JP2021034673A - Substrate treatment method - Google Patents

Abstract

To provide a substrate treatment method that can enhance an effect of ozone on a substrate.SOLUTION: The substrate treatment method includes the steps of holding a substrate WF having a first surface S1 and a second surface S2 opposite to the first surface S1, supplying the second surface S2 of the wafer WF with a treatment solution mixed with bubbles having a particle diameter of 50 nm or less containing ozone gas, and heating the treatment solution at a use point for the treatment of the substrate WF.SELECTED DRAWING: Figure 3

Description

The present invention relates to a substrate processing method, and more particularly to a substrate processing method using ozone gas.

In many cases, the resist film is removed from the substrate after the process using the resist film is performed on the wafer (substrate). In particular, since the resist film used as the implantation mask for the ion implantation process is difficult to remove, a cleaning solution having a strong action is generally used. As a cleaning solution having a strong action, sulfuric acid, hydrogen peroxide solution, and a mixture (SPM) have been widely known. However, since the burden of waste liquid treatment is heavy, a substrate treatment method that does not use SPM has been required in recent years.

Japanese Patent Application Laid-Open No. 2008-15365 discloses a substrate cleaning method for cleaning a substrate using ozone water generated without additives by a gas-liquid mixing method. Here, the particle size R of the ozone bubbles contained in the ozone water is 0 <R ≦ 50 nm. Further, it is disclosed that the generated ozone water is heated before being supplied to the treatment tank. The heating temperature is exemplified in the range of 30 ° C. to 80 ° C. According to the above gazette, the following first and second discussions are asserted.

First, since the buoyancy of ozone bubbles received from ozone water is extremely small because the particle size is suppressed to 50 nm or less, it is difficult for ozone bubbles to rise to the water surface. That is, it stably stays in ozone water. Ozone bubbles that stay stably are rarely degassed by the impact when ozone water collides with a substrate or the like. These realize effective suppression of ozone degassing.

Secondly, by raising the temperature of ozone water to an appropriate temperature for cleaning, cleaning can be performed efficiently. The appropriate temperature may depend on the properties of the object to be cleaned, the difference between local cleaning and overall cleaning, the length of the cleaning time, and other environments, but it is generally preferable that the temperature is high. On the other hand, since ozone is more easily dissolved when the water temperature is lower, it is a fact that heating ozone water makes it easier to degas and thermally decompose. In this respect, since the particle size of ozone bubbles contained in ozone water is 50 nm or less, the buoyancy received is still small even if there is expansion due to heating. Therefore, ozone bubbles still stay in ozone water and are not easily degassed. It is presumed that the ozone water could be raised to around 80 ° C. because the particle size of the ozone bubbles was sufficiently small.

As described above, according to the above publication, it is claimed that a sufficient cleaning effect can be obtained by not easily degassing.

Japanese Unexamined Patent Publication No. 2008-15365

According to the studies by the present inventors, in the technique described in the above publication, when ozone water as a treatment liquid is used without heating, the action on the substrate is often insufficient. Although the action becomes stronger as the ozone concentration is increased, the ozone concentration in ozone water is usually limited to about 80 ppm. Therefore, in order to promote the chemical action of ozone, heating to a certain temperature is desired. In the technique of the above publication, the heating of ozone water as a treatment liquid is performed before the treatment liquid is supplied to the treatment tank. According to the study by the present inventors, in this case, it becomes difficult to maintain the state in which ozone bubbles are dispersed in the treatment liquid at a high concentration until the point of use (POU) of the treatment liquid. As a result, the unique effect obtained by mixing minute ozone bubbles is reduced. Therefore, the treatment effect of ozone is weakened.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a substrate processing method capable of strengthening the action of ozone on a substrate.

The first aspect is a substrate processing method, which comprises a step of holding a substrate having a first surface and a second surface opposite to the first surface, and containing ozone gas in the second surface of the substrate. The process includes a step of supplying a treatment liquid mixed with bubbles having a particle size of 50 nm or less, and a step of heating the treatment liquid at a use point for processing the substrate. In addition to bubbles having a particle size of 50 nm or less, bubbles having a particle size of more than 50 nm may be mixed in the treatment liquid.

The second aspect is the substrate processing method of the first aspect, and the step of holding the substrate is performed so that the second surface of the substrate faces downward.

The third aspect is the substrate processing method of the first or second aspect, and the step of heating the treatment liquid includes a step of heating the substrate from the first surface.

The fourth aspect is the substrate processing method of the first or second aspect, and the step of heating the treatment liquid includes a step of heating the substrate from the second surface.

A fifth aspect is the substrate processing method of the first or second aspect, and the step of heating the treatment liquid includes a step of simultaneously heating the substrate from the first surface and the second surface.

A sixth aspect is the substrate processing method according to any one of the first to fifth aspects, and the step of supplying the processing liquid includes a step of discharging the processing liquid toward the second surface of the substrate.

A seventh aspect is the substrate processing method according to any one of the first to fifth aspects, and in the step of supplying the processing liquid, the second surface of the substrate is put into the processing liquid stored in the processing tank. Includes a step of immersion.

The eighth aspect is the substrate processing method of the seventh aspect, and the step of immersing the second surface of the substrate is such that the first surface of the substrate is located above the liquid surface of the treatment liquid. Will be done.

A ninth aspect is the substrate processing method of the seventh or eighth aspect, and the step of immersing the second surface of the substrate includes a step of sealing the processing tank in which the processing liquid is stored.

A tenth aspect is the substrate processing method according to any one of the first to ninth aspects, wherein the treatment liquid contains water.

The eleventh aspect is the substrate processing method of the tenth aspect, and the treatment liquid contains at least one of ammonia and hydrogen peroxide.

A twelfth aspect is the substrate processing method according to any one of the first to ninth aspects, further comprising a step of producing a processing liquid. The step of producing the treatment liquid includes a step of mixing bubbles having a particle size of 50 nm or less containing ozone gas into an aqueous solution containing ozone water.

A thirteenth aspect is the substrate treatment method of the twelfth aspect, wherein the aqueous solution contains at least one of ammonia and hydrogen peroxide.

According to the first aspect, since the treatment liquid is heated at the use point, the temperature of the treatment liquid can be kept relatively low until immediately before the use point. As a result, it is easy to maintain a state in which ozone bubbles are dispersed in the treatment liquid at a high concentration until the point of use. Therefore, ozone bubbles can be supplied to the second surface of the substrate at a high concentration. Then, when the treatment liquid is heated at the point of use, the bubbles expand. As a result, the surface area of the bubbles is increased, so that the bubbles can easily come into contact with the second surface of the substrate. A thin film of the treatment liquid is formed between the bubbles in contact with the second surface of the substrate and the second surface of the substrate. This thin film of treatment liquid has a high ozone concentration by being adjacent to bubbles. Furthermore, due to the heating described above, the ozone in this thin film has a high temperature. Therefore, since ozone in this thin film of the treatment liquid has both a high concentration and a high temperature, the second surface of the substrate in contact with the thin film is strongly affected by ozone. From the above, the action of ozone on the substrate can be strengthened.

According to the second aspect, the treatment liquid is supplied to the downward facing second surface of the substrate. As a result, the second surface of the substrate is positioned above the supplied processing liquid. Then, when the treatment liquid is heated, the microbubbles expand. The expanded bubbles tend to float in the treatment liquid. In other words, the bubbles are more likely to move toward the second surface of the substrate. This makes it easier for the bubbles to come into contact with the second surface of the substrate. Therefore, the action of ozone on the substrate can be further strengthened.

According to the third aspect, the step of heating the treatment liquid includes a step of heating the substrate from the first surface. This makes it difficult for the adverse effects of heating to reach the second surface.

According to the fourth aspect, the step of heating the treatment liquid includes a step of heating the substrate from the second surface. As a result, the second surface, which is the surface to be processed among the first surface and the second surface, can be preferentially heated.

According to the fifth aspect, the step of heating the treatment liquid includes a step of simultaneously heating the substrate from the first surface and the second surface. This makes it easier for the second surface, which is the surface to be treated, to be sufficiently heated.

According to the sixth aspect, the step of supplying the treatment liquid includes a step of discharging the treatment liquid toward the second surface of the substrate. As a result, the processing liquid can be continuously supplied toward the second surface of the substrate. Therefore, it is possible to prevent the action of ozone from being weakened by deactivation.

According to the seventh aspect, the step of supplying the treatment liquid includes a step of immersing the second surface of the substrate in the treatment liquid stored in the treatment tank. As a result, it is possible to secure a longer time for the bubbles in the treatment liquid to expand and move toward the second surface of the substrate.

According to the eighth aspect, the step of immersing the second surface of the substrate is performed so that the first surface of the substrate is located above the liquid surface of the treatment liquid. As a result, the height of the second surface of the substrate becomes close to the liquid level where the density of bubbles tends to increase. Therefore, the air bubbles are more likely to come into contact with the second surface of the substrate. Therefore, the action of ozone on the substrate can be further strengthened.

According to the ninth aspect, the step of immersing the second surface of the substrate includes a step of sealing the treatment tank in which the treatment liquid is stored. This makes it difficult for ozone to escape from the treatment liquid. Therefore, the action of ozone on the substrate can be further strengthened.

According to the tenth aspect, the treatment liquid contains water. As a result, ozone water can be allowed to act on the substrate.

According to the eleventh aspect, the treatment liquid contains at least one of ammonia and hydrogen peroxide. Thereby, the processing of the substrate can be promoted.

According to the twelfth aspect, the step of producing the treatment liquid includes a step of mixing bubbles having a particle size of 50 nm or less containing ozone gas into an aqueous solution containing ozone water. Thereby, the action of ozone on the substrate can be further strengthened.

According to a thirteenth aspect, the aqueous solution contains at least one of ammonia and hydrogen peroxide. Thereby, the processing of the substrate can be promoted.

It is a block diagram which shows schematic structure of the substrate processing system in Embodiment 1 of this invention. It is a block diagram which shows schematic structure of the control part included in the board processing system of FIG. It is sectional drawing which shows schematic the structure of the substrate processing apparatus in Embodiment 1 of this invention. It is a flow figure which shows typically the substrate processing method in Embodiment 1 of this invention. It is sectional drawing which shows schematic the structure of the substrate processing apparatus in Embodiment 2 of this invention. It is sectional drawing which shows schematic the structure of the substrate processing apparatus in Embodiment 3 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings below, the same or corresponding parts are given the same reference numbers and the explanations are not repeated.

(Embodiment 1)
FIG. 1 is a block diagram schematically showing a configuration of a substrate processing system according to the first embodiment. The board processing system includes an indexer 310, a reversing mechanism 320, a center robot 330 (conveying mechanism), a processing device 101 (board processing device), a processing device 201, and a control unit 90 (controller). ..

The indexer 310 is a mechanism capable of sending and receiving wafers (boards). The reversing mechanism 320 is arranged between the indexer 310 and the center robot 330, and reverses the wafer passing between them. The center robot 330 transfers the wafer between each of the processing device 101 and the processing device 201 and the reversing mechanism 320.

The processing apparatus 101 is a single-wafer type apparatus that can be used for processing for removing organic substances adhering to the wafer. This organic material is typically a used resist film. This resist film is used, for example, as an injection mask for an ion implantation process.

The processing device 201 may be the same as or different from the processing device 101. The number of processing devices in the substrate processing system is arbitrary.

FIG. 2 is a block diagram schematically showing the configuration of the control unit 90 (FIG. 1). The control unit 90 may be configured by a general computer having an electric circuit. Specifically, the control unit 90 includes a CPU (Central Processing Unit) 91, a ROM (Read Only Memory) 92, a RAM (Random Access Memory) 93, a storage device 94, an input unit 96, a display unit 97, and a communication unit 98. , It has a bus line 95 that interconnects them.

The ROM 92 stores the basic program. The RAM 93 is provided as a work area when the CPU 91 performs a predetermined process. The storage device 94 is composed of a non-volatile storage device such as a flash memory or a hard disk device. The input unit 96 is composed of various switches, a touch panel, or the like, and receives an input setting instruction such as a processing recipe from the operator. The display unit 97 is composed of, for example, a liquid crystal display device, a lamp, or the like, and displays various information under the control of the CPU 91. The communication unit 98 has a data communication function via a LAN (Local Area Network) or the like. The storage device 94 is preset with a plurality of modes for controlling each device constituting the substrate processing system (FIG. 1). When the CPU 91 executes the processing program 94P, one of the plurality of modes is selected, and each device is controlled by the mode. Further, the processing program 94P may be stored in the recording medium. By using this recording medium, the processing program 94P can be installed in the control unit 90. Further, a part or all of the functions executed by the control unit 90 do not necessarily have to be realized by software, and may be realized by hardware such as a dedicated logic circuit.

FIG. 3 is a cross-sectional view schematically showing the configuration of the processing device 101. The processing apparatus 101 includes a processing liquid supply unit 121, a heating unit 141, and a holding unit 151. In the figure, in addition to the processing device 101, the wafer WF (board) processed by the processing device 101 is also shown. The wafer WF has a back surface S1 (first surface) and a processed surface S2 (second surface opposite to the first surface).

The treatment liquid supply unit 121 includes a deionized water (DIW: De-Ionized Water) source 21, an ozone gas source 22, a bubble generator 23, and a treatment liquid nozzle 31. The bubble generator 23 mixes ozone gas with deionized water. As a result, bubbles having a particle size of 50 nm or less containing ozone gas are mixed in the deionized water. In the following, bubbles having such a particle size will also be referred to as microbubbles. The particle size distribution of the microbubbles typically includes those having a particle size of 1 nm or more, and particularly includes those having a particle size of, for example, about 10 nm. The deionized water mixed with the fine bubbles containing ozone gas will be used as the treatment liquid in the treatment apparatus 101. In addition to the fine bubbles, bubbles having a particle size of more than 50 nm may be mixed in the treatment liquid. The processing liquid nozzle 31 has an upwardly facing tip, and discharges the processing liquid toward the processing surface S2 of the wafer WF as shown by an arrow D2.

The heating unit 141 has a lamp heater 41. The lamp heater 41 radiates light LT toward the back surface S1 of the wafer WF. The back surface S1 is heated by absorbing the light LT. Therefore, it is preferable that the optical LT includes light having a wavelength that is easily absorbed by the wafer WF. The lamp heater 41 preferably has a light emitting diode (LED: Light Emitting Diode).

Further, the heating unit 141 may have an arm 56 for holding the lamp heater 41, a rotation shaft 57, and a rotation angle adjuster 58. The rotation angle adjuster 58 configured by the actuator adjusts the rotation angle of the rotation shaft 57 as shown by the arrow AG. The arm 56 extends radially from the rotation shaft 57. By operating the rotation angle adjuster 58, the position where the light LT from the lamp heater 41 is strongly received is scanned on the back surface S1. As a result, the back surface S1 can be heated more uniformly.

Further, the heating unit 141 may have a hot water source 51 and a hot water nozzle 52. The hot water nozzle 52 supplies hot water from the hot water source 51 to the back surface S1. The hot water on the back surface S1 alleviates the rapid heating of the back surface S1 by the optical LT. Thereby, the warp of the wafer WF due to non-uniform heating can be suppressed. The hot water nozzle 52 may be attached to the arm 56, whereby the displacement of the lamp heater 41 and the displacement of the hot water nozzle 52 can be easily synchronized. Cold water (unheated water) may be used instead of hot water. Alternatively, the hot water source 51 and the hot water nozzle 52 may be omitted.

The holding portion 151 includes a holding pin 11, a rotating plate 61, and a motor 65. The holding pin 11 supports the wafer WF. The rotating plate 61 supports the holding pin 11. The motor 65 rotates the rotating plate 61 as shown by the arrow RT. With this configuration, the wafer WF can be rotated. Since the wafer WF is rotating, the processing liquid discharged as shown by the arrow D2 spreads over the entire processing surface S2 as shown by the arrow SR due to the centrifugal force.

The operation of each of the above-described units of the processing device 101 may be controlled by the control unit 90 (FIG. 1).

Next, the wafer (board) processing method of the present embodiment will be described below.

With reference to step S10 (FIG. 4), the indexer 310 (FIG. 1) feeds the wafer WF to the reversing mechanism 320. At the time of being sent to the reversing mechanism 320, the processing surface S2 of the wafer WF faces upward. With reference to step S20 (FIG. 4), the inversion mechanism 320 inverts the wafer WF so that the processing surface S2 of the wafer WF faces downward. The inverted wafer WF is sent to the processing device 101 by the center robot 330 (FIG. 1).

With reference to step S30 (FIG. 4), the holding pin 11 (FIG. 3) holds the wafer WF (board). As a result of the inversion, this holding is performed so that the processing surface S2 of the wafer WF faces downward. Next, the wafer WF is rotated by rotating the rotating plate 61 (FIG. 3) (arrow RT).

With reference to step S40 (FIG. 4), the processing liquid nozzle 31 ejects the processing liquid mixed with the fine bubbles containing ozone gas toward the processing surface S2 of the wafer WF (arrow D2). As a result, the processing liquid is supplied to the processing surface S2 of the wafer WF. The supplied treatment liquid spreads over the entire treatment surface S2 by centrifugal force as shown by the arrow SR.

With reference to step S50 (FIG. 4), the wafer WF is heated from the back surface S1 by the heating unit 141. Specifically, the back surface S1 of the wafer WF is heated by absorbing the light LT from the lamp heater 41. The treated surface S2 is heated by heat conduction from the back surface S1. The heat conduction from the heated treatment surface S2 heats the treatment liquid on the treatment surface S2. Preferably, the treatment liquid is heated to a temperature of 40 ° C. or higher and below the boiling point, and more preferably, it is heated to a temperature close to the boiling point within this temperature range. The position on the processing surface S2 (in other words, the position directly below the processing surface S2) is a position where the processing liquid acts on the wafer WF, that is, a use point for processing the wafer WF. Therefore, the treatment liquid is heated at the use point for processing the wafer WF by the above heating. The wafer WF is processed by the heated processing liquid acting on the processing surface S2. Specifically, the wafer WF is washed, for example, resist is removed.

With reference to step S60 (FIG. 4), the wafer WF rinsing step is performed after the cleaning step. The rinsing step may be performed by the processing device 101 (FIG. 3) or may be performed by the processing device 201 (FIG. 1). When the treatment device 101 is used, the bubble generator 23 (FIG. 3) may send the deionized water from the deionized water source 21 to the treatment liquid nozzle 31 as it is without mixing ozone gas. After the rinsing step, the wafer WF is dried, for example, by spin drying. The dried wafer WF is sent to the reversing mechanism 320 by the center robot 330 (FIG. 1).

With reference to step S70 (FIG. 4), the inversion mechanism 320 (FIG. 1) inverts the wafer WF so that the processing surface S2 of the wafer WF faces upward again. With reference to step S80 (FIG. 4), the indexer 310 (FIG. 1) receives the wafer WF from the reversing mechanism 320.

With the above, the processing to the wafer WF is completed.

According to this embodiment, since the treatment liquid is heated at the use point, the temperature of the treatment liquid can be kept relatively low until just before the use point. As a result, it is easy to maintain a state in which fine ozone bubbles are dispersed in the treatment liquid at a high concentration until the point of use. Therefore, fine bubbles of ozone can be supplied to the processing surface S2 of the wafer WF at a high concentration. Then, when the treatment liquid is heated at the point of use, the bubbles expand. As a result, the surface area of the bubbles becomes large, so that the bubbles easily come into contact with the processing surface S2 of the wafer WF. A thin film of the processing liquid is formed between the air bubbles in contact with the processing surface S2 of the wafer WF and the processing surface S2 of the wafer WF. This thin film of treatment liquid has a high ozone concentration by being adjacent to bubbles. Furthermore, due to the heating described above, the ozone in this thin film has a high temperature. Therefore, since ozone in this thin film of the treatment liquid has both a high concentration and a high temperature, the treatment surface S2 of the wafer WF in contact with the thin film is strongly affected by ozone. From the above, the action of ozone on the wafer WF can be strengthened.

The processing liquid is supplied to the downwardly facing processing surface S2 of the wafer WF. As a result, the processing surface S2 of the wafer WF is positioned above the supplied processing liquid. Then, when the treatment liquid is heated, the microbubbles expand. The expanded bubbles tend to float in the treatment liquid. In other words, the air bubbles easily move toward the processing surface S2 of the wafer WF. This makes it easier for the bubbles to come into contact with the processing surface S2 of the wafer WF. Therefore, the action of ozone on the wafer WF can be further strengthened.

The treatment liquid is heated by heating the wafer WF from the back surface S1. As a result, the adverse effect of heating is less likely to reach the treated surface S2. Specifically, the light LT (FIG. 3) from the lamp heater 41 is blocked by the wafer WF so that it does not substantially reach the processing surface S2. This prevents the resist on the treated surface S2 from being cured by the photosensitive action of the optical LT. Therefore, it is prevented that the resist is difficult to be removed due to curing. Therefore, the effect of wafer processing can be enhanced.

The processing liquid is supplied by discharging the processing liquid toward the processing surface S2 of the wafer WF. As a result, the processing liquid can be continuously supplied toward the processing surface S2 of the wafer WF. Therefore, it is possible to prevent the action of ozone from being weakened by deactivation.

The treatment liquid contains water. As a result, ozone water can be allowed to act on the wafer WF.

(Modified Example of Embodiment 1)
The method for heating the wafer WF is not limited to the method described above. The wafer WF (FIG. 3) may be heated from the processing surface S2 instead of the back surface S1. As a result, the processed surface S2, which is the surface to be processed among the back surface S1 and the processed surface S2, can be preferentially heated. Heating from the processing surface S2 can be performed using, for example, a heater 43 (see FIG. 6 described later). Alternatively, the wafer WF may be heated simultaneously from the back surface S1 and the processing surface S2. This makes it easier for the treated surface S2 to be sufficiently heated.

The water in the treatment liquid may contain at least one of ammonia and hydrogen peroxide, and may contain both of them. Thereby, the processing of the wafer WF can be promoted.

The treatment liquid may be generated by mixing fine bubbles containing ozone gas with an aqueous solution containing ozone water in advance. For that purpose, an ozone water source may be used instead of the deionized water source 21. Thereby, the action of ozone on the wafer WF can be further strengthened. Further, the aqueous solution may contain at least one of ammonia and hydrogen peroxide, and may contain both of them. Thereby, the processing of the wafer WF can be promoted.

(Embodiment 2)
FIG. 5 is a cross-sectional view schematically showing the configuration of the processing device 102 (board processing device) according to the second embodiment. The processing device 102 can be used in place of the processing device 101 (FIG. 3: Embodiment 1) in the substrate processing system (FIG. 1). The processing apparatus 102 includes a processing liquid supply unit 122, a heater 42 as a heating unit, and a holding ring 12 as a holding unit for the wafer WF.

The treatment liquid supply unit 122 has a treatment liquid introduction pipe 32 in place of the treatment liquid nozzle 31 (FIG. 3: Embodiment 1), and further has a valve 24 and a treatment tank 62. The valve 24 is arranged between the treatment liquid introduction pipe 32 and the bubble generator 23. When the valve 24 is in the open state, the treatment liquid introduction pipe 32 introduces the treatment liquid into the treatment tank 62 as shown by the arrow IR. When the valve 24 is closed, the introduction of the treatment liquid from the treatment liquid introduction pipe 32 is stopped.

After the treatment liquid is sufficiently introduced, a region filled with the treatment liquid is formed immediately below the treatment surface S2 of the wafer WF so as to be in contact with the treatment surface S2. In the vertical direction, this region is in a state in which the treatment liquid is not leaked by being sandwiched between the members of the treatment device 102 (for example, the treatment tank 62 and the treatment liquid introduction pipe 32) and the wafer WF, in other words, in a liquidtight state. .. In particular, when the valve 24 is closed, this region is in a state where neither the treatment liquid leaks nor is introduced in the vertical direction.

The heater 42 as the heating unit may be, for example, a heat generating heater built in the processing tank 62. The heater 42 faces the processing surface S2 of the wafer WF. Therefore, the wafer WF is heated from the processing surface S2 by the heater 42. The holding ring 12 as a holding portion supports the wafer WF in the processing tank 62.

Next, the wafer (board) processing method of the present embodiment will be described below mainly with respect to the differences from the first embodiment.

With reference to step S30 (FIG. 4), the retaining ring 12 (FIG. 5) holds the wafer WF. This holding is performed so that the processing surface S2 of the wafer WF faces downward. In the present embodiment, unlike the first embodiment, the wafer WF does not need to be rotated.

With reference to step S40 (FIG. 4), the treatment liquid introduction pipe 32 introduces the treatment liquid LP mixed with the fine bubbles containing ozone gas into the treatment tank 62 (arrow IR). As a result, the treatment liquid LP is stored in the treatment tank 62. As the treatment liquid LP is introduced, the liquid level LS rises and eventually reaches the treatment surface S2 of the wafer WF. In other words, the treatment surface S2 is immersed in the treatment liquid LP stored in the treatment tank 62.

With reference to step S50 (FIG. 4), the wafer WF is heated from the processing surface S2 by the heater 42 as a heating unit. Specifically, the heat radiation from the heater 42 heats the processing surface S2 of the wafer WF. Further, the heat radiation from the heater 42 heats the treatment liquid on the treatment surface S2. The position on the processing surface S2 (in other words, the position directly below the processing surface S2) is a position where the processing liquid LP acts on the wafer WF, that is, a use point for processing the wafer WF. Therefore, the above heating heats the processing liquid LP at the point of use for processing the wafer WF. The wafer WF is processed by the heated processing liquid LP acting on the processing surface S2. Specifically, the wafer WF is washed, for example, resist is removed.

The immersion of the processing surface S2 of the wafer WF described above is preferably performed so that the back surface S1 is located above the liquid surface LS of the processing liquid LP. In such a positional relationship, the treatment liquid LP is transferred to the arrow OF at the height between the treatment surface S2 and the back surface S1 while the treatment liquid is continuously introduced into the treatment tank 62 as shown by the arrow IR during immersion. It may be realized by overflowing as shown.

Since the configurations and methods other than the above are almost the same as the configurations of the above-described first embodiment or its modified examples, the same or corresponding elements are designated by the same reference numerals, and the description thereof will not be repeated.

The same effect as that of the first embodiment described above can be obtained by this embodiment as well. Further, in the present embodiment, unlike the first embodiment described above, the processing surface S2 of the wafer WF is immersed in the processing liquid LP stored in the processing tank 62. As a result, the flow of the treatment liquid facing the treatment surface S2 can be slowed down or substantially stopped. Therefore, it is possible to secure a longer time for the expanded bubbles to float due to heating at the point of use. In other words, it is possible to secure a longer time for the bubbles to move toward the processing surface S2 of the wafer WF. This makes it easier for the bubbles to come into contact with the processing surface S2 of the wafer WF. Therefore, the action of ozone on the wafer WF can be further strengthened.

The processing liquid LP is heated by heating the wafer WF from the processing surface S2. As a result, the processed surface S2, which is the surface to be processed among the back surface S1 and the processed surface S2, can be preferentially heated.

When the back surface S1 of the wafer WF is immersed in the processing surface S2 of the wafer WF so that the back surface S1 of the wafer WF is located above the liquid surface of the processing liquid, the height of the processing surface S2 tends to increase the density of bubbles. It will be closer to LS. Therefore, the air bubbles are more likely to come into contact with the processing surface S2 of the wafer WF. Therefore, the action of ozone on the wafer WF can be further strengthened.

(Modified Example of Embodiment 2)
The method for heating the wafer WF is not limited to the method described above. The wafer WF may be heated from the back surface S1 instead of the processing surface S2. Heating from the back surface S1 can be performed using, for example, the heating unit 141 (FIG. 3: Embodiment 1). Alternatively, the wafer WF may be heated simultaneously from the back surface S1 and the processing surface S2. This makes it easier for the treated surface S2 to be sufficiently heated.

When the processing surface S2 of the wafer WF is immersed, the processing tank 62 in which the processing liquid LP is stored may be sealed. This makes it difficult for ozone to escape from the treatment liquid LP. Therefore, the action of ozone on the wafer WF can be further strengthened. The sealing is obtained, for example, by not providing a gap GP between the edge of the processing tank 62 and the holding ring 12. For that purpose, a sealing member such as an O-ring may be provided between the edge of the processing tank 62 and the holding ring 12.

(Embodiment 3)
FIG. 6 is a cross-sectional view schematically showing the configuration of the processing device 103 (board processing device) according to the third embodiment. The processing device 103 can be used in place of the processing device 101 (FIG. 3: Embodiment 1) in the substrate processing system (FIG. 1), in which case the reversing mechanism 320 is unnecessary.

The processing device 103 includes a processing liquid supply unit 123, a heater 43 as a heating unit, and a holding unit 153. The treatment liquid supply unit 123 has a treatment liquid nozzle 33 in place of the treatment liquid nozzle 31 (FIG. 3: Embodiment 1). The processing liquid nozzle 33 has a tip facing downward, and discharges the processing liquid toward the processing surface S2 of the wafer WF as shown by an arrow D2.

The heater 43 as the heating unit dissipates heat toward the back surface S1 of the wafer WF as shown by the arrow RD. As a result, the back surface S1 is heated. By sufficiently increasing the size of the heater 43, the uniformity of heating can be ensured to some extent even without the scanning operation of the heater as described in the first embodiment.

The holding portion 153 has a holding pin 11, a rotating ring 63, and a motor 65. The rotating ring 63 supports the holding pin 11. The motor 65 rotates the rotating ring 63. With this configuration, the wafer WF can be rotated as shown by the arrow RT. Since the wafer WF is rotating, the processing liquid discharged as shown by the arrow D2 spreads over the entire processing surface S2 as shown by the arrow SR due to the centrifugal force.

In the wafer (board) processing method using the processing device 103, the wafer WF is held so that the processing surface S2 faces upward. Further, when the treatment liquid is heated, the wafer WF is heated from the back surface S1.

Since the configurations and methods other than the above are almost the same as the configurations of the above-described first embodiment or its modified examples, the same or corresponding elements are designated by the same reference numerals, and the description thereof will not be repeated.

According to the present embodiment, as in the first embodiment, the treatment liquid is heated at the use point, so that the temperature of the treatment liquid can be kept relatively low until immediately before the use point. As a result, it is easy to maintain a state in which ozone bubbles are dispersed in the treatment liquid at a high concentration until the point of use. Therefore, ozone bubbles can be supplied to the processing surface S2 of the wafer WF at a high concentration. Then, when the treatment liquid is heated at the point of use, the bubbles expand. As a result, the surface area of the bubbles becomes large, so that the bubbles easily come into contact with the processing surface S2 of the wafer WF. A thin film of the processing liquid is formed between the air bubbles in contact with the processing surface S2 of the wafer WF and the processing surface S2 of the wafer WF. This thin film of treatment liquid has a high ozone concentration by being adjacent to bubbles. Furthermore, due to the heating described above, the ozone in this thin film has a high temperature. Therefore, since ozone in this thin film of the treatment liquid has both a high concentration and a high temperature, the treatment surface S2 of the wafer WF in contact with the thin film is strongly affected by ozone. From the above, the action of ozone on the wafer WF can be strengthened.

(Modified Example of Embodiment 3)
The method for heating the wafer WF is not limited to the method described above. The wafer WF may be heated from the processing surface S2 instead of the back surface S1. As a result, the processed surface S2, which is the surface to be processed among the back surface S1 and the processed surface S2, can be preferentially heated. Alternatively, the wafer WF may be heated simultaneously from the back surface S1 and the processing surface S2. This makes it easier for the treated surface S2 to be sufficiently heated.

Although the present invention has been described in detail, the above description is exemplary in all aspects and the invention is not limited thereto. It is understood that innumerable variations not illustrated can be assumed without departing from the scope of the present invention. The configurations described in the above embodiments and the modifications can be appropriately combined or omitted as long as they do not conflict with each other.

11: Holding pin 12: Holding ring 21: Deionized water source 22: Ozone gas source 23: Bubble generator 24: Valve 31, 33: Treatment liquid nozzle 32: Treatment liquid introduction pipe 41: Lamp heater 42, 43: Heater 51: Hot water Source 52: Hot water nozzle 56: Arm 57: Rotating shaft 58: Rotation angle adjuster 61: Rotating plate 62: Processing tank 63: Rotating ring 65: Motor 90: Control unit 101-103: Processing device (board processing device)
121-123: Treatment liquid supply unit 141: Heating unit 151, 153: Holding unit LP: Treatment liquid S1: Back surface (first surface)
S2: Processed surface (second surface)
WF: Wafer (board)

Claims (13)

A step of holding a substrate having a first surface and a second surface opposite to the first surface, and
A step of supplying a treatment liquid containing ozone gas-containing bubbles having a particle size of 50 nm or less to the second surface of the substrate.
The process of heating the treatment liquid at the use point for processing the substrate, and
A substrate processing method. The substrate processing method according to claim 1, wherein the step of holding the substrate is performed so that the second surface of the substrate faces downward. The substrate processing method according to claim 1 or 2, wherein the step of heating the treatment liquid includes a step of heating the substrate from the first surface. The substrate processing method according to claim 1 or 2, wherein the step of heating the treatment liquid includes a step of heating the substrate from the second surface. The substrate processing method according to claim 1 or 2, wherein the step of heating the treatment liquid includes a step of simultaneously heating the substrate from the first surface and the second surface. The substrate processing method according to any one of claims 1 to 5, wherein the step of supplying the treatment liquid includes a step of discharging the treatment liquid toward the second surface of the substrate. The substrate according to any one of claims 1 to 5, wherein the step of supplying the treatment liquid includes a step of immersing the second surface of the substrate in the treatment liquid stored in the treatment tank. Processing method. The substrate processing method according to claim 7, wherein the step of immersing the second surface of the substrate is performed so that the first surface of the substrate is located above the liquid surface of the treatment liquid. The substrate processing method according to claim 7 or 8, wherein the step of immersing the second surface of the substrate includes a step of sealing the processing tank in which the processing liquid is stored. The substrate treatment method according to any one of claims 1 to 9, wherein the treatment liquid contains water. The substrate treatment method according to claim 10, wherein the treatment liquid contains at least one of ammonia and hydrogen peroxide. The step of producing the treatment liquid further comprises a step of mixing bubbles having a particle size of 50 nm or less containing ozone gas into an aqueous solution containing ozone water, according to claims 1 to 9. The substrate processing method according to any one item. The substrate treatment method according to claim 12, wherein the aqueous solution contains at least one of ammonia and hydrogen peroxide.

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