US20230085449A1

US20230085449A1 - Substrate processing method and substrate processing apparatus

Info

Publication number: US20230085449A1
Application number: US17/759,648
Authority: US
Inventors: Takafumi Niwa
Original assignee: Tokyo Electron Ltd
Current assignee: Tokyo Electron Ltd
Priority date: 2020-02-03
Filing date: 2021-01-20
Publication date: 2023-03-16
Also published as: WO2021157353A1; TW202145330A; KR20220136385A; JP7267470B2; JPWO2021157353A1

Abstract

A substrate processing method includes holding a substrate W by using a holder 52 configured to hold the substrate; supplying a plating liquid L onto a top surface of the held substrate; covering the substrate by using a cover body 6 before or after the supplying of the plating liquid; heating the plating liquid on the substrate by using a heating device 63 provided in the cover body, while keeping the substrate covered with the cover body; and supplying a cooling gas to a bottom surface of the substrate or the holder from below the substrate in the heating of the plating liquid.

Description

TECHNICAL FIELD

The various aspects and embodiments described herein pertain generally to a substrate processing method and a substrate processing apparatus.

BACKGROUND

Conventionally, there is known a technique of electroless-plating a substrate such as a semiconductor wafer by using a plating liquid. Patent Document 1 discloses a technique of forming a plating film on the substrate by accumulating the plating liquid on a top surface of the substrate, covering the substrate with a cover body, and then heating the plating liquid on the substrate by using a heater provided in the cover body.

PRIOR ART DOCUMENT

Patent Document 1: Japanese Patent Laid-open Publication No. 2018-003097

DISCLOSURE OF THE INVENTION

Problems to be Solved by the Invention

Exemplary embodiments provide a technique enabling to easily maintain a temperature of a plating liquid on a substrate constant.

Means for Solving the Problems

In an exemplary embodiment, a substrate processing method includes holding a substrate; supplying a plating liquid; covering the substrate; heating the plating liquid; and supplying a cooling gas. In the holding of the substrate, the substrate is held by using a holder configured to hold the substrate. In the supplying of the plating liquid, the plating liquid is supplied onto a top surface of the held substrate. In the covering of the substrate, the substrate is covered by using a cover body before or after the supplying of the plating liquid. In the heating of the plating liquid, the plating liquid on the substrate is heated by using a heating device provided in the cover body, while keeping the substrate covered with the cover body. In the supplying of the cooling gas, the cooling gas is supplied to a bottom surface of the substrate or the holder from below the substrate in the heating of the plating liquid.

Effect of the Invention

According to the exemplary embodiments, it is possible to easily maintain the temperature of the plating liquid on the substrate constant.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a configuration of a substrate processing apparatus according to an exemplary embodiment.

FIG. 2 is a diagram illustrating a configuration of a plating unit according to the exemplary embodiment.

FIG. 3 is a diagram illustrating a configuration of a cooling gas supply according to the exemplary embodiment.

FIG. 4 is a flowchart illustrating a sequence of processings performed by the plating unit according to the exemplary embodiment.

FIG. 5 is an explanatory diagram illustrating a substrate holding processing shown in FIG. 4 .

FIG. 6 is an explanatory diagram illustrating a plating liquid accumulating processing shown in FIG. 4 .

FIG. 7 is an explanatory diagram illustrating a processing of covering a substrate with a cover body shown in FIG. 4 .

FIG. 8 is an explanatory diagram illustrating a cooling processing shown in FIG. 4 .

FIG. 9 is a graph schematically illustrating temperature variations of a plating liquid in a heating processing.

FIG. 10 is a diagram illustrating a configuration of a plating unit according to a first modification example.

FIG. 11 is a flowchart illustrating a sequence of processings performed by the plating unit according to the first modification example.

FIG. 12 is a diagram illustrating a configuration of a plating unit according to a second modification example.

FIG. 13 is a diagram schematically illustrating a positional relationship between a plurality of heating regions of a heater and a plurality of cooling gas nozzles.

DETAILED DESCRIPTION

Hereinafter, embodiments for a substrate processing method and a substrate processing apparatus according to the present disclosure (hereinafter, referred to as “exemplary embodiments”) will be described in detail with reference to the accompanying drawings. Further, it should be noted that the present disclosure is not limited by the exemplary embodiments. Further, unless processing contents are contradictory, the various exemplary embodiments can be appropriately combined. Furthermore, in the various exemplary embodiments to be described below, same parts will be assigned same reference numerals, and redundant description will be omitted.
Further, in the following exemplary embodiments, expressions such as “constant,” “perpendicular,” “vertical” and “parallel” may be used. These expressions, however, do not imply strictly “constant”, “perpendicular,” “vertical” and “parallel”. That is, these expressions allow some tolerable errors in, for example, manufacturing accuracy, installation accuracy, or the like.
Moreover, in the various accompanying drawings, for the purpose of clear understanding, there may be used a rectangular coordinate system in which the X-axis direction, Y-axis direction and Z-axis direction which are orthogonal to one another are defined and the positive Z-axis direction is defined as a vertically upward direction. Further, a rotational direction around a vertical axis may be referred to as θ direction.
<Configuration of Substrate Processing Apparatus>
FIG. 1 is a diagram illustrating a configuration of a substrate processing apparatus according to an exemplary embodiment. As depicted in FIG. 1 , a substrate processing apparatus 1 includes a carry-in/out station 2 and a processing station 3. The carry-in/out station 2 and the processing station 3 are provided adjacent to each other.
The carry-in/out station 2 is equipped with a carrier placing table 11 and a transfer section 12. On the carrier placing table 11, a plurality of carriers C is placed to horizontally accommodate therein a plurality of semiconductor wafers W (hereinafter, referred to as “substrates W”) in the present exemplary embodiment.
On the carrier placing table 11, a plurality of load ports are arranged so as to be adjacent to the transfer section 12, and the carriers C are placed on the plurality of load ports in one-to-one correspondence.
The transfer section 12 is provided adjacent to the carrier placing table 11, and is equipped with a substrate transfer device 13 and a delivery unit 14. The substrate transfer device 13 is equipped with a wafer holding mechanism configured to hold the substrate W. Further, the substrate transfer device 13 is movable in a horizontal direction and a vertical direction and pivotable around a vertical axis, and serves to transfer the substrate W between the carrier C and the delivery unit 14 by using the wafer holding mechanism.
The processing station 3 is provided adjacent to the transfer section 12. The processing station 3 is equipped with a transfer section 15 and a plurality of plating units 5. The plurality of plating units 5 are arranged on both sides of the transfer section 15. A configuration of the plating unit 5 will be elaborated later.
The transfer section 15 has therein a substrate transfer device 17. The substrate transfer device 17 includes a wafer holding mechanism configured to hold the substrate W. Further, the substrate transfer device 17 is movable in a horizontal direction and a vertical direction and pivotable around a vertical axis, and transfers the substrate W between the delivery unit 14 and the plating unit 5 by using the wafer holding mechanism.
Further, the substrate processing apparatus 1 is equipped with a control device 9. The control device 9 is, for example, a computer, and includes a controller 91 and a storage 92. The storage 92 stores therein a program that controls various processings performed in the substrate processing apparatus 1. The controller 91 controls an operation of the substrate processing apparatus 1 by reading and executing the program stored in the storage 92.
Further, the program may be recorded in a computer-readable recording medium and may be installed from the recording medium to the storage 92 of the control device 9. The computer-readable recording medium may be, for example, a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magneto optical disc (MO), a memory card, or the like.
In the substrate processing apparatus 1 configured as described above, the substrate transfer device 13 of the carry-in/out station 2 first takes out the substrate W from the carrier C placed on the carrier placing table 11, and then places the taken substrate W in the delivery unit 14. The substrate W placed in the delivery unit 14 is taken out from the delivery unit 14 by the substrate transfer device 17 of the processing station 3, and carried into and processed by the plating unit 5. By way of example, a recess such as a trench or a via is formed in a front surface of the substrate W, and the plating unit 5 fills this recess with a metal by an electroless plating method.
The substrate W processed by the plating unit 5 is carried out of the plating unit 5 by the substrate transfer device 17 and placed on the delivery unit 14. The substrate W placed in the delivery unit 14 after being completely processed is returned back into the carrier C of the carrier placing table 11 by the substrate transfer device 13.
<Configuration of Plating Unit>
Now, the configuration of a plating unit will be described with reference to FIG. 2 . FIG. 2 is a diagram illustrating the configuration of the plating unit 5 according to the exemplary embodiment.
The plating unit 5 is configured to perform a liquid processing including electroless plating. The plating unit 5 includes a chamber 51; a substrate holder 52 disposed in the chamber 51 and configured to hold the substrate W horizontally; and a plating liquid supply 53 configured to supply a plating liquid L1 (processing liquid) onto the front surface (top surface) of the substrate W held by the substrate holder 52.
In the present exemplary embodiment, the substrate holder 52 includes a chuck member 521 configured to vacuum-attract a bottom surface (rear surface) of the substrate W. This chuck member 521 is of a so-called vacuum chuck type.
A rotation motor 523 (rotational driving unit) is connected to the substrate holder 52 with a rotation shaft 522 therebetween. When this rotation motor 523 is driven, the substrate holder 52 is rotated along with the substrate W. The rotation motor 523 is supported on a base 524 which is fixed to the chamber 51. In addition, a heating source, such as a heater, is not provided within the substrate holder 52.
The plating liquid supply 53 includes a plating liquid nozzle 531 configured to discharge (supply) the plating liquid L1 onto the substrate W held by the substrate holder 52; and a plating liquid source 532 configured to supply the plating liquid L1 to the plating liquid nozzle 531. Here, the plating liquid source 532 is configured to supply the plating liquid L1 heated or regulated to a predetermined temperature to the plating liquid nozzle 531 through a plating liquid line 533. The temperature of the plating liquid L1 at the moment when it is discharged from the plating liquid nozzle 531 is in a range of, e.g., 55° C. to 75° C., and, more desirably, in a range of 60° C. to 70° C. The plating liquid nozzle 531 is held by a nozzle arm 56 and is configured to be movable.
The plating liquid L1 is an autocatalytic (reduction) plating liquid for electroless plating. The plating liquid L1 contains, for example, a metal ion and a reducing agent. The metal ion contained in the plating liquid L1 may be, by way of non-limiting example, a cobalt (Co) ion, a nickel (Ni) ion, a tungsten (W) ion; a copper (Cu) ion, a palladium (Pd) ion, a gold (Au) ion, a ruthenium (Ru) ion, or the like. Further, the reducing agent included in the plating liquid L1 may be hypophosphorous acid, dimethylamine borane, glyoxylic acid, or the like. A plating film formed by the plating processing using the plating liquid L1 may be, by way of non-limiting example, CoWB, CoB, CoWP, CoWBP, NiWB, NiB, NiWP, NiWBP, Cu, Pd, Ru, or the like. Further, the plating film may be composed of a single layer, or two or more layers. When the plating film has a double-layer structure, it may have a layer structure of CoWB/CoB or Pd/CoB stacked in sequence from a base metal layer (seed layer) side.
The plating unit 5 further includes a cleaning liquid supply 54 configured to supply a cleaning liquid L2 onto the front surface of the substrate W held by the substrate holder 52; and a rinse liquid supply 55 configured to supply a rinse liquid L3 onto the front surface of the substrate W.
The cleaning liquid supply 54 supplies the cleaning liquid L2 onto the substrate W held and rotated by the substrate holder 52 to pre-clean the seed layer formed on the substrate W. This cleaning liquid supply 54 includes a cleaning liquid nozzle 541 configured to discharge the cleaning liquid L2 onto the substrate W held by the substrate holder 52; and a cleaning liquid source 542 configured to supply the cleaning liquid L2 to the cleaning liquid nozzle 541. Here, the cleaning liquid source 542 is configured to supply the cleaning liquid L2 heated or regulated to a preset temperature to the cleaning liquid nozzle 541 through a cleaning liquid line 543, as will be described later. The cleaning liquid nozzle 541 is held by the nozzle arm 56 and is configured to be moved along with the plating liquid nozzle 531.
Dicarboxylic acid or tricarboxylic acid may be used as the cleaning liquid L2. As an example of the dicarboxylic acid, an organic acid such as a malic acid, a succinic acid, a malonic acid, an oxalic acid, a glutaric acid, an adipic acid, or a tartaric acid may be used. Further, as an example of the tricarboxylic acid, an organic acid such as a citric acid may be used.
The rinse liquid supply 55 is equipped with a rinse liquid nozzle 551 configured to discharge the rinse liquid L3 onto the substrate W held by the substrate holder 52; and a rinse liquid source 552 configured to supply the rinse liquid L3 to the rinse liquid nozzle 551. Here, the rinse liquid nozzle 551 is held by the nozzle arm 56 and configured to be moved along with the plating liquid nozzle 531 and the cleaning liquid nozzle 541. Further, the rinse liquid source 552 is configured to supply the rinse liquid L3 to the rinse liquid nozzle 551 through a rinse liquid line 553. DIW or the like may be used as an example of the rinse liquid L3.
A non-illustrated nozzle moving mechanism is connected to the nozzle arm 56 which holds the plating liquid nozzle 531, the cleaning liquid nozzle 541 and the rinse liquid nozzle 551 described above. This nozzle moving mechanism is configured to move the nozzle arm 56 horizontally and vertically. To be more specific, the nozzle arm 56 is configured to be moved by the nozzle moving mechanism between a discharge position where the processing liquid (the plating liquid L1, the cleaning liquid L2 or the rinse liquid L3) is discharged onto the substrate W and a retreat position where the nozzle arm 56 is retreated from the discharge position. Here, the discharge position is not particularly limited as long as the processing liquid can be supplied to a certain position on the front surface of the substrate W. By way of example, it is desirable that the discharge position is set such that the processing liquid can be supplied to the center of the substrate W. The discharge position of the nozzle arm 56 may be set to be different when the plating liquid L1 is supplied, when the cleaning liquid L2 is supplied, and when the rinse liquid L3 is supplied onto the substrate W. The retreat position is a position within the chamber 51 which is not overlapped with the substrate W when viewed from above and far from the discharge position. When the nozzle arm 56 is placed at the retreat position, interference between this nozzle arm 56 and a cover body 6 being moved is avoided.
A cup 571 is disposed around the substrate holder 52. The cup 571 has a ring shape when viewed from above, and serves to receive the processing liquid scattered from the substrate W when the substrate W is rotated and guide the received processing liquid to a drain duct 581. An atmosphere blocking cover 572 is provided around the cup 571 to suppress diffusion of an atmosphere around the substrate W into the chamber 51. This atmosphere blocking cover 572 has a vertically extending cylindrical shape with an open top. The cover body 6 to be described later is configured to be inserted into the atmosphere blocking cover 572 from above.
In the present exemplary embodiment, the substrate W held by the substrate holder 52 is covered by the cover body 6. This cover body 6 has a ceiling member 61 and a sidewall member 62 extending downwards from the ceiling member 61.
The ceiling member 61 includes a first ceiling plate 611 and a second ceiling plate 612 provided on the first ceiling plate 611. A heater 63 (heating device) is disposed between the first ceiling plate 611 and the second ceiling plate 612. The first ceiling plate 611 and the second ceiling plate 612 are configured to seal the heater 63 so that the heater 63 may not come into contact with the processing liquid such as the plating liquid L1. To be more specific, a seal ring 613 is disposed around the heater 63, and the heater 63 is sealed by this seal ring 613. Desirably, the first ceiling plate 611 and the second ceiling plate 612 have corrosion resistance against the processing liquid such as the plating liquid L1, and may be made of, by way of example, an aluminium alloy. Further, to enhance the corrosion resistance, the first ceiling plate 611, the second ceiling plate 612 and the sidewall member 62 may be coated with Teflon (registered trademark).
A cover moving mechanism 7 is connected to the cover body 6 with a cover arm 71 therebetween. The cover moving mechanism 7 is configured to move the cover body 6 horizontally and vertically. To be more specific, the cover moving mechanism 7 includes a turning motor 72 configured to move the cover body 6 horizontally; and a cylinder 73 (distance adjuster) configured to move the cover body 6 vertically. Here, the turning motor 72 is mounted on a supporting plate 74 configured to be movable vertically with respect to the cylinder 73. As an alternative to the cylinder 73, an actuator (not shown) including a motor and a ball screw may be used.
The turning motor 72 of the cover moving mechanism 7 is configured to move the cover body 6 between an upper position where the cover body 6 is placed above the substrate W held by the substrate holder 52 and a retreat position where the cover body 6 is retreated from the upper position. Here, the upper position is a position facing the substrate W held by the substrate holder 52 with a relatively large gap therebetween, overlapping the substrate W when viewed from above. The retreat position is a position within the chamber 51 which does not overlap the substrate W when viewed from above. When the cover body 6 is placed at the retreat position, interference between the nozzle arm 56 being moved and the cover body 6 is avoided. A rotation axis of the turning motor 72 extends vertically, and the cover body 6 is configured to be pivotable horizontally between the upper position and the retreat position.
The cylinder 73 of the cover moving mechanism 7 is configured to move the cover body 6 vertically to adjust a distance between the substrate W on which the plating liquid L1 has been supplied and the first ceiling plate 611 of the ceiling member 61. To be more specific, the cylinder 73 locates the cover body 6 at a lower position (a position indicated by a solid line in FIG. 2 ) or the upper position (a position indicated by a dashed double-dotted line in FIG. 2 ).
In the present exemplary embodiment, the heater 63 is driven to heat the plating liquid L1 on the substrate W or the substrate holder 52 when the cover body 6 is placed at the above-described lower position.
The ceiling member 61 and the sidewall member 62 of the cover body 6 are covered with a cover lid 64. This cover lid 64 is disposed on the second ceiling plate 612 of the cover body 6 with supporting members 65 therebetween. That is, the second ceiling plate 612 is provided with the supporting members 65 protruding upwards from a top surface thereof, and the cover lid 64 is placed on these supporting members 65. The cover lid 64 is configured to be moved horizontally and vertically along with the cover body 6. Further, it is desirable that the cover lid 64 has insulation property higher than those of the ceiling member 61 and the sidewall member 62 to suppress heat within the cover body 6 from leaking to the vicinity thereof. By way of example, the cover lid 64 is desirably made of a resin material, and, more desirably, the resin material has heat resistance.
As described above, in the present exemplary embodiment, the cover body 6 equipped with the heater 63 is configured as one body with the cover lid 64, and a cover unit 10 configured to cover the substrate holder 52 or the substrate W when located at the lower position is composed of the cover body 6 and the cover lid 64.
A fan filter unit 59 (gas supply) is provided at an upper portion of the chamber 51 to supply clean air (gas) to the vicinity of the cover body 6. The fan filter unit 59 supplies the air into the chamber 51 (particularly, into the atmosphere blocking cover 572), and the supplied air flows toward an exhaust line 81. A downflow of the air flowing downwards is formed around the cover body 6, and a gas vaporized from the processing liquid such as the plating liquid L1 flows toward the exhaust line 81 by being carried by this downflow. Accordingly, the gas vaporized from the processing liquid is suppressed from rising and diffusing into the chamber 51.
The gas supplied from the above-described fan filter unit 59 is exhausted by an exhaust mechanism 8.
<Configuration of Cooling Gas Supply>
The plating unit 5 according to the exemplary embodiment is further equipped with a cooling gas supply configured to supply a cooling gas to the bottom surface of the substrate W or the chuck member 521. A configuration of this cooling gas supply will be explained with reference to FIG. 3 . FIG. 3 is a diagram illustrating the configuration of the cooling gas supply according to the exemplary embodiment.
As shown in FIG. 3 , the cooling gas supply 4 includes a cooling gas nozzle 41 configured to discharge the cooling gas; and a cooling gas source 42 configured to supply the cooling gas to the cooling gas nozzle 41. In the present exemplary embodiment, the cooling gas source 42 supplies the cooling gas of a room temperature (which is not temperature-regulated) to the cooling gas nozzle 41 via a cooling gas line 43. By way of non-limiting example, an inert gas such as nitrogen or argon is used as the cooling gas.
The cooling gas nozzle 41 is disposed below the substrate W held by the chuck member 521, and discharges the cooling gas toward the bottom surface of the substrate W. In the present exemplary embodiment, the cooling gas nozzle 41 discharges the cooling gas outwards in a diametrical direction of the substrate W. Accordingly, the cooling gas can be efficiently supplied to the entire bottom surface of the substrate W. Further, without being limited to the present example, the cooling gas nozzle 41 may discharge the cooling gas vertically upwards. In addition, the cooling gas nozzle 41 may discharge the cooling gas to the chuck member 521.
<Specific Operation of Plating Unit>
Now, a specific operation of the above-described plating unit 5 will be described with reference to FIG. 4 to FIG. 8 . FIG. 4 is a flowchart illustrating a sequence of processings performed by the plating unit 5 according to the exemplary embodiment. FIG. 5 is an explanatory diagram illustrating a substrate holding processing shown in FIG. 4 , and FIG. 6 is an explanatory diagram illustrating a plating liquid accumulating processing shown in FIG. 4 . Further, FIG. 7 is an explanatory diagram illustrating a processing of covering the substrate W with the cover body 6 shown in FIG. 4 , and FIG. 8 is an explanatory diagram illustrating a cooling processing shown in FIG. 4 . The series of processes shown in FIG. 4 are performed under the control of the controller 91.
As shown in FIG. 4 , the substrate W carried in into the plating unit 5 is first held by the substrate holder 52 (process S101). Here, a central portion of the bottom surface of the substrate W is vacuum-attracted, so that the substrate W is held horizontally by the substrate holder 52 (see FIG. 5 ).
Subsequently, the substrate W held by the substrate holder 52 is subjected to a cleaning processing (process S102). In this case, the rotation motor 523 is first driven to rotate the substrate W at a predetermined rotation speed. Next, the nozzle arm 56 located at the retreat position (the position indicated by the solid line in FIG. 2 ) is moved to the discharge position above the center of the substrate W. Then, the cleaning liquid L2 is supplied from the cleaning liquid nozzle 541 onto the substrate W being rotated, so that the front surface of the substrate W is cleaned. Accordingly, a deposit or the like adhering to the substrate W is removed from the substrate W. The cleaning liquid L2 supplied onto the substrate W is drained into the drain duct 581.
Then, the substrate W after being cleaned is subjected to a rinsing processing (process S103). In this case, the rinse liquid L3 is supplied from the rinse liquid nozzle 551 onto the substrate W being rotated, so that the front surface of the substrate W is rinsed. As a result, the cleaning liquid L2 remaining on the substrate W is washed away. The rinse liquid L3 supplied to the substrate W is drained into the drain duct 581.
Thereafter, the plating liquid L1 is supplied to and accumulated on the substrate W after being rinsed (process S104). In this case, the rotation speed of the substrate W is reduced from the rotation speed in the rinsing processing. For example, the rotation speed of the substrate W may be set to be 50 rpm to 150 rpm. Accordingly, the plating film formed on the substrate W can be made uniform. Alternatively, the rotation of the substrate W may be even stopped.
Subsequently, the plating liquid L1 is discharged from the plating liquid nozzle 531 onto the front surface of the substrate W. The discharged plating liquid L1 stays on the front surface of the substrate W due to a surface tension. As the plating liquid L1 is accumulated on the front surface of the substrate W, a layer (so-called puddle) of the plating liquid L1 is formed (see FIG. 6 ). Some of the plating liquid L1 flows out from the front surface of the substrate W to be drained from the drain duct 581. After a predetermined amount of the plating liquid L1 is discharged from the plating liquid nozzle 531, the discharge of the plating liquid L1 is stopped. Thereafter, the nozzle arm 56 located at the discharge position is moved to the retreat position.
Next, the plating liquid L1 accumulated on the substrate W is heated. First, the substrate W is covered by the cover body 6 (process S105). In this case, the turning motor 72 of the cover moving mechanism 7 is first driven, so that the cover body 6 is pivoted horizontally to be placed at the upper position (the position indicated by the dashed double-dotted line in FIG. 2 ).
Afterwards, the cylinder 73 of the cover moving mechanism 7 is driven, so that the cover body 6 located at the upper position is lowered to be placed at a processing position. Accordingly, the distance between the plating liquid L1 on the substrate W and the first ceiling plate 611 of the cover body 6 becomes a first distance, and the sidewall member 62 of the cover body 6 is placed to surround the substrate W. In the present exemplary embodiment, a lower end of the sidewall member 62 of the cover body 6 is located at a position lower than the bottom surface of the substrate W. In this way, the substrate W is covered with the cover body 6, and the space around the substrate W is closed (refer FIG. 7 ).
Then, a heating processing is begun (process S106). Specifically, the heater 63 is turned on, and the plating liquid L1 accumulated on the substrate W is heated. A set temperature of the heater 63 is fixed to a constant target temperature throughout the heating processing. The target temperature is in a range of, e.g., 90° C. to 100° C. When the temperature of the plating liquid L1 is raised up to a temperature at which a component of the plating liquid L1 is precipitated, the component of the plating liquid L1 is precipitated on a surface of the seed layer, so that the plating film is formed.
Subsequently, the controller 91 determines whether the temperature of the plating liquid L1 on the substrate W has reached the target temperature (process S107). For example, this determination is made based on an elapsed time after the heating processing is begun in the process S106. That is, the controller 91 makes a determination that the temperature of the plating liquid L1 has reached the target temperature when a preset time has elapsed after the beginning of the heating processing. The controller 91 repeats the determination of the process S107 until the preset time passes by (process S107, No).
When it is determined in the process S107 that the temperature of the plating liquid L1 has reached the target temperature (process S107, Yes), a cooling processing is begun (process S108). Specifically, the supply of the cooling gas from the cooling gas supply 4 to the bottom surface of the substrate W is started (see FIG. 8 ).
FIG. 9 is a graph schematically illustrating temperature variations of the plating liquid L1 in the heating processing. In FIG. 9 , the temperature variation of the plating liquid L1 in the case when the cooling processing is not performed is shown by a dashed-dotted line. Further, in FIG. 9 , a reference numeral TO denotes a temperature of the plating liquid L1 at the beginning of the heating processing (for example, a temperature equal to or less than a temperature of the plating liquid L1 supplied from the plating liquid supply 53). Further, a reference numeral T1 denotes the target temperature of the plating liquid L1.
As shown in FIG. 9 , when the cooling processing is not performed, the temperature of the plating liquid L1 continues to rise for a while even after it reaches the target temperature T1. In order to suppress this temperature rise, it may be considered to increase the set temperature of the heater 63 stepwise toward the target temperature T1. However, this is not desirable in that the time required for the heating processing becomes long. Further, in order to improve uniformity of the temperature of the plating liquid L1 within the surface of the substrate W, the heater 63 may have multiple heating regions whose temperatures can be set individually (which will be elaborated later). In this case, the set temperature of the heater 63 is adjusted for each heating region so that the in-surface uniformity of the temperature of the plating liquid L1 may be increased. Therefore, in such a case, if the set temperature is dynamically changed during the heating processing, there is a risk that the in-surface uniformity of the temperature of the plating liquid L1 may be rather deteriorated.
In view of this, in the plating unit 5 according to the present exemplary embodiment, by supplying the cooling gas to the bottom surface of the substrate W when the temperature of the plating liquid L1 reaches the target temperature T1, a temperature rise of the plating liquid L1 beyond the target temperature T1 is suppressed. Therefore, in the plating unit 5 according to the exemplary embodiment, the temperature of the plating liquid L1 on the substrate W can be easily maintained constant even when the heating processing is performed with the set temperature of the heater 63 fixed to the target temperature.
Thereafter, for example, upon the lapse of a preset time as a processing time of the heating processing after the heating processing is begun in the process S106, the heating processing and the cooling processing are ended (process S109). Specifically, the heater 63 is turned off, and the supply of the cooling gas from the cooling gas supply 4 to the bottom surface of the substrate W is stopped.
Then, a cover body retreating processing is performed (process S110). In the cover body retreating processing, the cover moving mechanism 7 is driven, so that the cover body 6 is placed at the retreat position. In this case, as the cylinder 73 of the cover moving mechanism 7 is first driven, the cover body 6 is raised to be located at the upper position. Then, the turning motor 72 of the cover moving mechanism 7 is driven, so that the cover body 6 located at the upper position is pivoted horizontally to be placed at the retreat position.
Subsequently, the substrate W is subjected to a rinsing processing (process S111). In this case, the rotation speed of the substrate W is increased to be higher than the rotation speed in the plating processing. For example, the substrate W is rotated at the same rotation speed as that in the rinsing processing (process S103) before the plating processing. Then, the rinse liquid nozzle 551 located at the retreat position is moved to the discharge position. Thereafter, the rinse liquid L3 is supplied from the rinse liquid nozzle 551 onto the substrate W being rotated, so that the front surface of the substrate W is cleaned. As a result, the plating liquid L1 remaining on the substrate W is washed away.
Afterwards, the substrate W after being rinsed is subjected to a drying processing (process S112). In this case, the rotation speed of the substrate W is increased to be higher than the rotation speed in the rinsing processing (process S111), for example, to thereby rotate the substrate W at a high speed. Accordingly, the rinse liquid L3 remaining on the substrate W is scattered off, so that the substrate W is dried.
Upon the completion of the drying processing, the substrate W is taken out from the plating unit 5 and transferred to the delivery unit 14 by the substrate transfer device 17. Further, the substrate W transferred to the delivery unit 14 is taken out from the delivery unit 14 by the substrate transfer device 13, and is accommodated in the carrier C. Through these operations, the series of processings of the electroless plating on a single sheet of the substrate W are ended.

First Modification Example

FIG. 10 is a diagram showing a configuration of a plating unit according to a first modification example. As depicted in FIG. 10 , a plating unit 5A according to the first modification example has a configuration in which a cover body 6A and a plating liquid nozzle 531A of a plating liquid supply 53A are integrated.
To elaborate, the plating liquid nozzle 531A is formed to penetrate the ceiling member 61 of the cover body 6A, the heater 63, and the cover lid 64. The plating liquid nozzle 531A is moved together with the cover body 6A by the cover moving mechanism 7.
Here, although an example in which the plating liquid nozzle 531A is disposed above the center of the substrate W held by the substrate holder 52 is illustrated, the plating liquid nozzle 531A may be disposed at a position shifted from immediately above the center of the substrate W.
Now, a specific operation of the plating unit 5A according to the first modification example will be described with reference to FIG. 11 . FIG. 11 is a flowchart showing a sequence of processings performed by the plating unit according to the first modification example.
Among processings of processes S201 to S212 shown in FIG. 11 , the processings other than the processes S204 and S205 are identical to, among the processings of the processes S101 to S112 performed by the plating unit 5 according to the above-described exemplary embodiment, the processings other than the processes S104 and S105. Specifically, the processings of the processes S201 to S203 are the same as the processings of the processes S101 to S103, and the processings of the processes S206 to S212 are the same as the processings of the processes S106 to S112.
As depicted in FIG. 11 , in the plating unit 5A according to the first modification example, after a processing of covering the substrate W with the cover body 6A (process S204) is performed, a processing of accumulating the plating liquid L1 (process S205) is carried out.
In this way, by supplying the plating liquid L1 onto the substrate W after the substrate W is covered with the cover body 6A, a temperature decline of the plating liquid L1 on the substrate W can be suppressed, as compared to the case where the substrate W is covered with the cover body 6A after the plating liquid L1 is supplied. That is, it is possible to suppress a temperature decline of the plating liquid L1 that occurs before the cover body 6A is moved to cover the substrate W after the plating liquid L1 is supplied onto the substrate W.
In addition, after covering the substrate W with the cover body 6A in the process S204, the plating unit 5A may pre-heat the substrate W by turning on the heater 63 before supplying the plating liquid L1 onto the substrate W.
Further, in the plating unit 5A, when covering the substrate W with the cover body 6A in the process S204, the cover body 6A may be disposed at a position allowing the first ceiling plate 611 of the cover body 6A comes into contact with the plating liquid L1 accumulated on the substrate W in the process S205. Accordingly, in the subsequent heating processings (processes S206 to S209), the heat of the heater 63 can be efficiently transmitted to the plating liquid L1. Therefore, the heating efficiency of the plating liquid L1 can be increased.
In this configuration in which the cover body 6A is brought into contact with the plating liquid L1, the plating unit 5A may perform a rinsing processing (process S211) and a drying processing (process S212) in the state that the substrate W is covered with the cover body 6A. Accordingly, the plating liquid L1 adhering to the first ceiling plate 611 of the cover body 6A can be washed away by the rinse liquid L3, and the first ceiling plate 611 can be dried. In this case, the rinse liquid source 552 needs to be connected to the plating liquid nozzle 531A via the rinse liquid line 553. In addition, a drying gas source may be connected to the plating liquid nozzle 531A via a pipeline. With this configuration, in the drying processing (process S212), the plating unit 5A is capable of drying the substrate W and the cover body 6A by supplying a drying gas (for example, an inert gas such as nitrogen) supplied from the drying gas source into the cover body 6A.

Second Modification Example

FIG. 12 is a diagram illustrating a configuration of a plating unit according to a second modification example. FIG. 13 is a diagram schematically illustrating a positional relationship between a plurality of heating regions of a heater and a plurality of cooling gas nozzles.
As depicted in FIG. 12 , a cover body 6B belonging to a plating unit 5B according to the second modification example is equipped with a heater 63B.
The heater 63B according to the second modification example has a plurality of heating regions 631 to 633 whose temperatures can be set individually. The plurality of heating regions 631 to 633 are arranged concentrically, for example (see FIG. 13 ). These heating regions 631 to 633 are arranged in the order of the heating region 631, the heating region 632, and the heating region 633 as they go outwards from the center of the substrate W. Among the plurality of heating regions 631 to 633, the heating region 631 has substantially the same diameter as the chuck member 521, for example.
Further, the plating unit 5B according to the second modification example includes a plurality of cooling gas supplies 4B1 to 4B3. Each of the cooling gas supplies 4B1 to 4B3 has the same configuration as the above-described cooling gas supply 4. These cooling gas supplies 4B1 to 4B3 are equipped with cooling gas nozzles 411 to 413, cooling gas sources 421 to 423, and cooling gas lines 431 to 433, respectively. Further, the plurality of cooling gas nozzles 411 may be connected to a single cooling gas nozzle.
The cooling gas nozzles 411 to 413 are disposed at positions corresponding to the plurality of heating regions 631 to 633. Specifically, the cooling gas nozzle 411 is disposed under the heating region 631 and discharges a cooling gas from below toward a bottom surface of the chuck member 521 positioned under the heating region 631. Further, the cooling gas nozzle 412 is disposed under the heating region 632 and discharges a cooling gas from below toward the bottom surface of the substrate W located below the heating region 632. Moreover, the cooling gas nozzle 413 is disposed under the heating region 633 and discharges a cooling gas from below toward the bottom surface of the substrate W located below the heating region 633.
As shown in FIG. 13 , the plurality of cooling gas nozzles 411 (412, 413) may be provided for the heating region 631.
Here, although an example where the cooling gas is discharged vertically upwards from the cooling gas nozzles 411 to 413 is illustrated, the cooling gas nozzles 411 to 413 may discharge the cooling gas obliquely toward the substrate W or the chuck member 521.
As described above, the plating unit 5B may be provided with the plurality of cooling gas nozzles 411 to 413 corresponding to the plurality of heating regions 631 to 633 whose temperatures can be set individually. Accordingly, in the plating unit 5B, the temperature of the plating liquid L1 on the substrate W can be maintained constant more easily.

Other Modification Examples

In the above-described exemplary embodiment, the supply of the cooling gas is started when the temperature of the plating liquid L1 reaches the target temperature. However, the cooling gas may be supplied even before the temperature of the plating liquid L1 reaches the target temperature. By way of example, the supply of the cooling gas and the heating processing may be started concurrently. In this case, a flow rate (first flow rate) of the cooling gas in the heating processing (first heating processing) before the plating liquid L1 reaches the target temperature T1 is set to be smaller than a flow rate (second flow rate) of the cooling gas in the heating processing (second heating processing) after the plating liquid L1 reaches the target temperature T1.
Although the above-described exemplary embodiment has been described for the example where the cooling gas of the room temperature is supplied, the temperature of the cooling gas may not necessarily be the room temperature as long as it is lower than the target temperature T1 at least. However, it is desirable to use the cooling gas of the room temperature in that an additional device for adjusting the temperature of the cooling gas is not required.
As described above, a substrate processing method according to the exemplary embodiment includes holding a substrate (as an example, the substrate holding processing), supplying a plating liquid (as an example, the plating liquid accumulating processing), covering the substrate (as an example, the processing of covering the substrate with a cover body), heating the plating liquid (as an example, the heating processing), and supplying a cooling gas (as an example, the cooling processing). In the holding of the substrate, the substrate (as an example, the substrate W) is held by using a holder (as an example, the substrate holder 52) which is configured to hold the substrate. In the supplying of the plating liquid, the plating liquid (as an example, the plating liquid L1) is supplied onto a top surface of the held substrate. In the covering of the substrate, the substrate is covered by using a cover body (as an example, the cover body 6) before or after the supplying of the plating liquid. In the heating of the plating liquid, the plating liquid on the substrate is heated by using a heating device (as an example, the heater 63) provided in the cover body in the state that the substrate is covered with the cover body. In the supplying of the cooling gas, the cooling gas (as an example, the inert gas) is supplied to a bottom surface of the substrate or the holder from below the substrate in the heating of the plating liquid. Therefore, according to the substrate processing method of the present exemplary embodiment, the temperature of the plating liquid on the substrate may be easily maintained constant.
In the supplying of the cooling gas, the cooling gas may be supplied to the bottom surface of the substrate or the holder when the temperature of the plating liquid reaches a target temperature (as an example, the target temperature T1). Accordingly, a temperature rise of the plating liquid exceeding the target temperature can be suppressed. Therefore, it is easy to maintain the temperature of the plating liquid on the substrate constant even when the heating processing is performed while fixing a set temperature of the heating device to the target temperature, for example.
The target temperature is the set temperature of the heating device. The temperature of the plating liquid continues to rise for a while even after reaching the target temperature, which is the set temperature of the heating device. In the substrate processing method according to the exemplary embodiment, when the temperature of the plating liquid reaches the target temperature, by supplying the cooling gas to the bottom surface of the substrate or the holder, it is possible to suppress a temperature rise of the plating liquid beyond the target temperature.
The temperature of the cooling gas is a room temperature. Thus, an additional device for adjusting the temperature of the cooling gas is not required.
The heating device has multiple heating regions whose temperatures can be set individually. In this case, in the supplying of the cooling gas, the cooling gas may be supplied from multiple nozzles disposed below the substrate while being located at positions respectively corresponding to the multiple heating regions. Therefore, the temperature of the plating liquid on the substrate may be maintained constant more easily.
In addition, a substrate processing apparatus according to the exemplary embodiment (as an example, the plating unit 5) includes a holder (as an example, the substrate holder 52), a plating liquid supply (as an example, the plating liquid supply 53), a cover body (as an example, the cover body 6), a moving mechanism (as an example, the cover moving mechanism 7), a heating device (as an example, the heater 63), and a cooling gas supply (as an example, the cooling gas supply 4) and a controller (as an example, the controller 91). The holder holds a substrate (as an example, the substrate W). The plating liquid supply supplies a plating liquid (as an example, the plating liquid 1_1) onto a top surface of the substrate held by the holder. The cover body covers the substrate held by the holder. The moving mechanism moves the cover body. The heating device is provided in the cover body. The cooling gas supply is disposed below the substrate held by the holder, and supplies a cooling gas (as an example, the inert gas) to a bottom surface of the substrate or the holder. The controller outputs control signals such that holding the substrate by using the holder (as an example, the substrate holding processing), supplying the plating liquid onto the top surface of the substrate by using the plating liquid supply (as an example, the plating liquid accumulating processing), covering the substrate by using the cover body before or after the supplying of the plating liquid (as an example, the processing of covering the substrate with the cover body), heating the plating liquid on the substrate by using the heating device while keeping the substrate covered with the cover body (as an example, the heating processing), and supplying the cooling gas from the cooling gas supply to the bottom surface of the substrate or the holder in the heating of the plating liquid (as an example, the cooling processing) are performed. Therefore, according to the substrate processing apparatus of the present exemplary embodiment, it is possible to maintain the temperature of the plating liquid on the substrate constant easily.
It should be noted that the above-described exemplary embodiment is illustrative in all aspects and is not anyway limiting. In fact, the above-described exemplary embodiment can be embodied in various forms. Further, the above-described exemplary embodiment may be omitted, replaced and modified in various ways without departing from the scope and the spirit of claims.

EXPLANATION OF CODES

1: Substrate processing apparatus
4: Cooling gas supply
5: Plating unit
6: Cover body
7: Cover moving mechanism
9: Control device
41: Cooling gas nozzle
42: Cooling gas source
43: Cooling gas line
52: Substrate holder
53: Plating liquid supply
63: Heater
91: Controller
92: Storage
411 to 413: Cooling gas nozzle
421 to 423: Cooling gas source
431 to 433: Cooling gas line
521: Chuck member
531: Plating liquid nozzle
532: Plating liquid source
533: Plating liquid line
631 to 633: Heating region
L1: Plating liquid
L2: Cleaning liquid
L3: Rinse liquid
T1: Target temperature
W: Substrate

Claims

1. A substrate processing method, comprising:

holding a substrate by using a holder configured to hold the substrate;

supplying a plating liquid onto a top surface of the held substrate;

covering the substrate by using a cover body before or after the supplying of the plating liquid;

heating the plating liquid on the substrate by using a heating device provided in the cover body, while keeping the substrate covered with the cover body; and

supplying a cooling gas to a bottom surface of the substrate or the holder from below the substrate in the heating of the plating liquid.

2. The substrate processing method of claim 1,

wherein in the supplying of the cooling gas, the cooling gas is supplied to the bottom surface of the substrate or the holder when a temperature of the plating liquid reaches a target temperature.

3. The substrate processing method of claim 2,

wherein the target temperature is a set temperature of the heating device.

4. The substrate processing method of claim 1,

wherein the cooling gas has a room temperature.

5. The substrate processing method of claim 1,

wherein the heating device has multiple heating regions whose temperatures are individually allowed to be adjusted, and

in the supplying of the cooling gas, the cooling gas is supplied from multiple nozzles disposed below the substrate while being located at positions respectively corresponding to the multiple heating regions.

6. A substrate processing apparatus, comprising:

a holder configured to hold a substrate;

a plating liquid supply configured to supply a plating liquid onto a top surface of the substrate held by the holder;

a cover body configured to cover the substrate held by the holder;

a moving mechanism configured to move the cover body;

a heating device provided in the cover body;

a cooling gas supply disposed below the substrate held by the holder, and configured to supply a cooling gas to a bottom surface of the substrate or the holder; and

a controller configured to output a control signal such that holding the substrate by using the holder, supplying the plating liquid onto the top surface of the substrate by using the plating liquid supply, covering the substrate by using the cover body before or after the supplying of the plating liquid, heating the plating liquid on the substrate by using the heating device while keeping the substrate covered with the cover body, and supplying the cooling gas from the cooling gas supply to the bottom surface of the substrate or the holder in the heating of the plating liquid are performed.