Substrate processing method

Abstract

A substrate processing method includes: 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 having a particle diameter of 50 nm or less containing an ozone gas to the second surface of the substrate; and a step of heating the processing liquid at a use point at which processing of the substrate is performed.

Description

Technical Field

[0001] This invention relates to substrate processing methods, and more particularly to substrate processing methods using ozone gas. Background Technology

[0002] After the step of applying a resist film to the wafer (substrate), in most cases, the resist film is removed from the substrate. In particular, because the resist film used as an implantation mask in the ion implantation step is difficult to remove, a strong cleaning solution is generally used. Strong cleaning solutions, such as sulfuric acid / hydrogen peroxide mixture (SPM), have been widely known in the past. However, due to the heavy burden of waste liquid treatment, there has been a demand in recent years for substrate processing methods that do not use SPM.

[0003] According to Japanese Patent Application Publication No. 2008-153605, a substrate washing method is disclosed that uses ozone water generated without additives through a gas-liquid mixing method to wash a substrate. Here, the particle size R of the ozone bubbles contained in the ozone water is 0 < R ≤ 50 nm. Furthermore, it is disclosed that the generated ozone water is heated before being supplied to the processing tank. An example of the heating temperature is a range of 30°C to 80°C. Based on the above publication, the following first and second issues are claimed.

[0004] First, by suppressing the particle size to below 50nm, the buoyancy received by ozone bubbles from ozonated water is minimal, thus preventing them from rising to the surface. In other words, they remain stably within the ozonated water. Furthermore, the stable ozone bubbles are rarely degassed due to impacts from collisions between the ozonated water and the substrate. These factors effectively suppress ozone degassed.

[0005] Secondly, efficient washing can be achieved by raising the temperature of the ozone water to a suitable level for washing. While the suitable temperature can be affected by factors such as the nature of the object being washed, whether it is a partial or full wash, the washing time, and the environment, a higher temperature is generally preferred. On the other hand, since ozone dissolves easily at low water temperatures, heating the ozone water can easily lead to degassing and thermal decomposition. However, because the ozone bubbles in the ozone water have a particle size of less than 50 nm, even if they expand due to heating, the buoyancy they experience is still very small. Therefore, the ozone bubbles remain trapped in the ozone water and are not easily degassed. It is speculated that the ability to raise the temperature of the ozone water to around 80°C is due to the sufficiently small particle size of the ozone bubbles.

[0006] As stated above, according to the aforementioned press release, it is claimed that sufficient washing effect can be obtained due to the fact that it is not easy to degas.

[0007] Previous technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2008-153605 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] According to the researchers of the present invention, in the technology described in the above-mentioned publication, the effect on the substrate is mostly insufficient when using ozone water as the treatment solution without heating. Although the effect is enhanced by increasing the ozone concentration, the upper limit of the ozone concentration in ozone water is usually around 80 ppm. Therefore, in order to promote ozone-based chemical action, it is desirable to heat to a certain temperature. In the technology of the above-mentioned publication, the heating of the ozone water as the treatment solution is performed before the treatment solution is supplied to the treatment tank. According to the researchers of the present invention, in this case, it is difficult to maintain a high concentration of ozone bubbles dispersed in the treatment solution until the point of use (POU) of the treatment solution. As a result, the unique effect obtained by mixing tiny ozone bubbles is reduced. Therefore, the ozone-based treatment effect is weakened.

[0012] This invention was made to solve the problems mentioned above, and its purpose is to provide a substrate treatment method that can enhance the effect of ozone on the substrate.

[0013] Technical means to solve the problem

[0014] The first method is a substrate processing method comprising: holding a substrate having a first side and a second side opposite to the first side; supplying a processing liquid containing air bubbles with a particle size of 50 nm or less containing ozone gas to the second side of the substrate; and heating the processing liquid at the point of use for processing the substrate. It should be noted that, in addition to air bubbles with a particle size of 50 nm or less, air bubbles with a particle size greater than 50 nm may also be mixed into the processing liquid.

[0015] The second method is the same as the substrate processing method in the first method, but the step of holding the substrate is performed with the second surface of the substrate facing downwards.

[0016] The third method is that in the substrate processing method of the first or second method, the step of heating the processing liquid includes the step of heating the substrate from the first surface.

[0017] The fourth method is that in the substrate processing method of the first or second method, the step of heating the processing liquid includes the step of heating the substrate from the second side.

[0018] The fifth method is a substrate processing method in the first or second method, in which the step of heating the processing liquid includes the step of simultaneously heating the substrate from the first side and the second side.

[0019] The sixth method is a substrate processing method in any of the first to fifth methods, wherein the step of supplying the processing liquid includes the step of discharging the processing liquid toward the second surface of the substrate.

[0020] The seventh method is a substrate processing method in any of the first to fifth methods, wherein the step of supplying the processing liquid includes immersing the second side of the substrate in the processing liquid stored in the processing tank.

[0021] The eighth method is a substrate processing method in the seventh method in which the step of immersing the second side of the substrate is performed such that the first side of the substrate is positioned above the surface of the processing liquid.

[0022] The ninth method is a substrate processing method in the seventh or eighth method, in which the step of immersing the second side of the substrate includes a step of sealing the processing tank containing the processing liquid.

[0023] The 10th method is a substrate processing method in any of the 1st to 9th methods, wherein the processing liquid contains water.

[0024] The 11th method is a substrate processing method of the 10th method, wherein the processing liquid contains at least one of ammonia and hydrogen peroxide.

[0025] The 12th method further includes a step of generating a processing liquid in any of the 1st to 9th methods of substrate processing. The step of generating the processing liquid includes a step of mixing bubbles with a particle size of 50 nm or less containing ozone gas into an aqueous solution containing ozone water.

[0026] The 13th method is a substrate processing method in the 12th method in which the aqueous solution contains at least one of ammonia and hydrogen peroxide.

[0027] The effects of the invention

[0028] According to the first method, since the processing liquid is heated at the point of use, the temperature of the processing liquid can be suppressed to a low level before reaching the point of use. This makes it easy to maintain ozone bubbles in the processing 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. Furthermore, by heating the processing liquid at the point of use, the bubbles expand. As a result, the surface area of ​​the bubbles increases, making it easier for the bubbles to contact the second surface of the substrate. A thin film of the processing liquid is formed between the bubbles that contact the second surface of the substrate and the second surface of the substrate. This thin film of the processing liquid has a high ozone concentration due to its proximity to the bubbles. Furthermore, through the aforementioned heating, the ozone in this thin film has a high temperature. Therefore, because the ozone in this thin film of the processing liquid has both a high concentration and a high temperature, the second surface of the substrate in contact with this thin film is strongly affected by ozone. As described above, the effect of ozone on the substrate can be strengthened.

[0029] According to the second method, the processing liquid is supplied to the downward-facing second surface of the substrate. Thus, the second surface of the substrate is positioned above the supplied processing liquid. Furthermore, by heating the processing liquid, microbubbles expand. The expanded bubbles easily float in the processing liquid. In other words, the bubbles easily move towards the second surface of the substrate. Therefore, the bubbles more easily contact the second surface of the substrate. Thus, the effect of ozone on the substrate can be further enhanced.

[0030] According to the third method, the step of heating the processing liquid includes heating the substrate from the first surface. Therefore, the adverse effects of heating are less likely to spread to the second surface.

[0031] According to the fourth method, the step of heating the processing liquid includes heating the substrate from the second surface. Therefore, the second surface, which is the surface to be processed, can be heated preferentially between the first and second surfaces.

[0032] According to the fifth method, the step of heating the processing liquid includes simultaneously heating the substrate from both the first and second surfaces. This ensures that the second surface, which is the surface to be processed, is sufficiently heated.

[0033] According to the sixth method, the step of supplying the processing liquid includes the step of discharging the processing liquid toward the second surface of the substrate. This allows for a continuous supply of the processing liquid toward the second surface of the substrate. Therefore, it is possible to prevent the effect of ozone from weakening due to deactivation.

[0034] According to the seventh method, the step of supplying the processing liquid includes immersing the second surface of the substrate in the processing liquid stored in the processing tank. This allows for a longer period of time for bubbles in the processing liquid to expand and move toward the second surface of the substrate.

[0035] According to the eighth method, the step of immersing the second side of the substrate is performed with the first side of the substrate positioned above the surface of the processing liquid. As a result, the height of the second side of the substrate is close to the surface of the liquid where the density of bubbles tends to be higher. Therefore, bubbles can more easily contact the second side of the substrate. Thus, the effect of ozone on the substrate can be further enhanced.

[0036] According to the ninth method, the step of immersing the second side of the substrate includes sealing the processing tank containing the processing solution. This prevents ozone from escaping from the processing solution. Therefore, the effect of ozone on the substrate can be further enhanced.

[0037] According to method 10, the treatment solution contains water. This allows the ozone water to act on the substrate.

[0038] According to the 11th method, the processing liquid contains at least one of ammonia and hydrogen peroxide. This facilitates the processing of the substrate.

[0039] According to the 12th method, the step of generating the processing liquid includes mixing bubbles with a particle size of 50 nm or less containing ozone gas into an aqueous solution containing ozone water. This further enhances the effect of ozone on the substrate.

[0040] According to method 13, the aqueous solution contains at least one of ammonia and hydrogen peroxide. This facilitates the processing of the substrate. Attached Figure Description

[0041] Figure 1 This is a block diagram that schematically illustrates the configuration of the substrate processing system in Embodiment 1 of the present invention.

[0042] Figure 2 It is a general representation Figure 1 A block diagram showing the configuration of the control unit included in the substrate processing system.

[0043] Figure 3 This is a cross-sectional view that schematically shows the configuration of the substrate processing apparatus in Embodiment 1 of the present invention.

[0044] Figure 4 This is a flowchart that roughly illustrates the substrate processing method in Embodiment 1 of the present invention.

[0045] Figure 5 This is a cross-sectional view that schematically shows the configuration of the substrate processing apparatus in Embodiment 2 of the present invention.

[0046] Figure 6 This is a cross-sectional view that schematically shows the configuration of the substrate processing apparatus in Embodiment 3 of the present invention. Detailed Implementation

[0047] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that in the following drawings, the same or equivalent parts are labeled with the same reference numerals and their descriptions are not repeated.

[0048] (Implementation Method 1)

[0049] Figure 1 This is a block diagram that schematically illustrates the configuration of the substrate processing system in Embodiment 1. The substrate processing system includes an indexing machine 310, a flipping mechanism 320, a central robot 330 (transport mechanism), a processing device 101 (substrate processing device), a processing device 201, and a control unit 90 (controller).

[0050] The indexing machine 310 is a mechanism for feeding and receiving wafers (substrates). The flipping mechanism 320 is disposed between the indexing machine 310 and the central robot 330, and flips the wafers passing between them. The central robot 330 transports wafers between each processing unit 101 and processing unit 201 and the flipping mechanism 320.

[0051] Processing apparatus 101 is a monolithic device capable of removing organic matter adhering to a wafer. Typically, the organic matter is a used photoresist film. This photoresist film can, for example, be used as an implantation mask for an ion implantation step.

[0052] The processing device 201 may be the same as or different from the processing device 101. It should be noted that the number of processing devices in the substrate processing system is arbitrary.

[0053] Figure 2 This is a rough representation of the control unit 90 ( Figure 1 The control unit 90 is a block diagram of the structure. The control unit 90 can be constructed using a general computer with electrical circuits. 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, a communication unit 98, and a bus 95 that connects them to each other.

[0054] ROM 92 stores the basic program. RAM 93 is used as a working area when the CPU 91 performs predetermined processing. Storage device 94 is composed of non-volatile storage devices such as flash memory or hard disk drives. Input unit 96 is composed of various switches or touch panels, etc., and receives input setting instructions such as processing recipes from the operator. Display unit 97 is composed of, for example, a liquid crystal display device and lights, and displays various information under the control of CPU 91. Communication unit 98 has data communication functions via LAN (Local Area Network), etc. Storage device 94 is pre-set with the components constituting the board processing system ( Figure 1 The control unit 90 has multiple modes related to the control of each device. The CPU 91 executes a processing program 94P to select one of these multiple modes, and controls each device using that mode. Furthermore, the processing program 94P can also be stored on a recording medium. If this recording medium is used, the processing program 94P can be installed on the control unit 90. Moreover, some or all of the functions performed by the control unit 90 do not necessarily have to be implemented in software; they can also be implemented in hardware such as dedicated logic circuits.

[0055] Figure 3 This is a schematic cross-sectional view showing the configuration of the processing apparatus 101. The processing apparatus 101 includes a processing liquid supply unit 121, a heating unit 141, and a holding unit 151. It should be noted that, in addition to the processing apparatus 101, a wafer WF (substrate) being processed by the processing apparatus 101 is also shown in the figure. The wafer WF has a back surface S1 (first surface) and a processing surface S2 (second surface opposite to the first surface).

[0056] The processing liquid supply unit 121 includes a deionized water (DIW) 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 the deionized water. This results in the inclusion of ozone-containing bubbles with a particle size of 50 nm or less in the deionized water. Hereinafter, bubbles with such a particle size will also be referred to as microbubbles. Typically, the particle size distribution of microbubbles includes bubbles with a particle size of 1 nm or more, for example, a particularly large number of bubbles around 10 nm. The deionized water mixed with ozone-containing microbubbles is used as the processing liquid in the processing apparatus 101. It should be noted that, in addition to microbubbles, the processing liquid may also contain bubbles with a particle size greater than 50 nm. The processing liquid nozzle 31 has an upward-facing tip, as shown by arrow D2, and discharges the processing liquid toward the processing surface S2 of the wafer WF.

[0057] The heating section 141 includes 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, the light LT preferably contains light of a wavelength that is easily absorbed by the wafer WF. The lamp heater 41 preferably includes a light-emitting diode (LED).

[0058] Furthermore, the heating unit 141 may also include a robotic arm 56 for holding the lamp heater 41, a rotating shaft 57, and a rotation angle adjuster 58. The rotation angle adjuster 58, which is composed of an actuator, adjusts the rotation angle of the rotating shaft 57 as shown by arrow AG. The robotic arm 56 extends radially from the rotating shaft 57. By actuating the rotation angle adjuster 58, the position of the light LT from the lamp heater 41 is scanned on the back surface S1 more strongly. As a result, the back surface S1 can be heated more uniformly.

[0059] Furthermore, the heating unit 141 may also include 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 moderates the rapid heating of the back surface S1 by the light LT. This helps to suppress wafer warping caused by uneven heating. The warm water nozzle 52 can be mounted on the robotic arm 56, thereby easily synchronizing the displacement of the lamp heater 41 with the displacement of the warm water nozzle 52. It should be noted that cold water (unheated water) can also be used instead of warm water. Alternatively, the warm water source 51 and the warm water nozzle 52 can be omitted.

[0060] The holding section 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 indicated by arrow RT. With this configuration, the wafer WF can be rotated. The processing liquid discharged as indicated by arrow D2 is diffused throughout the processing surface S2 by centrifugal force due to the rotation of the wafer WF, as indicated by arrow SR.

[0061] It should be noted that the operation of each of the aforementioned components in the processing device 101 can be controlled by the control unit 90. Figure 1 To control.

[0062] Next, the wafer (substrate) processing method of this embodiment will be described below.

[0063] Refer to step S10 ( Figure 4 Indexing machine 310 ( Figure 1 The wafer WF is transported to the flipping mechanism 320. At the moment of delivery to the flipping mechanism 320, the processing surface S2 of the wafer WF faces upwards. Refer to step S20 (...). Figure 4The wafer WF is flipped by the flipping mechanism 320, so that the processing surface S2 of the wafer WF faces downward. The flipped wafer WF is then passed through the central robot 330. Figure 1 It is transported to the processing unit 101.

[0064] Refer to step S30 ( Figure 4 ), keep sales 11 ( Figure 3 The wafer WF (substrate) is held in place. As a result of the aforementioned flipping, this holding is performed with the processed surface S2 of the wafer WF facing downwards. Next, the rotating plate 61 ( Figure 3 Rotate (arrow RT) to rotate the wafer WF.

[0065] Refer to step S40 ( Figure 4 The processing fluid nozzle 31 discharges a processing fluid containing tiny bubbles of ozone gas toward the processing surface S2 of the wafer WF (arrow D2). This supplies processing fluid to the processing surface S2 of the wafer WF. The supplied processing fluid is diffused throughout the processing surface S2 by centrifugal force, as indicated by arrow SR.

[0066] Refer to step S50 ( Figure 4 The wafer WF is heated from the back surface S1 by the heating section 141. Specifically, the back surface S1 of the wafer WF is heated by absorbing light LT from the lamp heater 41. 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. Preferably, the processing liquid is heated to a temperature of 40°C or higher but lower than its boiling point; more preferably, the processing liquid is heated to a temperature close to its 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 the position where the processing liquid acts on the wafer WF, i.e., the point of use for processing the wafer WF. Therefore, by the above heating, the processing liquid is heated at the point of use for processing the wafer WF. The wafer WF is processed by the heated processing liquid acting on the processing surface S2. Specifically, the wafer WF is washed, for example, by removing resist.

[0067] Refer to step S60 ( Figure 4 Following the aforementioned washing steps, a wafer rinsing step (WF) is performed. This rinsing step can be achieved through the processing unit 101 (…). Figure 3 It can be performed by processing device 201, or it can be performed by processing device 201. Figure 1 When using the processing device 101, the process can be carried out directly by the bubble generator 23, as long as it is not mixed with ozone gas. Figure 3Deionized water from deionized water source 21 is delivered to processing fluid nozzle 31. After the rinsing step, the wafer WF is dried, for example, by spin drying. The dried wafer WF is then passed through a central robot 330 ( Figure 1 It is transported to the flipping mechanism 320.

[0068] Refer to step S70 ( Figure 4 ), via the flipping mechanism 320 ( Figure 1 Flip the wafer WF so that the processed surface S2 of the wafer WF faces upward again. Refer to step S80 ( Figure 4 Indexing machine 310 ( Figure 1 ) Receive wafer WF from flipping mechanism 320.

[0069] The above describes the completion of the wafer WF processing.

[0070] 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 it reaches the point of use. This allows the microbubbles of ozone to be easily maintained at a high concentration in the processing liquid until the point of use. Therefore, microbubbles of ozone can be supplied to the processing surface S2 of the wafer WF at a high concentration. Furthermore, the bubbles expand due to the heating of the processing liquid at the point of use. As the surface area of ​​the bubbles increases, they easily come into contact with the processing surface S2 of the wafer WF. A thin film of processing liquid is formed between the bubble in contact with the processing surface S2 of the wafer WF and the processing surface S2 of the wafer WF. This thin film of processing liquid has a high ozone concentration due to its proximity to the bubbles. Furthermore, through the aforementioned heating, the ozone in this thin film has a high temperature. Therefore, because the thin film of processing liquid has both a high concentration and a high temperature of ozone, the processing surface S2 of the wafer WF in contact with this film is strongly affected by ozone. As described above, the effect of ozone on the wafer WF can be strengthened.

[0071] The processing solution is supplied to the downward-facing processing surface S2 of the wafer WF. Thus, the processing surface S2 of the wafer WF is positioned above the supplied processing solution. Furthermore, the processing solution is heated, causing microbubbles to expand. These expanded bubbles easily float in the processing solution. In other words, the bubbles easily move towards the processing surface S2 of the wafer WF. Therefore, the bubbles more easily come into contact with the processing surface S2 of the wafer WF. Thus, the effect of ozone on the wafer WF can be further enhanced.

[0072] Heating of the processing solution is achieved by heating the wafer WF from the back side S1. Therefore, adverse effects of heating are less likely to spread to the processing surface S2. Specifically, the light LT (from the lamp heater 41) Figure 3Because it is blocked by the wafer WF, it does not actually reach the processing surface S2. Therefore, it prevents the resist on the processing surface S2 from curing due to the photosensitive effect of the light LT. Thus, it prevents the resist from becoming difficult to remove due to curing. Therefore, it improves the wafer processing effect.

[0073] The processing solution is supplied by discharging it toward the processing surface S2 of the wafer WF. This allows for a continuous supply of processing solution to the processing surface S2 of the wafer WF. Therefore, the weakening of ozone's effect due to deactivation can be avoided.

[0074] The treatment solution contains water. This allows ozone water to act on the wafer WF (Wastewater Processing).

[0075] (A variation of Implementation Method 1)

[0076] The heating method for wafer WF is not limited to the methods described above. Wafer WF ( Figure 3 Alternatively, the back surface S1 can be replaced, and the processing surface S2 can be heated instead. Therefore, the processing surface S2, which is the surface to be processed, can be preferentially heated, between the back surface S1 and the processing surface S2. Heating from the processing surface S2 can be achieved, for example, using a heater 43 (see below). Figure 6 Alternatively, the wafer WF can be heated simultaneously from the back side S1 and the processing surface S2. This allows the processing surface S2 to be heated sufficiently.

[0077] The water in the processing solution may contain at least one of ammonia and hydrogen peroxide, or both. This facilitates the wafer wetted surface treatment (WF).

[0078] The treatment solution can also be generated by pre-mixing microbubbles containing ozone gas into an aqueous solution containing ozone water. Therefore, it is sufficient to use an ozone water source instead of deionized water source 21. This further enhances the effect of ozone on wafer WF. Furthermore, the aforementioned aqueous solution may contain at least one of ammonia and hydrogen peroxide, or both. This facilitates the processing of wafer WF.

[0079] (Implementation Method 2)

[0080] Figure 5 This is a cross-sectional view schematically showing the configuration of the processing apparatus 102 (substrate processing apparatus) in Embodiment 2. The processing apparatus 102 is part of the substrate processing system ( Figure 1 In ), the alternative processing device 101 ( Figure 3 : Embodiment 1) is used. 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.

[0081] The treatment fluid supply unit 122 replaces the treatment fluid nozzle 31. Figure 3Embodiment 1) includes a treatment liquid inlet pipe 32, and further includes a valve 24 and a treatment tank 62. The valve 24 is positioned between the treatment liquid inlet pipe 32 and the bubble generator 23. When the valve 24 is open, the treatment liquid inlet pipe 32 introduces the treatment liquid into the treatment tank 62 as indicated by arrow IR. If the valve 24 is closed, the introduction of treatment liquid from the treatment liquid inlet pipe 32 stops.

[0082] After the processing fluid is fully introduced, a region filled with processing fluid is formed directly below the processing surface S2 of the wafer WF, in contact with the processing surface S2. This region is in a liquid-tight state where it is clamped between the components of the processing apparatus 102 (e.g., the processing tank 62 and the processing fluid inlet pipe 32) and the wafer WF in the vertical direction, preventing leakage of the processing fluid. In particular, if the valve 24 is set to the closed state, this region is in a state where the processing fluid neither leaks nor is introduced in the vertical direction.

[0083] The heater 42, serving as a heating element, can be, for example, a heating heater built into 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, serving as a holding element, supports the wafer WF within the processing tank 62.

[0084] Next, the wafer (substrate) processing method of this embodiment will be described below, mainly focusing on the differences from Embodiment 1.

[0085] Refer to step S30 ( Figure 4 ), keep ring 12 ( Figure 5 The wafer WF is held in such a way that the processing surface S2 of the wafer WF faces downward. This embodiment differs from Embodiment 1 in that the wafer WF is not rotated.

[0086] Refer to step S40 ( Figure 4 The processing solution inlet pipe 32 introduces the processing solution LP, which contains microbubbles of ozone gas, into the processing tank 62 (arrow IR). Thus, the processing solution LP is stored within the processing tank 62. As the processing solution LP is introduced, its liquid level LS rises, eventually reaching the processing surface S2 of the wafer WF. In other words, the processing surface S2 is immersed in the processing solution LP stored within the processing tank 62.

[0087] Refer to step S50 ( Figure 4The wafer WF is heated from the processing surface S2 by heater 42, which serves as the heating unit. Specifically, the processing surface S2 of the wafer WF is heated by heat dissipation from heater 42. Furthermore, the processing liquid on the processing surface S2 is heated by heat dissipation from 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, i.e., the point of use for processing the wafer WF. Therefore, by the above heating, the processing liquid LP is heated 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, by removing resist.

[0088] The immersion of the processing surface S2 of the aforementioned wafer WF is preferably performed with the back surface S1 positioned above the liquid surface LS of the processing liquid LP. This positional relationship can be achieved by continuously introducing the processing liquid into the processing tank 62 as indicated by arrow IR during the immersion process, while allowing the processing liquid LP to overflow at the height between the processing surface S2 and the back surface S1 as indicated by arrow OF.

[0089] It should be noted that, regarding the configurations and methods other than those described above, since they are substantially the same as those in Embodiment 1 or its variations, the same or corresponding elements are assigned the same symbols and their descriptions are not repeated.

[0090] This embodiment achieves roughly the same effects as Embodiment 1 described above. Furthermore, unlike Embodiment 1, in this embodiment, the processing surface S2 of the wafer WF is immersed in the processing liquid LP stored in the processing tank 62. This slows down or essentially stops the flow of the processing liquid towards the processing surface S2. Therefore, the time for bubbles that expand due to heating at the point of use to rise is extended. In other words, the time for bubbles to move towards the processing surface S2 of the wafer WF is extended. Consequently, bubbles more easily contact the processing surface S2 of the wafer WF. Therefore, the effect of ozone on the wafer WF can be further enhanced.

[0091] Heating of the processing solution LP is performed by heating the wafer WF from the processing surface S2. This allows for preferential heating of the back surface S1 and the processing surface S2, which is the surface being processed.

[0092] When the immersion of the processing surface S2 of the wafer WF is performed with the back surface S1 of the wafer WF positioned above the surface of the processing liquid, the height of the processing surface S2 is close to the liquid surface LS where the bubble density tends to be higher. Therefore, bubbles are more likely to contact the processing surface S2 of the wafer WF. This further enhances the effect of ozone on the wafer WF.

[0093] (A variation of Implementation Method 2)

[0094] The heating method for the wafer WF is not limited to the method described above. The wafer WF can also be heated from the back side S1 instead of the processing surface S2. Heating from the back side S1 can, for example, be performed using a heating element 141 (…). Figure 3 : Implementation method 1) is performed. Alternatively, the wafer WF can also be heated simultaneously from the back side S1 and the processing surface S2. As a result, the processing surface S2 can be easily and sufficiently heated.

[0095] When the processing surface S2 of the wafer WF is immersed, the processing tank 62 containing the processing liquid LP can also be sealed. This prevents ozone from escaping from the processing liquid LP. Therefore, the effect of ozone on the wafer WF can be further enhanced. This sealing can be achieved, for example, by not providing 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 can also be provided between the edge of the processing tank 62 and the retaining ring 12.

[0096] (Implementation Method 3)

[0097] Figure 6 This is a cross-sectional view schematically showing the configuration of the processing apparatus 103 (substrate processing apparatus) in Embodiment 3. The processing apparatus 103 is part of the substrate processing system ( Figure 1 In ), the alternative processing device 101 ( Figure 3 : Implementation method 1) is used, in which case the flipping mechanism 320 is not required.

[0098] The processing apparatus 103 includes a processing fluid supply unit 123, a heater 43 serving as a heating unit, and a holding unit 153. The processing fluid supply unit 123 replaces the processing fluid nozzle 31. Figure 3 : Embodiment 1), and has a processing liquid nozzle 33. The processing liquid nozzle 33 has a downward-facing front end, which discharges processing liquid toward the processing surface S2 of the wafer WF as shown by arrow D2.

[0099] The heater 43, serving as the heating element, releases heat toward the back surface S1 of the wafer WF as indicated by arrow RD. As a result, the back surface S1 is heated. By sufficiently increasing the size of the heater 43, a certain degree of heating uniformity can be ensured even without performing the heater scanning operation as described in Embodiment 1.

[0100] The holding part 153 includes 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 indicated by arrow RT. The processing liquid discharged as indicated by arrow D2 is diffused throughout the processing surface S2 by centrifugal force due to the rotation of the wafer WF, as indicated by arrow SR.

[0101] In the wafer (substrate) processing method using processing apparatus 103, the wafer WF is held with the processing surface S2 facing upwards. Furthermore, when the processing liquid is heated, the wafer WF is heated from the back surface S1.

[0102] It should be noted that, regarding the configurations and methods other than those described above, since they are substantially the same as those in Embodiment 1 or its variations, the same or corresponding elements are assigned the same symbols and are not described repeatedly.

[0103] According to this embodiment, similar to Embodiment 1, since the processing liquid is heated at the point of use, the temperature of the processing liquid can be kept low until it reaches the point of use. This makes it easy to maintain ozone bubbles in the processing 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. Furthermore, the bubbles expand due to the heating of the processing liquid at the point of use. As a result, the surface area of ​​the bubbles increases, making it easier for the bubbles to contact the processing surface S2 of the wafer WF. A thin film of 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. This thin film of processing liquid has a high ozone concentration due to its proximity to the bubbles. Furthermore, the ozone in this thin film has a high temperature due to the heating process described above. Therefore, because the ozone in this thin film of processing liquid has both a high concentration and a high temperature, the processing surface S2 of the wafer WF in contact with this film is strongly affected by the ozone. This strengthens the effect of ozone on the wafer WF.

[0104] (A variation of implementation method 3)

[0105] The heating method for the wafer surface (WF) is not limited to the method described above. The wafer WF may also be heated from the processing surface (S2) instead of the back surface (S1). This allows for preferential heating of the processing surface (S2), which is the surface to be processed, between the back surface (S1) and the processing surface (S2). Alternatively, the wafer WF may be heated simultaneously from both the back surface (S1) and the processing surface (S2). This ensures that the processing surface (S2) is easily and sufficiently heated.

[0106] Although the present invention has been described in detail, the above description is merely illustrative in all embodiments and the invention is not limited thereto. Numerous modifications not illustrated are to be understood without departing from the scope of the invention. The configurations described using the above embodiments and modifications can be appropriately combined or omitted, as long as they do not contradict each other.

[0107] Symbol Explanation

[0108] 11: Keep the pins

[0109] 12: Keep the ring

[0110] 21: Deionized water source

[0111] 22: Ozone gas source

[0112] 23: Bubble Generator

[0113] 24: Valve

[0114] 31, 33: Processing fluid nozzles

[0115] 32: Treatment fluid inlet tube

[0116] 41: Lamp heater

[0117] 42, 43: Heater

[0118] 51: Warm water source

[0119] 52: Warm water nozzle

[0120] 56: Robotic Arm

[0121] 57: Rotation axis

[0122] 58: Rotation Angle Adjuster

[0123] 61: Rotating plate

[0124] 62: Processing tank

[0125] 63: Rotating Ring

[0126] 65: Motor

[0127] 90: Control Department

[0128] 101-103: Processing apparatus (substrate processing apparatus)

[0129] 121-123: Processing fluid supply unit

[0130] 141: Heating section

[0131] 151, 153: Maintaining section

[0132] LP: Treatment fluid

[0133] S1: Back side (side 1)

[0134] S2: Processing surface (second surface)

[0135] WF: Wafer (substrate).

Claims

1. A substrate processing method comprising: 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 having a particle size of 50 nm or less containing an ozone gas to the second surface of the substrate; and a step of heating the processing liquid by applying heat to the processing liquid at a use point at which the processing liquid acts on the substrate in order to perform processing of the substrate. The step of holding the substrate is performed with the second surface of the substrate facing downward. The step of heating the processing liquid includes a step of heating the substrate from the first surface. The step of heating the processing liquid includes a step of heating the substrate from the second surface.

2. The substrate processing method of claim 1, wherein, The step of heating the processing liquid includes a step of simultaneously heating the substrate from the first surface and the second surface.

3. The substrate processing method according to 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.

4. The substrate processing method according to 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.

5. The substrate processing method as recited in claim 1 or 2, wherein, The step of immersing the second surface of the substrate is performed with the first surface of the substrate located higher than a liquid surface of the processing liquid.

6. The substrate processing method as recited in claim 1 or 2, wherein The step of immersing the second surface of the substrate includes a step of sealing a processing tank storing the processing liquid.

7. The substrate processing method as recited in claim 1 or 2, wherein, The processing liquid contains water.

8. The substrate processing method of claim 7, wherein, The processing liquid contains at least either one of ammonia and hydrogen peroxide.

9. The substrate processing method of claim 7, wherein, The method further comprises a step of generating the processing liquid, and the step of generating the processing liquid includes a step of mixing bubbles having a particle size of 50 nm or less containing an ozone gas into an aqueous solution containing ozone water.

10. The substrate processing method as recited in claim 1 or 2, wherein, The aqueous solution contains at least either one of ammonia and hydrogen peroxide.

11. The substrate processing method of claim 10, wherein, ​ 12. The substrate processing method as recited in claim 1 or 2, wherein, ​ 13. The substrate processing method of claim 12, wherein, ​

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