TWI898209B - Substrate processing method and substrate processing device - Google Patents

Abstract

The substrate processing method and the substrate processing apparatus supply a hydrogen peroxide solution to the surface of the substrate W having the resist pattern 100 formed thereon. The substrate processing method and the substrate processing apparatus supply ozone gas to the hydrogen peroxide solution in contact with the substrate W.

Description

Substrate processing method and substrate processing device

The present invention relates to a substrate processing method and substrate processing apparatus for processing substrates. Examples of substrates include semiconductor wafers, liquid crystal display (LCD) devices, organic EL (electroluminescence) display (FPD) substrates, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, photomask substrates, ceramic substrates, and solar cell substrates.

Patent Document 1 discloses a method for removing a hardened resist from a substrate surface by heating the substrate to a temperature above 150°C while supplying ozone gas to the substrate surface. Subsequently, a treatment solution containing sulfuric acid, such as an SPM (sulfuric acid/hydrogen peroxide mixture), is supplied to the substrate surface. [Prior Art Document] [Patent Document]

[Patent Document 1] Japanese Patent Publication No. 2022-41077

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One embodiment of the present invention provides a substrate processing method and substrate processing apparatus capable of more efficiently stripping or removing an etchant from a substrate. [Technical Solution]

One embodiment of the present invention provides a substrate processing method, comprising: a hydrogen peroxide solution supplying step of supplying a hydrogen peroxide solution to a surface of a substrate having an anti-etching pattern formed thereon; and an ozone gas supplying step of supplying ozone gas to the hydrogen peroxide solution in contact with the substrate.

According to this method, a hydrogen peroxide solution is brought into contact with the resist pattern formed on the surface of the substrate. Furthermore, ozone gas is brought into contact with the hydrogen peroxide solution. Hydroxyl radicals are generated by the reaction between the ozone gas and the hydrogen peroxide. The hydroxyl radicals oxidize and decompose the resist pattern. As a result, at least a portion of the resist pattern is stripped or removed. The redox potential of hydroxyl radicals is higher than that of ozone gas, and their oxidizing power is stronger than that of ozone gas. Therefore, the resist pattern can be removed more efficiently than when ozone gas is used to oxidize and decompose the resist pattern. This reduces the amount of resist stripping solution containing sulfuric acid used or eliminates its use, thereby reducing the environmental burden.

If the anti-etching pattern is formed on the surface of a substrate, the substrate may be ion-implanted or non-ion-implanted. Ion implantation involves implanting impurity ions into the portion of the substrate surface exposed by the anti-etching pattern. In the former case, the surface layer of the anti-etching pattern may or may not be hardened by ion implantation.

A hydrogen peroxide solution is an aqueous solution _of hydrogen peroxide. A hydrogen peroxide solution is a liquid primarily composed of hydrogen peroxide ( _H2O2 ) and water ( _H2O ). If hydrogen peroxide and water are the primary components (e.g., the volume percentage concentration of hydrogen peroxide and water is 90% or greater), the hydrogen peroxide solution may contain substances other than hydrogen peroxide and water.

Ozone gas is ozone-containing gas that contains ozone at a higher concentration than that in air. Ozone-containing gas is a gas in which ozone is evenly dispersed. Ozone-containing gas can contain only ozone or other components besides ozone. In the latter case, ozone-containing gas can contain components other than ozone, such as oxygen or carbon dioxide.

In the above embodiment, at least one of the following features may be added to the above substrate processing method.

The substrate processing method further includes a hydrogen peroxide solution heating step, which is to heat the hydrogen peroxide solution at a peeling promotion temperature higher than room temperature before or after the hydrogen peroxide solution is supplied to the substrate.

According to this method, after being supplied to the substrate, the hydrogen peroxide solution is heated indirectly or directly. Alternatively, the heated hydrogen peroxide solution is supplied to the substrate. This allows the ozone gas to come into contact with the hydrogen peroxide solution at a temperature above room temperature, which is a temperature that promotes the stripping process. This promotes the generation of hydroxyl radicals. As a result, the number of hydroxyl radicals that react with the resist pattern increases, enabling more efficient removal of the resist pattern.

The hydrogen peroxide solution heating step may be any of an indirect heating step, a direct heating step, and a preheating step, or may include two or more of these. The indirect heating step is a step in which the hydrogen peroxide solution in contact with the substrate is brought into contact with at least one of the heated substrate and the heated gas, thereby heating the hydrogen peroxide solution to the peeling-promoting temperature. The direct heating step is a step in which the hydrogen peroxide solution in contact with the substrate is irradiated with electromagnetic waves emitted from a heat source such as a lamp, thereby heating the hydrogen peroxide solution to the peeling-promoting temperature. The preheating step is a step of heating the hydrogen peroxide solution supplied to the substrate at the peeling promoting temperature before the hydrogen peroxide solution is supplied to the substrate.

The above-mentioned peeling promotion temperature does not reach the boiling point of the above-mentioned hydrogen peroxide solution.

According to this method, the hydrogen peroxide solution is heated to a temperature below its boiling point. This reduces the rate of evaporation from the substrate and maintains the hydrogen peroxide solution on the substrate. If a large amount of hydrogen peroxide solution is retained on the substrate, even if it is heated above its boiling point, the hydrogen peroxide solution can be maintained on the substrate for a relatively long time. However, in this case, the thickness of the hydrogen peroxide solution droplet or film on the substrate increases, reducing the number of hydroxyl radicals reaching the surface of the anti-etching pattern. By heating the hydrogen peroxide solution at a temperature lower than the boiling point of the hydrogen peroxide solution, the hydrogen peroxide solution can be maintained on the substrate even if thick droplets or a liquid film of the hydrogen peroxide solution is not formed on the substrate.

The above-mentioned peeling promotion temperature does not reach the boiling point of water.

According to this method, the hydrogen peroxide solution is heated to a temperature below the boiling point of water, that is, below 100°C. This reduces the rate of water evaporation from the hydrogen peroxide solution on the substrate, maintaining the water level on the substrate without forming thick hydrogen peroxide droplets or films on the substrate. Hydroxyl radicals are generated not only by the reaction of ozone gas with hydrogen peroxide, but also by the reaction of ozone gas with water. This increases the number of hydroxyl radicals available for reaction with the resist pattern.

When the resist pattern is heated, the solvent contained in it vaporizes. If a hardened layer forms on the surface of the resist pattern, the vaporized solvent is difficult to expel, causing the internal pressure of the resist pattern to increase. The series of steps from resist application to resist stripping includes pre-baking and post-baking, which involve heating the substrate. The maximum substrate temperature during this series of steps is defined as the maximum temperature. If a hardened layer forms on the surface of the resist pattern, the internal pressure of the resist pattern tends to increase when the temperature of the heated resist pattern is significantly higher than the maximum temperature.

When heating the hydrogen peroxide solution at a peeling-promoting temperature higher than room temperature, setting the peeling-promoting temperature to a temperature lower than the boiling point of the hydrogen peroxide solution or lower than the boiling point of water allows the temperature of the heated resist pattern to approach the maximum temperature of the substrate during the aforementioned series of steps, i.e., the highest temperature. Alternatively, the temperature of the heated resist pattern can be set below the highest temperature. This prevents the internal pressure of the resist pattern from increasing, even when a hardened layer is formed on the surface of the resist pattern.

The hydrogen peroxide solution supplying step includes: an initial supplying step of supplying the hydrogen peroxide solution to the surface of the substrate; and a resupplying step of supplying the hydrogen peroxide solution to the surface of the substrate after terminating the supply of the hydrogen peroxide solution to the surface of the substrate. In other words, the hydrogen peroxide solution supplying step includes interrupting the supply of the hydrogen peroxide solution at least once.

According to this method, a hydrogen peroxide solution is heated to a peeling-promoting temperature above room temperature and intermittently supplied to the substrate surface. Specifically, the hydrogen peroxide solution is supplied to the substrate surface and maintained there. During the period when the hydrogen peroxide supply is stopped (the period when the addition of hydrogen peroxide is stopped), the amount of hydrogen peroxide on the substrate decreases due to evaporation and reaction with ozone gas. The supply of hydrogen peroxide to the substrate surface is then resumed, and the hydrogen peroxide solution is added to the substrate surface. This reduces the consumption of hydrogen peroxide solution compared to a continuous supply of hydrogen peroxide solution, while maintaining the hydrogen peroxide solution on the substrate. In addition, compared to the case of continuously supplying the hydrogen peroxide solution, the droplets or liquid film of the hydrogen peroxide solution on the substrate can be made thinner.

The ozone gas supplying step includes supplying the ozone gas to the hydrogen peroxide solution in contact with the substrate while a plurality of hydrogen peroxide solution droplets are dispersed over the entire surface of the substrate. The shape of the hydrogen peroxide solution droplets when viewed perpendicular to the substrate surface may be any of a circle, an ellipse, and a line, or may be other shapes.

According to this method, ozone gas is brought into contact with the hydrogen peroxide solution in contact with the substrate, rather than with the entire substrate surface being covered by a film of hydrogen peroxide solution. This method allows for more efficient removal of the resist pattern than when the entire substrate surface is covered by a film of hydrogen peroxide solution. The reasons are as follows.

The number of hydroxyl radicals (OH) supplied to the interface between the resist pattern and the hydrogen peroxide solution, known as the solid-liquid interface (see Figure 4), increases as the distance from the ozone gas, hydrogen peroxide solution, and resist pattern, known as the three-state boundary (see Figure 4), increases. This is because hydroxyl radicals quickly transform back into hydrogen peroxide. Therefore, if the shortest distance from the surface of the hydrogen peroxide solution droplet or film to the solid-liquid interface is long, the hydroxyl radicals will disappear before reaching the solid-liquid interface. Therefore, resist patterns in contact with the hydrogen peroxide solution are more effectively removed near the three-state boundary than at locations farther from it.

The total length (aggregate length) of the three-state boundary when multiple hydrogen peroxide droplets are dispersed over the entire surface of the substrate is greater than the total length of the three-state boundary when the entire substrate surface is covered by a liquid film of hydrogen peroxide. As described above, the resist pattern in contact with the hydrogen peroxide solution can be removed more efficiently near the three-state boundary than at locations farther from the three-state boundary. For these reasons, the resist pattern can be removed more efficiently than when the entire substrate surface is covered by a liquid film of hydrogen peroxide solution.

The hydrogen peroxide solution supplying step includes a mist supplying step of supplying a mist of the hydrogen peroxide solution to the surface of the substrate.

According to this method, a hydrogen peroxide solution mist is applied to the surface of the substrate. The hydrogen peroxide solution mist is composed of multiple hydrogen peroxide solution particles. The hydrogen peroxide solution particles on the substrate combine with other hydrogen peroxide solution particles, forming hydrogen peroxide solution droplets (aggregates of hydrogen peroxide solution with a diameter larger than the hydrogen peroxide solution particles) on the substrate surface. If the surface of the anti-etching pattern is hydrophobic, multiple hydrogen peroxide solution droplets are formed and dispersed over the entire surface of the substrate. If the surface of the anti-etching pattern is hydrophilic, a hydrogen peroxide solution film is formed that covers the entire surface of the substrate. Thus, thinner droplets or liquid films of hydrogen peroxide solution can be formed compared to the case where a continuous liquid column of hydrogen peroxide solution is formed from the liquid column nozzle to the surface of the substrate.

The hydrogen peroxide solution supplying step includes a liquid column supplying step of supplying the hydrogen peroxide solution to the surface of the substrate by forming a liquid column of the hydrogen peroxide solution continuously from a liquid column nozzle to the surface of the substrate.

According to this method, a hydrogen peroxide solution is continuously sprayed from a liquid column nozzle toward the surface of a substrate, causing the hydrogen peroxide solution to collide with the substrate surface. The hydrogen peroxide solution ejected from the liquid column nozzle forms a continuous stream of hydrogen peroxide solution from the liquid column nozzle to the surface of the substrate. If the surface of the anti-etching pattern is hydrophobic, multiple droplets of hydrogen peroxide solution are formed and dispersed over the entire surface of the substrate. If the surface of the anti-etching pattern is hydrophilic, a liquid film of hydrogen peroxide solution is formed covering the entire surface of the substrate. This method enables the formation of droplets or a liquid film of hydrogen peroxide solution in a shorter time than when a mist of hydrogen peroxide solution is supplied to the substrate surface.

The substrate processing method further includes a hydrophilization step, which is to reduce the contact angle of water with the surface of the anti-etching pattern by allowing the ozone gas to contact the surface of the substrate before supplying the hydrogen peroxide solution to the surface of the substrate.

According to this method, ozone gas is brought into contact with the substrate surface, weakening the hydrophobicity of the anti-etching pattern. This reduces the contact angle of water with the anti-etching pattern. Under this condition, a hydrogen peroxide solution is supplied to the substrate surface. If the anti-etching pattern surface is hydrophobic, a hydrogen peroxide film that covers the entire substrate surface cannot be formed unless the hydrogen peroxide solution is supplied at a high flow rate. However, in this case, hydrogen peroxide consumption increases, resulting in a thicker hydrogen peroxide film. Applying hydrogen peroxide solution after the surface of the resist pattern has been hydrophilized can reduce hydrogen peroxide consumption and form a thinner hydrogen peroxide film covering the entire surface of the substrate. Furthermore, since ozone gas is used not only to remove the resist pattern but also to hydrophilize the surface of the resist pattern, the number of fluid equipment such as piping and valves used to process the substrate can be reduced compared to using liquids or gases other than ozone to hydrophilize the surface of the resist pattern.

The substrate processing method further includes a stripping liquid supplying step, which is to supply the ozone gas to the hydrogen peroxide solution in contact with the substrate, and then supply an anti-etching agent stripping liquid to the surface of the substrate for stripping the anti-etching pattern from the surface of the substrate.

According to this method, after stripping or removing all or part of the resist pattern using hydroxyl radicals generated by the reaction of ozone gas and hydrogen peroxide, a resist stripping liquid is applied to the substrate surface. Even if a portion of the resist pattern remains on the substrate surface, it will be stripped from the substrate surface due to contact with the resist stripping liquid. Even if residue from the resist pattern remains on the substrate surface, it will be washed away by the resist stripping liquid. This reduces the amount of resist remaining on the substrate surface.

Another embodiment of the present invention, used to achieve the above-mentioned objectives, provides a substrate processing apparatus comprising: a hydrogen peroxide solution nozzle for supplying a hydrogen peroxide solution to the surface of a substrate having a resist pattern formed thereon; and an ozone nozzle for supplying ozone gas to the hydrogen peroxide solution in contact with the substrate. This apparatus can achieve the same effects as the above-mentioned substrate processing method. At least one of the features described above with respect to the substrate processing method can be incorporated into the substrate processing apparatus of this embodiment.

The above contents and further other purposes, features and effects of the present invention will become clear through the following description of the embodiments described with reference to the accompanying drawings.

FIG1 is a diagram showing an example of a process for processing a substrate W including resist stripping according to an embodiment of the present invention. FIG2 is a schematic cross-sectional view showing an example of a resist pattern 100 according to an embodiment of the present invention.

In the processing of the substrate W shown in Figure 1 , resist coating is performed (step S1 in Figure 1 ). This is achieved by coating the surface of a substrate W, such as a silicon wafer, with a photoresist solution containing a resin and a solvent, forming a resist film that covers the entire surface of the substrate W. Subsequently, a pre-bake (step S2 in Figure 1 ) is performed. With the entire surface of the substrate W covered by the resist film, the substrate W is heated at a pre-bake temperature to evaporate the solvent contained in the resist film. Subsequently, an exposure step (step S3 in Figure 1 ) is performed. This is achieved by irradiating the resist film on the substrate W with light such as ultraviolet light through a photomask, thereby transferring the circuit pattern formed on the photomask to the resist film.

After exposure, development is performed (step S3 of FIG. 1 ), which involves supplying a developer solution to the substrate W to remove unwanted portions of the resist film, thereby forming a resist pattern 100 on the surface of the substrate W that corresponds to the remaining resist film. Subsequently, post-baking is performed (step S4 of FIG. 1 ), which involves heating the substrate W at a post-baking temperature. A post-exposure bake, in which the substrate W is heated after exposure and before development, may be performed. After post-baking, ion implantation is performed (step S5 of FIG. 1 ), which involves implanting impurity ions into portions of the surface of the substrate W exposed from the resist pattern 100. Subsequently, resist stripping is performed (step S6 of FIG. 1 ), which removes unwanted portions of the resist pattern 100 from the surface of the substrate W.

During ion implantation, impurity ions collide not only with a portion of the surface of substrate W but also with resist pattern 100, which acts as an anti-etching mask. Consequently, the entire or majority of the surface layer of resist pattern 100 undergoes degradation, such as carbonization, transforming into hardened layer 101. Meanwhile, the interior of resist pattern 100 remains unhardened, inside hardened layer 101. Figure 2 illustrates an example in which a non-hardened portion 102, corresponding to the unhardened portion of resist pattern 100, contacts the surface of substrate W, with the front end and both side surfaces of non-hardened portion 102 covered by hardened layer 101. The following describes the resist stripping process for removing such a resist pattern 100 from the surface of substrate W.

Two examples of resist stripping according to one embodiment of the present invention are described below.

In the following description, unless otherwise specified, the substrate W refers to both the substrate W equivalent to the base material and the anti-etching pattern 100 formed on the base material, and the surface of the substrate W refers to both the surface of the anti-etching pattern 100 and the portion of the surface of the substrate W exposed from the anti-etching pattern 100.

Figures 3A, 3B, 3C, 3D, 3E, and 3F are schematic diagrams illustrating an example of resist stripping according to an embodiment of the present invention. Figures 3A to 3F show a horizontal view of a substrate W. Figure 4 is a schematic diagram illustrating the reaction between ozone gas dissolved in a hydrogen peroxide solution droplet on a substrate W and hydrogen peroxide contained in the hydrogen peroxide solution to generate hydroxyl radicals. The thick solid line in Figure 4 represents the interface between the resist pattern 100 and the hydrogen peroxide solution, namely, the solid-liquid interface 111. Figure 5 is a vertical cross-sectional view showing an example of an image of the resist pattern 100 with voids 103 formed in the hardened layer 101.

As shown in FIG3A , when removing the anti-etching pattern 100 having the hardened layer 101 from the substrate W, the substrate W is uniformly heated at a peeling-promoting temperature higher than room temperature (constant or substantially constant temperature within the range of 15-30°C), maintaining the entire substrate W at the peeling-promoting temperature. FIG3A illustrates an example in which the substrate W, with the surface of the substrate W having the anti-etching pattern 100 formed thereon facing upward, is horizontally positioned on a heated heating plate 30. The substrate W is uniformly heated at the peeling-promoting temperature by contacting the lower surface of the substrate W with the heating plate 30. In addition to or instead of heating the substrate W in this manner, the substrate W may be heated by contacting a heating gas or a heating liquid having a temperature higher than room temperature with the substrate W, or by irradiating the substrate W with electromagnetic waves emitted from a heat source such as a lamp.

Next, as shown in FIG3B , while the substrate W is uniformly heated at the peeling-promoting temperature in a horizontal position, a mist of hydrogen peroxide solution is supplied from a mist nozzle 51A, which is an example of a hydrogen peroxide solution nozzle, onto the surface of the substrate W, so that a plurality of hydrogen peroxide solution droplets are dispersed over the entire surface of the substrate W. The supply of the hydrogen peroxide solution mist onto the substrate W can be performed by spraying the hydrogen peroxide solution mist onto the surface of the substrate W, or by diffusing the hydrogen peroxide solution mist into the space above the substrate W and allowing the diffused hydrogen peroxide solution mist to fall onto the surface of the substrate W. Alternatively, the hydrogen peroxide solution mist can be supplied to the surface of the substrate W by methods other than these.

The hydrogen peroxide mist is composed of multiple hydrogen peroxide particles. The hydrogen peroxide particles supplied to the substrate W combine with other hydrogen peroxide particles to form hydrogen peroxide droplets on the surface of the substrate W. As the hydrogen peroxide mist continues to be supplied, the hydrogen peroxide droplets on the substrate W gradually grow larger. However, because the surface of the anti-etching pattern 100 is hydrophobic, a hydrogen peroxide film does not form that covers the entire surface of the substrate W. Instead, as shown in FIG3B , multiple, separate hydrogen peroxide droplets are dispersed across the entire surface of the substrate W, covering only a portion of the surface of the substrate W.

Next, as shown in FIG3C , while the horizontal substrate W is uniformly heated at the peeling-promoting temperature and the plurality of hydrogen peroxide solution droplets are dispersed over the entire surface of the substrate W, ozone gas is brought into contact with the plurality of hydrogen peroxide solution droplets on the substrate W. For example, by exhausting the gas in the heat treatment chamber 34 (see FIG10A and FIG10B ) containing the substrate W while continuously supplying ozone gas into the heat treatment chamber 34, the heat treatment chamber 34 is kept filled with ozone gas, and new ozone gas is continuously supplied to the substrate W.

Alternatively, after the heat treatment chamber 34 is filled with ozone gas, the supply of ozone gas to the heat treatment chamber 34 may be stopped, and the interior of the heat treatment chamber 34 may be sealed. In this case, the ozone gas in the heat treatment chamber 34 may be replaced with new ozone gas at a predetermined interval. The ozone gas supplied to the heat treatment chamber 34 may be at room temperature or a temperature higher than room temperature.

As shown in Figure 4 , ozone gas dissolves in the hydrogen peroxide solution on substrate W and reacts with the hydrogen peroxide contained in the hydrogen peroxide solution. This generates hydroxyl radicals ("OH" in Figure 4 ) and hydrogen peroxide radicals ("HO" in Figure 4 ) through the chemical reaction "O ₃ + H ₂ O ₂ → OH + HO _{2 +} O ₂ ." Some of the hydroxyl radicals generated within the hydrogen peroxide solution droplet diffuse within the droplet and reach the interface between the resist pattern 100 and the hydrogen peroxide solution, namely, the solid-liquid interface 111. Hydroxyl radicals are also generated at the solid-liquid interface 111. Hydroxyl radicals react with the hardened layer 101 (see FIG. 5 ) of the resist pattern 100 at the solid-liquid interface 111, oxidizing and decomposing the hardened layer 101. Hydroxyl radicals that reach the non-hardened portion 102 (see FIG. 5 ) oxidize and decompose the non-hardened portion 102. As a result, at least a portion of the resist pattern 100 is vaporized and removed from the substrate W.

As described above, while the horizontal substrate W is uniformly heated at the peeling-promoting temperature and multiple hydrogen peroxide solution droplets are dispersed over the entire surface of the substrate W, ozone gas is brought into contact with the multiple hydrogen peroxide solution droplets on the substrate W. Heating the substrate W indirectly heats the hydrogen peroxide solution on the substrate W, increasing the reactivity between the ozone gas and hydrogen peroxide. This increases the total number of hydroxyl radicals, thereby increasing the number of hydroxyl radicals available to react with the hardened layer 101.

On the other hand, when the hydrogen peroxide solution on the substrate W is heated, the rate of evaporation of the hydrogen peroxide solution from the substrate W increases. Therefore, after stopping the supply of hydrogen peroxide solution mist to the substrate W, a new hydrogen peroxide solution mist can be supplied to the substrate W. Alternatively, the supply of hydrogen peroxide solution mist can be continued (added) even after the supply of ozone gas begins. Figure 3D shows a state where the hydrogen peroxide solution droplets on the substrate W are reduced in size, while Figure 3E shows a state where the hydrogen peroxide solution droplets on the substrate W are increased in size by the replenishment of hydrogen peroxide solution mist. Even if the hydrogen peroxide solution on the substrate W is not heated, the hydrogen peroxide is reduced from the substrate W due to the reaction between the ozone gas and the hydrogen peroxide. Therefore, a new mist of the hydrogen peroxide solution may be supplied to the substrate W to compensate for this.

Figure 4 shows a vertical cross-section (a cross-section cut along a vertical plane) of a hydrogen peroxide solution droplet on a substrate W. Symbol 112 in Figure 4 indicates the boundary between the ozone gas, hydrogen peroxide solution, and the anti-etching pattern 100, namely the three-state boundary. The hatched area in Figure 4 represents a region where the supply of hydroxyl radicals is relatively high. The supply of hydroxyl radicals to the solid-liquid interface 111 increases as it approaches the three-state boundary 112. This is because hydroxyl radicals quickly convert back to hydrogen peroxide. Therefore, if the shortest distance from the surface of the hydrogen peroxide solution droplet or liquid film to the solid-liquid interface 111 is long, the hydroxyl radicals will disappear before reaching the solid-liquid interface 111. In other words, near the three-state boundary 112 , the shortest distance from the surface of the hydrogen peroxide solution droplet or liquid film to the solid-liquid interface 111 is shorter, and hydroxyl radicals can easily reach or be generated.

Figure 5 shows an example of a cavity 103 formed in the hardened layer 101 near the three-state boundary 112. In this example, two of the three hydrogen peroxide droplets are placed on the two anti-etching patterns 100, and the remaining one is placed between the two anti-etching patterns 100. Three of the five cavities 103 extend from the periphery of the two hydrogen peroxide droplets in the thickness direction of the substrate W, while two extend from the sides of the two anti-etching patterns 100 in the in-plane direction of the substrate W (a direction perpendicular to the thickness of the substrate W, or horizontally in Figure 5). Each cavity 103 penetrates the hardened layer 101 and reaches the non-hardened portion 102.

As described above, the number of hydroxyl radicals supplied to the solid-liquid interface 111 increases as the three-state boundary 112 is approached. Consequently, as shown in FIG5 , a cavity 103 is formed near the periphery of the hydrogen peroxide solution droplet, and the remaining portion of the cured layer 101 is subsequently decomposed by the hydroxyl radicals. The supply of ozone gas to the substrate W may be stopped after a time period assuming that the cavity 103 reaches the non-cured portion 102, or after a time period assuming that all portions of the cured layer 101 in contact with the hydrogen peroxide solution are decomposed by the hydroxyl radicals.

As described above, because the surface of the anti-etching pattern 100 is hydrophobic, when a hydrogen peroxide solution mist is supplied to the substrate W, a hydrogen peroxide solution film is not formed that covers the entire surface of the substrate W. Instead, multiple hydrogen peroxide solution droplets are dispersed across the entire surface of the substrate W. However, the hydrophobicity of the portion of the anti-etching pattern 100 that comes into contact with the hydrogen peroxide solution decreases due to reaction with the hydrogen peroxide solution or hydroxyl radicals. The hydrophobicity of the portion of the anti-etching pattern 100 that does not come into contact with the hydrogen peroxide solution also decreases due to reaction with the ozone gas. Therefore, while the substrate W is continuously supplied with a new mist of hydrogen peroxide solution, or while the substrate W is intermittently supplied with a mist of hydrogen peroxide solution, the ozone gas reacts with the hydrogen peroxide, and the hydrophobicity of the surface of the anti-etching pattern 100 is weakened, and the multiple droplets of hydrogen peroxide solution on the substrate W are transformed into a liquid film of hydrogen peroxide solution covering the entire surface of the substrate W.

When multiple droplets of hydrogen peroxide solution are dispersed over the entire surface of substrate W, a portion of the surface of anti-etching pattern 100 may not be in contact with the hydrogen peroxide solution on substrate W. In contrast, when a hydrogen peroxide solution film covers the entire surface of substrate W, the entire or substantially entire surface of anti-etching pattern 100 is in contact with the hydrogen peroxide solution on substrate W. Therefore, when the hydrogen peroxide solution film is formed, the area of the surface of anti-etching pattern 100 that is supplied with hydroxyl radicals expands, and the portion of hardened layer 101 decomposed by hydroxyl radicals increases. Consequently, more hardened layer 101 can be decomposed by hydroxyl radicals.

After at least a portion of the hardened layer 101 of the resist pattern 100 is decomposed by hydroxyl radicals, ozone gas is exhausted from the interior of the heat treatment chamber 34 (see Figures 10A and 10B) housing the substrate W. The process then waits until all of the hydrogen peroxide solution has evaporated from the substrate W, after which heating of the substrate W is discontinued. At this point, the substrate W can continue to be heated at the peeling-promoting temperature, or the time required to dry the substrate W can be shortened by heating the substrate W at a drying temperature higher than the peeling-promoting temperature. After terminating heating of the substrate W, the substrate W can be forcefully cooled to room temperature or a temperature near room temperature. In addition to or instead of heating the substrate W, the hydrogen peroxide solution may be removed from the substrate W by other drying methods such as reducing the gas pressure or supplying gas to the substrate W.

Next, as shown in FIG3F , a resist stripping liquid is supplied to the surface of the substrate W to strip the remaining resist pattern 100 from the substrate W. FIG3F shows an example of a stripping liquid nozzle 85 spraying SPM (a mixture of sulfuric acid and hydrogen peroxide solution) as an example of a resist stripping liquid onto the upper surface (surface) of the rotating substrate W. The resist stripping liquid is a liquid containing a compound that chemically reacts with the resist pattern 100. The resist stripping liquid is also called a resist removal liquid. The resist stripping liquid can be SPM or SC1 (a mixture of ammonia, hydrogen peroxide, and water), or other liquids.

When a cavity 103 is formed in the hardened layer 101 by reaching the unhardened portion 102 as shown in FIG5 , when a resist stripping liquid is supplied to the substrate W, the resist stripping liquid reacts with the unhardened portion 102, and the unhardened portion 102 and the hardened layer 101 are both stripped (lifted) from the substrate W. This removes the resist pattern 100 from the substrate W. Even if all or nearly all of the hardened layer 101 is decomposed by hydroxyl radicals, the resist stripping liquid reacts with the unhardened portion 102, and the unhardened portion 102 is stripped from the substrate W. Therefore, if the resist stripping liquid can reach the non-hardened portion 102, even if the hardened layer 101 remains, all or almost all of the resist pattern 100 can be removed from the substrate W by supplying the resist stripping liquid.

After applying the resist stripping liquid to the substrate W, the resist stripping liquid adhering to the substrate W is rinsed with a rinse solution such as pure water, and then the substrate W is dried. The resist stripping liquid can be applied to the substrate W by spraying the resist stripping liquid onto the upper or lower surface of the substrate W while rotating the substrate W horizontally about a line passing through the center of the substrate W. Alternatively, the substrate W can be immersed in the resist stripping liquid. The same procedure applies to the rinse solution applied to the substrate W. The substrate W may be dried by spin drying, which involves spinning the substrate W at high speed to disperse the liquid adhering to the substrate W. Alternatively, the substrate may be dried by other drying methods other than spin drying, such as vacuum drying.

As described above, when ozone gas contacts the hydrogen peroxide solution on substrate W, substrate W is uniformly heated at a stripping-promoting temperature above room temperature. The stripping-promoting temperature can be equal to, higher than, or lower than the pre-bake temperature. Similarly, the stripping-promoting temperature can be equal to, higher than, or lower than the post-bake temperature. The stripping-promoting temperature can be lower than the boiling point of the hydrogen peroxide solution or lower than the boiling point of water. The boiling point of hydrogen peroxide is 150.2°C. Therefore, the stripping-promoting temperature can be lower than 150.2°C or lower than 100°C. The concentration of the hydrogen peroxide solution can be between 30 and 40 wt% (mass percent concentration), or outside this range. The boiling point of a 30 wt% hydrogen peroxide solution is 106°C, and the boiling point of a 35 wt% hydrogen peroxide solution is 108°C.

Next, another example of resist stripping according to one embodiment of the present invention will be described.

Figures 6A, 6B, 6C, and 6D are schematic diagrams illustrating another example of resist stripping according to an embodiment of the present invention. Figures 6A to 6D illustrate a horizontal view of a substrate W. Figure 7 is a schematic diagram illustrating the reaction of ozone gas dissolved in a hydrogen peroxide solution film on substrate W with hydrogen peroxide contained in the hydrogen peroxide solution to generate hydroxyl radicals.

In another example of resist stripping, similar to the first example of resist stripping, a horizontally positioned substrate W is uniformly heated at a stripping-promoting temperature. Subsequently, rather than supplying a mist of hydrogen peroxide solution to substrate W, ozone gas is brought into contact with the entire surface of substrate W, as shown in FIG6A . The contacting method is the same as in the first example of resist stripping. When ozone gas reacts with the surface of resist pattern 100, the contact angle of water with respect to the surface of resist pattern 100 decreases, weakening the hydrophobicity of the surface of resist pattern 100. As a result, the surface of resist pattern 100 becomes hydrophilic.

Next, while the horizontal substrate W is uniformly heated at the stripping-promoting temperature, a hydrogen peroxide solution is supplied to the substrate W, forming a hydrogen peroxide solution film covering the entire surface of the substrate W. Specifically, similar to the aforementioned anti-etching agent stripping example, a hydrogen peroxide solution mist is supplied to the surface of the substrate W. As the hydrogen peroxide solution mist is continued to be supplied, multiple hydrogen peroxide solution droplets form on the substrate W and gradually grow larger. Due to the reaction with the ozone gas, the hydrophobicity of the surface of the anti-etching pattern 100 is weakened. As a result, the multiple hydrogen peroxide solution droplets are not dispersed across the entire surface of the substrate W, but rather coalesce on the surface of the substrate W. Thereby, a liquid film of the hydrogen peroxide solution covering the entire surface of the substrate W is formed.

When forming a hydrogen peroxide solution film, in addition to or in lieu of supplying a hydrogen peroxide solution mist to the surface of the substrate W, the hydrogen peroxide solution may be continuously sprayed onto the surface of the substrate W. Specifically, as shown in FIG6B , by continuously spraying the hydrogen peroxide solution from a liquid column nozzle 51B, which is an example of a hydrogen peroxide solution nozzle, a continuous liquid column of hydrogen peroxide solution having a diameter approximately the same as that of the liquid column nozzle 51B (e.g., a diameter in the range of 5 to 20 mm) is formed, flowing from the liquid column nozzle 51B toward the center of the surface of the substrate W. The hydrogen peroxide solution forming this liquid column can also be caused to collide with the center of the surface of the substrate W, which is stationary in a horizontal position.

While holding the substrate W in a horizontal position, hydrogen peroxide solution is continuously sprayed toward the center of the substrate W's surface. The sprayed hydrogen peroxide solution collides with the center of the substrate W's surface and then flows radially from the center along the surface of the substrate W. The hydrogen peroxide solution on the substrate W is pushed outward by subsequent hydrogen peroxide solution and discharged outward from the outer periphery of the substrate W's surface. This forms a hydrogen peroxide solution film covering the entire surface of the substrate W.

The supply of hydrogen peroxide solution to the substrate W can also be performed while the substrate W is rotated in a horizontal position, rather than while the substrate W is stationary in a horizontal position. Specifically, the substrate W can be rotated in a horizontal plane about a straight line passing through the center of the substrate W while the hydrogen peroxide solution is continuously sprayed onto the upper surface (surface) of the substrate W. In this case, the centrifugal force generated by the rotation of the substrate W applies to the hydrogen peroxide solution on the substrate W, thereby shortening the time required to form a hydrogen peroxide solution film covering the entire surface of the substrate W.

Compared to simply supplying a hydrogen peroxide solution mist onto the surface of the substrate W, continuously spraying the hydrogen peroxide solution onto the surface of the substrate W allows a hydrogen peroxide solution film to be formed covering the entire surface of the substrate W in a shorter time. When the hydrogen peroxide solution is continuously sprayed onto the surface of the substrate W while the substrate W is rotated in a horizontal position, a thinner hydrogen peroxide solution film can be formed by controlling the flow rate of the sprayed hydrogen peroxide solution and the rotation speed of the substrate W. When supplying a hydrogen peroxide solution mist onto the substrate W, a thinner hydrogen peroxide solution film can be formed than when the hydrogen peroxide solution is continuously sprayed onto the surface of the substrate W.

After forming a liquid film of hydrogen peroxide solution covering the entire surface of the substrate W, the supply of hydrogen peroxide solution mist to the substrate W may be stopped or continued. In the former case, the supply of hydrogen peroxide solution mist to the substrate W may be resumed after a predetermined time has elapsed since the supply of hydrogen peroxide solution mist was stopped. Similarly, after forming a liquid film of hydrogen peroxide solution covering the entire surface of the substrate W, the spraying of hydrogen peroxide solution from the liquid column nozzle 51B may be stopped or continued. In the former case, the spraying of hydrogen peroxide solution may be resumed after a predetermined time has elapsed since the spraying of hydrogen peroxide solution was stopped.

Next, as shown in FIG6C , after the horizontal substrate W is uniformly heated at the peeling-promoting temperature and the entire surface of the substrate W is covered by the hydrogen peroxide film, ozone gas is brought into contact with the hydrogen peroxide film on the substrate W. The supply of ozone gas to the substrate W may continue from the time the surface of the resist pattern 100 is hydrophilized, or it may be resumed after the hydrogen peroxide film is formed. In the latter case, ozone gas may be exhausted from the interior of the heat treatment chamber 34 before the hydrogen peroxide film is formed.

When ozone gas comes into contact with the hydrogen peroxide solution on the substrate W, similar to the resist stripping example, the ozone gas reacts with the hydrogen peroxide to generate hydroxyl radicals, which decompose the hardened layer 101 of the resist pattern 100 (see FIG. 5 ). Consequently, cavities 103 (see FIG. 5 ) that reach the non-hardened portion 102 (see FIG. 5 ) are formed in the hardened layer 101. The supply of ozone gas to the substrate W may be stopped when the cavities 103 that reach the non-hardened portion 102 are formed in the hardened layer 101, or may be continued until all or nearly all of the hardened layer 101 is decomposed by the hydroxyl radicals.

As shown in Figures 6C and 7 , the shortest distance from the surface of the hydrogen peroxide film to the interface between the anti-etching pattern 100 and the hydrogen peroxide solution, i.e., the solid-liquid interface 111, is constant or substantially constant except at the periphery of the hydrogen peroxide film. Therefore, hydroxyl radicals can be uniformly supplied to the solid-liquid interface 111, enabling uniform stripping of the anti-etching pattern 100 across the entire surface of the substrate W. On the other hand, if the hydrogen peroxide film is thicker, fewer hydroxyl radicals will reach the solid-liquid interface 111. Therefore, it is preferable to minimize the thickness of the hydrogen peroxide film.

After stopping the supply of ozone gas to the substrate W, the substrate W is dried in the same manner as in the resist stripping process. Subsequently, as shown in FIG6D , a resist stripping liquid is supplied to the substrate W to remove the resist pattern 100 from the substrate W. FIG6D illustrates an example in which the stripping liquid nozzle 85 sprays SPM, an example of a resist stripping liquid, onto the upper surface (surface) of the rotating substrate W.

As described above, in the two examples of resist stripping, a resist stripping step is performed by supplying ozone gas and hydrogen peroxide solution to the surface of the substrate W to strip at least a portion of the resist pattern 100 from the surface of the substrate W. Subsequently, a residual resist stripping step is performed by supplying a resist stripping solution to the surface of the substrate W. Even if residual resist remains on the surface of the substrate W after the resist stripping step, the residual resist can be stripped from the surface of the substrate W using the resist stripping solution. In this way, all resist can be removed from the substrate W. Alternatively, the amount of resist remaining on the substrate W can be reduced.

FIG8 is a schematic top view showing the layout of a substrate processing apparatus 1 according to an embodiment of the present invention.

The substrate processing apparatus 1 is a single-wafer device that processes substrates W one by one. Substrates W are, for example, semiconductor wafers. The substrate processing apparatus 1 includes a plurality of loading ports LP, each of which holds a plurality of carriers C that accommodate substrates W, and a plurality of processing units 2, which process the substrates W transferred from the loading ports LP using processing fluids such as processing liquids and processing gases.

The substrate processing apparatus 1 further includes transport units (IR, SH, CR) for transporting substrates W, and a control device (controller) 3 for controlling the substrate processing apparatus 1. The control device 3 is typically a computer and includes a memory 3m for storing information such as programs, and a processor 3p for controlling the substrate processing apparatus 1 based on the information stored in the memory 3m.

The transport units (IR, SH, CR) include an indexing robot IR, a shuttle SH, and a center robot CR, which are arranged on a transport path extending from a plurality of loading ports LP to a plurality of processing units 2. The indexing robot IR transports substrates W between the plurality of loading ports LP and the shuttle SH. The shuttle SH reciprocates between the indexing robot IR and the center robot CR to transport substrates W. The center robot CR transports substrates W between the shuttle SH and a plurality of processing units 2. The center robot CR, in turn, transports substrates W between the plurality of processing units 2. The thick solid arrows shown in FIG8 indicate the movement directions of the indexing robot IR and the shuttle SH.

The processing units 2 form four towers, each arranged at four horizontally spaced locations. Each tower includes a plurality of processing units 2 stacked vertically. The four towers are arranged two by two on either side of the transport path. The processing units 2 include: a plurality of pre-processing units 2D, which process substrates W while heating or cooling them; and a plurality of post-processing units 2W, which use a processing liquid to treat the substrates W processed by the pre-processing units 2D. The two towers on the loading port LP side are formed by the pre-processing units 2D, and the remaining two towers are formed by the post-processing units 2W.

Next, the 2D pre-processing unit is explained.

Figure 9 is a cross-sectional view showing an example of a vertical cross-section of pre-treatment unit 2D. Figure 10A is a cross-sectional view showing an example of a vertical cross-section of heat treatment unit 8. Figure 10B is a cross-sectional view showing another example of a vertical cross-section of heat treatment unit 8. In the following description, "line" refers to a flow path formed by fluid devices such as piping and valves. For example, gas supply line 49 corresponds to a flow path for supplying gas.

The pre-processing unit 2D includes a chamber 4 with a loading/unloading port 4a through which substrates W pass; a shutter 5 that opens and closes the loading/unloading port 4a; a thermal treatment unit 8 that heats the substrates W within the chamber 4 while supplying processing fluids such as a processing liquid and a processing gas to the substrates W; a cooling unit 7 that cools the substrates W heated by the thermal treatment unit 8 within the chamber 4; and an in-chamber transfer mechanism 6 that transfers the substrates W within the chamber 4. The central robot CR transfers substrates W into and out of the chamber 4 through the loading/unloading port 4a. The cooling unit 7 is located within the chamber 4 near the loading/unloading port 4a.

The cooling unit 7 includes a cooling plate 20, lifting pins 22 that extend through the cooling plate 20 and move vertically, and a pin-lifting drive mechanism 23 that moves the lifting pins 22 vertically. The cooling plate 20 includes a cooling surface 20a on which substrates W are placed. A cooling medium path (not shown) circulates a coolant (typically cooling water) within the cooling plate 20. The lifting pins 22 move vertically between an upper position, where they support the substrates W, and a lower position, where their tips are submerged below the cooling surface 20a.

Heat treatment unit 8 includes a heater 33. More specifically, heat treatment unit 8 comprises a heating plate 30, a heat treatment chamber 34 that houses heating plate 30, lift pins 38 that extend through heating plate 30 and move up and down, and a pin lift drive mechanism 39 that moves lift pins 38 up and down. Heating plate 30 includes a heating surface 30a on which substrate W is placed and houses heater 33.

The heater 33 is configured to heat the substrate W placed on the heating surface 30a at a constant temperature above room temperature, for example, up to 250°C. The heating surface 30a follows the shape of the substrate W, having a planar shape slightly larger than the substrate W. Specifically, if the substrate W is circular, the heating surface 30a is formed into a circular shape slightly larger than the substrate W.

The heat treatment chamber 34 includes a chamber body 35 and a lid 36 that moves up and down above the chamber body 35. The heat treatment unit 8 includes a lid lift drive mechanism 37 that lifts and lowers the lid 36. The chamber body 35 has an opening 35a that opens upward, and the lid 36 opens and closes the opening 35a. The lid 36 moves up and down between a closed position (lower position) in which it blocks the opening 35a of the chamber body 35 and forms a sealed processing space within the heat treatment chamber 34, and an upper position in which it retracts upward to open the opening 35a. The lift pin 38 moves up and down between an upper position in which it supports the substrate W above the heating surface 30a and a lower position in which its tip is submerged below the heating surface 30a.

An exhaust port 41 is formed at the bottom of the chamber body 35. The exhaust ports 41 are preferably arranged at multiple locations (e.g., three locations) spaced apart in the circumferential direction. The exhaust ports 41 are connected to an exhaust device via an exhaust line 42.

The lid 36 comprises a plate portion 45 extending parallel to the heating surface 30a and a cylindrical portion 46 extending downward from the periphery of the plate portion 45. Specifically, the plate portion 45 is generally circular, while the cylindrical portion 46 is cylindrical. The lower end of the cylindrical portion 46 faces the upper end of the chamber body 35. Thus, the opening 35a of the chamber body 35 can be opened and closed by moving the lid 36 up and down.

As shown in FIG10A , a mist nozzle 51A for spraying a hydrogen peroxide solution mist toward the upper surface of substrate W and an ozone nozzle 55 for spraying ozone gas toward the upper surface of substrate W are mounted on cover 36 . FIG10A illustrates an example in which mist nozzle 51A and ozone nozzle 55 are inserted into two holes in plate portion 45 extending vertically through cover 36 . The positions of mist nozzle 51A and ozone nozzle 55 relative to cover 36 are not limited to this example.

Mist nozzle 51A is connected to a hydrogen peroxide solution line 52, which directs hydrogen peroxide solution from a hydrogen peroxide solution supply source 54 to mist nozzle 51A. A hydrogen peroxide solution valve 53 is disposed on hydrogen peroxide solution line 52. When control device 3 opens hydrogen peroxide solution valve 53, hydrogen peroxide solution is supplied to mist nozzle 51A, and mist nozzle 51A sprays hydrogen peroxide solution mist. When control device 3 closes hydrogen peroxide solution valve 53, the supply of hydrogen peroxide solution to mist nozzle 51A ceases, and the spraying of hydrogen peroxide solution mist from mist nozzle 51A stops.

The ozone nozzle 55 is connected to an ozone line 56, which directs ozone gas from an ozone generator 58 to the ozone nozzle 55. An ozone valve 57 is disposed on the ozone line 56. When the control device 3 opens the ozone valve 57, ozone gas is supplied to the ozone nozzle 55, and the ozone nozzle 55 begins to discharge ozone gas. When the control device 3 closes the ozone valve 57, the supply of ozone gas to the ozone nozzle 55 ceases, and ozone gas discharge from the ozone nozzle 55 also ceases.

A shower plate 59 is positioned between the mist nozzle 51A and the ozone nozzle 55 and the substrate W on the heating plate 30. The hydrogen peroxide solution mist sprayed from the mist nozzle 51A diffuses in the space between the shower plate 59 and the lid 36 and passes through the plurality of holes extending through the shower plate 59. This uniformly supplies the hydrogen peroxide solution mist to the upper surface of the substrate W on the heating plate 30. Similarly, the ozone gas sprayed from the ozone nozzle 55 diffuses in the space between the shower plate 59 and the lid 36 and passes through the plurality of holes extending through the shower plate 59. This uniformly supplies the ozone gas to the upper surface of the substrate W on the heating plate 30.

As shown in Figure 10B, heat treatment unit 8 may also include a liquid column nozzle 51B that continuously sprays hydrogen peroxide solution, instead of or in addition to mist nozzle 51A. In this case, shower plate 59 is preferably omitted. Furthermore, liquid column nozzle 51B preferably sprays hydrogen peroxide solution toward the center of the upper surface of substrate W on heating plate 30. A gas-liquid separator 60, which separates liquid from the exhaust gas in exhaust line 42, may be positioned upstream of the exhaust system.

When the control device 3 opens the hydrogen peroxide solution valve 53, hydrogen peroxide solution is supplied to the liquid column nozzle 51B, and the liquid column nozzle 51B begins to spray hydrogen peroxide solution. This forms a continuous liquid column of hydrogen peroxide solution from the liquid column nozzle 51B to the upper surface of the substrate W. The hydrogen peroxide solution collides with the center of the upper surface of the substrate W and flows outward along the upper surface of the substrate W, and is discharged outward from the outer periphery of the upper surface of the substrate W. When the control device 3 closes the hydrogen peroxide solution valve 53, the supply of hydrogen peroxide solution to the liquid column nozzle 51B and the spraying of hydrogen peroxide solution from the liquid column nozzle 51B cease.

As shown in FIG9 , the indoor transfer mechanism 6 transfers substrates W within the chamber 4 . More specifically, the indoor transfer mechanism 6 includes an indoor transfer hand 6H for transferring substrates W between the cooling unit 7 and the thermal treatment unit 8 . The indoor transfer hand 6H is configured to receive substrates W between the lifting pins 22 of the cooling unit 7 and the lifting pins 38 of the thermal treatment unit 8 . Thus, the indoor transfer hand 6H receives substrates W from the lifting pins 22 of the cooling unit 7 and transfers them to the lifting pins 38 of the thermal treatment unit 8 . Furthermore, the indoor transfer hand 6H receives substrates W from the lifting pins 38 of the thermal treatment unit 8 and transfers them to the lifting pins 22 of the cooling unit 7 .

Typical actions of the 2D pre-processing unit are described below.

When the central robot CR (see FIG8 ) carries the substrate W into the chamber 4, the baffle 5 is controlled to be in the open position to open the loading and unloading port 4a. In this state, the hand H of the central robot CR enters the chamber 4 and places the substrate W above the cooling plate 20. Then, the lifting pin 22 rises to the upper position and receives the substrate W from the hand H of the central robot CR. Thereafter, the hand H of the central robot CR retreats to the outside of the chamber 4. Subsequently, the indoor transfer hand 6H of the indoor transfer mechanism 6 receives the substrate W from the lifting pin 22 and transfers the substrate W to the lifting pin 38 of the heat treatment unit 8. At this time, the cover 36 is in the open position (upper position), and the lifting pin 38 supports the received substrate W in the upper position. After the indoor transfer arm 6H retreats from the heat treatment chamber 34, the lift pins 38 descend to their lower positions, placing the substrate W on the heating surface 30a. Meanwhile, the lid 36 descends to its closed position (lower position), creating a sealed processing chamber that houses the heating plate 30. In this state, the substrate W undergoes heat treatment.

When the heat treatment is complete, the lid 36 rises to the open position (upper position), opening the heat treatment chamber 34. Furthermore, the lift pins 38 rise to the upper position, pushing the substrate W above the heating surface 30a. In this state, the indoor transfer hand 6H of the indoor transfer mechanism 6 receives the substrate W from the lift pins 38 and transfers it to the lift pins 22 of the cooling unit 7. The lift pins 22 support the received substrate W in the upper position. The indoor transfer hand 6H retreats, and the lift pins 22 descend to the lower position, placing the substrate W on the cooling surface 20a of the cooling plate 20. This cools the substrate W.

When cooling of the substrate W is complete, the lift pins 22 rise to their upper positions, pushing the substrate W above the cooling surface 20a. In this state, the shutter 5 opens, and the hand H of the central robot CR enters the chamber 4 and is positioned beneath the substrate W, which is supported by the lift pins 22 in the upper position. In this state, the lift pins 22 descend, transferring the substrate W to the hand H of the central robot CR. The hand H, holding the substrate W, retreats outside the chamber 4, and the shutter 5 closes the load/unload port 4a.

FIG11 is a cross-sectional view showing an example of a vertical cross section of the post-processing unit 2W.

The post-processing unit 2W is a single-wafer liquid processing unit that processes substrates W one by one. It comprises a box-shaped chamber 9 (see Figure 8 ) with a divided interior; a rotary chuck 70 (substrate holding mechanism, substrate holder) that holds a substrate W horizontally within the chamber 9 and rotates it about a linear axis A1 passing through the center of the substrate W; a stripping liquid supply unit 71 that supplies SPM, a type of resist stripping liquid, to the substrate W held on the rotary chuck 70; a rinse liquid supply unit 72; and a cylindrical cup 73 surrounding the rotary chuck 70. 8, the chamber 9 is formed with a loading/unloading port 9a for passing the substrate W, and is provided with a shutter 10 for opening and closing the loading/unloading port 9a. The chamber 9 is an example of a liquid processing chamber in which substrate processing using a processing liquid is performed.

The rotary chuck 70 includes a circular rotating base 74 that holds the substrate W horizontally; a plurality of chuck pins 75 that hold the substrate W horizontally above the rotating base 74; a rotation shaft 76 that extends downward from the center of the rotating base 74; and a rotary motor 77 that rotates the rotation shaft 76 to rotate the substrate W and the rotating base 74 about a rotation axis A1. The rotary chuck 70 is not limited to a clamping chuck in which the plurality of chuck pins 75 contact the peripheral end surface of the substrate W. A vacuum chuck can also be used, which holds the substrate W horizontally by suctioning the back surface (lower surface) of the substrate W, which is not the device forming surface, to the upper surface of the rotating base 74.

Cup 73 is positioned outside the substrate W held on the spin chuck 70 (away from the rotation axis A1). Cup 73 surrounds the spin base 74. When processing liquid is supplied to the substrate W while the spin chuck 70 rotates the substrate W, cup 73 catches the processing liquid that is discharged around the substrate W. The processing liquid caught by cup 73 is then sent to a recovery device or drain unit (not shown).

The rinse liquid supply unit 72 includes a rinse liquid nozzle 80 that sprays rinse liquid toward the substrate W held on the spin chuck 70; a rinse liquid pipe 81 that supplies rinse liquid to the rinse liquid nozzle 80; and a rinse liquid valve 82 that switches the supply of rinse liquid from the rinse liquid pipe 81 to the rinse liquid nozzle 80 on and off. The rinse liquid nozzle 80 can be a fixed nozzle that sprays rinse liquid while its nozzle is stationary. The rinsing liquid supply unit 72 may include a rinsing liquid nozzle moving unit that moves the rinsing liquid nozzle 80 to move the landing position of the rinsing liquid on the upper surface of the substrate W.

When the rinse liquid valve 82 is opened, the rinse liquid supplied from the rinse liquid pipe 81 to the rinse liquid nozzle 80 is ejected from the rinse liquid nozzle 80 toward the center of the upper surface of the substrate W. The rinse liquid is, for example, pure water (deionized water: DIW). The rinse liquid is not limited to pure water and may also be carbonated water, electrolyzed ionized water, hydrogen water, ozone water, or hydrochloric acid water at a dilute concentration (e.g., approximately 10-100 ppm). The temperature of the rinse liquid may be room temperature or a temperature above room temperature (e.g., 70-90°C).

The stripping liquid supply unit 71 includes a stripping liquid nozzle 85 that sprays SPM toward the upper surface of the substrate W; a nozzle arm 86 having the stripping liquid nozzle 85 mounted at its front end; and a nozzle moving unit 87 that moves the stripping liquid nozzle 85 by moving the nozzle arm 86 .

The stripping liquid nozzle 85 is, for example, a straight nozzle that ejects SPM in a continuous flow. It is mounted on a nozzle arm 86 in a vertical position, for example, to eject the processing liquid perpendicularly to the upper surface of the substrate W. The nozzle arm 86 extends horizontally and is configured to rotate around a pivot axis (not shown) extending in the vertical direction around the rotary chuck 70.

The nozzle moving unit 87 rotates the nozzle arm 86 about a swing axis to horizontally move the stripping liquid nozzle 85 along a trajectory that passes through the center of the upper surface of the substrate W when viewed from above. The nozzle moving unit 87 horizontally moves the stripping liquid nozzle 85 between a processing position where the SPM ejected from the stripping liquid nozzle 85 lands on the upper surface of the substrate W and a stationary position where the stripping liquid nozzle 85 is located around the rotary chuck 70 when viewed from above. The processing positions include: a central position, where the SPM ejected from the stripping liquid nozzle 85 lands on the central portion of the upper surface of the substrate W; and a peripheral position, where the SPM ejected from the stripping liquid nozzle 85 lands on the peripheral portion of the upper surface of the substrate W.

The stripping liquid supply unit 71 includes a sulfuric acid pipe 89 connected to the stripping liquid nozzle 85 and supplied with sulfuric acid (H ₂ SO ₄ ) from a sulfuric acid supply source 88 ; and a hydrogen peroxide solution pipe 95 connected to the stripping liquid nozzle 85 and supplied with hydrogen peroxide solution (H ₂ O ₂ ) from a hydrogen peroxide solution supply source 94 .

The sulfuric acid supplied from the sulfuric acid supply source 88 and the hydrogen peroxide solution supplied from the hydrogen peroxide solution supply source 94 are both aqueous solutions. The concentration of the sulfuric acid is, for example, 90-98%, and the concentration of the hydrogen peroxide solution is, for example, 30-50%.

On the sulfuric acid piping 89 from the stripping liquid nozzle 85, a sulfuric acid valve 90 is installed in this order to open and close the sulfuric acid piping 89, a sulfuric acid flow regulating valve 91 is installed to change the flow rate of the sulfuric acid, and a heater 92 is installed to heat the sulfuric acid. Heater 92 heats the sulfuric acid to a temperature higher than room temperature (a fixed temperature within the range of 70-190°C, for example, 90°C).

A hydrogen peroxide valve 96 for opening and closing the hydrogen peroxide pipe 95 and a hydrogen peroxide flow regulating valve 97 for varying the flow rate of hydrogen peroxide are sequentially installed on the hydrogen peroxide pipe 95 from the stripping liquid nozzle 85. Unconditioned hydrogen peroxide at room temperature (e.g., approximately 23°C) is supplied to the hydrogen peroxide valve 96 through the hydrogen peroxide pipe 95.

The stripping liquid nozzle 85 has, for example, a generally cylindrical housing. A mixing chamber is formed within the housing. A sulfuric acid pipe 89 is connected to a sulfuric acid inlet located on the side wall of the stripping liquid nozzle 85 housing. A hydrogen peroxide solution pipe 95 is connected to a hydrogen peroxide solution inlet located on the side wall of the stripping liquid nozzle 85 housing.

When the sulfuric acid valve 90 and the hydrogen peroxide solution valve 96 are opened, sulfuric acid (high-temperature sulfuric acid) from the sulfuric acid pipe 89 is supplied to the mixing chamber inside the stripping liquid nozzle 85 from the sulfuric acid inlet, and hydrogen peroxide solution from the hydrogen peroxide solution pipe 95 is supplied to the mixing chamber inside the stripping liquid nozzle 85 from the hydrogen peroxide solution inlet.

The sulfuric acid and hydrogen peroxide solution flowing into the mixing chamber of the stripping liquid nozzle 85 are thoroughly stirred and mixed in the mixing chamber. This mixing uniformly mixes _the sulfuric acid and hydrogen peroxide solution, and through their reaction, SPM is produced. SPM contains peroxymonosulfuric acid ( _H2SO5 ), which has a strong oxidizing ability. Because the heated sulfuric acid is supplied at a high temperature, and the mixing of the sulfuric acid and hydrogen peroxide solution is an exothermic reaction, high-temperature SPM is produced. Specifically, SPM is produced at a temperature higher than the temperature of either the sulfuric acid or hydrogen peroxide solution before mixing (above 100°C, for example, 160°C). The high-temperature SPM generated in the mixing chamber of the stripping liquid nozzle 85 is ejected toward the substrate W from the nozzle opening at the front end (lower end) of the housing.

FIG12 is a flowchart showing an example of the process of processing a substrate W by the substrate processing apparatus 1. Hereinafter, reference will be made to FIG8, FIG9, FIG11, and FIG12. The control apparatus 3 is programmed so that the substrate processing apparatus 1 performs the following operations.

While substrate processing apparatus 1 is processing substrates W, index robot IR, shuttle SH, and center robot CR transport substrates W placed in carrier C at loading port LP to pre-processing unit 2D (step S11 in FIG. 12 ). In pre-processing unit 2D, one of the two aforementioned resist stripping methods is performed to remove at least a portion of resist pattern 100 (see FIG. 5 ) (step S12 in FIG. 12 ).

Specifically, the central robot CR moves the substrate W into the pre-treatment unit 2D, and the in-chamber transport mechanism 6 transports the substrate W to the thermal treatment unit 8. Subsequently, steps are performed in the thermal treatment unit 8 until the hydrogen peroxide solution on the substrate W evaporates, drying the substrate W. After drying the substrate W, the in-chamber transport mechanism 6 transfers the substrate W from the heating plate 30 to the cooling plate 20, as needed. The cooling plate 20 cools the substrate W to room temperature or a temperature near room temperature. After drying or cooling the substrate W, the central robot CR removes the substrate W from the pre-treatment unit 2D and moves the removed substrate W into the post-treatment unit 2W (step S13 in FIG. 12 ).

In the post-processing unit 2W, a wet treatment (step S14 in FIG. 12 ) is performed. This wet treatment involves supplying a treatment liquid, such as an anti-etching stripping liquid, onto the upper surface of the substrate W while the substrate W is rotated. Specifically, a resist stripping liquid supply step is performed, in which the stripping liquid nozzle 85 sprays the resist stripping liquid toward the upper surface of the substrate W while the substrate W is rotated. Subsequently, a rinse liquid supply step is performed, in which the rinse liquid nozzle 80 sprays the rinse liquid toward the upper surface of the substrate W while the substrate W is rotated. Subsequently, a drying step is performed, in which the substrate W is dried by rotating the substrate W at high speed. Thereafter, the index robot IR, the shuttle SH, and the central robot CR transport the substrate W in the post-processing unit 2W to the carrier C placed on the load port LP (step S15 in FIG. 12 ).

As described above, in this embodiment, a hydrogen peroxide solution is brought into contact with the anti-etching pattern 100 formed on the surface of the substrate W. Furthermore, ozone gas is brought into contact with the hydrogen peroxide solution. Hydroxyl radicals are generated by the reaction between the ozone gas and the hydrogen peroxide. The hydroxyl radicals oxidize and decompose the anti-etching pattern 100. As a result, at least a portion of the anti-etching pattern 100 is stripped or removed. Hydroxyl radicals have a higher redox potential than ozone gas and possess a stronger oxidizing ability than ozone gas. Therefore, compared to the case where the anti-etching pattern 100 is oxidized and decomposed by ozone gas, the anti-etching pattern 100 can be removed more efficiently. This can reduce the amount of anti-corrosion agent stripping fluid containing sulfuric acid or eliminate its use, thereby reducing the environmental burden.

In this embodiment, the hydrogen peroxide solution is heated indirectly or directly after being supplied to the substrate W. Alternatively, the heated hydrogen peroxide solution is supplied to the substrate W. This allows ozone gas to come into contact with the hydrogen peroxide solution at a temperature higher than room temperature, which promotes the generation of hydroxyl radicals. As a result, the number of hydroxyl radicals that react with the resist pattern 100 increases, enabling more efficient removal of the resist pattern 100.

In this embodiment, the hydrogen peroxide solution is heated at a temperature below its boiling point. This reduces the rate at which the hydrogen peroxide solution evaporates from the substrate W, maintaining the hydrogen peroxide solution on the substrate W. If a large amount of hydrogen peroxide solution is retained on the substrate W, even if the hydrogen peroxide solution is heated at a temperature above its boiling point, the hydrogen peroxide solution can be maintained on the substrate W for a relatively long time. However, in this case, the thickness of the hydrogen peroxide solution droplets or film on the substrate W increases, reducing the number of hydroxyl radicals reaching the surface of the anti-etching pattern 100. By heating the hydrogen peroxide solution at a temperature lower than the boiling point of the hydrogen peroxide solution, the hydrogen peroxide solution can be maintained on the substrate W even if thick hydrogen peroxide solution droplets or a liquid film is not formed on the substrate W.

In this embodiment, the hydrogen peroxide solution is heated to a temperature below the boiling point of water, namely 100°C. This reduces the rate of water evaporation from the hydrogen peroxide solution on the substrate W, maintaining the water level on the substrate W without forming thick hydrogen peroxide droplets or a film on the substrate W. Hydroxyl radicals are generated not only by the reaction between ozone gas and hydrogen peroxide, but also by the reaction between ozone gas and water. This increases the number of hydroxyl radicals that react with the anti-etching pattern 100.

When the resist pattern 100 is heated, the solvent contained in the resist pattern 100 vaporizes. When a hardened layer 101 forms on the surface of the resist pattern 100, the vaporized solvent is difficult to expel, causing the pressure inside the resist pattern 100 to increase. The series of steps from resist application to resist stripping includes heating the substrate W, such as pre-baking or post-baking. The maximum temperature of the substrate W during this series of steps is defined as the maximum temperature. Because the hardened layer 101 forms on the surface of the resist pattern 100, when the temperature of the resist pattern 100 is significantly higher than the maximum temperature, the pressure inside the resist pattern 100 is unlikely to increase.

When heating the hydrogen peroxide solution at a peeling-promoting temperature higher than room temperature, setting the peeling-promoting temperature to a temperature lower than the boiling point of the hydrogen peroxide solution or lower than the boiling point of water allows the temperature of the heated resist pattern 100 to approach the maximum temperature of the substrate W during the aforementioned series of steps. Alternatively, the temperature of the heated resist pattern 100 can be set below the maximum temperature. This prevents the internal pressure of the resist pattern 100 from increasing even when a hardened layer 101 is formed on the surface of the resist pattern 100.

In this embodiment, a hydrogen peroxide solution is heated to a peeling-promoting temperature higher than room temperature and intermittently supplied to the surface of the substrate W. Specifically, the hydrogen peroxide solution is supplied to the surface of the substrate W and maintained there. During the period when the supply of hydrogen peroxide solution is stopped (interrupted) (the period when the addition of hydrogen peroxide solution is stopped), the amount of hydrogen peroxide solution on the substrate W decreases due to evaporation or reaction with ozone gas. The supply of hydrogen peroxide solution to the surface of the substrate W is resumed, and the surface of the substrate W is added with hydrogen peroxide solution. This reduces the consumption of hydrogen peroxide solution compared to a continuous supply of hydrogen peroxide solution, and maintains the hydrogen peroxide solution on the substrate W. In addition, compared to the case of continuously supplying the hydrogen peroxide solution, the droplets or liquid film of the hydrogen peroxide solution on the substrate W can be made thinner.

In this embodiment, ozone gas is brought into contact with the hydrogen peroxide solution in contact with the substrate W, rather than with the entire surface of the substrate W being covered by a liquid film of hydrogen peroxide solution. Instead, multiple droplets of hydrogen peroxide solution are dispersed over the entire surface of the substrate W. This allows for more efficient removal of the resist pattern 100 than when the entire surface of the substrate W is covered by a liquid film of hydrogen peroxide solution. The reasons are as follows.

The number of hydroxyl radicals (OH) supplied to the interface between the resist pattern 100 and the hydrogen peroxide solution, namely the solid-liquid interface 111 (see FIG. 4 ), increases as the resist pattern 100 approaches the boundary between the ozone gas, the hydrogen peroxide solution, and the three-state boundary 112 (see FIG. 4 ). This is because hydroxyl radicals quickly transform back into hydrogen peroxide. Therefore, if the shortest distance from the surface of the hydrogen peroxide solution droplet or film to the solid-liquid interface 111 is long, the hydroxyl radicals will disappear before reaching the solid-liquid interface 111. Therefore, the resist pattern 100 in contact with the hydrogen peroxide solution can be more efficiently removed near the three-state boundary 112 than at locations farther from the three-state boundary 112.

The total length (total length) of the three-state boundary 112 when multiple droplets of hydrogen peroxide solution are dispersed over the entire surface of the substrate W is greater than the total length of the three-state boundary 112 when the entire surface of the substrate W is covered by a liquid film of hydrogen peroxide solution. As described above, the resist pattern 100 in contact with the hydrogen peroxide solution can be more efficiently removed near the three-state boundary 112 than at locations farther from the three-state boundary 112. For these reasons, the resist pattern 100 can be more efficiently removed than when the entire surface of the substrate W is covered by a liquid film of hydrogen peroxide solution.

In this embodiment, a hydrogen peroxide solution mist is applied to the surface of the substrate W. The hydrogen peroxide solution mist is composed of a plurality of hydrogen peroxide solution particles. The hydrogen peroxide solution particles on the substrate W combine with other hydrogen peroxide solution particles to form hydrogen peroxide solution droplets (aggregates of hydrogen peroxide solution with a diameter larger than the hydrogen peroxide solution particles) on the surface of the substrate W. If the surface of the anti-etching pattern 100 is hydrophobic, multiple hydrogen peroxide solution droplets are formed and dispersed over the entire surface of the substrate W. If the surface of the anti-etching pattern 100 is hydrophilic, a hydrogen peroxide solution film is formed that covers the entire surface of the substrate W. Thus, compared with the case where a continuous liquid column of hydrogen peroxide solution is formed from the liquid column nozzle 51B to the surface of the substrate W, thinner liquid droplets or liquid films of the hydrogen peroxide solution can be formed.

In this embodiment, hydrogen peroxide solution is continuously ejected from the liquid column nozzle 51B toward the surface of the substrate W, causing the hydrogen peroxide solution to collide with the surface of the substrate W. The hydrogen peroxide solution ejected from the liquid column nozzle 51B forms a continuous stream of hydrogen peroxide solution extending from the liquid column nozzle 51B to the surface of the substrate W. If the surface of the anti-etching pattern 100 is hydrophobic, multiple droplets of hydrogen peroxide solution are formed and dispersed over the entire surface of the substrate W. If the surface of the anti-etching pattern 100 is hydrophilic, a liquid film of hydrogen peroxide solution is formed that covers the entire surface of the substrate W. Thus, compared to the case where a mist of hydrogen peroxide solution is supplied to the surface of the substrate W, liquid droplets or a liquid film of the hydrogen peroxide solution can be formed in a shorter time.

In this embodiment, ozone gas is brought into contact with the surface of the substrate W to reduce the hydrophobicity of the surface of the anti-etching pattern 100. This reduces the contact angle of water with the surface of the anti-etching pattern 100. In this state, a hydrogen peroxide solution is supplied to the surface of the substrate W. If the surface of the anti-etching pattern 100 is hydrophobic, a hydrogen peroxide solution film that covers the entire surface of the substrate W cannot be formed unless the hydrogen peroxide solution is supplied at a high flow rate. However, in this case, the consumption of hydrogen peroxide solution increases, and a thicker hydrogen peroxide solution film is formed. By supplying the hydrogen peroxide solution after the surface of the resist pattern 100 has been hydrophilized, the consumption of the hydrogen peroxide solution can be reduced, and a thinner hydrogen peroxide solution film can be formed that covers the entire surface of the substrate W. Furthermore, because ozone gas is used not only to remove the resist pattern 100 but also to hydrophilize the surface of the resist pattern 100, the number of pipes, valves, and other fluid equipment used to process the substrate W can be reduced compared to the use of liquids or gases other than ozone gas to hydrophilize the surface of the resist pattern 100.

In this embodiment, after all or part of the resist pattern 100 is stripped or removed using hydroxyl radicals generated by the reaction of ozone gas and hydrogen peroxide, a resist stripping liquid is supplied to the surface of the substrate W. Even if a portion of the resist pattern 100 remains on the surface of the substrate W, the resist pattern 100 is stripped from the surface of the substrate W due to contact with the resist stripping liquid. Even if residue from the resist pattern 100 remains on the surface of the substrate W, it is washed away by the resist stripping liquid. This reduces the amount of resist remaining on the surface of the substrate W.

Another Embodiment If all or nearly all of the resist can be stripped from the substrate W by supplying ozone gas and hydrogen peroxide solution to the substrate W, then after supplying oxygen gas and hydrogen peroxide solution to the substrate W, a resist stripping solution with a higher oxidizing power than the rinse solution may not be supplied to the substrate W. In this case, a rinse solution such as pure water may be supplied to the surface of the substrate W to rinse away residue from the resist pattern 100. In particular, since the use of resist stripping solutions containing sulfuric acid, such as SPM, can be reduced or eliminated, the environmental load can be reduced.

If ozone gas and hydrogen peroxide solution are used to remove a portion of the hardened layer 101 of the resist pattern 100, the supply of ozone gas to the substrate W can be stopped before the cavity 103 (see FIG. 5 ) is formed in the hardened layer 101 by reaching the non-hardened portion 102. Even with this method, the time required to strip all of the resist pattern 100 from the substrate W can be shortened compared to a case where the resist stripping solution is supplied to the substrate W without removing a portion of the hardened layer 101 of the resist pattern 100.

Alternatively, the hydrogen peroxide solution can be heated to a temperature above its boiling point. In this case, the substrate W can be heated to a temperature above 150°C. Using this method, the ozone gas can be heated at a temperature above 150°C through the substrate W. This increases the activity of the ozone gas, allowing the ozone gas to not only generate hydroxyl radicals through the reaction between the ozone gas and hydrogen peroxide, but also oxidize and decompose the resist pattern 100.

Alternatively, the ozone gas may be in contact with a hydrogen peroxide solution at room temperature instead of the ozone gas. In other words, the substrate W may not be heated, or a hydrogen peroxide solution at a temperature higher than room temperature may not be supplied to the substrate W.

Supplying ozone gas and hydrogen peroxide solution to the surface of the substrate W and supplying an anti-etching stripping liquid to the surface of the substrate W can be performed in different substrate processing apparatuses 1. More specifically, after supplying ozone gas and hydrogen peroxide solution to the substrate W, the substrate W can be transported to another substrate processing apparatus 1, where the anti-etching stripping liquid can be supplied to the surface of the substrate W within the substrate processing apparatus 1. Alternatively, after supplying ozone gas and hydrogen peroxide solution to the substrate W, the anti-etching stripping liquid can be supplied to the surface of the substrate W without transporting the substrate W. For example, ozone gas and hydrogen peroxide solution may be supplied to the surface of the substrate W held on the spin chuck 70 , and then, an anti-etching agent stripping solution may be supplied to the surface of the substrate W held on the spin chuck 70 .

The substrate processing apparatus 1 is not limited to an apparatus for processing a circular plate-shaped substrate W, but may also be an apparatus for processing a polygonal substrate W.

You can combine two or more of the above components. You can also combine two or more of the above steps.

Although the embodiments of the present invention are described in detail, they are only used to illustrate specific examples of the technical content of the present invention and should not be limited to these specific examples. The scope of the present invention is only defined by the scope of the accompanying patents.

[Related Applications] This application is based upon and claims priority from Japanese Patent Application No. 2022-080693, filed on May 17, 2022. The entire contents of that application are incorporated herein by reference.

1: Substrate processing unit 2: Processing unit 2D: Pre-processing unit 2W: Post-processing unit 3: Control unit 3m: Memory 3p: Processor 4: Chamber 4a: Load/unload port 5: Baffle 6: In-chamber transfer mechanism 6H: In-chamber transfer arm 7: Cooling unit 8: Thermal treatment unit 9: Chamber 9a: Load/unload port 10: Baffle 20: Cooling plate 20a: Cooling surface 22: Lifting pin 23: Pin lift drive mechanism 30: Heating plate 30a: Heating surface 33: Heater 34: Thermal treatment chamber 35: Chamber body 35a: Opening 36: Lid 37: Lid lift drive mechanism 38: Lifting pin 39: Pin lift drive mechanism 41: Exhaust port 42: Exhaust line 45: Plate 46: Cylinder 49: Gas supply line 51A: Mist nozzle 51B: Liquid column nozzle 52: Hydrogen peroxide solution line 53: Hydrogen peroxide solution valve 54: Hydrogen peroxide solution supply source 55: Ozone nozzle 56: Ozone line 57: Ozone valve 58: Ozone generator 59: Shower plate 60: Gas-liquid separator 70: Rotary chuck 71: Stripping liquid supply unit 72: Rinse fluid supply unit 73: Cup 74: Rotary base 75: Chuck pin 76: Rotary shaft 77: Rotary motor 80: Rinse fluid nozzle 81: Rinse fluid piping 82: Rinse fluid valve 85: Stripping fluid nozzle 86: Nozzle arm 87: Nozzle movement unit 88: Sulfuric acid supply source 89: Sulfuric acid piping 90: Sulfuric acid valve 91: Sulfuric acid flow control valve 92: Heater 94: Hydrogen peroxide supply source 95: Hydrogen peroxide piping 96: Hydrogen peroxide valve 97: Hydrogen peroxide flow control valve 100: Anti-corrosion pattern 101: Hardened layer 102: Non-hardened area 103: Void 111: Solid-liquid interface 112: Tri-state boundary A1: Rotation axis C: Carrier CR: Center robot H: Hand IR: Indexing robot LP: Loading port S1: Step S2: Step S3: Step S4: Step S5: Step S6: Step S11: Step S12: Step S13: Step S14: Step S15: Step SH: Shuttle W: Substrate

Figure 1 is a diagram illustrating steps of an example substrate processing including resist stripping according to an embodiment of the present invention. Figure 2 is a schematic cross-sectional view illustrating an example resist pattern according to an embodiment of the present invention. Figures 3A-C are schematic diagrams illustrating an example resist stripping according to an embodiment of the present invention. Figures 3D-F are schematic diagrams illustrating an example resist stripping according to an embodiment of the present invention. Figure 4 is a schematic diagram illustrating a situation in which ozone gas in droplets of a hydrogen peroxide solution dissolved on a substrate reacts with hydrogen peroxide contained in the hydrogen peroxide solution to generate hydroxyl radicals. Figure 5 is a vertical cross-sectional view of a lead sheet showing an example of an image of a resist pattern with voids formed in a hardened layer. Figures 6A-C are schematic diagrams illustrating another example of resist stripping according to an embodiment of the present invention. Figure 6D is a schematic diagram illustrating another example of resist stripping according to an embodiment of the present invention. Figure 7 is a schematic diagram illustrating the reaction of ozone gas dissolved in a hydrogen peroxide solution film on a substrate with hydrogen peroxide contained in the hydrogen peroxide solution to generate hydroxyl radicals. Figure 8 is a schematic top view illustrating the layout of a substrate processing apparatus according to an embodiment of the present invention. Figure 9 is a cross-sectional view showing an example of a vertical cross section of a pre-processing unit. Figure 10A is a cross-sectional view showing an example of a vertical cross section of a heat treatment unit. Figure 10B is a cross-sectional view showing another example of a vertical cross section of a heat treatment unit. Figure 11 is a cross-sectional view showing an example of a vertical cross section of a post-processing unit. Figure 12 is a diagram showing an example of steps in substrate processing performed by the substrate processing apparatus.

100: Anti-corrosion pattern

101: Hardened layer

102: Non-hardened part

103: Hollow

112: Three-State Boundary

Claims (7)

A substrate processing method includes: a hydrogen peroxide solution supplying step of supplying a hydrogen peroxide solution mist to a surface of a substrate having an anti-etching pattern formed thereon; and an ozone gas supplying step of supplying ozone gas to the hydrogen peroxide solution in contact with the substrate. The ozone gas supplying step includes the following steps: supplying the ozone gas to the hydrogen peroxide solution in contact with the substrate while a plurality of hydrogen peroxide solution droplets are dispersed over the entire surface of the substrate. The substrate processing method of claim 1 further comprises a hydrogen peroxide solution heating step, which is to heat the hydrogen peroxide solution at a peeling promotion temperature higher than room temperature before or after the hydrogen peroxide solution is supplied to the substrate. The substrate processing method of claim 2, wherein the stripping promotion temperature does not reach the boiling point of the hydrogen peroxide solution. The substrate processing method of claim 2, wherein the above-mentioned stripping promotion temperature does not reach the boiling point of water. The substrate processing method of claim 2, wherein the hydrogen peroxide solution supplying step includes: an initial supplying step of supplying the hydrogen peroxide solution to the surface of the substrate; and a resupplying step of supplying the hydrogen peroxide solution to the surface of the substrate after stopping the supply of the hydrogen peroxide solution to the surface of the substrate. The substrate processing method of any one of claims 1 to 5 further includes a stripping liquid supply step, wherein after supplying the ozone gas to the hydrogen peroxide solution in contact with the substrate, an anti-etching agent stripping liquid is supplied to the surface of the substrate to strip the anti-etching pattern from the surface of the substrate. A substrate processing apparatus includes: a hydrogen peroxide solution nozzle for supplying a mist of hydrogen peroxide solution to a surface of a substrate having an anti-etching pattern formed thereon; and an ozone nozzle for supplying ozone gas to the hydrogen peroxide solution in contact with the substrate. The ozone nozzle supplies the ozone gas to the hydrogen peroxide solution in contact with the substrate while a plurality of hydrogen peroxide solution droplets are dispersed over the entire surface of the substrate.