JP2003031547A - Method and apparatus for supercritical drying - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rapidly execute supercritical drying by removing rinsing liquid retained in a pattern, in a short time. SOLUTION: A method for supercritically drying comprises the steps of fixing a substrate 104 immersed in the rinsing liquid to a substrate holder 102, then hermetically sealing a high-pressure chamber 101, and pumping a liquefied carbon dioxide from an inlet 105 to set in the chamber 101 to a state, in which the carbon dioxide is filled. The method further comprises the steps of introducing the liquefied carbon dioxide into the chamber 101 to a state, in which the substrate 104 is dipped in the liquefied carbon dioxide, and then supplying a power to an ultrasonic wave generating means 103 to generate ultrasonic waves.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supercritical drying method used when forming a fine pattern used for forming a semiconductor device, and more particularly to a supercritical drying method and apparatus used when forming a fine pattern by a lithography technique. .

[0002]

2. Description of the Related Art In order to manufacture a large-scale and high-performance device such as an LSI, it is necessary to form a fine pattern. As a technique for forming a fine pattern, there is a lithographic technique in which exposure, development, and rinse treatments are first performed for a resist pattern and the like. The resist pattern formed by this lithography technique is composed of a polymer material that is sensitive to light, X-rays, electron beams, and the like. Further, there is an etching technique that goes through etching, washing with water, and rinsing.

However, when an extremely fine pattern is formed by the above-described pattern forming technique, a phenomenon that the pattern collapses occurs, and there is a problem that a pattern that satisfies the intended purpose cannot be formed. Explaining the phenomenon that this pattern collapses, as shown in FIG. 6A, a resist pattern 602 formed on a substrate 601.
At the stage of removing the rinse liquid after immersing the rinse liquid 603 in the rinse liquid 603, as shown in FIG. 6B, the rinse liquid 603a remains between the adjacent resist patterns 602 at a minute interval. In such a state, the capillary force 610 of the rinse liquid 603 a acts on the pattern 602, and the rinse liquid 603 a.
After all the a is removed by drying, as shown in FIG.
The pattern 602 collapses.

The capillary force 610 is caused by the rinse liquid 603a remaining between a plurality of fine patterns arranged at fine intervals.
It occurs due to the difference between the internal pressure and the atmospheric pressure, and is related to the surface tension of the rinse liquid 603a. Therefore, the greater the surface tension of the rinse liquid, the greater the capillary force and the more easily the pattern collapses. In order to solve the pattern collapse due to the capillary force, the rinse treatment may be performed using a rinse liquid having a small surface tension.

Surface tension is generated in the state where an interface between liquid and gas is formed. Therefore, if the rinse process can be performed without forming the interface between the liquid and the gas, it is possible to suppress the pattern collapse. There is a method using a supercritical fluid as a method for performing a rinsing process without forming an interface between the liquid and the gas. In this method, after immersing in the rinse liquid, the rinse liquid is replaced with a supercritical fluid, and the supercritical fluid is vaporized in a state where only the supercritical fluid is in contact with the pattern.

The supercritical fluid has both gas diffusibility and liquid solubility (high density), and can change its state to gas without passing through the equilibrium line. Therefore, as described above, when drying is performed from the state of being filled with the supercritical state, the liquid / gas interface in which the surface tension is generated is not formed in the drying, and the drying can be performed in the state where the surface tension is not generated. . As a result, drying using supercritical fluid (rinsing process)
Then, it becomes possible to suppress pattern collapse.

As a supercritical fluid generally used,
There is a safe carbon dioxide that has a low critical point, which is a supercritical point, and is nonflammable. In addition, in order to perform supercritical drying,
As shown in FIG. 7, a high pressure chamber 70 capable of withstanding high pressure.
A supercritical drying apparatus including a substrate holder 702 on which a substrate 704 to be processed is placed is used. This apparatus is provided with an inlet 705 for introducing liquefied carbon dioxide and an outlet 706 for discharging the fluid inside the apparatus.

In supercritical drying using this supercritical drying apparatus, first, the resist pattern formed on the substrate 704 is immersed in a rinse liquid, and then the substrate 704 is held by the substrate holder 7.
02, and the high-pressure chamber 701 is sealed. Before the rinse liquid on the substrate 704 is not dried, liquefied carbon dioxide is introduced into the high-pressure chamber 701, the introduced liquefied carbon dioxide is mixed with the rinse liquid, and the rinse liquid adhering to the resist pattern is liquefied carbon dioxide. Replace with. Since carbon dioxide is liquefied even at room temperature when a pressure of about 6 MPa is applied, it is necessary to raise the pressure to this level in the high pressure chamber 701.

After the inside of the high-pressure chamber 701 is filled with liquefied carbon dioxide and the substrate 704 is completely covered with the liquefied carbon dioxide, the pressure and temperature in the high-pressure chamber 701 are controlled so that the liquefied carbon dioxide becomes a supercritical state. Then, the high pressure chamber 701 is filled with carbon dioxide in a supercritical state. After that, the introduction of liquefied carbon dioxide from the inlet 705 is stopped, and the fluid inside is continuously discharged from the outlet 706, thereby lowering the pressure in the high-pressure chamber 701 and vaporizing the supercritical carbon dioxide inside. , Dry the resist pattern. At this time, since supercritical carbon dioxide vaporizes on the resist pattern surface without liquefying, surface tension does not occur and pattern collapse does not occur.

In order to prevent pattern collapse due to the above-mentioned supercritical drying, it is essential to completely replace the rinse liquid adhering to the resist pattern surface as a result of the rinse treatment with liquefied carbon dioxide. . However, carbon dioxide, which has no dipole moment, basically has a low solubility property similar to a hydrocarbon solvent, and is therefore difficult to mix with alcohol or water generally used as a rinse liquid. Therefore, it takes a lot of time to introduce and replace the liquefied carbon dioxide. As a method for solving this problem, as described in JP-A-11-87306, a vibration plate that oscillates ultrasonic waves is attached outside the high pressure chamber to mix the rinse liquid and the liquefied carbon dioxide in the high pressure chamber. There is technology to promote it.

[0011]

However, in the above-mentioned conventional technique, since ultrasonic waves are applied through the wall of the high pressure chamber, the rinsing liquid and the liquefied carbon dioxide are not mixed in the high pressure chamber so much. Not promoted,
The time for this replacement could not be shortened much. The present invention has been made to solve the above problems, and by removing the rinse liquid remaining in the pattern in a shorter time, it is possible to more quickly perform supercritical drying. To aim.

[0012]

A supercritical drying method according to one aspect of the present invention comprises a first step of exposing a pattern layer having a predetermined pattern formed on a substrate to a rinse solution, and a rinse solution for the pattern layer. Second step of placing the substrate in a container in which the pattern layer is exposed, and introducing the liquid of the substance that is a gas in the atmosphere into the container so that the pattern layer is exposed to the liquid of the substance. And ultrasonic waves are applied to the liquid from an ultrasonic wave generation section arranged in the container away from the inner wall of the container to remove the rinse liquid adhering to the pattern layer.
And a fourth step of making the liquid of the substance introduced into the container into a supercritical fluid in a supercritical state and exposing the pattern layer to the supercritical fluid, and the supercritical fluid in the container The fifth step is to reduce the internal pressure of the container by discharging the supercritical fluid to vaporize the supercritical fluid so that the pattern layer is exposed to the gas. According to this supercritical drying method, by applying ultrasonic waves, the rinse liquid and the liquid of a substance that is a gas in the atmosphere become emulsified.

A supercritical drying method according to one aspect of the present invention includes a hermetically sealed container in which a substrate to be processed is placed, and a liquid supply means for supplying a liquid of a substance that is a gas in the atmosphere into the container. A discharge means for discharging the fluid introduced into the reaction chamber, a control means for pressurizing and controlling the pressure in the reaction chamber to a pressure at which the substance becomes a supercritical state, and a temperature control for controlling the temperature in the reaction chamber to a predetermined temperature. And an ultrasonic wave generation means provided with an ultrasonic wave generation unit which is disposed in the container away from the inner wall of the container and applies an ultrasonic wave into the container. According to this supercritical drying apparatus, ultrasonic waves are applied to the liquid introduced into the container from the ultrasonic wave generating unit without passing through the container.

In the above-mentioned supercritical drying apparatus, the ultrasonic wave generating section can be included in, for example, a substrate holder on which a substrate placed in a container is placed. Further, the ultrasonic wave generating means may be composed of a vibrator arranged outside the container, and an ultrasonic wave generating unit serving as a resonator that resonates with the vibration oscillated by the vibrator to generate ultrasonic vibration. it can.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing a configuration example of a supercritical drying device according to an embodiment of the present invention. This supercritical drying device has, for example, 10M inside.
An ultrasonic wave generation means 103 is provided on a substrate holder 102 fixed in the high pressure chamber 101, which is provided with a high pressure chamber (container) 101 capable of containing a supercritical fluid of about Pa.
Is included. The ultrasonic wave generation means 103 is composed of an ultrasonic wave oscillator and a vibration plate (ultrasonic wave generation section).

The ultrasonic wave generation means 103 has a vibrating plate as a resonator fixed to a vibrator, which is an electromechanical conversion element in which vibration is excited when an electric signal is applied, and the resonator resonates. A large-amplitude ultrasonic vibration is generated by utilizing the action. By supplying power to the ultrasonic vibrator to generate ultrasonic vibration, the ultrasonic generator 10
The vibrating plate 3 (ultrasonic wave generator) generates ultrasonic waves, and the generated ultrasonic waves propagate inside the high-pressure chamber 101.

The supercritical drying device is provided with an inlet 105 for introducing a liquid of a substance that is a gas in the atmosphere such as liquefied carbon dioxide, and the liquid is pressure-fed by communicating with the inlet 105 (not shown). And a liquid supply means such as a cylinder for storing the liquid. Further, the supercritical drying device is provided with a discharge port (discharge means) 106 for discharging the fluid in the high pressure chamber 101. Outlet 106
Although not shown in the figure, a control valve or the like for controlling the discharge amount is provided, and the pressure inside the high-pressure chamber 101 can be controlled.

The supercritical drying method using the supercritical drying apparatus shown in FIG. 1 will be described below. After the substrate 104 soaked in the rinse liquid is fixed to the substrate holder 102, the high pressure chamber 101 is closed and the inlet port is introduced. Liquefied carbon dioxide is pressure-fed from 105 so that the inside of the high-pressure chamber 101 is filled with the liquefied carbon dioxide. When liquefied carbon dioxide is introduced into the high-pressure chamber 101 and the substrate 104 is immersed in the liquefied carbon dioxide, electric power is supplied to the ultrasonic wave generation means 103 to generate ultrasonic waves.

As a result, the rinse liquid adhering to the pattern (pattern layer) on the substrate 104 quickly mixes with the liquefied carbon dioxide, and the liquefied carbon dioxide of the rinse liquid adhered to the pattern is Replacement is completed in a shorter time. After this replacement, the pressure in the high-pressure chamber 101 is set to 7.5 MPa, and the temperature is set to 31 ° C.
With the above, the liquefied carbon dioxide in the high pressure chamber 101 is brought into a supercritical state. At this time, the periphery of the pattern on the substrate 104 is in a state of only supercritical carbon dioxide.

After the carbon dioxide in the high-pressure chamber 101 is brought into a supercritical state, the introduction of liquefied carbon dioxide from the inlet 105 is stopped and the fluid inside is discharged from the outlet 106, whereby the pressure in the high-pressure chamber 101 is increased. And vaporize supercritical carbon dioxide. At this time, since the supercritical carbon dioxide is vaporized without being liquefied, no surface tension is generated. As a result, the pattern on the substrate 104 is dried without pattern collapse.

Here, the promotion of the mixing of the rinse liquid and the liquefied carbon dioxide by the application of the above-mentioned ultrasonic waves will be described.
First, as shown in FIG. 2A, a rinse liquid 203 is attached to a pattern 202 on a substrate 201, and the pattern 202 is placed in liquefied carbon dioxide 204. When applied, a cavitation phenomenon occurs. The cavitation phenomenon is a phenomenon in which bubbles are generated when a negative pressure is applied in a sound pressure cycle of a sound wave in a liquid, and the generated bubbles are crushed when the positive pressure is applied. When the bubbles are crushed, the shock wave generated at this time causes pressure fluctuation. When the ultrasonic wave of MHz body is applied, the cavitation phenomenon is reduced, but the rectilinear flow is generated. Due to the effect of this straight flow, the stirring action of the liquefied carbon dioxide in the high-pressure chamber 101 occurs.

As a result, as shown in FIG. 2B, the rinse liquid 203 attached to the pattern 202 is
Dispersed in the surrounding liquefied carbon dioxide 204,
The surrounding liquefied carbon dioxide 204 is dispersed in the rinse liquid 203 and diffuses with each other, resulting in liquefied carbon dioxide 204
And the rinse liquid 203 is emulsified. As a result of emulsification of the rinse liquid 203 and the liquefied carbon dioxide 204, pattern 20
The rinse liquid 203 disappears on the second surface, and as shown in FIG. 2C, the surroundings of the pattern 202 are liquefied carbon dioxide 204.
It will be covered with. After that, as described above, if the liquefied carbon dioxide is brought into a supercritical state and is vaporized, the drying can be performed without pattern collapse.

Conventionally, since the ultrasonic wave generating portion is fixed to the outer wall portion of the high pressure chamber having a structure (thickness of several cm or more) thick enough to withstand a high pressure of 10 MPa, first, a sufficient ultrasonic wave is generated. Could not be added to the liquid inside. Therefore, conventionally, even when ultrasonic waves are used, the mixing of the rinse liquid and the liquefied carbon dioxide in the high-pressure chamber is not promoted so much, and the time for this replacement cannot be shortened so much. . Also, in the past, since the ultrasonic wave generator (vibration plate) was fixed directly to the high-pressure chamber, the high-pressure chamber also resonated, and the joint part of the pipe for introducing and discharging high-pressure fluid was loosened and liquid leaked. Occasionally, it also occurred.

In contrast to such a conventional technique, in the present embodiment, the ultrasonic wave generator is arranged in the high pressure chamber at a distance from the inner wall, so that the liquefied carbon dioxide in the high pressure chamber (gas in the atmosphere is gas). It is possible to efficiently apply ultrasonic waves to the (liquid of the substance) and to efficiently replace (emulsify) the rinse liquid. Further, the high pressure chamber does not resonate, and the loosening of the joint portion of the pipe for introducing and discharging the high pressure fluid does not occur.

The frequency of ultrasonic waves is 20 to 1500 kHz, which is a commonly used band. Among them, 20 to 50 kHz is known as a frequency band in which the cavitation phenomenon easily occurs. Therefore, the most efficient frequency of the ultrasonic wave generated by the ultrasonic wave generation means 103 is 20 to 50 kHz. When a so-called megasonic having a frequency higher than this, for example, about 1 MHz is generated, the substitution efficiency is somewhat lower than the agitation by the cavitation because the agitation by the straight flow is mainly performed as described above. However, the use of high frequency reduces the resonance thickness, and as a result, it is possible to reduce the size of the thin layer below the ultrasonic wave generation, which is convenient for mounting the ultrasonic wave generation unit in a narrow high pressure chamber.

By the way, as shown in FIG. 1, in the structure in which the ultrasonic wave generating means 103 is arranged in the substrate holder 102, it is not necessary for the substrate holder 102 to withstand a high internal pressure. Therefore, it is not necessary to form the substrate holder 102 as thick as the high-pressure chamber 101, the distance from the ultrasonic wave generation means 103 to the surface of the substrate holder 102 can be shortened, and the ultrasonic wave generation means 103 is generated. Ultrasonic waves to the liquid around the substrate holder 102,
Can be added efficiently.

If the ultrasonic wave generating means 103 cannot be integrated in the substrate holder 102 and there is a space, as shown in FIG. 3, a resin is provided in the gap between the ultrasonic wave generating means 103 inside the substrate holder 102. It is sufficient to fill 301. By doing so, the deformation of the substrate holder 102 due to the high pressure in the high pressure chamber 101 can be suppressed.

The ultrasonic wave generating means 103 does not need to be entirely contained in the substrate holder 102, and a part of the vibration plate (ultrasonic wave generating portion) constituting the ultrasonic wave generating means 103 is in the high pressure chamber 101. To exist in. For example, as shown in FIG.
May be arranged in the high pressure chamber 101 above the substrate holder 102. Also, as shown in FIG.
The vibrator 103a is arranged outside the high-pressure chamber 101 and vibrates the vibration generated by the vibrator 103a.
It is also possible to extend a part (b) of ultrasonic wave (b) into the high-pressure chamber 101 and place the substrate 104 thereon. In this case, the high pressure chamber 101 of the vibration plate 103b
A portion that extends inside and on which the substrate 104 is placed serves as an ultrasonic wave generation unit.

The resonator does not have to be plate-shaped like a diaphragm, and may have any structure and form capable of resonating the vibration generated from the vibrator, and may be rod-shaped.
Further, the resonator that resonates the vibration from the vibrator into ultrasonic waves may be provided in the high-pressure chamber 101, and may be disposed, for example, on the side portion of the substrate holder 102. In any case, the ultrasonic wave generator may be arranged in the high-pressure chamber so as to be separated from the inner wall of the high-pressure chamber.

[0030]

Embodiments will be described in detail below based on embodiments. <Example 1> First, electron beam resist ZEP-7000 (manufactured by Zeon Corporation) was spin-coated on a silicon substrate to form a resist film having a film thickness of 250 nm. Then
The formed resist film is exposed to an electron beam to form a desired latent image, and then development treatment with normal hexyl acetate is performed.
-Perform a rinse treatment with propanol (rinse solution),
A resist pattern was formed on the silicon substrate. The formed pattern width was 20 to 100 nm.

Thereafter, within a time period during which the resist pattern can be kept wet with the rinse liquid, the silicon substrate (substrate 1
04) is placed on the substrate holder 102 in the high-pressure chamber 101, the high-pressure chamber 101 is sealed, and then the discharge port 1
With 06 closed, liquefied carbon dioxide was pressure-fed into the high-pressure chamber 101 at a rate of 100 ml / min from the inlet 105, so that the high-pressure chamber 101 was filled with liquefied carbon dioxide. At this time, the temperature of the high-pressure chamber 101 was set to 23 ° C. by controlling a container temperature controller (not shown).

At the same time as the inside of the high-pressure chamber 101 was filled with liquefied carbon dioxide, ultrasonic waves were generated by the ultrasonic wave generation means 103 and mixed with the liquefied carbon dioxide into which the rinse liquid adhering to the resist pattern was introduced. At this time, liquefied carbon dioxide in a predetermined pressure-feeding state was continuously introduced into the high-pressure chamber 101 while controlling the degree of opening of the discharge port 106, and the pressure in the high-pressure chamber 101 was controlled to be 7.5 MPa. . After ultrasonic waves were generated for 5 minutes, the temperature inside the high pressure chamber 101 was raised to 35 ° C. while maintaining the pressure inside the high pressure chamber 101 at 7.5 MPa.
Liquefied carbon dioxide in the high-pressure chamber 101 was brought into a supercritical state.

After that, the inlet 105 was closed to stop the supply of liquefied carbon dioxide, and the carbon dioxide was just discharged from the outlet 106, and the pressure in the high-pressure chamber 101 was set to atmospheric pressure. As a result, the substrate holder 102
On the silicon substrate placed on top, carbon dioxide in a supercritical state is vaporized and supercritical drying is performed. The resist pattern on the silicon substrate obtained as a result of this supercritical drying had no pattern collapse and a good pattern shape was obtained.

<Second Embodiment> Next, a second embodiment will be described. First, NEB-31, which is an electron beam resist, was spin-coated on a silicon substrate to form a resist film having a film thickness of 250 nm. Next, the formed resist film is exposed to an electron beam to form a desired latent image, followed by development treatment with an aqueous solution of tetramethylammonium hydroxide and rinsing treatment with pure water (rinse solution) to form a resist on the silicon substrate. A pattern was formed. The formed pattern width was 20 to 100 nm.

Thereafter, within a time period during which the resist pattern can be kept wet with the rinse liquid, the silicon substrate (substrate 1
04) is placed on the substrate holder 102 in the high-pressure chamber 101, the high-pressure chamber 101 is sealed, and then the discharge port 1
With 06 closed, liquefied carbon dioxide was pressure-fed into the high-pressure chamber 101 at a rate of 100 ml / min from the inlet 105, so that the high-pressure chamber 101 was filled with liquefied carbon dioxide. At this time, the temperature of the high-pressure chamber 101 was set to 23 ° C. by controlling a container temperature controller (not shown).

At the same time as the inside of the high-pressure chamber 101 was filled with liquefied carbon dioxide, ultrasonic waves were generated by the ultrasonic wave generation means 103 and mixed with the liquefied carbon dioxide into which the rinse liquid adhering to the resist pattern was introduced. At this time, liquefied carbon dioxide in a predetermined pressure-feeding state was continuously introduced into the high-pressure chamber 101 while controlling the degree of opening of the discharge port 106, and the pressure in the high-pressure chamber 101 was controlled to be 7.5 MPa. . After ultrasonic waves were generated for 5 minutes, the temperature inside the high pressure chamber 101 was raised to 35 ° C. while maintaining the pressure inside the high pressure chamber 101 at 7.5 MPa.
Liquefied carbon dioxide in the high-pressure chamber 101 was brought into a supercritical state.

After that, the inlet 105 was closed to stop the supply of liquefied carbon dioxide, and the carbon dioxide was only discharged from the outlet 106, and the pressure in the high-pressure chamber 101 was atmospheric pressure. As a result, the substrate holder 102
On the silicon substrate placed on top, carbon dioxide in a supercritical state is vaporized and supercritical drying is performed. The resist pattern on the silicon substrate obtained as a result of this supercritical drying had no pattern collapse and a good pattern shape was obtained.

By the way, in the above-described embodiment, the electron beam resist such as ZEP-7000 or NEB is used as the resist.
-31 using normal hexyl acetate, T as a developing solution
Using MAH, 2-propanol, water,
Although ethanol is used, it is not limited to this. The developing and rinsing processes may be performed inside the high pressure chamber 101 or may be performed outside.

Further, in the above description, the resist pattern of the polymer material is taken as an example of the pattern to be dried, but it may be applied to the drying of the pattern made of silicon or compound semiconductor. Further, although carbon dioxide is used as the supercritical fluid in the above description, it is not limited to this, and CHF
A substance having a critical point such as ₃ or NO ₂ may be used.

[0040]

As described above, according to the present invention,
Since the ultrasonic wave generator is arranged inside the container, removing the rinse liquid remaining in the pattern in a shorter time has an excellent effect that supercritical drying can be performed more quickly.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a configuration example of a supercritical drying device according to an embodiment of the present invention.

FIG. 2 is a process chart for explaining promotion of mixing of a rinse liquid and liquefied carbon dioxide by application of ultrasonic waves.

FIG. 3 is a schematic cross-sectional view showing a configuration of a substrate holder 102.

FIG. 4 is a schematic cross-sectional view showing a configuration example of a supercritical drying device according to another embodiment of the present invention.

FIG. 5 is a schematic cross-sectional view showing a configuration example of a supercritical drying apparatus according to another aspect of the present invention.

FIG. 6 is an explanatory diagram illustrating a phenomenon in which a pattern falls.

FIG. 7 is a schematic sectional view showing a configuration example of a conventional supercritical drying apparatus.

[Explanation of symbols]

101 ... High-pressure chamber (container), 102 ... Substrate holder, 103 ... Ultrasonic wave generation means, 104 ... Substrate, 105 ...
Inlet port, 106 ... Discharge port (discharging means).

Claims (4)

[Claims] 1. A first step of exposing a pattern layer having a predetermined pattern formed on a substrate to a rinse liquid, and a state in which the rinse liquid adheres to the pattern layer,
A second step of placing the substrate in a container, introducing a liquid of a substance that is a gas in the atmosphere into the container, and leaving the pattern layer exposed to the liquid of the substance; And a third step of applying ultrasonic waves to the liquid from an ultrasonic wave generating portion arranged apart from the inner wall of the container to remove the rinse liquid adhering to the pattern layer, and being introduced into the container. A fourth step in which the liquid of the substance is a supercritical fluid in a supercritical state and the pattern layer is exposed to the supercritical fluid; and the supercritical fluid in the container is discharged to the outside of the container. By so doing, the pressure inside the container is lowered, and the fifth step of vaporizing the supercritical fluid to leave the pattern layer exposed to the gas is included. 2. A hermetically sealed container in which a substrate to be processed is placed, a liquid supply means for supplying a liquid of a substance that is a gas in the atmosphere into the container, and a fluid introduced into the reaction chamber. A discharge means for discharging, a control means for pressurizing the pressure in the reaction chamber to a pressure at which the substance becomes a supercritical state, a temperature control means for controlling the temperature in the reaction chamber to a predetermined temperature, and the container A supercritical drying device, comprising: an ultrasonic wave generation unit provided inside the container, spaced apart from an inner wall of the container and provided with an ultrasonic wave generation unit for applying an ultrasonic wave into the container. 3. The supercritical drying device according to claim 2, wherein the ultrasonic wave generation unit is included in a substrate holder on which the substrate placed in the container is placed. Supercritical dryer. 4. The supercritical drying apparatus according to claim 2, wherein the ultrasonic wave generation means resonates with a vibrator arranged outside the container and a vibration oscillated by the vibrator to generate ultrasonic vibration. A supercritical drying apparatus comprising: the ultrasonic wave generating section that serves as a resonator for generating the ultrasonic wave.