JP2022146850A - Plasma generator, plasma generation method, and substrate processing device - Google Patents

Abstract

To provide a technology that can control a temperature of a plasma source with higher precision.SOLUTION: A plasma generator 1 includes: a plasma source 2; a cooling member 4; a temperature measurement part 6; and a control unit. The plasma source 2 generates plasma. The cooling member 4 has at least one air supply port 411 for supplying a cooling gas to the plasma source 2. The temperature measurement part 6 measures a temperature of the plasma source 2. The control unit controls a flow rate of the cooling gas based on the measurement temperature measured by the temperature measurement part 6.SELECTED DRAWING: Figure 4

Description

TECHNICAL FIELD The present application relates to a plasma generation apparatus, a plasma generation method, and a substrate processing apparatus.

Conventionally, a plasma source that generates plasma under atmospheric pressure has been proposed (for example, Patent Document 1). In Patent Literature 1, a plasma source includes a plurality of first linear conductors, a plurality of second linear conductors, and a plate-like isolation member. A plurality of first linear conductors are provided parallel to each other on one side of the isolation member, and a plurality of second linear conductors are provided parallel to each other on the other side of the isolation member. The first linear conductors and the second linear conductors are not opposed to each other in the thickness direction of the isolation member, and the first linear conductors and the second linear conductors are alternately arranged when viewed along the thickness direction. be done.

In such a plasma source, plasma is generated around the plasma source by applying an AC voltage between the first linear conductor and the second linear conductor.

JP 2019-61759 A

As heat is generated by the plasma, the temperature of the plasma source increases. If the plasma source is made of highly heat-resistant material, the plasma source can withstand high temperatures, but the manufacturing cost increases.

Therefore, cooling the plasma source is conceivable. However, if the plasma source is cooled too much, the plasma can be extinguished.

An object of the present application is to provide a technology capable of controlling the temperature of the plasma source with higher accuracy.

A first aspect of a plasma generator comprises a plasma source for generating plasma, a cooling member having at least one air inlet for supplying a cooling gas to the plasma source, and measuring the temperature of the plasma source. A temperature measurement unit and a control unit that controls the flow rate of the cooling gas based on the measured temperature measured by the temperature measurement unit.

A second aspect of the plasma generator is the plasma generator according to the first aspect, wherein the plasma source includes a partition member that partitions a processing space on the processing target side and a cooling space on the opposite side of the processing space. and the at least one air inlet is provided in the cooling space.

A third aspect of the plasma generator is the plasma generator according to the second aspect, wherein the plasma source includes a first linear electrode and a second linear electrode, and the partition member comprises the first It has a first hole into which a linear electrode is inserted and a second hole into which the second linear electrode is inserted.

A fourth aspect of the plasma generator is the plasma generator according to the second aspect, wherein the plasma source includes a first linear electrode provided on the opposite side of the partition member from the object to be processed; a second linear electrode provided closer to the object to be processed than the partition member and provided at a position not facing the first linear electrode in the thickness direction of the partition member; 1 gas and a second gas that is more likely to become plasma than the first gas.

A fifth aspect of the plasma generation device is the plasma generation device according to the fourth aspect, wherein the control unit adjusts the flow rate of the first gas when the measured temperature is the first temperature to the measured temperature is a second temperature lower than the first temperature.

A sixth aspect of the plasma generator is the plasma generator according to the fourth or fifth aspect, wherein the controller controls the flow rate of the second gas when the measured temperature is the first temperature to The flow rate of the second gas is made smaller than when the measured temperature is a second temperature lower than the first temperature.

A seventh aspect of the plasma generator is the plasma generator according to any one of the second to sixth aspects, wherein the at least one air supply port is on the cooling surface of the partition member in contact with the cooling space. and the at least one air supply port opens toward the cooling surface of the partition member.

An eighth aspect of the plasma generator is the plasma generator according to the seventh aspect, wherein the cooling member is provided on the side opposite to the processing target with respect to the partition member, forming a gas space with the plasma source, wherein the at least one air inlet opens in the gas space; At least one exhaust path is formed for exhausting the cooling gas from the space.

A ninth aspect of the plasma generator is the plasma generator according to the eighth aspect, wherein the side wall of the flow path forming member is formed with a plurality of the exhaust paths, and the plurality of the exhaust paths are formed at different positions in the circumferential direction of the side wall of the flow path forming member.

A tenth aspect of the plasma generator is the plasma generator according to any one of the first to seventh aspects, wherein the cooling member includes a plurality of the air supply ports, and the plurality of the air supply ports causes the cooling gas to flow out toward a plurality of different regions of the plasma source, and the controller individually controls the flow rate of the cooling gas supplied to each of the plurality of regions.

An eleventh aspect of the plasma generation device is the plasma generation device according to the tenth aspect, wherein the cooling member comprises a flow path that partitions a plurality of gas flow paths through which the cooling gas flows toward the plurality of regions. A road partition member is further provided.

A twelfth aspect of the plasma generator is the plasma generator according to the eleventh aspect, wherein the cooling member further includes a plurality of exhaust passages provided respectively corresponding to the plurality of gas passages.

A thirteenth aspect of the plasma generation device is the plasma generation device according to the second aspect, wherein the cooling member includes a plurality of cooling members that flow the cooling gas toward a plurality of mutually different regions of the plasma source. the air supply port; a flow path partitioning member for partitioning a plurality of gas flow paths through which the cooling gas flows toward the plurality of regions; and a plurality of exhaust gases provided corresponding to the plurality of gas flow paths, respectively. and a passage, wherein the control unit individually controls the flow rate of the cooling gas supplied to each of the plurality of regions, and the passage partitioning member is a cooling surface of the partitioning member in contact with the cooling space. is in contact with

A fourteenth aspect of the plasma generator is the plasma generator according to any one of the tenth to thirteenth aspects, wherein the control unit measures the temperatures of the plurality of regions measured by the temperature measurement unit. The flow rate of the cooling gas is individually controlled so that the difference is reduced.

A fifteenth aspect of the plasma generator is the plasma generator according to any one of the first to fourteenth aspects, wherein the temperature measurement unit is positioned on the opposite side of the plasma source from the object to be processed. provided in

A sixteenth aspect of the plasma generator is the plasma generator according to any one of the first to fifteenth aspects, wherein the cooling member cools the cooling gas flowing out of the at least one air supply port. A rectifying member for rectifying is included, and the cooling gas is supplied to the plasma source through the rectifying member.

A substrate processing apparatus according to any one of the tenth to fourteenth aspects includes a substrate holding portion for holding a substrate, and a nozzle for supplying a processing liquid to a main surface of the substrate held by the substrate holding portion. The plasma source is provided at a position facing the main surface of the substrate held by the substrate holding part, and the plurality of regions of the plasma source are, in plan view, the a second central region facing the first central region of the main surface of the substrate; and a second peripheral region corresponding to the first peripheral region of the main surface of the substrate, wherein the controller controls the second peripheral The flow rate of the cooling gas is adjusted so that the temperature of the region is higher than the temperature of the second central region.

An aspect of the plasma generation method comprises the steps of generating plasma from a plasma source, measuring the temperature of the plasma source with a temperature measurement unit, and supplying a cooling gas at a flow rate based on the temperature measured by the temperature measurement unit. and supplying to said plasma source.

According to the first aspect of the plasma generator and the aspect of the plasma generation method, the temperature rise of the plasma source can be suppressed with high accuracy. Therefore, it is possible to more reliably suppress problems associated with the temperature rise of the plasma source.

According to the second aspect of the plasma generator, it is difficult for the cooling gas to flow into the processing space, so that plasma in the processing space is less likely to be disturbed. Therefore, the active species generated by the plasma can be more appropriately supplied to the object to be processed.

According to the third aspect of the plasma generator, it is possible to suppress contamination of the object to be processed due to sputtering of the first linear electrode and the second linear electrode. In addition, since the partition member covers both the first linear electrode and the second linear electrode, it is more advantageous than the case where separate members are provided to individually cover the first linear electrode and the second linear electrode. structure is simple.

According to the fourth aspect of the plasma generator, since the second gas that easily turns into plasma is also supplied, the temperature of the plasma source can be further lowered while maintaining plasma generation.

According to the 5th aspect of a plasma generator, temperature can be controlled appropriately.

According to the sixth aspect of the plasma generator, since the flow rate of the second gas is small when the temperature is high, it is possible to reduce the consumption of the second gas when the plasma is unlikely to disappear. On the other hand, since the flow rate of the second gas is large when the temperature is low, the plasma can be maintained more reliably when there is a high possibility that the plasma will be extinguished.

According to the seventh aspect of the plasma generator, the cooling gas flowing out from the air supply port collides with the main surface of the partition member along the direction perpendicular to the partition member, so that the cooling gas is caused to act on the partition member. Cheap.

According to the eighth aspect of the plasma generator, the cooling gas collides with the cooling surface of the partition member, flows along the plasma source, and is discharged to the outside through the exhaust path on the side wall of the flow path forming member. Therefore, the plasma source can be cooled more effectively.

According to the ninth aspect of the plasma generator, the cooling gas is discharged from the plurality of exhaust passages. Therefore, the cooling gas can be made to act more uniformly on the plasma source.

According to the tenth aspect of the plasma generator, the temperature of each region of the plasma source can be controlled independently of each other.

According to the eleventh aspect of the plasma generator, the cooling gas flowing out from each air supply port can be more reliably supplied to the corresponding region.

According to the twelfth aspect of the plasma generator, the cooling gas supplied to each gas flow path is discharged through the corresponding exhaust path. Therefore, it is possible to suppress the cooling gas from flowing between the gas flow paths. As a result, the flow rate of the cooling gas flowing through each gas flow path can be individually and more accurately adjusted, and the temperature of each region can be controlled with higher accuracy.

According to the thirteenth aspect of the plasma generator, it is possible to further suppress the cooling gas from flowing between the gas flow paths.

According to the fourteenth aspect of the plasma generator, the temperature of the plasma source can be made more uniform.

According to the fifteenth aspect of the plasma generator, since the temperature measuring section is not located between the plasma source and the processing object, it does not prevent active species from the plasma from acting on the processing object.

According to the sixteenth aspect of the plasma generator, the cooling gas can be more uniformly supplied to the plasma source.

According to this aspect of the substrate processing apparatus, since the temperature of the second peripheral region of the plasma source is higher than the temperature of the second central region, more plasma is generated in the second peripheral region, resulting in more of active species are generated. Therefore, more active species can act on the treatment liquid on the first peripheral region of the main surface of the substrate.

By the way, the processing liquid may swell in the first peripheral region of the main surface of the substrate. That is, the liquid film of the processing liquid on the main surface of the substrate may be thicker in the first peripheral region than in the first central region. In such a case, the action of the active species is less likely to act on the side near the periphery of the substrate. Therefore, undertreatment may occur in the first peripheral region of the substrate.

According to the aspect of the substrate processing apparatus, more active species are supplied to the first peripheral region of the substrate. Therefore, it is possible to suppress or avoid insufficient processing in the first peripheral region of the substrate.

1 is a plan view schematically showing an example of the configuration of a substrate processing system; FIG. 3 is a functional block diagram schematically showing an example of the internal configuration of a control unit; FIG. It is a figure which shows roughly an example of a structure of a processing unit (substrate processing apparatus). It is a sectional side view showing roughly an example of composition of a plasma generator. 1 is a plan view schematically showing an example of the configuration of a plasma source; FIG. 1 is a cross-sectional view schematically showing an example of the configuration of a plasma source; FIG. It is a flow chart which shows an example of operation of a plasma generator. FIG. 2 is a side cross-sectional view schematically showing an example of the configuration of a plasma generator and a cooling gas supply section; FIG. 5 is a side cross-sectional view schematically showing another example of the configuration of the plasma generator and the cooling gas supply section; FIG. 4 is a cross-sectional view schematically showing an example of the configuration of a flow path forming member; FIG. 2 is a cross-sectional view schematically showing an example of the configuration of a substrate; FIG. 5 is a side cross-sectional view schematically showing another example of the configuration of the plasma generator and the cooling gas supply section; 1 is a plan view schematically showing an example of the configuration of a plasma source; FIG. 1 is a cross-sectional view schematically showing an example of the configuration of a plasma source; FIG. FIG. 5 is a side cross-sectional view schematically showing another example of the configuration of the plasma generator and the cooling gas supply section;

Embodiments will be described below with reference to the accompanying drawings. Note that the components described in this embodiment are merely examples, and the scope of the present disclosure is not intended to be limited to them. In the drawings, for ease of understanding, the dimensions or number of each part may be exaggerated or simplified as necessary.

Expressions indicating relative or absolute positional relationships (e.g., "in one direction", "along one direction", "parallel", "perpendicular", "center", "concentric", "coaxial", etc.) are used unless otherwise specified. Not only the positional relationship is strictly expressed, but also the relatively displaced state in terms of angle or distance within the range of tolerance or equivalent function. Expressions indicating equality (e.g., "same", "equal", "homogeneous", etc.), unless otherwise specified, not only express quantitatively strictly equality, but also tolerances or equivalent functions can be obtained It shall also represent the state in which there is a difference. Expressions indicating shapes (e.g., "square shape" or "cylindrical shape"), unless otherwise specified, not only represent the shape strictly geometrically, but also to the extent that the same effect can be obtained, such as Shapes having unevenness or chamfering are also represented. The terms "comprise", "comprise", "comprise", "include" or "have" an element are not exclusive expressions that exclude the presence of other elements. The phrase "at least one of A, B and C" includes only A, only B, only C, any two of A, B and C, and all of A, B and C.

<Overall Configuration of Substrate Processing System>
FIG. 1 is a plan view schematically showing an example of the configuration of a substrate processing system 100 to which a plasma generator is applied. The substrate processing system 100 is a single wafer processing apparatus that processes substrates W to be processed one by one.

The substrate W is, for example, a semiconductor substrate and has a disk shape. In addition to the semiconductor substrate, the substrate W includes a photomask glass substrate, a liquid crystal display glass substrate, a plasma display glass substrate, a FED (Field Emission Display) substrate, an optical disk substrate, a magnetic disk substrate, and a magneto-optical substrate. Various substrates such as disk substrates can be applied. Also, the shape of the substrate is not limited to a disk shape, and various shapes such as a rectangular plate shape can be adopted.

The substrate processing system 100 includes a load port 101 , an indexer robot 110 , a main transfer robot 120 , a plurality of processing units 130 and a controller 90 .

A plurality of load ports 101 are arranged side by side along one horizontal direction. Each load port 101 is an interface section for loading/unloading the substrate W into/from the substrate processing system 100 . A carrier C containing substrates W is loaded into each load port 101 from the outside. Each load port 101 holds the loaded carrier C. As shown in FIG. As the carrier C, a FOUP (Front Opening Unified Pod), a SMIF (Standard Mechanical Interface) pod, or an OC (Open Cassette) that exposes the substrate W to the outside air may be employed.

The indexer robot 110 is a transport robot that transports the substrate W between the carrier C held at each load port 101 and the main transport robot 120 . The indexer robot 110 can move along the direction in which the load ports 101 are arranged, and can stop at a position facing each carrier C. As shown in FIG. The indexer robot 110 can perform an operation of picking up a substrate W from each carrier C and an operation of transferring a substrate W to each carrier C. As shown in FIG.

The main transport robot 120 is a transport robot that transports substrates W between the indexer robot 110 and each processing unit 130 . The main transport robot 120 can perform an operation of receiving the substrate W from the indexer robot 110 and an operation of transferring the substrate W to the indexer robot 110 . Further, the main transport robot 120 can perform an operation of loading the substrate W into each processing unit 130 and an operation of unloading the substrate W from each processing unit 130 .

For example, 12 processing units 130 are arranged in the substrate processing system 100 . Specifically, four towers each including three vertically stacked processing units 130 are provided so as to surround the main transfer robot 120 . In FIG. 1, one of the three-tiered processing units 130 is schematically shown. Note that the number of processing units 130 in the substrate processing system 100 is not limited to twelve, and may be changed as appropriate.

The main transfer robot 120 is provided so as to be surrounded by four towers. The main transport robot 120 loads unprocessed substrates W received from the indexer robot 110 into the processing units 130 . Each processing unit 130 processes a substrate W. FIG. Further, the main transport robot 120 unloads the processed substrate W from each processing unit 130 and passes it to the indexer robot 110 .

The control unit 90 controls operations of each component of the substrate processing system 100 . FIG. 2 is a functional block diagram schematically showing an example of the internal configuration of the control section 90. As shown in FIG. The control unit 90 is an electronic circuit and has, for example, a data processing unit 91 and a storage unit 92 . In the specific example of FIG. 2, the data processing section 91 and the storage section 92 are interconnected via a bus 93 . The data processing unit 91 may be an arithmetic processing device such as a CPU (Central Processor Unit). The storage unit 92 may have a non-temporary storage unit (eg, ROM (Read Only Memory) or hard disk) 921 and a temporary storage unit (eg, RAM (Random Access Memory)) 922 . The non-temporary storage unit 921 may store, for example, a program that defines processing to be executed by the control unit 90 . By the data processing unit 91 executing this program, the control unit 90 can execute the processing specified in the program. Of course, part or all of the processing executed by the control unit 90 may be executed by hardware. In the specific example of FIG. 2, an aspect in which the indexer robot 110, the main transport robot 120 and the processing unit 130 are connected to the bus 93 is schematically shown as an example.

Note that the control unit 90 may have a main control unit and a plurality of local control units. A main controller controls the entire substrate processing system 100 , and a local controller is provided for each processing unit 130 . The local control section is provided so as to be able to communicate with the main control section, and controls the processing unit 130 based on instructions from the main control section. Each of the main control unit and the local control unit has a data processing unit 91 and a storage unit 92, as in FIG. 2, for example.

<Substrate processing equipment>
FIG. 3 is a diagram schematically showing an example of the configuration of the processing unit (corresponding to the substrate processing apparatus) 130. As shown in FIG. It is not necessary for all the processing units 130 belonging to the substrate processing system 100 to have the configuration shown in FIG. 3, and at least one processing unit 130 may have the configuration.

The processing unit 130 illustrated in FIG. 3 is an apparatus that performs processing on the substrate W using plasma. Processing using plasma is not particularly limited, but includes resist removal processing as a specific example. The resist removal process is a process of removing the resist formed on the main surface of the substrate W. As shown in FIG. The substrate W is, for example, a semiconductor substrate and has a disk shape. Although the size of the substrate W is not particularly limited, its diameter is, for example, about 300 mm.

In the example of FIG. 3, the processing unit 130 includes the plasma generator 1, the substrate holder 11, the nozzle 12 and the guard 13. FIG.

The substrate holding part 11 holds the substrate W in a horizontal posture. The horizontal posture referred to here is a posture in which the thickness direction of the substrate W is along the vertical direction. In the example of FIG. 3, the substrate holder 11 includes a stage 111 and multiple chuck pins 112 . The stage 111 has a disk shape and is provided below the substrate W in the vertical direction. The stage 111 is provided in such a posture that its thickness direction is along the vertical direction. A plurality of chuck pins 112 are erected on the upper surface of the stage 111 and grip the peripheral edge of the substrate W. As shown in FIG. It should be noted that the substrate holding part 11 does not necessarily have to have the chuck pins 112 . For example, the substrate holding part 11 may suck the substrate W by sucking the lower surface of the substrate W. As shown in FIG.

In the example of FIG. 3, the substrate holder 11 further includes a rotation mechanism 113, which rotates the substrate W around the rotation axis Q1. The rotation axis Q1 is an axis that passes through the center of the substrate W and extends in the vertical direction. Rotation mechanism 113 includes, for example, shaft 114 and motor 115 . The upper end of the shaft 114 is connected to the lower surface of the stage 111 and extends from the lower surface of the stage 111 along the rotation axis Q1. The motor 115 rotates the shaft 114 around the rotation axis Q1 to rotate the stage 111 . Thereby, the substrate W held by the plurality of chuck pins 112 rotates around the rotation axis Q1. Such a substrate holding part 11 can also be called a spin chuck.

The nozzle 12 is used to supply the substrate W with the processing liquid. The nozzle 12 is connected to a processing liquid supply source 124 via a supply pipe 121 . That is, the downstream end of the supply pipe 121 is connected to the nozzle 12 and the upstream end of the supply pipe 121 is connected to the processing liquid supply source 124 . The processing liquid supply source 124 includes, for example, a tank (not shown) that stores the processing liquid, and supplies the processing liquid to the supply pipe 121 . Examples of the treatment liquid include hydrochloric acid, hydrofluoric acid, phosphoric acid, nitric acid, sulfuric acid, sulfate, peroxosulfuric acid, peroxosulfate, hydrogen peroxide, tetramethylammonium hydroxide, and a mixture of ammonia and hydrogen peroxide (SC1). , a mixture of hydrochloric acid and hydrogen peroxide (SC2), or a liquid containing deionized water (DIW) can be used. In this embodiment, the treatment using sulfuric acid as the treatment liquid will be described.

In the example of FIG. 3, the supply pipe 121 is provided with a valve 122 and a flow rate adjusting section 123 . By opening the valve 122 , the processing liquid from the processing liquid supply source 124 is supplied to the nozzle 12 through the supply pipe 121 and ejected from the ejection port 12 a of the nozzle 12 . The flow rate adjusting section 123 adjusts the flow rate of the processing liquid flowing through the supply pipe 121 . The flow rate adjusting unit 123 is, for example, a mass flow controller.

In the example of FIG. 3, the nozzle 12 is provided so as to be movable by a nozzle moving mechanism 15 . The nozzle moving mechanism 15 moves the nozzle 12 between the first processing position and the first standby position. The first processing position is a position where the nozzle 12 discharges the processing liquid toward the main surface (for example, the upper surface) of the substrate W. As shown in FIG. The first processing position is, for example, a position vertically above the substrate W and facing the central portion of the substrate W in the vertical direction. The first standby position is a position where the nozzle 12 does not discharge the processing liquid toward the main surface of the substrate W, and is a position further away from the substrate W than the first processing position. The first standby position is also a position where the nozzle 12 does not interfere with the transport path of the substrate W by the main transport robot 120 . As a specific example, the first standby position is a position radially outside the peripheral edge of the substrate W. As shown in FIG. FIG. 3 shows the nozzle 12 stopped at the first standby position.

The nozzle moving mechanism 15 has, for example, a ball screw mechanism or an arm turning mechanism. The arm turning mechanism includes an arm, a support column, and a motor (none of which are shown). The arm has a horizontally extending rod-like shape, the tip of the arm is connected to the nozzle 12, and the base end of the arm is connected to the support column. The support column extends vertically and is rotatable around its central axis. When the motor rotates the support column, the arm turns and the nozzle 12 moves in the circumferential direction around the central axis. A support column is provided so that the first processing position and the first standby position are positioned on the moving path of the nozzle 12 .

When the valve 122 is opened while the substrate holder 11 rotates the substrate W with the nozzle 12 positioned at the first processing position, the processing liquid is discharged from the nozzle 12 toward the upper surface of the substrate W during rotation. . The processing liquid lands on the upper surface of the substrate W, spreads over the upper surface of the substrate W as the substrate W rotates, and scatters outward from the peripheral edge of the substrate W. FIG. As a result, a liquid film of the processing liquid is formed on the upper surface of the substrate W. As shown in FIG.

The guard 13 has a cylindrical shape surrounding the substrate W held by the substrate holding part 11 . The processing liquid scattered from the peripheral edge of the substrate W hits the inner peripheral surface of the guard 13 and flows vertically downward along the inner peripheral surface. The processing liquid flows, for example, through a collection pipe (not shown) and is collected in the tank of the processing liquid supply source 124 . According to this, the treatment liquid can be reused.

The plasma generator 1 is a device that generates plasma, and is provided at a position facing the main surface (for example, the upper surface) of the substrate W held by the substrate holder 11 in the vertical direction. In the example of FIG. 3, the plasma generator 1 is provided vertically above the upper surface of the substrate W. As shown in FIG. The plasma generator 1 is connected to a power supply 8, receives power from the power supply 8, and converts surrounding gas into plasma. Here, as an example, the plasma generator 1 generates plasma under atmospheric pressure. The atmospheric pressure here is, for example, 80% or more of the standard pressure and 120% or less of the standard pressure. An example of a specific configuration of the plasma generator 1 will be detailed later.

As illustrated in FIG. 3 , the plasma generator 1 may be movably provided by a plasma moving mechanism 14 . The plasma moving mechanism 14 reciprocates the plasma generator 1 between the second processing position and the second standby position. The second processing position is a position where the substrate W is processed using plasma from the plasma generator 1 . At the second processing position, the distance between the plasma generator 1 and the upper surface of the substrate W is, for example, several millimeters.

The second standby position is a position when the substrate W is not processed using plasma, and is a position further away from the substrate W than the second processing position. The second standby position is also a position where the plasma generator 1 does not interfere with the transport path of the substrate W by the main transport robot 120 . As a specific example, the second standby position is a position vertically above the second processing position. In this case, the plasma moving mechanism 14 raises and lowers the plasma generator 1 along the vertical direction. FIG. 3 shows the plasma generator 1 stopped at the second standby position. The plasma moving mechanism 14 has, for example, a moving mechanism such as a ball screw mechanism or an air cylinder.

For example, the plasma generator 1 can move from the second standby position to the second processing position while the nozzle 12 is retracted to the first standby position. For example, when a liquid film of the processing liquid is formed on the upper surface of the substrate W by discharging the processing liquid from the nozzle 12 at the first processing position, the valve 122 is closed and the nozzle moving mechanism 15 moves the nozzle 12 to the first position. It is moved from the first processing position to the first standby position. On the other hand, for example, the power supply 8 outputs a voltage to the plasma generator 1 while the plasma generator 1 is positioned at the second standby position. Thereby, the plasma generator 1 generates plasma at a position farther from the substrate W than the second processing position. At this time, for example, in parallel with the nozzle 12 supplying the liquid film of the processing liquid onto the upper surface of the substrate W at the first processing position, the plasma generator 1 generates plasma, and the plasma is generated. Waiting time can be reduced.

After that, the plasma moving mechanism 14 moves the plasma generator 1 from the second standby position to the second processing position. According to this, since the nozzle 12 does not exist directly above the substrate W, the plasma generator 1 can be brought closer to the upper surface of the substrate W. FIG. In other words, the second processing position can be set closer to the substrate W.

Further, as a result, the plasma generator 1 generates plasma at a position near the upper surface of the substrate W toward the processing liquid on the upper surface of the substrate. Various active species are generated with the generation of this plasma. For example, plasmatization of air can generate various active species such as oxygen radicals, hydroxyl radicals, and ozone gas. These active species act on the upper surface of the substrate W. As shown in FIG. As a specific example, the active species act on the liquid film of the processing liquid (here, sulfuric acid) on the upper surface of the substrate W. As shown in FIG. This enhances the processing performance of the processing liquid. Specifically, the reaction between active species and sulfuric acid produces caro's acid with high processing performance (here, oxidizing power). Caro's acid is also called peroxomonosulfate. The Caro's acid acts on the resist on the substrate W, so that the resist can be removed by oxidation.

As described above, since the active species act on the processing liquid on the main surface of the substrate W, the processing performance of the processing liquid can be improved. Therefore, the substrate W can be processed quickly.

<Overview of Plasma Generator>
Next, an overview of the configuration of the plasma generator 1 will be described. FIG. 4 is a side cross-sectional view schematically showing an example of the configuration of the plasma generator 1. As shown in FIG. A plasma generator 1 includes a plasma source 2 , a cooling member 4 and a temperature measuring section 6 .

The plasma source 2 is a device that generates plasma. Plasma source 2 may also be referred to as a plasma reactor. When plasma is generated around the plasma source 2, the temperature of the plasma source 2 rises due to the plasma generation. If the temperature of the plasma source 2 rises more than necessary, various problems may occur. For example, problems such as an increase in the manufacturing cost of the plasma source 2 due to improved heat resistance, thermal damage to the substrate W to be processed, or contamination of peripheral members due to boiling of the processing liquid on the main surface of the substrate W. can occur.

The cooling member 4 has an air supply port 411 for supplying cooling gas to the plasma source 2 . In the example of FIG. 4, the air supply port 411 faces the plasma source 2 with a gap therebetween. The air supply port 411 is provided at the downstream end of the air supply path 412 , and the cooling gas is supplied from the cooling gas supply unit 5 to the air supply path 412 . The cooling gas includes at least one of nitrogen gas and air, for example. The cooling gas flows through the air supply path 412 toward the air supply port 411 and flows out from the air supply port 411 .

The cooling gas flowing out from the air supply port 411 flows toward the plasma source 2 and is supplied to the plasma source 2 . By supplying the cooling gas to the plasma source 2, the plasma source 2 can be air-cooled. Thereby, the temperature rise of the plasma source 2 can be mitigated. On the other hand, if the temperature of the plasma source 2 drops too low, the plasma may extinguish.

A temperature measuring unit 6 measures the temperature of the plasma source 2 . Temperature measurement unit 6 outputs an electrical signal indicating the measurement result to control unit 90 .

The control unit 90 controls the flow rate of cooling gas supplied to the plasma source 2 based on the temperature measured by the temperature measurement unit 6 .

According to such a plasma generator 1 , the plasma source 2 can be air-cooled while monitoring the temperature of the plasma source 2 . Therefore, the temperature of the plasma source 2 can be controlled with high precision. Therefore, it is possible to more reliably suppress the above problems due to temperature rise and temperature drop.

In the above example, plasma is generated over the entire plasma source 2 while the plasma source 2 is positioned at the second waiting position, which is further from the substrate W than the second processing position. Then, the temperature of the plasma source 2 is cooled to a temperature suitable for processing the substrate W. FIG. After that, the plasma source 2 is moved from the second waiting position to the second processing position. By doing so, damage to the substrate W and peripheral members due to high heat caused by plasma generation can be suppressed compared to the case where the plasma is generated at a position near the upper surface of the substrate W. Further, the upper surface of the substrate W can be uniformly processed by moving the plasma source 2 to the second processing position after plasma is generated over the entire plasma source 2 .

A more detailed example of each configuration of the plasma generator 1 will be described below.

<Plasma source>
FIG. 5 is a plan view schematically showing an example of the configuration of the plasma source 2, and FIG. 6 is a cross-sectional view schematically showing an example of the configuration of the plasma source 2. As shown in FIG. FIG. 6 shows the AA section of FIG. In the examples of FIGS. 4-6, the plasma source 2 includes a first electrode section 21 and a second electrode section 22 .

5 and 6, the first electrode section 21 includes a plurality of first linear electrodes 211 and a first collective electrode 212, and the second electrode section 22 includes a plurality of second linear electrodes 221 and a second and a collection electrode 222 .

The first linear electrode 211 is made of a conductive material such as a metal material (eg, tungsten) and has a rod-like shape (eg, a columnar shape) extending along the longitudinal direction D1. The plurality of first linear electrodes 211 are arranged side by side in an arrangement direction D2 perpendicular to the longitudinal direction D1, and ideally parallel to each other.

The first collective electrode 212 is made of a conductive material such as a metal material (for example, aluminum), and connects ends (base ends) on one side of the plurality of first linear electrodes 211 in the longitudinal direction D1. In the example of FIG. 5, the first collective electrode 212 has an arcuate plate shape that bulges to one side in the longitudinal direction D1. A plurality of first linear electrodes 211 extend from the first collective electrode 212 toward the other side in the longitudinal direction D1.

The second linear electrode 221 is made of a conductive material such as a metal material (eg, tungsten) and has a rod-like shape (eg, a columnar shape) extending along the longitudinal direction D1. The plurality of second linear electrodes 221 are arranged side by side in the arrangement direction D2 and ideally parallel to each other. Each of the second linear electrodes 221 is two of the plurality of first linear electrodes 211 adjacent to each other in a plan view (that is, when viewed along a direction D3 perpendicular to the longitudinal direction D1 and the arrangement direction D2). is set between In the example of FIG. 5, the first linear electrodes 211 and the second linear electrodes 221 are alternately arranged in the arrangement direction D2 in plan view. Each of the first linear electrodes 211 does not face the second linear electrodes 221 in the direction D3.

The second collective electrode 222 is made of a conductive material such as a metal material (for example, aluminum) and connects the ends (basal ends) of the plurality of second linear electrodes 221 on the other side in the longitudinal direction D1. In the example of FIG. 5, the second collective electrode 222 bulges in the opposite direction to the first collective electrode 212 and has an arcuate plate shape with approximately the same diameter as the first collective electrode 212 . A plurality of second linear electrodes 221 extend from the second collective electrode 222 toward one side in the longitudinal direction D1.

In the examples of FIGS. 4-6, each first linear electrode 211 is covered with a first dielectric 31 . The plurality of first dielectrics 31 are made of a dielectric material such as quartz or ceramics. For example, each first dielectric 31 has a tubular shape extending along the longitudinal direction D1, and the first linear electrode 211 is inserted into the first dielectric 31 along the longitudinal direction D1. By covering the first linear electrodes 211 with the first dielectric 31, it is possible to prevent the substrate W from being contaminated due to sputtering of the first linear electrodes 211 by plasma.

In the examples of FIGS. 4-6, each second linear electrode 221 is covered with a second dielectric 32 . The plurality of second dielectrics 32 are made of a dielectric material such as quartz or ceramics. For example, each second dielectric 32 has a tubular shape extending along the longitudinal direction D1, and the second linear electrode 221 is inserted into the second dielectric 32 along the longitudinal direction D1. By covering the second linear electrodes 221 with the second dielectric 32, it is possible to prevent the substrate W from being contaminated due to sputtering of the second linear electrodes 221 by plasma.

In the examples of FIGS. 4 to 6, the plasma source 2 is provided with a partition member 33 . The partition member 33 is made of a dielectric material such as quartz or ceramics. In the illustrated example, the partition member 33 has a plate-like shape. Hereinafter, the main surface on one side of the partition member 33 is called a processing surface 33a, and the main surface on the other side is called a cooling surface 33b. The processing surface 33a and the cooling surface 33b are surfaces facing each other in the thickness direction of the partition member 33 . The partition member 33 is provided so that its thickness direction is along the direction D3. In the example of FIG. 5, the processing surface 33a and the cooling surface 33b of the partition member 33 have a circular shape in plan view. The thickness of the partition member 33 (the distance between the processing surface 33a and the cooling surface 33b) is set to, for example, about several hundred μm (eg, 300 μm).

The first electrode portion 21 and the first dielectric 31 are provided on the processing surface 33a side of the partition member 33, and the second electrode portion 22 and the second dielectric 32 are provided on the cooling surface 33b side of the partition member 33. there is Specifically, the first dielectric 31 is provided under the processing surface 33 a of the partition member 33 , and the second dielectric 32 is provided on the cooling surface 33 b of the partition member 33 .

The plasma source 2 is provided in the processing unit 130 in such a posture that the processing surface 33a faces the processing target (here, the substrate W). Specifically, the plasma source 2 is provided in such a posture that the direction D3 is along the vertical direction and the processing surface 33a faces the upper surface of the substrate W. As shown in FIG. This plasma source 2 faces the substrate W in the vertical direction.

The partition member 33 separates the first space on the side of the processing surface 33a from the second space on the side of the cooling surface 33b. Hereinafter, the first space will be referred to as a processing space, and the second space on the opposite side of the partition member 33 as the processing space will also be referred to as a cooling space. That is, the processing surface 33a of the partition member 33 is the surface in contact with the processing space, and the cooling surface 33b of the partition member 33 is the surface in contact with the cooling space.

As illustrated in FIG. 4 , the plasma source 2 may be provided with a holding member 34 . 5 and 6, the holding member 34 is omitted in order to avoid complication of the drawings. The holding member 34 is made of an insulating material such as fluorine-based resin, and holds the first electrode portion 21, the second electrode portion 22, the first dielectric 31, the second dielectric 32, and the partition member 33 integrally. For example, the holding member 34 has a ring shape having substantially the same diameter as the first collective electrode 212 and the second collective electrode 222 in plan view, and sandwiches the first collective electrode 212 and the second collective electrode 222 in the direction D3. .

In the example of FIG. 4 , the tip of the first dielectric 31 is held by the holding member 34 . Specifically, the tip of the first dielectric 31 is embedded in the holding member 34 . Therefore, both ends of the portion composed of the first linear electrode 211 and the first dielectric 31 are held by the holding member 34 . As a result, both ends of the portion can be held. In the example of FIG. 4, the tip of the second dielectric 32 is also held by the holding member 34 . Therefore, the holding member 34 can also hold both ends of the portion composed of the second linear electrode 221 and the second dielectric 32 .

The first electrode portion 21 and the second electrode portion 22 are electrically connected to the power source 8 for plasma. More specifically, the first collective electrode 212 of the first electrode section 21 is electrically connected to the first output end 8a of the power source 8 via the wiring 81, and the second collective electrode 222 of the second electrode section 22 is electrically connected to the first output terminal 8a of the power source 8. It is electrically connected to the second output end 8b of the power supply 8 via the wiring 82. FIG. The power supply 8 has, for example, a switching power supply circuit (not shown), and outputs voltage for plasma between the first electrode portion 21 and the second electrode portion 22 . As a more specific example, the power supply 8 outputs a high-frequency voltage as a voltage for plasma to the first output end 8a and the second output end 8b.

When the power supply 8 outputs a voltage between the first electrode portion 21 and the second electrode portion 22 , an electric field for plasma is generated between the first linear electrode 211 and the second linear electrode 221 . The gas around the first linear electrode 211 and the second linear electrode 221 turns into plasma according to the electric field. According to this plasma source 2, the gas between the first linear electrode 211 and the second linear electrode 221 is turned into plasma on the processing surface 33a side and the cooling surface 33b side of the partition member 33, and plasma P1 and plasma P1 are generated, respectively. P2 occurs (see FIG. 6). Conversely, the power source 8 applies a voltage to the extent that the gas becomes plasma between the first electrode portion 21 and the second electrode portion 22 . The voltage is, for example, a high frequency voltage of about several tens of kV and several tens of kHz. In addition, in the example of FIG. 6, the contours of the regions where the plasmas P1 and P2 are generated are schematically indicated by two-dot chain lines. The plasma generation region can also be said to be a light emitting region where the plasma emits light.

<Cooling member>
Referring to FIG. 4, cooling member 4 has an air supply port 411 through which cooling gas flows. In the example of FIG. 4, the air supply port 411 is provided in the cooling space. That is, the air supply port 411 is provided on the opposite side of the partition member 33 to the processing target (here, the substrate W). The air supply port 411 is provided at a position facing the cooling surface 33b of the partition member 33 in the direction D3. provided in In the example of FIG. 4 , the air supply port 411 opens toward the cooling surface 33 b of the partition member 33 . More specifically, the opening direction of the air supply port 411 is the direction along the direction D3 perpendicular to the cooling surface 33b.

In the example of FIG. 4 , the cooling member 4 includes an air supply pipe 41 provided in the cooling space, and the downstream end of an air supply passage 412 inside the air supply pipe 41 corresponds to the air supply port 411 . The cooling gas flowing out from the air supply port 411 of the air supply pipe 41 flows toward the plasma source 2 .

A cooling gas is supplied from the cooling gas supply unit 5 to the air supply pipe 41 (see also FIG. 3). The cooling gas supply section 5 includes an air supply pipe 51 , a valve 52 and a flow rate adjustment section 53 . Air supply pipe 51 connects air supply pipe 41 and gas supply source 54 . In other words, the downstream end of the air supply pipe 51 is connected to the air supply pipe 41 and the upstream end of the air supply pipe 51 is connected to the gas supply source 54 . The air supply pipe 41 and the air supply pipe 51 may be different parts of one pipe. A gas supply source 54 supplies cooling gas to the air supply pipe 51 . The cooling gas is, for example, at least one of nitrogen gas and air.

A valve 52 and a flow control unit 53 are interposed in the air supply pipe 51 . Valve 52 is controlled by controller 90 . By opening the valve 52 , the cooling gas from the gas supply source 54 is supplied to the air supply pipe 41 through the air supply pipe 51 and flows out from the air supply port 411 . The cooling gas flowing out from the air supply port 411 flows toward the plasma source 2 and cools the plasma source 2 . The supply of the cooling gas is stopped by closing the valve 52 . The flow rate adjusting section 53 is controlled by the control section 90 and adjusts the flow rate of the cooling gas flowing through the air supply pipe 51 . The flow rate adjusting unit 53 is, for example, a mass flow controller.

In the example of FIG. 4, the cooling member 4 further includes a channel forming member 42. As shown in FIG. The flow path forming member 42 forms the gas space 40 through which the cooling gas flowing out from the air supply port 411 flows. The flow path forming member 42 is provided on the cooling space side with respect to the partition member 33 and is connected to the periphery of the plasma source 2 to form the gas space 40 together with the plasma source 2 . In the example of FIG. 4 , the flow path forming member 42 includes a cover portion 421 and side walls 422 . The cover part 421 has a plate-like shape, for example, and is provided in a posture in which the thickness direction thereof is along the direction D3. The cover part 421 has, for example, a disk shape with substantially the same diameter as the holding member 34, and is provided at a position facing the plasma source 2 in the direction D3. A through hole through which the air supply pipe 41 is arranged is formed in the central portion of the cover portion 421 . The air supply pipe 41 and the cover portion 421 are connected to each other. An air supply port 411 of the air supply pipe 41 opens in the gas space 40 .

The side wall 422 has a cylindrical shape erected on the peripheral edge of the cover portion 421 and extends toward the holding member 34 side. The inner peripheral surface of the side wall 422 is located outside the tip of the first linear electrode 211 and the tip of the second linear electrode 221 in plan view.

In the example of FIG. 4, the side wall 422 overlaps the retaining member 34 in the direction D3 and is connected to the retaining member 34 . The flow path forming member 42 may be configured integrally with the holding member 34, or may be configured by combining a plurality of members.

With such a flow path forming member 42, the gas space 40 surrounded by the cover portion 421, the side wall 422 and the plasma source 2 can be formed. Since the holding member 34 is also a part of the member forming the gas space 40 , it can be said that it belongs to the flow path forming member 42 . In other words, it is also possible to grasp the portion composed of the side wall 422 and the holding member 34 as the side wall 423 of the flow path forming member 42 .

An exhaust path 424 is provided in the flow path forming member 42 . In the example of FIG. 4, the exhaust path 424 is provided in the side wall 423 of the flow path forming member 42 (the holding member 34 in the figure). The exhaust path 424 is, for example, a through hole connecting the inner peripheral surface and the outer peripheral surface of the holding member 34 . The cooling gas flowing out from the air supply port 411 flows toward the plasma source 2 , collides with the plasma source 2 , flows along the plasma source 2 , and is discharged to the outside through the exhaust path 424 .

As illustrated in FIG. 4 , a plurality of exhaust passages 424 may be provided in the passage forming member 42 . The plurality of exhaust paths 424 are provided at different positions in the circumferential direction of the side wall 423, and as a more specific example, are provided at regular intervals.

Note that the exhaust path 424 does not necessarily have to be formed in the holding member 34 , and may be formed in the side wall 422 or at the boundary between the side wall 422 and the holding member 34 , for example.

In the example of FIG. 4, a straightening member 43 is provided between the air supply port 411 of the air supply pipe 41 and the plasma source 2 . The rectifying member 43 is a member for rectifying the cooling gas flowing out from the air supply port 411 and supplying the rectified cooling gas to the plasma source 2 . The rectifying member 43 has, for example, a plate-like shape, and is provided in a posture such that its thickness direction is along the direction D3. A plurality of through holes 43 a are formed in the rectifying member 43 . The through hole 43a penetrates the rectifying member 43 in the direction D3. The plurality of through holes 43a are two-dimensionally arranged in plan view, for example, in a matrix. The straightening member 43 has a disk shape, and its peripheral edge is fixed to the inner peripheral surface of the side wall 422 of the flow path forming member 42 .

In the cooling member 4, the cooling gas flowing out from the air supply port 411 is rectified by passing through the plurality of through holes 43a of the rectifying member 43, and the rectified cooling gas flows toward the plasma source 2. . After colliding with the plasma source 2 , the cooling gas flows toward the surroundings along the plasma source 2 and is discharged to the outside through a plurality of exhaust paths 424 . The exhaust path 424 is preferably provided downstream of the straightening member 43 .

<Temperature measurement unit>
Referring to FIG. 4, temperature measurement unit 6 measures the temperature of plasma source 2 . In the example of FIG. 4, the temperature measurement unit 6 is a temperature sensor that measures temperature in a non-contact manner, and as a specific example, it is an infrared sensor that detects infrared rays. The sensor includes a radiation thermometer.

In the example of FIG. 4, the temperature measurement unit 6 is provided on the cooling space side with respect to the plasma source 2 . Specifically, the temperature measurement unit 6 is provided on the side opposite to the plasma source 2 with respect to the flow path forming member 42 . A measurement window 425 is formed in the flow path forming member 42 , and the temperature measurement unit 6 measures the temperature of the plasma source 2 through the measurement window 425 . In the example of FIG. 4 , the measurement window 425 is formed in the cover portion 421 of the flow path forming member 42 . The measurement window 425 penetrates the cover portion 421 along the direction D3 and faces the plasma source 2 in the direction D3. The measurement window 425 may be, for example, a translucent member. This light-transmitting member is made of a light-transmitting material (for example, glass) having a high infrared transmittance (for example, 60% or more, preferably 90% or more). When the rectifying member 43 opaque to infrared rays is provided, the measurement window 425 is formed at a position facing the through hole 43a of the rectifying member 43 in the direction D3. When the rectifying member 43 is made of a translucent material, the measurement window 425 may be provided at a position facing the rectifying member 43 .

Part of the infrared rays emitted from the plasma source 2 passes through the through hole 43 a (or the rectifying member 43 ) and the measurement window 425 and enters the temperature measurement section 6 . The temperature measurement unit 6 detects the infrared rays and outputs an electric signal indicating the detection result to the control unit 90 as a temperature measurement value.

In the example of FIG. 4, a plurality of temperature measurement units 6 are provided. The plurality of temperature measurement units 6 may be provided, for example, at substantially equal intervals in the circumferential direction around the air supply pipe 41 in a plan view. A plurality of measurement windows 425 are formed in the cover portion 421 so as to correspond to the plurality of temperature measurement portions 6 . A plurality of temperature measurement units 6 measure the temperature of the plasma source 2 at mutually different positions in plan view. The control unit 90 may calculate the measured temperature of the plasma source 2 based on the temperatures measured by the multiple temperature measurement units 6 . For example, the control unit 90 may calculate an average value of a plurality of measured temperatures as the measured temperature.

The temperature measuring part 6 and the cooling member 4 are preferably moved together with the plasma source 2 . That is, the plasma moving mechanism 14 may move the plasma source 2, the cooling member 4, and the temperature measuring section 6 integrally. According to this, the cooling member 4 can cool the plasma source 2 regardless of the position of the plasma source 2, and the temperature measuring unit 6 can measure the temperature of the plasma source 2 regardless of the position of the plasma source 2. can be done.

In the above-described example, although the translucent member (measurement window 425) is provided in part of the cover part 421, the entire cover part 421 may be made of a translucent material. If the rectifying member 43 is also made of a translucent material, the infrared rays from the plasma source 2 can pass through the rectifying member 43 and the cover portion 421, so that the degree of freedom of the installation position of the temperature measuring portion 6 can be improved.

<Air cooling control>
FIG. 7 is a flow chart schematically showing an example of the operation of the plasma generator 1. As shown in FIG. The controller 90 controls the power source 8 to generate plasmas P1 and P2 around the plasma source 2 (step S1). Specifically, the power supply 8 outputs a plasma voltage (for example, a high-frequency voltage) to the plasma source 2 under the control of the controller 90 . As a result, an electric field for plasma is generated between the first linear electrode 211 and the second linear electrode 221, and the electric field acts on the gas to generate plasmas P1 and P2. The plasma source 2 generates plasmas P1 and P2 until the processing is finished.

Taking the processing unit 130 as an example, the plasma source 2 generates plasmas P1 and P2 at the second processing position, thereby supplying various active species caused by the plasma P1 to the processing liquid on the substrate W. can do. Thereby, as described above, the resist on the substrate W can be removed more quickly.

Further, the controller 90 opens the valve 52 to supply the cooling gas to the plasma source 2 (step S2). Specifically, the cooling gas is supplied from the gas supply source 54 to the air supply pipe 41 through the air supply pipe 51 and flows out from the air supply port 411 . The cooling gas flowing out from the air supply port 411 is rectified through the rectifying member 43 in the gas space 40 , and the rectified cooling gas is supplied to the plasma source 2 . The cooling gas that has collided with the plasma source 2 flows outward along the plasma source 2 and is discharged to the outside through the exhaust path 424 .

Next, the temperature measurement unit 6 measures the temperature of the plasma source 2 (step S3).

Next, the control section 90 controls the flow rate adjusting section 53 based on the measured temperature measured by the temperature measuring section 6 to control the flow rate of the cooling gas supplied to the plasma source 2 (step S4). Therefore, the cooling gas supply unit 5 and the cooling member 4 supply the cooling gas to the plasma source 2 at a flow rate based on the temperature measured by the temperature measurement unit 6 .

Specifically, the controller 90 controls the flow rate of the cooling gas when the measured temperature is the first temperature to be higher than the flow rate of the cooling gas when the measured temperature is the second temperature lower than the first temperature. Control the flow rate adjusting unit 53 so as to increase. That is, the control unit 90 increases the flow rate of the cooling gas when the measured temperature is high to decrease the temperature of the plasma source 2, and when the measured temperature is low, decreases the flow rate of the cooling gas. The temperature of plasma source 2 is increased. The controller 90 may continuously increase the flow rate of the cooling gas as the measured temperature increases, or may increase it stepwise.

Next, the control unit 90 determines whether or not to end the process (step S5). If the predetermined termination condition is satisfied, the control unit 90 determines to terminate the processing, and if the predetermined termination condition is not satisfied, the control unit 90 determines not to terminate the processing. For example, it may be determined that the end condition is satisfied when a predetermined period of time has passed since the voltage output by the power supply 8 . The predetermined period of time is, for example, sufficient time to remove the resist on the substrate W. As shown in FIG. If the termination condition is not met, step S3 is executed again, and if the termination condition is met, the process is terminated. Specifically, the controller 90 causes the power supply 8 to stop outputting voltage and closes the valve 52 .

As described above, the plasma generator 1 controls the flow rate of the cooling gas while monitoring the temperature of the plasma source 2 . Therefore, the temperature of the plasma source 2 can be controlled within a predetermined temperature range with high accuracy.

Also, in the above example, the plasma source 2 includes the partition member 33 , and the cooling member 4 supplies cooling gas to the plasma source 2 in the cooling space partitioned by the partition member 33 . Therefore, the cooling gas is less likely to flow into the processing space, and the plasma P1 between the plasma source 2 and the processing object (here, the substrate W) is less likely to be disturbed. Therefore, the active species caused by the plasma P1 can be supplied to the substrate W more uniformly.

Further, in the above example, the air supply port 411 of the cooling member 4 is provided at a position facing the cooling surface 33b of the partition member 33 and opens toward the cooling surface 33b. According to this, the cooling gas flowing out from the air supply port 411 flows toward the partition member 33 along the direction D3, so most of the cooling gas can collide with the plasma source 2 .

For comparison, a structure in which the cooling gas is flowed in a direction parallel to the cooling surface 33b of the partition member 33 is considered. In this case, among the cooling gases, the gas flowing away from the plasma source 2 does not come into direct contact with the plasma source 2 and thus does not contribute to the cooling of the plasma source 2 easily.

On the other hand, in the example described above, the cooling gas flows toward the plasma source 2 along the direction D3, so most of it tends to hit the plasma source 2 . Therefore, most of the cooling gas flowing out from the air supply port 411 tends to contribute to cooling the plasma source 2 . Therefore, the plasma source 2 can be cooled more effectively.

Further, in the above example, the exhaust path 424 is formed in the side wall 423 of the flow path forming member 42 . Therefore, the cooling gas that flows out from the air supply port 411 and collides with the plasma source 2 flows outward along the plasma source 2 and is discharged to the outside through the exhaust path 424 . Since the cooling gas flows along the plasma source 2 after the collision, the plasma source 2 can be cooled more effectively.

Further, in the above example, the plurality of exhaust paths 424 are provided on the side wall 423 of the flow path forming member 42 at different positions in the circumferential direction. As a specific example, the plurality of exhaust paths 424 are provided at regular intervals. Therefore, the cooling gas flows radially outward more evenly along the plasma source 2 and is discharged to the outside through the plurality of exhaust paths 424 . Therefore, the plasma source 2 can be cooled more uniformly. According to this, the temperature distribution of the plasma source 2 can be made more uniform. Therefore, the distribution of the amount of active species generated by the plasma source 2 can be made more uniform, and the active species can act on the substrate W more uniformly.

Further, in the example described above, the cooling member 4 includes the straightening member 43 . Therefore, the cooling gas can be more uniformly supplied to the plasma source 2 in plan view. Therefore, the temperature of plasma source 2 can be controlled more uniformly. In other words, the temperature distribution of the plasma source 2 in plan view can be made more uniform. According to this, the distribution of the amount of active species generated by the plasma source 2 can be made more uniform, and the active species can act on the substrate W more uniformly.

Further, in the above example, the temperature measurement unit 6 is provided closer to the cooling space than the partition member 33 is. In other words, the temperature measurement unit 6 is provided on the side of the plasma source 2 opposite to the processing target (here, the substrate W). According to this, since the temperature measuring part 6 is not provided between the plasma source 2 and the substrate W, movement of the active species toward the substrate W is not hindered. Also, the plasma source 2 can be brought closer to the object to be processed. In other words, the second processing position of the plasma generator 1 can be set closer to the substrate W. The temperature measuring unit 6 can measure the temperature of the plasma source 2 even when the plasma generator 1 is stopped at the second processing position. Temperature can be controlled with high precision.

In the above example, the control unit 90 controls the power source 8 to spread the plasma P1, Generate P2. Then, the plasma source 2 is cooled by the cooling gas so that the temperature of the plasma source 2 reaches a temperature suitable for processing the substrate W. FIG. After that, the plasma source 2 is moved from the second waiting position to the second processing position. By doing so, damage to the substrate W and peripheral members due to high heat caused by plasma generation can be suppressed compared to the case where the plasma is generated at a position near the upper surface of the substrate W.

<Timing of air cooling control>
When the plasma generator 1 is positioned at the second standby position, when positioned at the second processing position, and during movement between the second processing position and the second standby position, the control unit 90 performs can be done.

In the above example, the temperature measurement unit 6 is provided on the opposite side of the plasma source 2 to the processing target (here, the substrate W) in order to measure the temperature of the plasma source 2 during plasma processing. However, it is not necessary to measure the temperature of the plasma source 2 during plasma processing. For example, when the plasma generator 1 is stopped at the preparation position (including the second standby position) vertically above the second processing position, the power source 8 outputs a voltage to the plasma source 2 to generate plasmas P1 and P2. is generated, and the controller 90 controls the flow rate of the cooling gas based on the measured temperature of the plasma source 2 . Subsequently, the plasma generator 1 moves to the second processing position and performs plasma processing (supply of active species) on the substrate W. As shown in FIG. During plasma processing, the temperature measurement unit 6 does not perform temperature measurement, and the cooling gas supply unit 5 supplies the cooling gas at the gas flow rate when the temperature of the plasma source 2 is within a predetermined range at the preparation position. do. This also allows the temperature of the plasma source 2 to be maintained within a predetermined range during plasma processing.

In this case, the temperature measurement unit 6 does not necessarily have to be provided on the side opposite to the substrate W with respect to the plasma source 2 . The temperature measurement unit 6 may be provided on the substrate W side with respect to the plasma source 2 . For example, the temperature measurement unit 6 may be provided at a position closer to the substrate W than the plasma source 2 and outside the plasma source 2 . In FIG. 4, this temperature measuring section 6 is indicated by a chain double-dashed line. In this case, the temperature measurement unit 6 does not need to move together with the plasma source 2 and may be immovably fixed inside the processing unit 130 .

<Kind of temperature measurement part>
Although the temperature measurement unit 6 is an infrared sensor (radiation thermometer) in the above example, it may be a thermo camera, for example. Thermo cameras are also called thermography cameras. A thermo camera has, for example, a plurality of pixels arranged two-dimensionally. Each pixel receives infrared light and detects its intensity. A thermo camera can output an infrared image (so-called thermography).

The imaging range of the thermo camera may be a part of the plasma source 2 or the whole. The control unit 90 can grasp the temperature distribution within the imaging range of the plasma source 2 based on the image captured by the thermo camera. The controller 90 may average a plurality of temperatures of the plasma source 2 corresponding to a plurality of pixels to calculate the measured temperature of the plasma source 2 .

Also, in the above example, the temperature measurement unit 6 measures the intensity of infrared rays that correlate with temperature, but this is not necessarily the case. The temperature measurement unit 6 may measure parameters other than infrared rays that have a positive or negative correlation with temperature. As a specific example, the temperature measurement unit 6 may be a sensor that measures the emission intensity of the plasmas P1 and P2. If the type of gas is constant, the higher the temperature, the higher the luminous intensity of the plasma. The temperature of the plasma source 2 can be calculated based on the relationship measured in advance. The temperature measurement unit 6 may be a camera capable of sensing plasma light (for example, a visible light camera).

<Multiple types of gases>
As described above, in the plasma generator 1, the temperature of the plasma source 2 can be controlled by cooling the plasma source 2 with the cooling gas. Therefore, problems due to temperature rise can be suppressed, and plasma disappearance due to temperature drop can also be suppressed. However, it is difficult to further lower the temperature of the plasma source 2 while maintaining the plasma.

Therefore, here, it is intended to simultaneously reduce the temperature and generate the plasma P1. Specifically, as the cooling gas, a first gas and a second gas, which is more likely to become plasma than the first gas, are employed. The first gas includes at least one of nitrogen gas and air, for example. The second gas is, for example, argon gas.

FIG. 8 is a diagram schematically showing another example of the configuration of the plasma generator 1 and the cooling gas supply section 5. As shown in FIG. In the example of FIG. 8, the air supply pipe 51 of the cooling gas supply unit 5 includes a branch pipe 51a, a branch pipe 51b, and a junction pipe 51c. The downstream end of the confluence pipe 51 c corresponds to the downstream end of the air supply pipe 51 and is connected to the air supply pipe 41 .

The downstream end of the branch pipe 51a is connected to the upstream end of the junction pipe 51c, and the upstream end of the branch pipe 51a is connected to the first gas supply source 54a. The first gas supply source 54a supplies the first gas to the branch pipe 51a. A valve 52a and a flow rate adjusting portion 53a are interposed in the branch pipe 51a. The valve 52a is controlled by the controller 90. FIG. By opening the valve 52 a , the first gas from the first gas supply source 54 a is supplied to the air supply pipe 41 through the branch pipe 51 a and the junction pipe 51 c and flows out from the air supply port 411 . The first gas flowing out from the air supply port 411 flows toward the plasma source 2 . The supply of the first gas is stopped by closing the valve 52a. The flow rate adjusting section 53a is controlled by the control section 90 and adjusts the flow rate of the first gas flowing through the branch pipe 51a. The flow rate adjusting section 53a is, for example, a mass flow controller.

The downstream end of the branch pipe 51b is connected to the upstream end of the junction pipe 51c, and the upstream end of the branch pipe 51b is connected to the second gas supply source 54b. The second gas supply source 54b supplies the second gas to the branch pipe 51b. A valve 52b and a flow control portion 53b are interposed in the branch pipe 51b. The valve 52b is controlled by the controller 90. FIG. By opening the valve 52 b , the second gas from the second gas supply source 54 b is supplied to the air supply pipe 41 through the branch pipe 51 b and the junction pipe 51 c and flows out from the air supply port 411 . The second gas flowing out from the air supply port 411 flows toward the plasma source 2 . The supply of the second gas is stopped by closing the valve 52b. The flow rate adjusting section 53b is controlled by the control section 90 and adjusts the flow rate of the second gas flowing through the branch pipe 51b. The flow rate adjusting section 53b is, for example, a mass flow controller.

According to the cooling gas supply unit 5, the control unit 90 opens the valves 52a and 52b, so that the mixed gas of the first gas and the second gas that is more likely to generate plasma than the first gas is used as the cooling gas. It can be supplied to the plasma source 2 . As will be described later, the first gas is mainly used for cooling the plasma source 2, and the second gas is mainly used for maintaining the plasma P2.

The control unit 90 controls the flow rate of the cooling gas based on the temperature measured by the temperature measurement unit 6 . Specifically, the controller 90 controls the flow rate of the first gas when the measured temperature is the first temperature to be higher than the flow rate of the first gas when the measured temperature is a second temperature lower than the first temperature. Control the flow rate adjusting unit 53a so as to increase. That is, the controller 90 increases the flow rate of the first gas to lower the temperature of the plasma source 2 when the measured temperature is high, and reduces the flow rate of the first gas to lower the temperature of the plasma source 2 when the measured temperature is low. to raise The control unit 90 may continuously increase the flow rate of the first gas as the measured temperature increases, or may increase it stepwise.

As described above, since the flow rate of the first gas is controlled based on the measured temperature, the temperature of the plasma source 2 can be controlled within a predetermined range with high accuracy.

In addition, the plasma source 2 is also supplied with the second gas, which easily becomes plasma. For example, the control unit 90 may control the flow rate adjusting unit 53b so that the flow rate of the second gas becomes a preset constant value. By supplying the second gas, the generation of the plasmas P1 and P2 around the plasma source 2 can be maintained. Specifically, even if the temperature of the plasma source 2 drops, the second gas is turned into plasma on the cooling space side of the partition member 33, so the plasma P2 can be maintained (see also FIG. 6). Moreover, the applicant confirmed that the plasma P1 is maintained also on the processing space side due to the maintenance of the plasma P2 on the cooling space side.

As described above, by adopting the mixed gas of the first gas and the second gas, which is more likely to become plasma than the first gas, as the cooling gas, it is possible to both lower the temperature and maintain the plasmas P1 and P2. be able to. In other words, the temperature range in which the plasmas P1 and P2 can be maintained can be widened.

<Flow Control of Second Gas>
The flow rate of the second gas does not necessarily have to be controlled constant. The control section 90 may also control the flow rate of the second gas based on the measured temperature measured by the temperature measurement section 6 . More specifically, the controller 90 determines that the flow rate of the second gas when the measured temperature is the first temperature is higher than the flow rate of the second gas when the measured temperature is a second temperature lower than the first temperature. You may control the flow volume adjustment part 53b so that it may become small. That is, the controller 90 may decrease the flow rate of the second gas when the measured temperature is high, and increase the flow rate of the second gas when the measured temperature is low.

According to this, the plasmas P1 and P2 can be more reliably maintained by increasing the flow rate of the second gas at low temperatures when the possibility of the plasmas P1 and P2 being extinguished is high. On the other hand, the consumption of the second gas is reduced at high temperatures when the plasmas P1 and P2 are less likely to disappear. According to this, it is possible to reduce the consumption of the second gas while maintaining the plasmas P1 and P2 at high temperatures. The flow rate of the second gas may be zero.

<Air cooling control for each area>
FIG. 9 is a cross-sectional view schematically showing another example of the plasma generator 1 and the cooling gas supply section 5. As shown in FIG. Below, the plasma generator 1 of FIG. 9 is called 1 A of plasma generators. The plasma generator 1A has the same configuration as the plasma generator 1 described above, except for the configuration of the cooling member 4. As shown in FIG.

In plasma generator 1</b>A, cooling member 4 has a plurality of air supply ports 411 . The plurality of air supply ports 411 are provided closer to the cooling space than the partition member 33, and are provided at positions facing the plasma source 2 in the direction D3. Therefore, the plurality of air supply ports 411 face different regions of the plasma source 2 in the direction D3.

In the example of FIG. 9, three air supply ports 411A, 411B1, and 411B2 are shown as the plurality of air supply ports 411. As shown in FIG. The air supply port 411A is formed at a position facing the central region of the plasma source 2 (specifically, the central region of the partition member 33, corresponding to the second central region) in the direction D3. The peripheral region (specifically, the peripheral region of the partition member 33, corresponding to the second peripheral region) is formed at a position facing in the direction D3, and the air supply port 411B2 is opposed to the air supply port 411A. on the opposite side to the peripheral region of the plasma source 2 in the direction D3. In the example of FIG. 9, the cooling member 4 includes three air supply pipes 41A, 41B1, 41B2, and air supply ports 411A, 411B1, 411B2 are formed at the downstream ends of the air supply pipes 41A, 41B1, 41B2, respectively.

The cooling gas supply unit 5 supplies cooling gas to the air supply pipes 41A, 41B1 and 41B2. In the example of FIG. 9, the air supply pipe 41A is connected to the gas supply source 54 via the air supply pipe 51A. A valve 52A and a flow rate adjusting portion 53A are interposed in the air supply pipe 51A. Valve 52A is controlled by controller 90 . By opening the valve 52A, the cooling gas from the gas supply source 54 is supplied to the air supply pipe 41A through the air supply pipe 51A and flows out from the air supply port 411A. The cooling gas flowing out from the air supply port 411A flows toward the central region of the plasma source 2. As shown in FIG. By closing the valve 52A, the supply of the cooling gas from the air supply port 411A is stopped. The flow rate adjusting section 53A is controlled by the control section 90 and adjusts the flow rate of the cooling gas flowing through the air supply pipe 51A. That is, the flow rate adjusting section 53A adjusts the flow rate of the cooling gas directed to the central region of the plasma source 2. FIG. 53 A of flow volume adjustment parts are mass flow controllers, for example.

In the example of FIG. 9, the air supply pipe 41B1 is connected to the gas supply source 54 via the branch pipe 51B1 and the common pipe 51B3, and the air supply pipe 41B2 is connected to the gas supply source 54 via the branch pipe 51B2 and the common pipe 51B3. . A valve 52B and a flow rate adjusting section 53B are interposed in the common pipe 51B3. Valve 52B is controlled by controller 90 . By opening the valve 52B, the cooling gas from the gas supply source 54 is supplied to the air supply pipes 41B1 and 41B2, respectively, and flows out from the air supply ports 411B1 and 411B2. The cooling gas flowing out from the air supply ports 411 B 1 and 411 B 2 flows toward the peripheral region of the plasma source 2 . By closing the valve 52B, the supply of the cooling gas from the air supply ports 411B1 and 411B2 is stopped. The flow rate adjusting section 53B is controlled by the control section 90 to adjust the flow rate of the cooling gas flowing through the common pipe 51B3. In other words, the flow rate adjusting section 53B adjusts the flow rate of the cooling gas directed to the peripheral region of the plasma source 2 . The flow rate adjusting section 53B is, for example, a mass flow controller.

According to the cooling member 4, the flow rate of the cooling gas supplied to the central region of the plasma source 2 and the flow rate of the cooling gas supplied to the peripheral region of the plasma source 2 are controlled by the flow rate adjusting units 53A and 53B. They can be controlled independently of each other.

In the example of FIG. 9, the cooling member 4 further includes a channel partition member 44. As shown in FIG. FIG. 10 is a cross-sectional view schematically showing an example of the configuration of the cooling member 4, showing a cross section perpendicular to the direction D3. The channel partitioning member 44 is a member that partitions the gas space 40 inside the channel forming member 42 into a plurality of gas channels. In the examples of FIGS. 9 and 10 , the channel partitioning member 44 has a cylindrical shape that stands on the lower surface of the cover portion 421 of the channel forming member 42 . According to this, the gas space 40 of the flow path forming member 42 is divided into the central flow path 40A inside the flow path partitioning member 44 and the peripheral flow path 40B between the flow path partitioning member 44 and the side wall 422. can be done.

The central channel 40A faces the central region of the plasma source 2 in the direction D3, and the peripheral channel 40B faces the peripheral region of the plasma source 2 in the direction D3. In the example of FIG. 10, the substrate W is indicated by a chain double-dashed line. This two-dot chain line indicates the substrate W in the state where the plasma generator 1 is positioned at the second processing position in the processing unit 130 . As can be understood from FIG. 10, the central region of the plasma source 2 is located in the direction D3 with the central region (corresponding to the first central region) of the upper surface of the substrate W in the state where the plasma generator 1 is positioned at the second processing position. opposite. The peripheral region of the plasma source 2 faces the peripheral region (corresponding to the first peripheral region) of the upper surface of the substrate W in the direction D3 when the plasma generator 1 is positioned at the second processing position.

The air supply port 411A opens at the central flow path 40A. Therefore, the cooling gas flowing out from the air supply port 411A flows through the central flow path 40A and collides with the central region of the plasma source 2 . In the example of FIG. 9, the flow path partitioning member 44 is not in contact with the plasma source 2, and the cooling gas that has collided with the central region of the plasma source 2 passes between the flow path partitioning member 44 and the plasma source 2. , is exhausted to the outside through an exhaust path 424 .

The air supply ports 411B1 and 411B2 open in the peripheral channel 40B. Therefore, the cooling gas flowing out from the air supply ports 411 B 1 and 411 B 2 flows through the peripheral channel 40 B and collides with the peripheral region of the plasma source 2 . The cooling gas that has collided with the peripheral region of the plasma source 2 is exhausted to the outside through the exhaust path 424 .

In the examples of FIGS. 9 and 10, since the flow path partitioning member 44 is provided, the cooling gas flowing out from the air supply port 411A can be more reliably supplied to the central region of the plasma source 2. The cooling gas flowing out from the ports 411B1 and 411B2 can be supplied to the peripheral region of the plasma source 2 more reliably.

In the example of FIG. 9, a straightening member 43A is provided in the central channel 40A, and a straightening member 43B is provided in the peripheral channel 40B. Like the rectifying member 43, the rectifying members 43A and 43B have a plurality of through holes 43a. The straightening member 43A has a disk shape, and its side surface is fixed to the inner peripheral surface of the flow path partitioning member 44 . The straightening member 43</b>B has a ring-shaped plate shape, the outer peripheral surface thereof is fixed to the inner peripheral surface of the side wall 422 , and the inner peripheral surface thereof is fixed to the outer peripheral surface of the flow path partitioning member 44 .

The cooling gas flowing out from the air supply port 411A is rectified through the rectifying member 43A and supplied to the central region of the plasma source 2. As shown in FIG. The cooling gas flowing out from the air supply ports 411 B 1 and 411 B 2 is rectified through the rectifying member 43 B and supplied to the peripheral region of the plasma source 2 .

In the example of FIG. 9, temperature measurement units 6A and 6B are provided as the temperature measurement unit 6. In FIG. The temperature measuring section 6A measures the temperature of the central region of the plasma source 2, and the temperature measuring section 6B measures the temperature of the peripheral region of the plasma source 2. FIG. That is, the temperature measurement unit 6A measures the temperature of the region to which the cooling gas flowing out from the air supply port 411A is supplied, and the temperature measurement unit 6B measures the temperature of the cooling gas flowing out from the air supply ports 411B1 and 411B2. Measure the temperature of the destination area.

The control unit 90 controls the flow rate adjustment unit 53A based on the measured temperature measured by the temperature measurement unit 6A to control the flow rate of the cooling gas supplied to the central region of the plasma source 2. FIG. The control unit 90 also controls the flow rate adjustment unit 53B based on the measured temperature measured by the temperature measurement unit 6B to control the flow rate of the cooling gas supplied to the peripheral region of the plasma source 2 .

According to this, the temperatures of the central region and the peripheral region of the plasma source 2 can be individually controlled. For example, the controller 90 controls the flow controllers 53A and 53B so that the temperature difference between the central region and the peripheral region of the plasma source 2 is reduced. Specifically, the control unit 90 controls the flow rate adjusting units 53A and 53B so that the temperature difference becomes smaller than a predetermined temperature difference reference value. Thereby, the temperature distribution of the plasma source 2 can be made more uniform.

Incidentally, the liquid film F of the processing liquid formed on the upper surface of the substrate W may swell along the periphery of the substrate W due to various factors such as surface tension. FIG. 11 is a diagram schematically showing an example of the configuration of the substrate W. As shown in FIG. As illustrated in FIG. 11, the thickness of the liquid film F on the peripheral region of the substrate W is greater than the thickness of the liquid film F on the central region of the substrate W. As shown in FIG. When the thickness of the liquid film F is large, it is difficult for active species supplied from the plasma generator 1 to reach the vicinity of the upper surface of the substrate W, so Caro's acid is difficult to reach the upper surface of the substrate W. FIG. Therefore, removal of the resist in the peripheral region of the substrate W may be insufficient. In order to suppress such insufficient processing of the peripheral region of the substrate W, it is desirable to supply more active species to the peripheral region of the substrate W. That is, when the liquid film F rises in the peripheral region of the substrate W, it is desirable to supply more active species to the peripheral region than to the central region of the substrate W. In the example of FIG. 11, the active species supplied to the substrate W are schematically indicated by arrows, and the amount of the active species is indicated by the distance between the arrows.

Therefore, the controller 90 adjusts the flow rate so that the temperature of the peripheral region of the plasma source 2 facing the peripheral region of the substrate W is higher than the temperature of the central region of the plasma source 2 facing the central region of the substrate W. 53A and 53B may be controlled. Since the higher the temperature, the more plasma is generated, more plasma is generated around the peripheral regions of the plasma source 2 than in the central region of the plasma source 2 . Therefore, more active species are generated around the edge region of the plasma source 2 .

According to this, more active species can be supplied to the liquid film F of the processing liquid on the peripheral region of the substrate W than to the liquid film F on the central region of the substrate W. Therefore, a large amount of Caro's acid can be generated in the liquid film F on the peripheral region of the substrate W having a large thickness. can act. Therefore, insufficient processing (insufficient removal of resist) in the peripheral region of the substrate W can be suppressed or avoided.

In the above example, the flow rates of the cooling gas supplied to the central region and the peripheral region of the plasma source 2 are separately controlled. However, the regions defining the plasma source 2 are not necessarily limited to the central region and the peripheral region. For example, in plan view, the plasma source 2 may be bisected along the arrangement direction D2. In short, the cooling member 4 has a plurality of air supply ports 411 that supply cooling gas to a plurality of regions of the plasma source 2, respectively, and the controller 90 individually controls the flow rate of the cooling gas supplied to each region. should be controlled to In other words, the flow rate adjusting section 53 may be provided on a pipe connected to each air supply port 411 and each flow rate adjusting section 53 may be individually controlled by the control section 90 . Thereby, the temperature of each region of the plasma source 2 can be controlled individually. For example, an air supply port 411 is provided corresponding to each region in which the plasma source 2 is two-dimensionally divided into a plurality of areas in plan view, and the flow rate of the cooling gas flowing out from each air supply port 411 is individually controlled. good too.

Further, the control unit 90 may adjust the flow rate of each cooling gas so that the temperature difference between the regions of the plasma source 2 becomes small as described above. Alternatively, the controller 90 may adjust the flow rate of each cooling gas so that the plasma source 2 has a predetermined temperature distribution. For example, the density distribution of impurities (ions) implanted into the resist on the upper surface of the substrate W may vary. Since the resist in the region where the impurity dose is high is more difficult to remove than the region where the impurity density is small, it is difficult to remove the resist in the region where the impurity density is high, and it is easy to remove the resist in the region where the impurity density is low. is. The easy area for easy resist removal and the difficult area for difficult resist removal are predetermined for each substrate W, and the information is controlled by an operator or an upstream device in a series of processing steps of the substrate W. It is input to section 90 . Therefore, the controller 90 controls the temperature of the region of the plasma source 2 facing the difficult region of the substrate W in the direction D3 to be higher than the temperature of the region of the plasma source 2 facing the easy region of the substrate W in the direction D3. Moreover, the flow rate of the cooling gas flowing out from each air supply port 411 may be individually controlled.

Although only one gas supply source 54 is shown in the example of FIG. 9, a mixed gas of the first gas and the second gas may also be used as the cooling gas in the plasma generator 1A. In this case, the flow rate of the first gas flowing out from the air supply port 411A may be controlled independently of the flow rate of the first gas flowing out from the air supply ports 411B1 and 411B2. Also, the flow rate of the second gas flowing out from the air supply port 411A may be controlled independently of the flow rate of the second gas flowing out from the air supply ports 411B1 and 411B2.

According to this, the first gas and the second gas can be supplied to the central region and the peripheral region of the plasma source 2 at flow rates controlled independently of each other.

<Plasma generator 1B>
FIG. 12 is a cross-sectional view schematically showing another example of the plasma generator 1 and the cooling gas supply section 5. As shown in FIG. Below, the plasma generator 1 of FIG. 12 is called the plasma generator 1B. A plasma generator 1B includes a plasma source 2B, a cooling member 4, and a temperature measuring section 6. As shown in FIG. The plasma source 2B generates plasma similarly to the plasma source 2, but differs from the plasma source 2 in its specific configuration.

<Plasma source>
FIG. 13 is a plan view schematically showing an example of the configuration of the plasma source 2B, and FIG. 14 is a cross-sectional view schematically showing an example of the configuration of the plasma source 2B. FIG. 14 shows a CC section of FIG. FIG. 12 corresponds to the DD section of FIG. As shown in FIGS. 12 to 14, the plasma source 2B includes a first electrode portion 21, a second electrode portion 22 and a partition member 35. FIG.

Although the partition member 35 partitions the cooling space and the processing space like the partition member 33 of the plasma source 2, unlike the partition member 33, both the first linear electrodes 211 and the second linear electrodes 221 are separated from each other. covering the In other words, most of the first linear electrodes 211 and the second linear electrodes 221 are arranged inside the partition member 35 .

The partition member 35 is made of dielectric material such as quartz and ceramics. In the illustrated example, the partition member 35 has a plate-like shape and is arranged with its thickness direction along the direction D3. The partition member 35 has a processing surface 35a, a cooling surface 35b and side surfaces 35c. The processing surface 35a and the cooling surface 35b are surfaces facing each other in the direction D3, and are, for example, flat surfaces orthogonal to the direction D3. The side surface 35c is a surface that connects the periphery of the processing surface 35a and the periphery of the cooling surface 35b. In the example of FIG. 13, since the partition member 35 has a disk shape, the processing surface 35a and the cooling surface 35b are circular planes, and the side surface 35c is a cylindrical surface. A processing surface 35a of the partition member 35 is a surface in contact with the processing space, and a cooling surface 35b of the partition member 35 is a surface in contact with the cooling space. The thickness of the partition member 35 is, for example, about 5 mm.

A plurality of first holes 36 and a plurality of second holes 37 are formed in the partition member 35 . Each first hole 36 extends along the longitudinal direction D<b>1 , and one end thereof opens at a side surface 35 c of the partition member 35 . Each first linear electrode 211 is inserted into the first hole 36 along the longitudinal direction D1. Since the partition member 35 covers the first linear electrodes 211 in this way, it is possible to prevent the substrate W from being contaminated due to the plasma sputtering of the first linear electrodes 211 .

Each second hole 37 extends along the longitudinal direction D1, and the end on the other side opens on the side surface 35c of the partition member 35. As shown in FIG. Each second linear electrode 221 is inserted into the second hole 37 along the longitudinal direction D1. Since the partition member 35 covers the second linear electrodes 221 in this way, it is possible to prevent the substrate W from being contaminated due to the plasma sputtering of the second linear electrodes 221 .

In the example of FIG. 12, the plurality of first linear electrodes 211 and the plurality of second linear electrodes 221 are provided on the same plane. Therefore, the plurality of first holes 36 and the plurality of second holes 37 are also formed on the same plane.

In the example of FIG. 12 , the distance between the first linear electrode 211 and the processing surface 35 a of the partition member 35 is narrower than the distance between the first linear electrode 211 and the cooling surface 35 b of the partition member 35 . Similarly, the distance between the second linear electrode 221 and the processing surface 35 a of the partition member 35 is narrower than the distance between the second linear electrode 221 and the cooling surface 35 b of the partition member 35 . In other words, the first linear electrode 211 and the second linear electrode 221 are provided closer to the processing surface 35a than the cooling surface 35b. Therefore, the first hole 36 and the second hole 37 are also formed closer to the processing surface 35a than the cooling surface 35b.

The plasma generator 1B is disposed in such a posture that the processing surface 35a faces the processing target (here, the substrate W). The gas in the vicinity of the processing surface 35a is turned into plasma by the plasma generator 1B as will be described later, and active species generated by the plasma act on the processing object.

In the example of FIG. 13 , the first collective electrode 212 and the second collective electrode 222 are provided outside the partition member 35 . Therefore, the base end of the first linear electrode 211 protrudes outward from the side surface 35c of the partition member 35 and is connected to the first collective electrode 212, and the base end of the second linear electrode 221 protrudes outward from the side surface 35c of the partition member 35. are protruded outward from and connected to the second collective electrode 222 . In other words, in the illustrated example, the partition member 35 covers the portions of the first linear electrodes 211 other than the base ends and the portions of the second linear electrodes 221 other than the base ends.

The first collective electrode 212 and the second collective electrode 222 are connected to a power source 8 for plasma, and the voltage output from this power source 8 causes the gap between the first linear electrode 211 and the second linear electrode 221 for plasma. An electric field of In the above example, since the distance between the first linear electrode 211 and the processing surface 35a and the distance between the second linear electrode 221 and the processing surface 35a are narrow, the electric field tends to act on the gas in the vicinity of the processing surface 35a. Gas can be easily turned into plasma.

On the other hand, in the above example, since the distance between the first linear electrode 211 and the cooling surface 35b and the distance between the second linear electrode 221 and the cooling surface 35b are large, the electric field acts on the gas near the cooling surface 35b. hard to do. Therefore, generation of unnecessary plasma that does not contribute to the processing of the substrate W can also be suppressed. Moreover, since the thickness between the cooling surface 35b and the processing surface 35a of the partition member 35 can be increased, the strength and rigidity of the partition member 35 can be improved.

Also, in the above example, the single partition member 35 covers both the first linear electrodes 211 and the second linear electrodes 221 . Therefore, the structure of plasma source 2B is simpler than plasma source 2 including first dielectric 31 and second dielectric 32 covering first linear electrode 211 and second linear electrode 221, respectively. Especially in the above-described example, the processing surface 35a of the partition member 35 is flat, so the shape is simpler than that of the plasma source 2 in which the second dielectric 32 and the partition member 33 form a stepped shape. . Therefore, even if the processing liquid on the substrate W to be processed volatilizes and adheres to the plasma source 2B (for example, the processing surface 35a), the plasma source 2B can be washed to easily remove the processing liquid.

<Cooling member>
The cooling member 4 of the plasma generator 1B illustrated in FIG. 12 is similar to the cooling member 4 of the plasma generator 1. As shown in FIG. However, in the example of FIG. 12, the flow passage forming member 42 of the cooling member 4 is attached to the peripheral portion of the cooling surface 35b of the partition member 35 and forms the gas space 40 together with the plasma source 2. As shown in FIG. As a more specific example, the side wall 422 of the flow path forming member 42 is attached to the peripheral edge portion of the cooling surface 35b of the partition member 35 by an attachment portion (eg, adhesive or screws) (not shown).

The air supply port 411 of the cooling member 4 is formed at a position facing the cooling surface 35b of the plasma source 2B in the direction D3, similarly to the plasma generator 1, and opens toward the cooling surface 35b. In the example of FIG. 12 , the exhaust path 424 of the cooling member 4 is formed in the side wall 422 of the flow path forming member 42 . For example, a plurality of exhaust passages 424 are arranged at regular intervals along the circumferential direction of the side wall 422 . The cooling gas that has flowed into the gas space 40 from the air supply port 411 flows toward the cooling surface 35b of the plasma source 2B, collides with the cooling surface 35b of the plasma source 2, flows along the cooling surface 35b, and flows through the exhaust path 424. It is discharged outside. Thereby, the plasma source 2B can be air-cooled.

<Temperature measurement unit>
The temperature measurement unit 6 of the plasma generator 1B is also the same as that of the plasma generator 1. FIG. That is, the temperature measurement unit 6 measures the temperature of the plasma source 2B and outputs an electrical signal indicating the measurement result to the control unit 90. FIG.

An operation example of the plasma generator 1</b>B is the same as that of the plasma generator 1 . Therefore, the same effect as the plasma generator 1 can be obtained in the plasma generator 1B. However, the plasma source 2B hardly generates plasma in the cooling space. Even if the plasma source 2B generates plasma in the cooling space, this plasma hardly affects the plasma in the processing space. Therefore, the cooling gas supplied by the cooling gas supply unit 5 is exclusively used for cooling the plasma source 2B.

<Plasma generator 1C>
FIG. 15 is a sectional view schematically showing another example of the plasma generator 1 and the cooling gas supply section 5. As shown in FIG. Below, the plasma generator 1 of FIG. 15 is called the plasma generator 1C. The plasma generator 1C differs from the plasma generator 1B in the presence or absence of the channel partitioning member 44 . The cooling member 4 of the plasma generator 1C further includes a channel partitioning member 44, similarly to the plasma generator 1A.

The channel partitioning member 44 is a member that partitions the gas space 40 into a plurality of gas channels, and is erected on the lower surface of the cover portion 421 of the channel forming member 42, for example. In the example of FIG. 15, the lower end of the channel partitioning member 44 is in contact with the cooling surface 35b of the partitioning member 35 of the plasma source 2B. Here, since the cooling surface 35b is a flat surface, the lower end surface of the flow path partition member 44 is also a flat surface. The channel partition member 44 partitions the gas space 40 into a plurality of gas channels. As a specific example, the channel partitioning member 44 has a cylindrical shape and partitions the gas space 40 into a central channel 40A and a peripheral channel 40B. The lower end surface of the flow path partitioning member 44 is in contact with the cooling surface 35b, for example, along the entire circumference.

In the example of FIG. 15, the flow path forming member 42 is formed with air supply ports 411A, 411B1, and 411B2, an exhaust path 424A for exhausting gas in the central flow path 40A, and a An exhaust path 424B is formed for exhausting the gas of the .

424 A of exhaust paths are provided corresponding to 40 A of central flow paths. In the example of FIG. 15, the exhaust path 424A is formed in the cover portion 421 of the flow path forming member 42 and passes through the cover portion 421 in the thickness direction. An inflow port (that is, an exhaust port) of the exhaust path 424A is formed in a region of the lower surface of the cover portion 421 facing the central flow path 40A. Therefore, the exhaust port of the exhaust path 424A opens toward the cooling surface 35b in the central flow path 40A. More specifically, the opening direction of the exhaust port is the direction along the direction D3. In the example of FIG. 15, a plurality of exhaust passages 424A are provided and, for example, arranged at equal intervals around the air supply port 411A.

The exhaust path 424B is provided corresponding to the peripheral flow path 40B. In the example of FIG. 15, the exhaust path 424B is formed in the side wall 422 of the flow path forming member 42 similarly to the exhaust path 424. As shown in FIG. In the example of FIG. 15, a plurality of exhaust passages 424B are provided and arranged at equal intervals along the circumferential direction, for example.

As described above, the cooling member 4 is formed with the dedicated air supply port 411A and the exhaust port of the exhaust path 424A in the central channel 40A, and the dedicated air supply ports 411B1 and 411B2 and the exhaust port 411B1 and 411B2 in the peripheral channel 40B. An outlet for channel 424B is formed.

According to such a plasma generator 1C, the cooling gas supplied from the air supply port 411A to the central flow path 40A cools the central portion of the plasma source 2B and is discharged to the outside through the exhaust path 424A. In the example described above, the lower end surface of the flow path partitioning member 44 is in contact with the cooling surface 35b of the partitioning member 35, so that the cooling gas that has flowed into the central flow path 40A hardly flows into the peripheral flow path 40B. Also, the cooling gas supplied to the peripheral channel 40B from the air supply ports 411B1 and 411B2 is discharged to the outside through the exhaust channel 424B while cooling the peripheral portion of the plasma source 2B. Similarly, the cooling gas that has flowed into the peripheral channel 40B hardly flows into the central channel 40A.

As described above, the cooling gas hardly moves between the central flow path 40A and the peripheral flow path 40B. It can be adjusted individually and more precisely. As a result, the temperature of the central portion and the peripheral portion of the plasma source 2B can be individually controlled with higher accuracy.

Note that the flow path partitioning member 44 may be slightly separated from the cooling surface 35b of the partitioning member 35 . Also in this structure, since the cooling member 4 is formed with the exhaust path 424A corresponding to the central flow path 40A, the cooling gas in the central flow path 40A can be discharged to the outside through the exhaust path 424A. Therefore, it is possible to suppress the inflow of the cooling gas from the central flow path 40A to the peripheral flow path 40B. Similarly, the exhaust path 424B corresponding to the peripheral channel 40B can suppress the inflow of the cooling gas from the peripheral channel 40B to the central channel 40A. Of course, if the channel partitioning member 44 is in contact with the cooling surface 35b of the partitioning member 35, the movement of the cooling gas between the central channel 40A and the peripheral channel 40B can be further suppressed.

Further, if the cooling surface 35b of the partition member 35 is a flat surface, the shape of the plasma source 2 is simpler than that of the plasma generator 1 in which the first dielectric 31 and the partition member 33 form a step. is. Therefore, the lower end surface of the flow path partitioning member 44 can be easily brought into close contact with the cooling surface 35b, and the gap between the flow path partitioning member 44 and the cooling surface 35b can be easily reduced. Conversely, the lower end surface of the flow path partitioning member 44 does not need to have a complicated shape. Therefore, the manufacturing cost of the plasma generator 1C can be reduced.

<Modification>
Since the plasma emission intensity depends on the temperature of the plasma sources 2 and 2B, the controller 90 may control the plasma emission intensity based on the flow rate of the cooling gas. For example, the control unit 90 may control the flow rate of the cooling gas so that the emission intensity is within a predetermined intensity range based on the plasma emission intensity measured by the emission intensity measurement unit (for example, a camera). good. By individually controlling the flow rate of the cooling gas for a plurality of regions of the plasma sources 2 and 2B, the plasma emission intensity in each region of the plasma sources 2 and 2B can also be individually controlled.

Moreover, in the plasma generators 1 and 1A, the first electrode portion 21 and the second electrode portion 22 may be provided on the same plane. In this case, the partition member 33 may not be provided.

Further, for example, in the plasma generators 1B and 1C, the first electrode portion 21 and the second electrode portion 22 may be provided at different positions in the direction D3. Specifically, the first linear electrode 211 and the second linear electrode 221 may be provided at different positions in the direction D3.

Further, the processing for the substrate W is not necessarily limited to the resist removal processing. As the treatment for the substrate W, any treatment that can improve the processing ability of the treatment liquid by means of active species, such as removal of a metal film, can be adopted. Moreover, it is not always necessary to supply the processing liquid to the substrate W. For example, plasma may be applied directly to the upper surface of the substrate W as the treatment using plasma. As an example of the treatment, surface modification treatment of the substrate W can be given.

As described above, the plasma generation apparatuses 1, 1A to 1C, the plasma generation method, and the processing unit (substrate processing apparatus) 130 have been described in detail. The plasma generators 1, 1A-1C, plasma generation method and processing unit 130 are not limited thereto. It is understood that numerous variations not illustrated can be envisioned without departing from the scope of this disclosure. Each configuration described in each of the above embodiments and modifications can be appropriately combined or omitted as long as they do not contradict each other.

Reference Signs List 1, 1A to 1C plasma generator 11 substrate holder 12 nozzle 2, 2B plasma source 211 first linear electrode 221 second linear electrode 33, 35 partition member 33b, 35b cooling surface 36 first hole 37 second hole 4 Cooling member 40 Gas space 411, 411A, 411B1, 411B2 Air supply port 42 Flow path forming member 422 Side wall 424, 424A, 424B Exhaust path 43 Straightening member 44 Flow path partitioning member 6 Temperature measurement unit 90 Control unit S1, S3, S4 Process (step)

Claims (18)

a plasma source for generating a plasma;
a cooling member having at least one air inlet for supplying a cooling gas to the plasma source;
a temperature measuring unit that measures the temperature of the plasma source;
and a control unit that controls the flow rate of the cooling gas based on the measured temperature measured by the temperature measurement unit. The plasma generator according to claim 1,
The plasma source has a partition member that partitions a processing space on the processing target side and a cooling space on the opposite side of the processing space,
The plasma generator, wherein the at least one air inlet is provided in the cooling space. The plasma generator according to claim 2,
The plasma source includes a first linear electrode and a second linear electrode,
The partition member is
a first hole into which the first linear electrode is inserted;
and a second hole into which the second linear electrode is inserted. The plasma generator according to claim 2,
The plasma source is
a first linear electrode provided on the side opposite to the processing target with respect to the partition member;
a second linear electrode provided closer to the processing target than the partition member and provided at a position not facing the first linear electrode in the thickness direction of the partition member;
The plasma generator, wherein the cooling gas includes a first gas and a second gas that is easier to plasmatize than the first gas. The plasma generator according to claim 4,
The controller controls the flow rate of the first gas when the measured temperature is the first temperature to be higher than the flow rate of the first gas when the measured temperature is a second temperature lower than the first temperature. Plasma generator to make it bigger. The plasma generator according to claim 4 or 5,
The controller controls the flow rate of the second gas when the measured temperature is the first temperature to be higher than the flow rate of the second gas when the measured temperature is a second temperature lower than the first temperature. Plasma generator to make smaller. The plasma generator according to any one of claims 2 to 6,
The at least one air supply port is provided at a position facing the cooling surface of the partition member that is in contact with the cooling space, and the at least one air supply port opens toward the cooling surface of the partition member. Generator. The plasma generator according to claim 7,
The cooling member is
further comprising a channel forming member provided on the side opposite to the processing target with respect to the partition member and connected to the periphery of the plasma source to form a gas space together with the plasma source;
the at least one air inlet opening into the gas space;
The plasma generator, wherein at least one exhaust path for discharging the cooling gas from the gas space is formed in a side wall of the flow path forming member. The plasma generator according to claim 8,
a plurality of exhaust passages are formed on the side wall of the flow passage forming member,
The plasma generating device, wherein the plurality of exhaust paths are formed at different positions in the circumferential direction of the side wall of the flow path forming member. The plasma generator according to any one of claims 1 to 7,
the cooling member includes a plurality of the air supply ports,
The plurality of air supply ports cause the cooling gas to flow out toward a plurality of different regions of the plasma source,
The plasma generator, wherein the controller individually controls the flow rate of the cooling gas supplied to each of the plurality of regions. The plasma generator according to claim 10,
The plasma generating device, wherein the cooling member further includes a flow path partitioning member that partitions a plurality of gas flow paths through which the cooling gas flows toward the plurality of regions. A plasma generator according to claim 11,
The plasma generator, wherein the cooling member further includes a plurality of exhaust passages provided corresponding to the plurality of gas passages, respectively. The plasma generator according to claim 2,
The cooling member is
a plurality of air supply ports for flowing the cooling gas toward a plurality of different regions of the plasma source;
a channel partitioning member that partitions a plurality of gas channels in which the cooling gas flows toward the plurality of regions;
a plurality of exhaust passages respectively provided corresponding to the plurality of gas passages;
including
The control unit individually controls the flow rate of the cooling gas supplied to each of the plurality of regions,
The plasma generator, wherein the flow path partitioning member is in contact with a cooling surface of the partitioning member that is in contact with the cooling space. The plasma generator according to any one of claims 10 to 13,
The plasma generator, wherein the control unit individually controls the flow rate of the cooling gas so as to reduce the temperature difference between the plurality of regions measured by the temperature measurement unit. The plasma generator according to any one of claims 1 to 14,
The plasma generating apparatus, wherein the temperature measuring unit is provided at a position opposite to the processing target with respect to the plasma source. The plasma generator according to any one of claims 1 to 15,
The plasma generator, wherein the cooling member includes a rectifying member that rectifies the cooling gas flowing out from the at least one air supply port, and supplies the cooling gas to the plasma source through the rectifying member. a substrate holder that holds the substrate;
a nozzle for supplying a treatment liquid to the main surface of the substrate held by the substrate holding part;
A plasma generator according to any one of claims 10 to 14,
The plasma source is provided at a position facing the main surface of the substrate held by the substrate holding part,
The plurality of regions of the plasma source include, in plan view, a second central region facing a first central region of the main surface of the substrate and a second peripheral region corresponding to the first peripheral region of the main surface of the substrate. a peripheral region;
The substrate processing apparatus, wherein the controller adjusts the flow rate of the cooling gas so that the temperature of the second peripheral region is higher than the temperature of the second central region. generating a plasma with a plasma source;
measuring the temperature of the plasma source with a temperature measuring unit;
and supplying a cooling gas to the plasma source at a flow rate based on the temperature measured by the temperature measuring unit.

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