TW202112460A - Substrate processing method - Google Patents

Abstract

The subject of the present invention is to provide a substrate processing method that can enhance the effect of ozone on the substrate. The substrate processing method of the present invention includes: a step of holding a substrate (WF) having a first surface (S1) and a second surface (S2) opposite to the first surface (S1); The second surface (S2) is a step of supplying a processing liquid mixed with bubbles containing ozone gas with a particle size of 50 nm or less; and a step of heating the processing liquid at the point of use for processing the substrate (WF).

Description

Substrate processing method

The present invention relates to a substrate processing method, especially to a substrate processing method using ozone gas.

After the step of using the photoresist film on the wafer (substrate), the photoresist film is removed from the substrate in most cases. In particular, since the photoresist film used as the implantation mask for the ion implantation step is not easily removed, a cleaning solution with a strong effect is generally used. As a cleaning solution with a strong effect, for example, sulfuric acid/hydrogen peroxide mixure (SPM) has been widely known from the past. However, due to the large burden of waste liquid treatment, etc., in recent years, a substrate processing method that does not use SPM has been required.

According to Japanese Patent Laid-Open No. 2008-153605, there is disclosed a substrate cleaning method that uses ozone water generated by a gas-liquid mixing method without addition to clean the substrate. Here, the particle size R of the ozone bubbles contained in the ozone water is 0<R≦50nm. In addition, it is disclosed that the generated ozone water is heated before being supplied to the treatment tank. As the heating temperature, a range of 30°C to 80°C is exemplified. According to the above-mentioned communiqué, the following issues 1 and 2 are advocated.

First, since the ozone bubbles have extremely low buoyancy received from the ozone water because the particle size is suppressed to 50 nm or less, the ozone bubbles cannot easily rise to the surface of the water. That is, it will stay in ozone water stably. Ozone bubbles that stay stably will be out of gas due to the impact when ozone water collides with the substrate or the like. These can achieve effective suppression of ozone degassing.

Secondly, the temperature of ozone water is increased to an appropriate temperature for washing, so that washing can be performed efficiently. Although the proper temperature may be affected by the nature of the body to be cleaned, the difference between partial cleansing or overall cleansing, the length of the cleansing time, and other circumstances, the higher one is usually better. On the other hand, ozone is easier to dissolve as the water temperature is lower. Therefore, if the ozone water is heated, degassing or thermal decomposition is likely to occur. In this regard, because the particle size of the ozone bubbles contained in the ozone water is below 50nm, even if they expand due to heating, the buoyancy received will still be small. Therefore, the ozone bubbles will still remain in the ozone water and will not easily degas. It is assumed that the ozone water can be raised to around 80°C because the particle size of the ozone bubbles is small enough.

As described above, according to the above-mentioned publication, it is claimed that a sufficient cleaning effect can be obtained by not easily degassing. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2008-153605

(The problem to be solved by the invention)

According to the review by the inventors of the present application, in the technique described in the above publication, when ozone water as a treatment liquid is used without being heated, the effect on the substrate is often insufficient. Although the effect of increasing the ozone concentration will also enhance the effect, the upper limit of the ozone concentration in ozone water is usually about 80 ppm. Therefore, in order to promote the chemical action using ozone, it is desirable to heat to a certain temperature. In the technique of the above-mentioned publication, the heating of ozone water as the treatment liquid is performed before the treatment liquid is supplied to the treatment tank. According to the review of the inventors of the present case, in this case, it is difficult for ozone bubbles to maintain a state of being dispersed in the treatment liquid at a high concentration before reaching the point of use (POU: Point of Use) of the treatment liquid. As a result, the unique effect that can be obtained by mixing tiny ozone bubbles becomes smaller. Therefore, the treatment effect with ozone will be weakened.

The present invention is accomplished in order to solve the above problems, and its purpose is to provide a substrate processing method that can enhance the effect of ozone on the substrate. (Technical means to solve the problem)

The first aspect is a substrate processing method including: a step of holding a substrate having a first surface and a second surface opposite to the first surface; and supplying the second surface of the substrate with a particle size of 50 nm mixed with ozone gas The following steps are the steps of bubble treatment liquid; and the steps of heating the treatment liquid at the point of use for substrate processing. Furthermore, in addition to bubbles with a particle size of 50 nm or less, bubbles with a particle size of more than 50 nm may be mixed in the treatment liquid.

In the second aspect, in the substrate processing method of the first aspect, the step of holding the substrate is performed with the second surface of the substrate facing downward.

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

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

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

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

The seventh aspect is in the substrate processing method of any one of the first to fifth aspects, and the step of supplying the processing liquid includes immersing the second surface of the substrate in the processing liquid stored in the processing tank step.

The eighth aspect is that in the substrate processing method of the seventh aspect, the step of immersing the second surface of the substrate is performed in such a manner that the first surface of the substrate is located above the liquid level of the processing liquid.

The ninth aspect is the step of immersing the second surface of the substrate in the substrate processing method of the seventh or eighth aspect, and includes the step of sealing the processing tank storing the processing liquid.

The tenth aspect is in the substrate processing method of any one of the first to ninth aspects, and the processing liquid includes water.

The eleventh aspect is that in the substrate processing method of the tenth aspect, the processing liquid includes at least any one of ammonia and hydrogen peroxide.

The twelfth aspect is the substrate processing method of any one of the first to ninth aspects, and further includes a step of generating a processing liquid. The step of generating the treatment liquid includes a step of mixing bubbles containing ozone gas with a particle diameter of 50 nm or less into an aqueous solution containing ozone water.

The 13th aspect is that in the substrate processing method of the 12th aspect, the aqueous solution includes at least any one of ammonia and hydrogen peroxide. (Compared with the effect of previous technology)

According to the first aspect, since the treatment liquid is heated at the point of use, the temperature of the treatment liquid can be suppressed to be low just before the point of use. Thereby, the ozone bubbles can be easily maintained in a state of being dispersed at a high concentration in the treatment liquid before reaching the point of use. Therefore, ozone bubbles can be supplied to the second surface of the substrate at a high concentration. Then, the bubble treatment liquid is heated and expanded at the point of use. Thereby, since the surface area of the air bubbles becomes larger, the air bubbles become easier to contact the second surface of the substrate. A thin film of the processing liquid is formed between the bubbles contacting the second surface of the substrate and the second surface of the substrate. The thin film of the treatment liquid will have a higher ozone concentration by being adjacent to the bubbles. In addition, by the above-mentioned heating, the ozone of the film has a higher temperature. Therefore, since the ozone in the thin film of the treatment liquid has both a higher concentration and a higher temperature, the second surface of the substrate in contact with the thin film is strongly affected by the ozone. Thereby, the effect of ozone on the substrate can be strengthened.

According to the second aspect, the processing liquid is supplied to the downwardly facing second surface of the main substrate. Thereby, the second surface of the substrate is positioned above the supplied processing liquid. Then, as the treatment liquid is heated, the tiny bubbles will expand. The expanded bubbles tend to float in the treatment liquid. In other words, the bubbles easily move toward the second surface of the substrate. Thereby, the bubbles will more easily contact the second surface of the substrate. Therefore, the effect of ozone on the substrate can be further enhanced.

According to the third aspect, the step of heating the processing liquid includes the step of heating the substrate from the first surface. Thereby, the adverse effects of heating will hardly spread to the second surface.

According to the fourth aspect, the step of heating the processing liquid includes a step of heating the substrate from the second surface. Thereby, it is possible to preferentially heat the second surface, which is the surface to be processed, among the first surface and the second surface.

According to the fifth aspect, the step of heating the processing liquid includes the step of simultaneously heating the substrate from the first surface and the second surface. Thereby, the second surface, which is the surface to be processed, can be easily and sufficiently heated.

According to the sixth aspect, the step of supplying the processing liquid includes the step of discharging the processing liquid toward the second surface of the substrate. Thereby, the processing liquid can be continuously supplied to the second surface of the substrate again. Therefore, the effect of ozone can be prevented from being weakened by deactivation.

According to the seventh aspect, the step of supplying the processing liquid includes the step of immersing the second surface of the substrate in the processing liquid stored in the processing tank. This can ensure a longer time for the bubbles in the processing 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 in such a manner that the first surface of the substrate is located above the liquid level of the processing liquid. Thereby, the height of the second surface of the substrate is close to the liquid surface where the density of bubbles tends to increase. Therefore, the bubbles will more easily contact the second surface of the substrate. Therefore, the effect of ozone on the substrate can be further enhanced.

According to the ninth aspect, the step of immersing the second surface of the substrate includes a step of sealing the processing tank storing the processing liquid. Thereby, ozone will not easily escape from the treatment liquid. Therefore, the effect of ozone on the substrate can be further enhanced.

According to the tenth aspect, the treatment liquid contains water. This allows ozone water to act on the substrate.

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

According to the twelfth aspect, the step of generating the treatment liquid includes the step of mixing bubbles containing ozone gas with a particle diameter of 50 nm or less into an aqueous solution containing ozone water. In this way, the effect of ozone on the substrate can be further strengthened.

According to the 13th aspect, the aqueous solution contains at least any one of ammonia and hydrogen peroxide. Thereby, the processing of the substrate can be promoted.

Hereinafter, the embodiments of the present invention will be described based on the drawings. In addition, in the following drawings, the same or equivalent parts are labeled with the same reference numerals and the descriptions are not repeated.

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

The indexing machine 310 is a mechanism capable of sending and receiving wafers (substrates). The turning mechanism 320 is disposed between the indexing machine 310 and the central robot 330, and turns the wafers passing between them. The central robot 330 transports wafers between each of the processing device 101 and the processing device 201 and the turning mechanism 320.

The processing device 101 is a one-piece device that can be used for processing to remove organic matter attached to the wafer. The organic substance is typically a used photoresist film. The photoresist film is used by users as an implantation mask for the ion implantation step, for example.

The processing device 201 may be the same as the processing device 101 or different. Furthermore, the number of processing devices included 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 can be constituted 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, and a storage device 94 , The input unit 96, the display unit 97, the communication unit 98, and the bus line 95 connecting them to each other.

The ROM 92 stores basic programs. The RAM 93 is used as a work area when the CPU 91 performs predetermined processing. The storage device 94 is constituted by a non-volatile storage device such as a flash memory or a hard disk device. The input unit 96 is composed of various switches, touch panels, etc., and receives input setting instructions for processing recipes and the like from the operator. The display unit 97 is composed of, for example, a liquid crystal display device and a lamp, 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 regarding the control of each device constituting the substrate processing system (FIG. 1 ). One of the above-mentioned plural modes is selected by the CPU 91 executing the processing program 94P, so that each device is controlled by this mode. In addition, the processing program 94P can also be stored in a recording medium. If this recording medium is used, the processing program 94P can be installed in the control unit 90. In addition, part or all of the functions executed by the control unit 90 must be realized by software, and may also be realized by hardware such as dedicated logic circuits.

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

The processing liquid supply unit 121 has a deionized water (DIW: De-Ionized Water) source 21, an ozone gas source 22, a bubble generator 23, and a processing liquid nozzle 31. The bubble generator 23 mixes ozone gas with deionized water. Thereby, air bubbles with a particle size of 50 nm or less containing ozone gas are mixed in the deionized water. Hereinafter, bubbles having such a particle size are also referred to as "micro bubbles". The particle size distribution of the microbubbles typically includes those having a particle diameter of 1 nm or more, for example, it particularly includes many particles of about 10 nm. The deionized water mixed with fine bubbles containing ozone gas is used as a treatment liquid in the treatment device 101. Furthermore, in addition to fine bubbles, the processing liquid may also contain bubbles with a particle diameter exceeding 50 nm. The processing liquid nozzle 31 has an upward tip, and faces the processing surface S2 of the wafer WF, and discharges the processing liquid as indicated by the arrow D2.

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

In addition, the heating unit 141 may have a robot arm 56 that holds the lamp heater 41, a rotation shaft 57, and a rotation angle adjuster 58. The rotation angle adjuster 58 constituted by an actuator adjusts the rotation angle of the rotation shaft 57 as indicated by the arrow Ag. The robot arm 56 extends in the radial direction from the rotating shaft 57. When the rotation angle adjuster 58 operates, the position on the back surface S1 that will strongly receive the light LT from the lamp heater 41 will be scanned. Thereby, the heating of the back surface S1 can be performed more uniformly.

In addition, the heating unit 141 may have a warm water source 51 and a warm water nozzle 52. The warm water nozzle 52 supplies warm water from the warm water source 51 to the back surface S1. The warm water on the back surface S1 can alleviate the rapid heating of the back surface S1 by the light LT. Thereby, the warpage of the wafer WF caused by uneven heating can be suppressed. The warm water nozzle 52 can be installed on the robot arm 56 so that the displacement of the lamp heater 41 and the displacement of the warm water nozzle 52 can be easily synchronized. Furthermore, cold water (unheated water) can be used instead of warm water. Alternatively, the warm water source 51 and the warm water nozzle 52 may be omitted.

The holding portion 151 has 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 indicated by the arrow RT. With this configuration, the wafer WF can be rotated. The processing liquid discharged as indicated by the arrow D2 is spread over the entire processing surface S2 as indicated by the arrow SR due to the rotation of the wafer WF due to the centrifugal force.

Furthermore, the operations of the above-mentioned units included in the processing device 101 can be controlled by the control unit 90 (FIG. 1 ).

Next, the wafer (substrate) processing method of this embodiment will be described below.

Referring to step S10 (FIG. 4 ), the indexing machine 310 (FIG. 1) transfers the wafer WF toward the turning mechanism 320. At the time when the wafer WF is sent out toward the reversing mechanism 320, the processing surface S2 of the wafer WF faces upward. Referring to step S20 (FIG. 4), the wafer WF is turned over by the turning mechanism 320, and the processing surface S2 of the wafer WF faces downward. The flipped wafer WF is transported toward the processing device 101 by the central robot 330 (FIG. 1 ).

Referring to step S30 (FIG. 4), the holding pins 11 (FIG. 3) hold the wafer WF (substrate). As a result of the above-mentioned inversion, the holding is performed in such a manner that the processing surface S2 of the wafer WF faces downward. Next, by rotating the rotating plate 61 (FIG. 3) (arrow RT), the wafer WF will be rotated.

Referring to step S40 (FIG. 4 ), the processing liquid nozzle 31 discharges the processing liquid mixed with fine bubbles containing ozone gas toward the processing surface S2 of the wafer WF (arrow D2). Thereby, the processing liquid is supplied toward the processing surface S2 of the wafer WF. The supplied processing liquid spreads over the entire processing surface S2 as shown by the arrow SR due to centrifugal force.

Referring 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 the light LT from the lamp heater 41 being absorbed. The processing surface S2 is heated by heat conduction from the back surface S1. The processing liquid is heated on the processing surface S2 by heat conduction from the heated processing surface S2. It is preferable that the treatment liquid system is heated to a temperature above 40°C and below the boiling point, and it is more preferable to be heated to a temperature close to the boiling point within the temperature range. The position on the processing surface S2 (in other words, the position directly below the processing surface S2) is the position where the processing liquid acts on the wafer WF, that is, the point of use for processing the wafer WF. Therefore, the processing liquid is heated at the point of use of the processing wafer WF by the above-mentioned heating. The processing of the wafer WF is performed by the heated processing liquid acting on the processing surface S2. Specifically, the wafer WF is cleaned, such as photoresist removal.

Referring to step S60 (FIG. 4), after the above-mentioned washing step, a washing step of wafer WF is performed. The rinsing step may be performed by the processing device 101 (FIG. 3), or may also be performed by the processing device 201 (FIG. 1). When the processing device 101 is used, the bubble generator 23 (FIG. 3) only needs to send the deionized water from the deionized water source 21 directly to the processing liquid nozzle 31 without being mixed with ozone gas. After the rinsing step, the wafer WF is dried, for example, by spin drying. The dried wafer WF is transferred to the turning mechanism 320 by the central robot 330 (FIG. 1 ).

Referring to step S70 (FIG. 4 ), the wafer WF is turned over by the turning mechanism 320 (FIG. 1 ), and the processing surface S2 of the wafer WF faces upward again. Referring to step S80 (FIG. 4 ), the indexer 310 (FIG. 1) receives the wafer WF from the turning mechanism 320.

With this, the processing of the wafer WF will be completed.

According to this embodiment, since the processing liquid is heated at the point of use, the temperature of the processing liquid can be kept low until the point of use is about to be reached. Thereby, it is possible to easily maintain the state where the fine bubbles of ozone are dispersed at a high concentration in the treatment liquid until the point of use. Therefore, the fine bubbles of ozone can be supplied to the processing surface S2 of the wafer WF at a high concentration. Then, the bubbles will expand by the treatment liquid being heated at the point of use. Thereby, since the surface area of the bubbles becomes larger, the bubbles can easily contact the processing surface S2 of the wafer WF. A thin film of the processing liquid is formed between the bubbles in contact with the processing surface S2 of the wafer WF and the processing surface S2 of the wafer WF. The thin film of the treatment liquid has a higher ozone concentration by being adjacent to the bubbles. In addition, by the above-mentioned heating, the ozone of the film has a higher temperature. Because the ozone in the thin film of the processing liquid has both a higher concentration and a higher temperature, the processing surface S2 of the wafer WF in contact with the thin film strongly accepts the effect of ozone. In this way, the effect of ozone on the wafer WF can be enhanced.

The processing liquid is supplied to the downward processing surface S2 of the wafer WF. Thereby, the processing surface S2 of the wafer WF is located above the supplied processing liquid. Then, the tiny bubbles will expand due to the heating of the processing liquid. The expanded air bubbles tend to float in the treatment liquid. In other words, the bubbles easily move toward the processing surface S2 of the wafer WF. Thereby, the bubbles will more easily contact the processing surface S2 of the wafer WF. Therefore, the effect of ozone on the wafer WF can be further strengthened.

The heating of the processing liquid is performed by heating the wafer WF from the back surface S1. Thereby, the adverse effects of heating will hardly spread to the processing surface S2. Specifically, the light LT (FIG. 3) from the lamp heater 41 is blocked by the wafer WF and does not substantially reach the processing surface S2. Thereby, the photoresist on the processing surface S2 can be prevented from being hardened due to the photosensitive effect of the light LT. Therefore, it is possible to prevent the photoresist from being difficult to remove due to hardening. Therefore, the effect of wafer processing can be improved.

The supply of the processing liquid is performed by discharging the processing liquid toward the processing surface S2 of the wafer WF. Thereby, the processing liquid can be continuously supplied toward the processing surface S2 of the wafer WF again. Therefore, the situation where the effect of ozone becomes weak due to deactivation can be avoided.

The treatment liquid contains water. This allows ozone water to act on the wafer WF.

(Variations of Embodiment 1) The heating method of the wafer WF is not limited to the above-mentioned method. The wafer WF (Figure 3) can also replace the back surface S1 and be heated from the processing surface S2. Thereby, the processing surface S2 which is the surface to be processed among the back surface S1 and the processing surface S2 can be heated preferentially. The heating from the processing surface S2 can be performed using a heater 43 (refer to FIG. 6 described later), for example. Alternatively, the wafer WF may be heated simultaneously from the back surface S1 and the processing surface S2. Thereby, the processing surface S2 can be easily and sufficiently heated.

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

The treatment liquid can also be produced by mixing fine bubbles containing ozone gas into an aqueous solution containing ozone water in advance. Therefore, as long as the ozone water source can be used instead of the deionized water source 21. In this way, the effect of ozone on the wafer WF can be further strengthened. Moreover, the said aqueous solution may contain at least any 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 structure of the processing apparatus 102 (substrate processing apparatus) in the second embodiment. The processing device 102 can be used as an alternative to the processing device 101 (FIG. 3: Embodiment 1) in the substrate processing system (FIG. 1). The processing apparatus 102 has a processing liquid supply part 122, a heater 42 as a heating part, and a holding ring 12 as a holding part of the wafer WF.

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

After the processing liquid is sufficiently introduced, a region filled with the processing liquid is formed immediately below the processing surface S2 of the wafer WF so as to contact the processing surface S2. With respect to the vertical direction, this area is sandwiched by the components of the processing apparatus 102 (for example, the processing tank 62 and the processing liquid introduction pipe 32) and the wafer WF, and the processing liquid does not leak out, in other words, it is in a liquid-tight state. In particular, if the valve 24 is set to a closed state, the region will be in a state in which the treatment liquid will neither leak nor be 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, by the heater 42, the wafer WF is heated from the processing surface S2. The holding ring 12 as a holding portion supports the wafer WF in the processing tank 62.

Next, the wafer (substrate) processing method of the present embodiment will be described below mainly focusing on the differences of the first embodiment.

Referring to step S30 (FIG. 4), the holding ring 12 (FIG. 5) holds the wafer WF. This holding is performed so that the processing surface S2 of the wafer WF faces downward. This embodiment is different from the first embodiment in that the wafer WF is not rotated.

Referring to step S40 (FIG. 4 ), the processing liquid introduction pipe 32 introduces the processing liquid LP mixed with fine bubbles containing ozone gas into the processing tank 62 (arrow IR). Thereby, the processing liquid LP will be stored in the processing tank 62. As the processing liquid LP is introduced, the liquid level LS will rise and eventually reach the processing surface S2 of the wafer WF. In other words, the processing surface S2 is immersed in the processing liquid LP stored in the processing tank 62.

Referring to step S50 (FIG. 4 ), by the heater 42 as a heating part, the wafer WF is heated from the processing surface S2. Specifically, the processing surface S2 of the wafer WF is heated by the heat radiation from the heater 42. In addition, the processing liquid on the processing surface S2 is heated by the heat released from the heater 42. The position on the processing surface S2 (in other words, the position directly below the processing surface S2) is the position where the processing liquid LP acts on the wafer WF, that is, the point of use for processing the wafer WF. Therefore, by the above-mentioned heating, the processing liquid LP is heated at the point of use for processing the wafer WF. The processing of the wafer WF is performed by the heated processing liquid LP acting on the processing surface S2. Specifically, cleaning of the wafer WF (for example, photoresist removal) is performed.

The above-mentioned immersion of the processing surface S2 of the wafer WF is preferably performed in such a way that the back surface S1 is located above the liquid surface LS of the processing liquid LP. Such a positional relationship can be realized by the following way: While continuously introducing the treatment liquid into the treatment tank 62 as indicated by the arrow IR during immersion, the height of the treatment liquid LP between the treatment surface S2 and the back surface S1 is as indicated by the arrow OF. Like overflow.

In addition, the configurations and methods other than those described above are substantially the same as those of the above-mentioned Embodiment 1 or its modified examples. Therefore, the same reference numerals are assigned to the same or corresponding elements, and repeated descriptions are omitted.

According to this embodiment, it is also possible to obtain substantially the same effects as the above-mentioned first embodiment. In addition, in this embodiment, unlike the aforementioned first embodiment, the processing surface S2 of the wafer WF is immersed in the processing liquid LP stored in the processing tank 62. Thereby, the flow of the processing liquid facing the processing surface S2 can be relaxed, or can be stopped substantially. Therefore, it is possible to ensure a longer time for the bubbles to float due to the heating at the point of use. In other words, it is possible to ensure a longer time for the bubbles to move in the direction of the processing surface S2 of the wafer WF. Thereby, the bubbles can more easily contact the processing surface S2 of the wafer WF. Therefore, the effect of ozone on the wafer WF can be further strengthened.

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

When the immersion of the processing surface S2 of the wafer WF is performed with the back surface S1 of the wafer WF located above the liquid level of the processing liquid, the height of the processing surface S2 will be close to the liquid level LS where the density of bubbles tends to increase. . Therefore, the air bubbles can further easily contact the processing surface S2 of the wafer WF. Therefore, the effect of ozone on the wafer WF can be further strengthened.

(Variations of Embodiment 2) The heating method of the wafer WF is not limited to the above-mentioned method. The wafer WF can replace the processing surface S2 and be heated from the back surface S1. The heating performed from the back surface S1 can be performed, for example, using 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. Thereby, the processing surface S2 can be easily and sufficiently heated.

When the processing surface S2 of the wafer WF is immersed, the processing tank 62 storing the processing liquid LP may also be sealed. Thereby, ozone does not easily escape from the treatment liquid LP. Therefore, the effect of ozone on the wafer WF can be further strengthened. The above-mentioned airtightness can be obtained, for example, by not designing a gap GP between the edge of the processing tank 62 and the retaining ring 12. For this 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 structure of the processing apparatus 103 (substrate processing apparatus) in the third embodiment. The processing device 103 can be used as an alternative to the processing device 101 (FIG. 3: Embodiment 1) in the substrate processing system (FIG. 1). In this case, the turning mechanism 320 is not required.

The processing device 103 has a processing liquid supply unit 123, a heater 43 as a heating unit, and a holding unit 153. The processing liquid supply unit 123 has a processing liquid nozzle 33 instead of the processing liquid nozzle 31 (FIG. 3: Embodiment 1). The processing liquid nozzle 33 has a downwardly facing tip, and faces the processing surface S2 of the wafer WF, and discharges the processing liquid as indicated by the arrow D2.

The heater 43 as a heating part faces the back surface S1 of the wafer WF and radiates heat as indicated by the arrow RD. As a result, the back surface S1 will be heated. By setting the size of the heater 43 to be large enough, even if the scanning operation of the heater as described in the first embodiment is not performed, a certain degree of uniformity of heating can be ensured.

The holding part 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. The processing liquid discharged as shown by the arrow D2 is spread over the entire processing surface S2 as shown by the arrow SR by the centrifugal force due to the rotation of the wafer WF.

In the wafer (substrate) processing method using the processing apparatus 103, the wafer WF is held with the processing surface S2 facing upward. In addition, when the processing liquid is heated, the wafer WF is heated from the back surface S1.

In addition, the configurations and methods other than those described above are substantially the same as those of the above-mentioned Embodiment 1 or its modified examples. Therefore, the same reference numerals are assigned to the same or corresponding elements, and repeated descriptions are omitted.

According to this embodiment, as in the first embodiment, since the treatment liquid is heated at the point of use, the temperature of the treatment liquid can be lowered just before the point of use. Thereby, the state where ozone bubbles are dispersed at a high concentration in the treatment liquid can be easily maintained up to the point of use. Therefore, ozone bubbles can be supplied to the processing surface S2 of the wafer WF at a high concentration. Then, the bubbles will expand by the treatment liquid being heated at the point of use. Thereby, since the surface area of the air bubbles becomes larger, the air bubbles can easily come into contact with the processing surface S2 of the wafer WF. A thin film of the processing liquid is formed between the bubbles in contact with the processing surface S2 of the wafer WF and the processing surface S2 of the wafer WF. The thin film of the treatment liquid has a higher ozone concentration by being adjacent to the bubbles. In addition, by the above-mentioned heating, the ozone of the film has a higher temperature. Therefore, since the ozone in the thin film of the processing liquid has both a higher concentration and a higher temperature, the processing surface S2 of the wafer WF in contact with the thin film will strongly receive the effect of ozone. In this way, the effect of ozone on the wafer WF can be enhanced.

(Variations of Embodiment 3) The heating method of the wafer WF is not limited to the above-mentioned method. The wafer WF may replace the back surface S1 and be heated from the processing surface S2. Thereby, the processing surface S2 which is the surface to be processed among the back surface S1 and the processing surface S2 can be heated preferentially. Alternatively, the wafer WF may be heated simultaneously from the back surface S1 and the processing surface S2. Thereby, the processing surface S2 can be easily and sufficiently heated.

Although the present invention has been described in detail, the above description is only an example in all aspects, and the present invention is not limited to this. Numerous variations that are not illustrated should be understood as those that are conceivable without departing from the scope of the present invention. The configurations described in the above-mentioned embodiments and modifications can be appropriately combined or omitted as long as they are mentioned before they are not inconsistent with each other.

11: Keep pin 12: Retaining 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: warm water source 52: warm water nozzle 56: Robot arm 57: Rotation axis 58: Rotation angle adjuster 61: Rotating plate 62: processing tank 63: Rotating ring 65: Motor 90: Control Department 91: CPU 92: ROM 93: RAM 94: storage device 94P: Processing program 95: bus line 96: Input section 97: Display 98: Ministry of Communications 101~103,201: processing equipment (substrate processing equipment) 121~123: Treatment liquid supply part 141: Heating part 151, 153: Holder 310: Indexing machine 320: Flip mechanism 330: Central Robot GP: Gap LP: Treatment liquid LS: Liquid level LT: light S1: Back (side 1) S2: Treatment surface (Side 2) WF: Wafer (substrate)

Fig. 1 is a block diagram schematically showing the structure of a substrate processing system in Embodiment 1 of the present invention. Fig. 2 is a block diagram schematically showing the configuration of a control unit included in the substrate processing system of Fig. 1. Fig. 3 is a cross-sectional view schematically showing the structure of the substrate processing apparatus in the first embodiment of the present invention. Fig. 4 is a flowchart schematically showing a substrate processing method in Embodiment 1 of the present invention. Fig. 5 is a cross-sectional view schematically showing the structure of a substrate processing apparatus in Embodiment 2 of the present invention. Fig. 6 is a cross-sectional view schematically showing the structure of a substrate processing apparatus in Embodiment 3 of the present invention.

11: Keep pin

21: Deionized water source

22: Ozone gas source

23: bubble generator

31: Treatment liquid nozzle

41: lamp heater

51: warm water source

52: warm water nozzle

56: Robot arm

57: Rotation axis

58: Rotation angle adjuster

61: Rotating plate

65: Motor

121: Treatment liquid supply part

141: Heating part

151: holding part

LT: light

S1: Back (side 1)

S2: Treatment surface (Side 2)

WF: Wafer (substrate)

Claims (13)

A substrate processing method, which has: A step of holding a substrate having a first surface and a second surface opposite to the first surface; A step of supplying a processing liquid mixed with bubbles containing ozone gas with a particle size of 50 nm or less to the second surface of the substrate; and The step of heating the above-mentioned processing liquid at the point of use for processing the above-mentioned substrate. The substrate processing method according to claim 1, wherein the step of holding the substrate is performed with the second surface of the substrate facing downward. The substrate processing method of claim 1 or 2, wherein the step of heating the processing liquid includes a step of heating the substrate from the first surface. The substrate processing method of claim 1 or 2, wherein the step of heating the processing liquid includes a step of heating the substrate from the second surface. The substrate processing method of claim 1 or 2, wherein the step of heating the processing liquid includes a step of simultaneously heating the substrate from the first surface and the second surface. The substrate processing method of claim 1 or 2, wherein the step of supplying the processing liquid includes a step of discharging the processing liquid toward the second surface of the substrate. The substrate processing method of claim 1 or 2, wherein the step of supplying the processing liquid includes a step of immersing the second surface of the substrate in the processing liquid stored in a processing tank. The substrate processing method according to claim 7, wherein the step of immersing the second surface of the substrate is performed in such a manner that the first surface of the substrate is located above the liquid surface of the processing liquid. The substrate processing method of claim 7, wherein the step of immersing the second surface of the substrate includes a step of sealing a processing tank storing the processing liquid. The substrate processing method of claim 1 or 2, wherein the processing liquid contains water. The substrate processing method of claim 10, wherein the processing liquid contains at least any one of ammonia and hydrogen peroxide. The substrate processing method of claim 1 or 2, which further comprises: a step of generating the above-mentioned processing liquid; and the step of generating the above-mentioned processing liquid includes mixing bubbles with ozone gas having a particle diameter of 50 nm or less into the ozone-containing water Steps in aqueous solution. The substrate processing method of claim 12, wherein the aqueous solution contains at least any one of ammonia and hydrogen peroxide.

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