, e.g., a ROM or a RAM, or a hard disc, or disc-type storage medium such as a CD-ROM, a DVD-ROM, or a flexible disc may be used.
<Plating Method>
In the present example embodiment, operations of the plating system 90 and the plating apparatus 20 are controlled according to the plating program stored in the storage medium 161 such that a plating process is performed on the substrate W. Hereinafter, referring to
(Substrate Holding Process)
The single substrate W is loaded into the single plating apparatus 20 from the substrate transit chamber 98 by the substrate transfer device 88 of the substrate transfer unit 87.
In the plating apparatus 20, the cup 105 is moved down to a preset position and then, the loaded substrate W is held by the wafer chuck 113 of the substrate holding device 110 (substrate holding process 5300). Thereafter, the cup 105 is moved up by the elevating device 164 to a position where the draining opening 134 of the liquid draining device 140 faces an outer periphery of the substrate W.
(Cleaning Process)
Then, a cleaning process 5301 including a rinse process, a pre-cleaning process, and another rinse process is performed. The valve 78a of the rinse liquid supplying device 78 is opened, and a rinse liquid is supplied to a surface of the substrate W through the discharge opening 72 of the second discharge nozzle 70.
Thereafter, the pre-cleaning process is performed. The valve 77a of the cleaning liquid supplying device 77 is opened, and a cleaning liquid is supplied to the surface of the substrate W through the discharge opening 72 of the second discharge nozzle 70. By way of example, malic acid may be used as the cleaning liquid, and pure water may be used as the rinse liquid. Then, in the same manner as described above, the rinse liquid is supplied to the surface of the substrate W through the discharge opening 72 of the second discharge nozzle 70. The rinse liquid or the cleaning liquid used in performing the process is disposed of from the processing liquid draining path 130 through the draining opening 134 of the cup 105. Further, in the cleaning process S301 and all of the following processes, the substrate W is being rotated in a first rotation direction R1 (
(Pd Plating Process)
Then, a Pd plating process 5302 is performed. The Pd plating process 5302 is performed as the displacement plating process on the substrate W which is not dried after the pre-cleaning process. By performing the displacement plating process while the substrate W is not dried, it is possible to avoid a case where the displacement plating is not effectively performed since copper or the like on a plating target surface of the substrate W is oxidized.
In the Pd plating process, the cup 105 is moved down by the elevating device 164 to a position where the draining opening 129 of the liquid draining device 140 faces the outer periphery of the substrate W. Then, the valve 76a of the plating liquid supplying device 76 is opened, and a plating liquid containing Pd is discharged to the surface of the substrate W through the discharge opening 71 of the second discharge nozzle 70 at a desired flow rate. As such, the Pd plating process is performed on the surface of the substrate W. The plating liquid used in the Pd plating process is drained out through the draining opening 129 of the cup 105. The plating liquid drained out through the draining opening 129 is collected to be reused or disposed of from the liquid draining path 125.
(Rinse Process)
Then, as a pre-treatment performed before a Co plating process, for example, a rinse process 5303 is performed. During the rinse process 5303, for example, a rinse liquid as a pre-treatment liquid is supplied to the surface of the substrate W. Further, after the rinse process, the substrate W is cleaned by using a chemical liquid. Thereafter, a rinse process may be performed with a rinse liquid in order to clean the chemical liquid.
(Co Plating Process)
Then, a Co plating process 5304 is performed in the same plating apparatus 20 as used in performing the above-described processes 5301 to S303. The Co plating process S304 is performed as the chemical reduction plating process.
In the Co plating process S304, the controller 160 controls the substrate holding device 110, so that the substrate W held by the substrate holding device 110 is rotated. In this state, the plating liquid 35 heated to the discharge temperature by the heating unit 60 is discharged toward the surface of the substrate W through the discharge opening 46 of the first discharge nozzle 45.
By discharging the plating liquid 35 toward the substrate W from the first discharge nozzle 45, a Co plating layer is formed on a Pd plating layer on the substrate W. When the Co plating layer is formed to have a preset thickness, for example, 1 μm, the discharging of the plating liquid 35 from the first discharge nozzle 45 is stopped, and the Co plating process 5304 is completed. A time required for the Co plating process 5304 may be, for example, about 20 minutes to about 40 minutes.
Further, in the Co plating process 5304, it is not necessary to continuously rotate the substrate W at a constant rotation number. The rotation number may be temporarily increased or decreased, or the rotation may be temporarily stopped. Further, in the Co plating process 5304, the first discharge nozzle 45 may horizontally move (scan) from the central portion of the substrate W toward the peripheral portion of the substrate W.
Furthermore, in the Co plating process 5304, the cup 105 is moved down by the elevating device 164 to a position where the draining opening 124 faces the outer periphery of the substrate W. Therefore, the plating liquid 35 used in the Co plating process is drained out through the draining opening 124 of the cup 105. The drained out plating liquid 35 after the process may be collected to be reused from the liquid draining path 120.
Meanwhile, in the present example embodiment, during the Co plating process 5304, the controller 160 controls the gas supplying device 170 to supply the heated heating gas G (for example, steam) toward the rear surface of the substrate W at substantially the same time when the plating liquid 35 is discharged through the discharge opening 46 of the first discharge nozzle 45. That is, the gas supplying device 170 supplies the heating gas G, which is stored in the gas supply tank 181 and heated by the gas temperature controlling unit 183, toward the rear surface of the substrate W from the opening 176 of the back plate 171 via the gas supply line 182, the gas supply path 178 and the second flow path 177 in sequence. Otherwise, the gas supplying device 170 supplies the heating gas G from the plating liquid supply tank 31 or the temperature medium supplying unit 61 toward the rear surface of the substrate W through the opening 176 of the back plate 171.
The heating gas G from the gas supplying device 170 is continuously supplied while the plating liquid 35 is discharged through the first discharge nozzle 45. During this period, the heating gas G stays at the space S between the substrate W and the back plate 171 and continuously heats the substrate W. Further, the heating gas G heats the plating liquid 35 via the substrate W. In the present example embodiment, a gas, for example, steam, having a higher specific heat capacity than air is used as the heating gas G, so that the substrate W can be efficiently heated. Thereafter, when the discharge of the plating liquid 35 from the first discharge nozzle 45 is stopped, the supply of the heating gas G from the gas supplying device 170 is stopped. Otherwise, before or after the discharge of the plating liquid 35 from the first discharge nozzle 45 is stopped, the supply of the heating gas G by the gas supplying device 170 may be stopped.
By supplying the heated heating gas G toward the rear surface of the substrate W through the opening 176 of the back plate 171 as such, it is possible to control a temperature of the substrate W. Further, it is possible to suppress the temperature of the plating liquid from being decreased. Thus, the plating process can be performed while a temperature is maintained at a constant value (for example, about 60° C. to about 90° C.), so that the Co plating layer can be uniformly grown on the surface of the substrate W. Furthermore, since the heating gas G to be supplied toward the substrate W is supplied in the gas phase, it is possible to suppress the plating liquid 35 drained out from the draining opening 124 of the cup 105 from being mixed with water for heating. Therefore, the drained plating liquid 35 after the process can be easily reused. In particular, in the Co plating process 5304, a time required for the plating process may be, for example, about 20 minutes to about 40 minutes. Therefore, by reusing the plating liquid 35, it is possible to reduce an amount of a waste liquid with more efficiency.
Further, as described above, the heating gas G may contain at least one (for example, ammonia) of the components contained in the plating liquid 35. In this case, it is possible to suppress the components from being volatilized from the plating liquid 35 during the plating process, or possible to supplement the plating liquid 35 with the components contained in the heating gas G equivalent to the components volatilized from the plating liquid 35 during the plating process.
(Cleaning Process)
Then, a cleaning process S305 including a rinse process, a post-cleaning process, and another rinse process is performed on the surface of the substrate W on which the Co plating process has been performed. The cleaning process 5305 is performed in the substantially same manner as the above-described cleaning process S301. Accordingly, detailed explanation thereof will be omitted.
(Dry Process)
Thereafter, a dry process S306 of drying the substrate W is performed. By way of example, by rotating the turntable 112, a liquid adhering to the substrate W is dispersed outward by a centrifugal force, so that the substrate W is dried. That is, the turntable 112 may serve as a drying device configured to dry the surface of the substrate W.
As such, within the single plating apparatus 20, the Pd plating process is performed first on the surface of the substrate W by the displacement plating and then, the Co plating process is performed by the chemical reduction plating.
Then, the substrate W may be transferred to another plating apparatus 20 for Au plating process. In this case, within the another plating apparatus 20, an Au plating process is performed on the surface of the substrate W by the displacement plating. An Au plating process is substantially the same as the above-described the Pd plating process except that different plating liquid and cleaning liquid are used. Thus, detailed explanation thereof will be omitted.
As described above, in accordance with the present example embodiment, since the heating gas (for example, steam) having a higher specific heat capacity than air is heated and supplied toward the substrate W held by the substrate holding device 110, the substrate W can be efficiently heated and the plating layer made of the plating liquid 35 can be uniformly grown on the surface of the substrate W. Further, it is possible to suppress a plating liquid drained out from the liquid draining device 140 from being mixed with water or the like. Therefore, the discharged plating liquid can be easily reused.
Hereinafter, modification examples of the present example embodiment will be explained.
In the above-described example embodiment, there has been explained the case where the heated heating gas G (for example, steam) is supplied toward the rear surface of the substrate W at substantially the same time when the plating liquid 35 is discharged from the discharge opening 46 of the first discharge nozzle 45 during the Co plating process 5304. However, the example embodiment is not limited thereto. During the Co plating process 5304, before the plating liquid 35 is discharged from the discharge opening 46 of the first discharge nozzle 45, the heating gas G (for example, steam) may be supplied toward the rear surface of the substrate W.
In this case, the additional gas supplying unit 187 (
Further, in the above-described example embodiment, there has been explained the case where the heating gas G is supplied toward the rear surface of the substrate W. However, the example embodiment is not limited thereto. The heating gas G may also be supplied from a front surface side of the substrate W. That is, as depicted in
Otherwise, as depicted in
Further, as depicted in
Further, the top plate 151 is connected to the elevating device 154 and controlled by the controller 160, so that the top plate 151 can be moved up and down together with the cup 105. Furthermore, the top plate 151 may be moved up and down by the elevating device 154 independently of the cup 105. Thus, in the above-described substrate holding process S300, the substrate W can be loaded and unloaded with respect to the substrate holding device 110.
Since the top plate 151 that covers the entire surface of the substrate W is provided above the substrate W as such, the heating gas G supplied from the opening 176 of the back plate 171 and the gas nozzle 191 or a gas (for example, steam) generated from the plating liquid 35 stays in a space between the substrate W and the top plate 151. Thus, it is possible to heat the substrate W and the plating liquid 35 with more efficiency, and it becomes clear that a plating layer can be uniformly grown on the surface of the substrate W.
Further, in
Further, in
Furthermore, in the case illustrated in
Moreover, in
Further, in the example embodiments, there has been illustrated the case where the substrate W is rotated and held by the substrate holding device 110. However, the example embodiments are not limited thereto. That is, the substrate holding device 110 may not rotate the substrate W. In this case, the substrate holding device 110 holds the substrate W such that the substrate W is not rotated, and the plating liquid supplying device 30 may include a long nozzle of which opening is extended in one direction (not illustrated). In this case, the long nozzle may scan over the substrate W, so that the plating liquid 35 may be supplied to the substrate W.
Further, in the above-described example embodiments, there has been explained the case where the CoP plating liquid is used as the plating liquid 35 for the chemical reduction plating to be discharged from the first discharge nozzle 45 toward the substrate W. However, the plating liquid 35 to be used is not limited to the CoP plating liquid and various plating liquids 35 may be used. By way of example, various plating liquids 35 such as a CoWB plating liquid, a CoWP plating liquid, a CoB plating liquid, or a NiP plating liquid may be used as the plating liquid 35 for the chemical reduction plating.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011-259322 | Nov 2011 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2012/079204 | 11/12/2012 | WO | 00 | 5/28/2014 |
