CN114234569A

CN114234569A - Substrate drying device

Info

Publication number: CN114234569A
Application number: CN202111056537.6A
Authority: CN
Inventors: 申熙镛
Original assignee: Mujin Electronics Co ltd
Current assignee: Mujin Electronics Co ltd
Priority date: 2020-09-09
Filing date: 2021-09-09
Publication date: 2022-03-25
Also published as: KR102342095B1

Abstract

The present invention relates to a substrate drying apparatus including a substrate drying chamber, the substrate drying chamber including an upper housing; a lower case coupled to the upper case to be opened or closed; a wafer placing plate coupled to a bottom surface of the lower case and on which the substrate forming the organic solvent is placed; an integrated supply/discharge port formed to extend from a side surface of the lower case to a middle region of the lower case, and formed to place the plate facing the substrate in the middle region of the lower case and to provide a supply path of the supercritical fluid for initial pressurization and a discharge path of the mixed fluid in which the organic solvent formed on the substrate is dissolved; and an upper supply port formed to place the plate facing the substrate in a central region of the upper case to provide a supply path of the supercritical fluid for drying; and a flexible supply/discharge pipe coupled to a side surface of the lower case to provide a path through which the supercritical fluid for initial pressurization is supplied to the substrate drying chamber and a path through which the mixed fluid is discharged from the substrate drying chamber, and having a spiral coil shape.

Description

Substrate drying device

Technical Field

The present invention relates to a substrate drying apparatus. More particularly, the present invention relates to a substrate drying apparatus capable of improving supercritical drying efficiency by preventing a problem of damage to a metal pipe connected to a lower case due to repeated ascending/descending operations of the lower case, which are performed to open or close a chamber in a substrate drying process using a supercritical fluid, and thus fluid leakage, and by preventing heat loss of the fluid through a pipe.

Background

The manufacturing process of the semiconductor device includes various processes such as a photolithography process, an etching process, an ion implantation process, and the like. After each process is finished and before subsequent processes are performed, a cleaning process and a drying process are performed to remove impurities and residues remaining on the wafer surface to clean the wafer surface.

For example, in a wafer cleaning process after an etching process, a chemical liquid for the cleaning process is supplied onto a wafer surface, and then deionized water (DIW) is supplied to perform a rinsing process. After the rinsing process, a drying process is performed to remove DIW remaining on the surface of the wafer to dry the wafer.

For example, as a method of performing a drying process, a technique of drying a wafer by replacing DIW on the wafer with isopropyl IPA is known.

However, as shown in fig. 1, according to such a conventional drying technique, during drying, there arises a problem that a pattern formed on a wafer collapses due to the surface tension of IPA as a liquid.

In order to solve the above problems, a supercritical drying technique with zero surface tension has been proposed.

According to this supercritical drying technique, carbon dioxide CO in a supercritical state is subjected to₂Supplied to a wafer whose surface is wetted with IPA in a chamber so that the IPA on the wafer is dissolved in supercritical CO₂In a fluid. Then, the supercritical CO in which IPA is dissolved₂The fluid is gradually drained from the chamber so that the wafer can be dried without collapsing the pattern.

Fig. 2 illustrates a substrate processing chamber disclosed in korean patent laid-open application No. 10-2017-0137243, which is related art related to a substrate processing apparatus using such a supercritical fluid.

Referring to fig. 2, in the process of removing the organic solvent in the supercritical drying process, the organic solvent may be introduced into a coupling surface on which an upper body 430 and a lower body 420 constituting a high pressure chamber 410 contact each other. The organic solvent introduced onto the coupling surfaces of the upper body 430 and the lower body 420 becomes particles gathered around the coupling surfaces.

After the supercritical drying process is finished, the high pressure chamber 410 is opened to unload the processed wafer to the outside. In this case, particles around the coupling surfaces of the upper and

lower bodies

430 and 420 may be introduced into the inside of the high pressure chamber 410 due to a pressure difference between the inside of the high pressure chamber 410 and the outside thereof.

According to korean patent laid-open application No. 10-2017-0137243, since the substrate is located below the coupling surfaces of the upper and

lower bodies

430 and 420, when particles around the coupling surfaces of the upper and

lower bodies

430 and 420 are introduced into the interior of the high pressure chamber 410, some particles are likely to be introduced onto the substrate due to gravity.

As described above, since particles introduced onto the substrate may cause process defects, it is necessary to additionally install a blocking curtain around the coupling surface of the upper and

lower bodies

430 and 420 in order to prevent the particles from being introduced. Therefore, there is a problem that the entire structure of the apparatus is complicated.

In addition, according to the related art including korean patent laid-open application No. 10-2017-0137243, since the lower supply port 422 for supplying the initially pressurized supercritical fluid and the discharge port 426 for discharging the dried supercritical fluid are not located at the center of the lower body 420, an asymmetric flow of the supercritical fluid is formed when the supercritical fluid is supplied and discharged, making it difficult to uniformly distribute and supply the supercritical fluid in the high pressure chamber 410 and discharge the supercritical fluid from the high pressure chamber 410. Therefore, a problem of reduction in drying efficiency occurs.

Further, according to the related art including korean patent laid-open application No. 10-2017-0137243, in the drying process of dissolving the organic solvent wetting the pattern formed on the substrate in the supercritical fluid and discharging the organic solvent to the outside during the supply of the supercritical fluid for drying, when the temperature inside the chamber becomes lower than the critical point maintaining the supercritical state, there is a problem that the pattern formed on the substrate may collapse and the supercritical drying efficiency is reduced.

Fig. 3 and 4 are diagrams for describing a problem in which a metal tube providing a fluid moving path is damaged in another related art drying a substrate using a supercritical fluid.

According to the related art disclosed in fig. 3 and 4, in order to dry a substrate using a supercritical fluid, a chamber including an upper case and a lower case that can be opened or closed with respect to each other is applied.

According to the related art of drying a substrate using a supercritical fluid, in order to load and unload the substrate into and from the chamber after the substrate is dried, the chamber should be opened and closed, and for this reason, the lower housing performs repeated ascending/descending operations due to a driving force provided by the hydraulic cylinder.

Meanwhile, the lower case is connected to a metal hose for transferring the supercritical fluid supplied from the supercritical fluid supply part to the chamber, and to a metal hose for transferring the supercritical fluid remaining in the chamber after the drying process to the supercritical fluid discharge part. There is a problem in that these metal hoses may be damaged due to repeated ascending/descending operations of the lower case and fluid may leak.

The problems of the related art will be described in more detail below in connection with the supercritical drying cycle.

First, in order to dry the substrate using the supercritical fluid, the hydraulic cylinder raises the lower case to close the chamber by bringing the upper case and the lower case into close contact.

Next, the supercritical fluid stored in the supercritical fluid supply section is introduced into the chamber through the metal hose to dry the substrate, and then the by-product of the drying process is discharged to the supercritical fluid discharge section through the metal hose.

Finally, when the drying of the substrate is completed, the substrate transfer robot collects the dried substrate in a state where the hydraulic cylinder lowers the lower housing to open the chamber.

According to the related art, when such a series of cycles for drying the substrate is repeatedly performed, repeated fatigue occurs in a local portion (e.g., a portion bent or having a small radius of curvature) of the metal hose. The metal hose may be bent and cracked at a local point where fatigue is accumulated, thereby causing leakage of the high-pressure supercritical fluid.

In addition, since the metal hose exposed to the air is long, when the supercritical fluid is introduced, heat loss occurs, causing a phase change of the fluid, thereby inducing various defects during the drying process of the substrate.

[ related art documents ]

[ patent document ]

(patent document 1) korean patent laid-open application No. 10-2017-0137243 (published: 12/13/2017, title: apparatus and method for treating substrate)

Disclosure of Invention

1. Technical problem

The technical object of the present invention is to prevent a problem that a metal pipe connected to a lower case is damaged and thus fluid leaks due to repeated ascending/descending operations of the lower case, which are performed to open or close a chamber, during substrate drying using a supercritical fluid.

Further, another technical object of the present invention is to prevent heat loss of a fluid through a pipe to improve supercritical drying efficiency.

Further, still another technical object of the present invention is to control the internal temperature of a chamber to be greater than or equal to the critical point of a supercritical fluid when the supercritical fluid is supplied to the chamber using a heater embedded in at least one of an upper case and a lower case, thereby preventing the pattern formed on the substrate from collapsing and improving supercritical drying efficiency during a drying process of dissolving an organic solvent wetting the pattern formed on the substrate in the supercritical fluid and discharging the dissolved organic matter to the outside.

In addition, still another technical object of the present invention is to provide a supply path of a supercritical fluid for initial pressurization and a discharge path of a supercritical fluid in which an organic solvent formed on a substrate is dissolved after drying through one integrated supply/discharge port, thereby improving substrate drying efficiency by forming a symmetrical flow when supplying and discharging the supercritical fluid to uniformly distribute and supply the supercritical fluid in a chamber and discharge the supercritical fluid from the chamber.

Further, it is still another technical object of the present invention to reduce the drying process time by: blocking reintroduction of particles when the chamber is opened after termination of the drying process using a substrate placing plate necessary for substrate placement; blocking the supercritical fluid for initial pressurization from directly flowing to the surface of the substrate at an initial stage of the drying process to prevent the pattern formed on the substrate from collapsing; preventing the problem of deposition of particles, which may be contained in the supercritical fluid for initial pressurization, on the substrate or reducing the deposition amount of the particles; and reducing the working volume of the chamber due to the volume occupied by the substrate placement plate.

Further, another technical object of the present invention is to prevent the following problems: when the drying process is terminated and the chamber is opened, particles disposed around the sealing part on the coupling surfaces of the lower and upper cases are introduced onto the substrate due to gravity according to a height difference between the substrate and the coupling surfaces (by disposing the substrate on the substrate placing plate so as to be positioned higher than the coupling surfaces of the lower and upper cases).

2. Technical scheme

The substrate drying apparatus according to the present invention includes: a substrate drying chamber including an upper housing; a lower case coupled to the upper case to be opened or closed; a substrate placement plate coupled to a bottom surface of the lower case and on which a substrate forming an organic solvent is disposed; an integrated supply/discharge port formed to extend from a side surface of the lower case to a middle region of the lower case, and formed to place a plate facing the substrate in the middle region of the lower case and to provide a supply path of a supercritical fluid for initial pressurization and a discharge path of a mixed fluid in which an organic solvent formed on the substrate is dissolved; and an upper supply port formed to face the substrate placing plate at a central region of the upper case for providing a supply path of the supercritical fluid for drying; and a flexible supply/discharge tube coupled to the side surface of the lower case to provide a path through which the supercritical fluid for initial pressurization is supplied to the substrate drying chamber and a path through which the mixed fluid is discharged from the substrate drying chamber, and having a spiral coil shape.

In the substrate drying apparatus according to the present invention, the flexible supply/discharge tube may further include a metal tube providing a fluid flow path; and a first insulator formed on an outer surface of the metal tube.

In the substrate drying device according to the present invention, the flexible supply/discharge tube may further include a tube heating body formed on an outer surface of the first insulator; and a second insulator formed on an outer surface of the tube heating body.

In the substrate drying apparatus according to the present invention, the metal pipe may be made of any one of carbon steel, chromium (Cr) steel, nickel (Ni) steel, chromium-molybdenum steel, nickel-chromium-molybdenum steel, and stainless steel.

In the substrate drying device according to the present invention, each of the first insulator and the second insulator may be made of soft silicone, Polyimide (PI), Polyamide (PA), Perfluoroalkoxyalkane (PFA), Polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), Polychlorotrifluoroethylene (PCTFE), polypropylene (PP), and Polyetheretherketone (PEEK).

In the substrate drying device according to the present invention, the pipe heating body may be made of any one of Ni, Cr, Ni — Cr, and tungsten (W).

In the substrate drying apparatus according to the present invention, the substrate drying chamber may further include a heater embedded in at least one of the upper case and the lower case.

In the substrate drying device according to the present invention, the heater may include a plurality of heating bodies symmetrically disposed in the form of concentric circles in at least one of the upper case and the lower case.

In the substrate drying device according to the present invention, the heater may be operated to maintain the temperature of the supercritical fluid for initial pressurization supplied through the integrated supply/discharge port and the supercritical fluid for drying supplied through the upper supply port at greater than or equal to a critical point.

In the substrate drying device according to the present invention, the plurality of heating bodies constituting the heater may extend to an aperture formed in at least one side wall of the upper case and the lower case to be electrically connected to an external power source.

In the substrate drying apparatus according to the present invention, the integrated feed/discharge port may include a common conduit line formed from a side surface of the lower case to a middle region of the lower case; and a common port that is disposed in the intermediate region of the lower case so as to communicate with the common conduit line and that is formed to face the substrate placement board.

In the substrate drying apparatus according to the present invention, the supercritical fluid for initial pressurization may be supplied from the outside to the drying space sealed by the upper case and the lower case through the common conduit line and the common port, and the mixed fluid in which the organic solvent is dissolved in the supercritical fluid for drying may be discharged from the drying space to the outside through the common port and the common conduit line.

In the substrate drying apparatus according to the present invention, the substrate drying chamber may further include a sealing part provided on a coupling surface of the lower case and the upper case, the substrate may be disposed on the substrate placing plate to be positioned higher than the coupling surface of the lower case and the upper case, and when a drying process is terminated and the lower case and the upper case are opened, particles around the sealing part provided on the coupling surface are prevented from being introduced onto the substrate due to gravity according to a height difference between the substrate and the coupling surface.

In the substrate drying apparatus according to the present invention, the supercritical fluid for initial pressurization supplied through the common conduit line and the common port may be blocked by the substrate placing plate, so that the supercritical fluid for initial pressurization may be prevented from being directly injected onto the substrate.

In the substrate drying apparatus according to the present invention, the substrate drying chamber may further include a substrate placing plate supporting part having one end coupled to the bottom surface of the lower case and the other end coupled to the substrate placing plate and configured to separate the substrate placing plate from the bottom surface of the lower case while supporting the substrate placing plate.

In the substrate drying device according to the present invention, the first separation space existing between the bottom surface of the lower case and the substrate placing plate due to the substrate placing plate supporting part may guide the supercritical fluid for initial pressurization supplied through the integrated supply/discharge port to move along the bottom surface of the substrate placing plate to gradually diffuse into the process region in which the substrate is arranged.

In the substrate drying apparatus according to the present invention, the substrate drying chamber may further include a substrate supporting part having one end coupled to a top surface of the substrate placing plate and the other end coupled to the substrate and configured to separate the substrate from the top surface of the substrate placing plate while supporting the substrate.

In the substrate drying device according to the present invention, the second separation space existing between the top surface of the substrate placing plate and the substrate due to the substrate supporting part may expose the bottom surface of the substrate to the supercritical fluid for initial pressurization supplied through the integrated supply/discharge port and the supercritical fluid for drying supplied through the upper supply port, thereby reducing a drying process time.

3. Advantageous effects

According to the present invention, there is a problem that it is possible to prevent a metal pipe connected to a lower case from being damaged and thus a fluid from leaking due to a repeated ascending/descending operation of the lower case, which is performed to open or close a chamber, during a substrate drying process using a supercritical fluid.

Further, according to the present invention, the supercritical drying efficiency can be improved by preventing the heat loss of the fluid through the pipe.

Further, according to the present invention, the following effects are provided: when the supercritical fluid is supplied to the chamber using the heater embedded in at least one of the upper and lower cases, it is possible to control the internal temperature of the chamber to be greater than or equal to the critical point of the supercritical fluid, thereby preventing the pattern formed on the substrate from collapsing and improving supercritical drying efficiency during a drying process of dissolving an organic solvent wetting the pattern formed on the substrate in the supercritical fluid and discharging the dissolved organic matter to the outside.

Further, according to the present invention, the following effects are provided: a supply path of a supercritical fluid for initial pressurization and a discharge path of a supercritical fluid in which an organic solvent formed on a substrate is dissolved after drying are provided through an integrated supply/discharge port, thereby improving substrate drying efficiency by forming a symmetrical flow when supplying and discharging the supercritical fluid to uniformly distribute and supply the supercritical fluid in and discharge the supercritical fluid from a chamber.

Further, according to the present invention, the following effects are provided: by blocking re-introduction of particles when the chamber is opened after termination of the drying process using the substrate placing plate essential for substrate placement, collapse of the pattern formed on the substrate can be prevented; preventing the supercritical fluid for initial pressurization from directly flowing to the surface of the substrate at the initial stage of the drying process; preventing the problem of deposition of particles, which may be contained in the supercritical fluid for initial pressurization, on the substrate; reducing the deposition amount of particles; and reducing the working volume of the chamber due to the volume occupied by the substrate placing plate

Further, according to the present invention, the following effects are provided: it is possible to prevent particles disposed around the sealing part on the coupling surfaces of the lower and upper cases from being introduced onto the substrate due to gravity according to a height difference between the substrate and the coupling surfaces (by disposing the substrate on the substrate placing plate so as to be positioned higher than the coupling surfaces of the lower and upper cases) when the drying process is terminated and the chamber is opened.

Drawings

Fig. 1 illustrates a pattern collapse phenomenon occurring during a substrate drying process according to the related art.

Fig. 2 illustrates a substrate drying apparatus according to the related art.

Fig. 3 illustrates another substrate drying apparatus according to the related art.

Fig. 4 is a view for describing a problem in which a metal pipe is damaged in another substrate drying apparatus according to the related art.

Fig. 5 illustrates a substrate drying apparatus according to an embodiment of the present invention.

Fig. 6 illustrates an exemplary configuration of a flexible supply/exhaust pipe according to an embodiment of the present invention.

Fig. 7 illustrates an exemplary appearance of a lower case according to an embodiment of the present invention.

Fig. 8 illustrates an exemplary cross-sectional shape of a lower housing according to an embodiment of the present invention.

Fig. 9 illustrates a diffusion path of a supercritical fluid for initial pressurization according to an embodiment of the present invention.

Fig. 10 illustrates a diffusion path of a supercritical fluid for drying according to an embodiment of the present invention.

Fig. 11 illustrates a discharge path of a mixed fluid in which an organic solvent is dissolved according to an embodiment of the present invention.

Fig. 12 illustrates a state in which the drying process is completed and the lower and upper cases are opened in one embodiment of the present invention.

(description of reference numerals)

1: substrate drying chamber

10: upper shell

20: lower casing

22: bottom surface

24: side surface

28: middle area

30: sealing part

40: board for placing substrate

50: integrated supply/discharge port

60: upper supply port

70: substrate placing plate supporting part

80: substrate support part

90: shell driver

110: upper heater

201. 202, 203, and 204: heating body

210: lower heater

220: orifice

510: public conduit line

520: common port

600: fluid supply/discharge portion

610: flexible supply/discharge pipe

611: metal tube

612: first insulator

613: tubular heating body

614: second insulator

C: coupling surface

R1: first separation space

R2: second separated space

W: a substrate.

Detailed Description

The specific structural and functional descriptions of the embodiments of the present invention disclosed herein are merely illustrative for the purpose of describing embodiments according to the present inventive concept, which may be embodied in various forms and should not be construed as limited to the embodiments described herein.

Embodiments according to the inventive concept may be variously modified and may have various forms so that they will be illustrated in the drawings and described in detail herein. It should be understood, however, that there is no intention to limit embodiments according to the inventive concepts to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms first, second, etc. may be used to describe various elements, but the elements should not be limited by these terms. These terms may be used merely for the purpose of distinguishing one element from another, e.g., a first element may be termed a second element, and, similarly, a second element may be termed a first element, without departing from the scope of the present invention.

When an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, but it is understood that another element may be present between the element and the other element. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, it is understood that there may be no further element present between the element and the other element. Other expressions describing the relationship between components, i.e. "between …" and "directly between …", or "adjacent to …" and "directly adjacent to …" should also be construed as described above.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. In this specification, the terms "comprises," "comprising," "includes," "including," "has," "having," and the like, are used to specify the presence of stated features, quantities, steps, operations, elements, or combinations thereof, and it is to be understood that they do not preclude the presence or addition of one or more other features, quantities, steps, operations, elements, or combinations thereof.

Unless defined otherwise, all terms including technical or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. General terms defined in dictionaries should be interpreted as having a consistent meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Fig. 5 illustrates a substrate drying apparatus according to an embodiment of the present invention, fig. 6 illustrates an exemplary configuration of a flexible supply/discharge pipe according to an embodiment of the present invention, fig. 7 illustrates an exemplary external appearance of a lower case in one embodiment of the present invention, fig. 8 illustrates an exemplary cross-sectional shape of a lower case in one embodiment of the present invention, figure 9 illustrates a diffusion path of a supercritical fluid for initial pressurization according to one embodiment of the present invention, figure 10 illustrates a diffusion path of a supercritical fluid for drying according to one embodiment of the present invention, fig. 11 illustrates a discharge path of a mixed fluid in which an organic solvent is dissolved according to an embodiment of the present invention, fig. 12 illustrates a state in which the drying process is completed and the lower and upper cases are opened in one embodiment of the present invention.

Referring to fig. 5 to 12, the substrate drying apparatus according to one embodiment of the present invention includes a substrate drying chamber 1 and a flexible supply/discharge pipe 610.

Hereinafter, the flexible supply/discharge pipe 610 among the components of the substrate drying apparatus according to one embodiment of the present invention will be described first, and then the substrate drying chamber 1 will be described.

Although having been described previously with reference to fig. 3 and 4, according to the technique of applying a chamber including upper and lower housings that can be opened and closed with respect to each other to dry a substrate using a supercritical fluid, the substrate should be loaded into the chamber for substrate drying using the supercritical fluid, and the chamber should be opened and closed after the substrate is dried in order to load and unload the substrate into and from the chamber. For this reason, the lower housing performs repeated ascending/descending operations due to the driving force provided by the driving member such as the hydraulic cylinder.

More specifically, according to the related art, when such a series of cycles for drying the substrate is repeatedly performed, repeated fatigue occurs in a local portion (e.g., a portion that is bent or has a small radius of curvature) of the metal hose. The metal hose may be bent and cracked locally at which fatigue is accumulated, thereby causing leakage of the high-pressure supercritical fluid.

An embodiment of the present invention is to solve the problem of the related art, and according to an embodiment of the present invention, it is possible to prevent a problem that a metal pipe connected to the lower case 20 is damaged due to repeated ascending/descending operations of the lower case 20, which are performed to open and close the substrate drying chamber 1, and thus a fluid leaks, and to improve supercritical drying efficiency by preventing heat loss of the fluid through the pipe.

A supercritical drying cycle performed according to an embodiment of the present invention will be described as follows.

First, in order to dry the substrate W using the supercritical fluid, the housing driver 90 raises the lower housing 20 to bring the upper housing 10 and the lower housing 20 into close contact, thereby sealing the substrate drying chamber 1.

Next, the supercritical fluid for initial pressurization SCF _ IP stored in the fluid supply/discharge section 600 is introduced into the substrate drying chamber 1 through the flexible supply/discharge tube 610 and the common conduit line 510 and the common port 520 formed in the lower housing 20, the supercritical fluid for drying SCF _ D is introduced into the substrate drying chamber 1 through the upper supply port 60 provided in the upper housing 10 to dry the substrate W, and then the mixed fluid MF in which the organic solvent that is a byproduct of the drying process is dissolved is discharged to the fluid supply/discharge section 600 through the common port 520 and the common conduit line 510 and the flexible supply/discharge tube 610 formed in the lower housing 20.

Finally, when the drying of the substrate W is completed, the substrate transfer robot collects the dried substrate W in a state where the substrate drying chamber 1 is opened by lowering the lower housing 20 by the housing driver 90.

According to an embodiment of the present invention, even when such a series of cycles for drying the substrate W is repeatedly performed, damage to the flexible supply/discharge pipe 610 is minimized.

More specifically, even when a series of cycles for drying the substrate W is repeated, there is no bend or local portion having a small radius of curvature in the flexible supply/discharge pipe 610. That is, although the ascending/descending operation of the lower housing 20 is repeatedly performed, fatigue is not accumulated in the flexible supply/discharge pipe 610, thereby minimizing physical damage.

According to the related art, when a series of cycles for drying a substrate is repeatedly performed, repeated fatigue occurs in a local portion (e.g., a portion bent or having a small radius of curvature) of a metal pipe. Bending and cracking may occur at a local portion of the metal tube where fatigue is accumulated, resulting in leakage of the high-pressure supercritical fluid.

In addition, as described below, since the flexible supply/discharge tube 610 has a built-in insulation function and a heating function, it is possible to prevent heat loss that may occur when a supercritical fluid is introduced through the flexible supply/discharge tube 610. Therefore, the phase transition of the supercritical fluid can be prevented, thereby preventing defects in the substrate drying process.

The flexible supply/discharge pipe 610 is coupled to a side surface of the lower case 20 to provide a path through which the supercritical fluid SCF _ IP for initial pressurization is supplied to the substrate drying chamber 1 and a path through which the mixed fluid MF in which the organic solvent is dissolved is discharged from the substrate drying chamber 1, and is provided in a spiral coil shape.

For example, the flexible supply/discharge tube 610 may include a metal tube 611, a first insulator 612, a tube heating body 613, and a second insulator 614.

The metal pipe 611 located at the innermost side of the flexible supply/discharge pipe 610 provides a fluid flow path.

For example, the metal pipe 611 may be formed of any one material among carbon steel, chromium (Cr) steel, nickel (Ni) steel, chromium-molybdenum steel, nickel-chromium-molybdenum steel, and stainless steel.

The first insulator 612 is formed on the outer surface of the metal pipe 611 and performs a function of mainly preventing heat loss.

For example, each of the first and

second insulators

612 and 614, which will be described below, may be made of soft silicone, Polyimide (PI), Polyamide (PA), Perfluoroalkoxyalkane (PFA), Polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), Polychlorotrifluoroethylene (PCTFE), polypropylene (PP), and Polyetheretherketone (PEEK).

The tube heating body 613 is formed on an outer surface of the first insulator 612 and generates resistance heat according to supplied current under the control of a controller (not shown) to perform a function of heating the supercritical fluid in the metal tube 611.

For example, the pipe heater 613 may be formed of any one of Ni, Cr, Ni — Cr, and tungsten (W).

The second insulator 614 is formed on the outer surface of the pipe heater 613 to mainly prevent heat loss and may be formed of the same material as the first insulator 612.

The substrate drying chamber 1 includes an upper housing 10, a lower housing 20, a sealing part 30, a substrate placing plate 40, an integrated supply/discharge port 50, an upper supply port 60, a substrate placing plate support part 70, a substrate support part 80, a housing driver 90, and a heater.

The upper case 10 and the lower case 20 are coupled to be opened or closed with each other and provide a space to perform a drying process. For example, both the upper case 10 and the lower case 20 may be configured to have a cylindrical shape, but the present invention is not limited thereto. As described below, the upper supply port 60 is formed in the upper housing 10, and the integrated supply/discharge port 50 is formed in the lower housing 20.

The heater is embedded in at least one of the upper case 10 and the lower case 20.

Hereinafter, although an example in which the heater includes the upper heater 110 embedded in the upper case 10 and the lower heater 210 embedded in the lower case 20 will be described, this is merely an example, and the heater may include only the upper heater 110 or the lower heater 210.

In addition, the upper heater 110 and the lower heater 210 may have substantially the same shape, and in order to avoid repetitive description, the heaters will be described based on the lower heater 210, but the same description may be applied to the upper heater 110.

As shown in fig. 7 illustrating an exemplary external appearance of the lower case 20 and fig. 8 illustrating an exemplary cross-sectional shape of the lower case 20, the lower heater 210 may include a plurality of

heating bodies

201, 202, 203, and 204 symmetrically disposed in the lower case 20 in the form of concentric circles. As a specific example, a groove for disposing the lower heater 210 is provided inside the lower case 20, and the lower heater 210 may be provided in the groove.

For example, the plurality of

heating bodies

201, 202, 203, and 204 constituting the lower heater 210 extend to the orifice 220 formed in the sidewall of the lower case 20 to be electrically connected to an external power source (not shown) and may be configured to supply heat to the inside of the substrate drying chamber 1 in such a manner that heat is generated due to resistance heat when the external power source is applied.

For example, the lower heater 210 may be operated to maintain the initial pressurizing supercritical fluid SCF _ IP supplied through the integrated supply/discharge port 50 and the drying supercritical fluid SCF _ D supplied through the upper supply port 60 at or above a critical point. Although not shown in the drawings, as part of the above description, the control operation of the valve that controls the supply of the supercritical fluid for initial pressurization SCF _ IP supplied through the integrated supply/discharge port 50, the control operation of the valve that controls the supply of the supercritical fluid for drying SCF _ D through the upper supply port 60, and the control operation of the external power supply for supplying power to the lower heater 210 may be interlocked with each other.

As described above, the lower heater 210 operates to maintain the supercritical fluid for initial pressurization SCF _ IP supplied through the integrated supply/discharge port 50 and the supercritical fluid for drying SCF _ D supplied through the upper supply port 60 at or above the critical point, and to wet the pattern formed on the substrate W, such as isopropyl alcohol IOrganic solvents such as PA dissolved in carbon dioxide (CO)₂) So as to be discharged to the outside, so that it is possible to prevent collapse of the pattern formed on the substrate during the drying process.

The sealing part 30 is provided on the coupling surface C of the lower and

upper cases

20 and 10, and maintains airtightness of the coupling surface C of the lower and

upper cases

20 and 10 to isolate the inner region of the substrate drying chamber 1 from the outside.

For example, referring to fig. 12, when the drying process is terminated and the lower and

upper cases

20 and 10 are opened, the substrate W may be placed on the substrate placing plate 40 so as to be located at a position higher than the coupling surface C of the lower and

upper cases

20 and 10, and when the drying process is terminated and the lower and

upper cases

20 and 10 are opened, the substrate drying chamber 1 may be formed to prevent particles, which exist around the sealing part 30 provided on the coupling surface C, from flowing onto the substrate due to gravity due to a height difference between the substrate W and the coupling surface C.

The substrate placing plate 40 is coupled to the bottom surface 22 of the lower case 20, and is a member where the substrate W in which the organic solvent is formed is placed.

For example, the supercritical fluid SCF _ IP for initial pressurization, supplied through the common conduit line 510 and the common port 520 constituting the integrated supply/discharge port 50, may be blocked by the substrate placing plate 40 to prevent direct injection to the substrate W.

More specifically, as shown in fig. 9 showing a diffusion path of the supercritical fluid SCF _ IP for initial pressurization and fig. 11 showing a discharge path of the mixed fluid MF in which the organic solvent is dissolved, the drying process time can be reduced so that collapse of the pattern formed on the substrate W can be prevented by: the use of the substrate placement plate 40, which is indispensable for arranging the substrate W (which is the object of the drying process), prevents re-introduction of particles when opening the substrate drying chamber 1 after the termination of the drying process and blocks direct flow of the supercritical fluid for initial pressurization SCF _ IP toward the surface of the substrate W at the initial stage of the drying process, and prevents the problem of deposition of particles, which may be contained in the supercritical fluid for initial pressurization SCF _ IP, on the substrate W, and reduces the deposition amount of particles, and reduces the working volume of the substrate drying chamber 1 due to the volume occupied by the substrate placement plate 40.

The integrated supply/discharge port 50 is a member that extends from the side surface 24 of the lower casing 20 to the middle region 28 of the lower casing 20 and that places the plate 40 facing the substrate in the middle region 28 of the lower casing 20. The housing 20, thereby providing a supply path of the supercritical fluid SCF _ IP for initial pressurization and a discharge path of the mixed fluid MF in which the organic solvent formed on the substrate W is dissolved after drying.

The supply path of the supercritical fluid SCF _ IP for initial pressurization and the discharge path of the mixed fluid MF in which the organic solvent formed on the substrate W is dissolved after drying are provided through one integrated supply/discharge port 50, so that there is an effect of improving the substrate drying efficiency by: a symmetrical flow is formed when the supercritical fluid SCF _ IP is supplied and the mixed fluid MF is discharged to uniformly distribute and supply the supercritical fluid SCF _ IP into the substrate drying chamber 1 and discharge the mixed fluid MF from the substrate drying chamber 1.

For example, the integrated supply/discharge port 50 may include a common conduit line 510 formed from the side surface 24 of the lower case 20 to the middle region 28 thereof, and a common port 520 formed to communicate with the common conduit line 510 at the middle region 28 of the lower case 20 and formed to face the substrate placement plate 40. According to the above configuration, 1) the supercritical fluid for initial pressurization SCF _ IP is supplied from the outside of the substrate drying chamber 1 to the inside thereof, that is, into the drying space sealed by the upper and

lower housings

10 and 20 through the common conduit line 510 and the common port 520, and 2) the mixed fluid MF in which the organic solvent is dissolved in the supercritical fluid for drying SCF _ D is discharged from the drying space in the substrate drying chamber 1 to the outside thereof through the common port 520 and the common conduit line 510.

The upper supply port 60 is a member formed to be directed toward the substrate placing plate 40 in the central region of the upper casing 10 to provide a supply path of the supercritical fluid SCF _ D for drying.

The board placing board supporting part 70 is a member having one end coupled to the bottom surface 22 of the lower case 20 and the other end coupled to the board placing board 40 and separating the board placing board 40 from the bottom surface 22 of the lower case 20 while supporting the board placing board 40.

For example, the first separation space R1 existing between the bottom surface 22 of the lower case 20 and the substrate placing plate 40 due to the substrate placing plate supporting portion 70 may perform a function for inducing the supercritical fluid for initial pressurization SCF _ IP to gradually diffuse into the processing region in which the substrate W is arranged by moving the supercritical fluid for initial pressurization SCF _ IP supplied through the integrated supply/discharge port 50 along the bottom surface of the substrate placing plate 40.

The substrate supporting part 80 is a member having one end coupled to the top surface of the substrate placing plate 40 and the other end coupled to the substrate W and separating the substrate W from the top surface of the substrate placing plate 40 while supporting the substrate W.

For example, the second separation space R2 existing between the top surface of the substrate placing plate 40 and the substrate W due to the substrate support portion 80 performs a function of reducing the drying process time by exposing the bottom surface of the substrate to the initial pressurizing supercritical fluid SCF _ IP supplied through the integrated supply/discharge port 50 and the drying supercritical fluid SCF _ D supplied through the upper supply port 60.

The case driver 90 is a component for opening or closing the upper case 10 and the lower case 20. After the drying process is terminated, the case driver 90 lowers the lower case 20 to separate the lower case 20 from the upper case 10, so that the case driver 90 may perform a function of closing the substrate drying chamber 1 by raising the lower case 20 and coupling the lower case 20 to the upper case 10 when the substrate drying chamber 1 is opened, or when the drying process is started.

For example, the supercritical fluid for initial pressurization SCF _ IP and the supercritical fluid for drying SCF _ D may each include CO₂And the organic solvent may include alcohol, but the present invention is not limited thereto. As specific examples, the alcohol may include methanol, ethanol, 1-propanol, 2-propanol (IPA), and 1-butanol, but the present invention is not limited thereto.

For example, according to one embodiment of the present invention, CO will be in a supercritical state₂Is supplied to the substrate W whose surface is wetted with an organic solvent such as alcohol in the substrate drying chamber 1, and thus on the substrate WDissolving in supercritical CO₂In a fluid. Then, the CO dissolved with the alcohol₂The fluid is gradually discharged from the substrate drying chamber 1 so that the substrate W can be dried without collapsing the pattern.

As described above, according to the present invention, the following effects are provided: in the substrate drying process using the supercritical fluid, it is possible to prevent a problem that a metal pipe connected to the lower case is damaged and thus fluid leaks due to repeated ascending/descending operations of the lower case, which are performed to open or close the chamber.

Further, the following effects are provided: by preventing heat loss of the fluid through the pipe, supercritical drying efficiency can be improved.

Further, the following effects are provided: when the supercritical fluid is supplied to the chamber using the heater embedded in at least one of the upper and lower cases, it is possible to control the internal temperature of the chamber to be greater than or equal to the critical point of the supercritical fluid, thereby preventing the pattern formed on the substrate from collapsing and improving supercritical drying efficiency during a drying process of dissolving an organic solvent wetting the pattern formed on the substrate in the supercritical fluid and discharging the dissolved organic matter to the outside.

Further, the following effects are provided: a supply path of a supercritical fluid for initial pressurization and a discharge path of a supercritical fluid in which an organic solvent formed on a substrate is dissolved after drying are provided through an integrated supply/discharge port, thereby improving substrate drying efficiency by forming a symmetrical flow when supplying and discharging the supercritical fluid to uniformly distribute and supply the supercritical fluid in and discharge the supercritical fluid from a chamber.

In addition, it may have an effect of reducing the drying process time by: by blocking re-introduction of particles when the chamber is opened after the termination of the drying process using the substrate placing plate necessary for arranging the substrate, collapse of the pattern formed on the substrate can be prevented; preventing the supercritical fluid for initial pressurization from directly flowing to the surface of the substrate at the initial stage of the drying process; preventing the problem of deposition of particles, which may be contained in the supercritical fluid for initial pressurization, on the substrate; reducing the deposition amount of particles; and reducing the working volume of the chamber due to the volume occupied by the substrate placement plate.

Claims

1. A substrate drying apparatus comprising:

a substrate drying chamber comprising: an upper housing; a lower case coupled to the upper case to be opened or closed; a substrate placement plate coupled to a bottom surface of the lower case and on which a substrate on which an organic solvent is formed is disposed; an integrated supply/discharge port formed to extend from a side surface of the lower case to a middle region of the lower case, and formed to place a plate facing the substrate in the middle region of the lower case and to provide a supply path of a supercritical fluid for initial pressurization and a discharge path of a mixed fluid in which an organic solvent formed on the substrate is dissolved; and an upper supply port formed to face the substrate placing plate in a central region of the upper case to provide a supply path of the supercritical fluid for drying; and

a flexible supply/discharge tube coupled to the side surface of the lower case to provide a path through which the supercritical fluid for initial pressurization is supplied to the substrate drying chamber and a path through which the mixed fluid is discharged from the substrate drying chamber, and having a spiral coil shape.

2. The substrate drying apparatus of claim 1, wherein the flexible supply/exhaust pipe comprises:

a metal tube providing a fluid flow path; and

a first insulator formed on an outer surface of the metal tube.

3. The substrate drying apparatus of claim 2, wherein the flexible supply/exhaust pipe further comprises:

a tube heater formed on an outer surface of the first insulator; and

a second insulator formed on an outer surface of the tube heating body.

4. The substrate drying apparatus of claim 3, wherein the metal pipe is made of any one of carbon steel, chromium (Cr) steel, nickel (Ni) steel, chromium-molybdenum steel, nickel-chromium-molybdenum steel, and stainless steel.

5. The substrate drying apparatus of claim 3, wherein each of the first insulator and the second insulator is made of soft silicone, Polyimide (PI), Polyamide (PA), perfluoroalkoxy alkane (PFA), Polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), Polychlorotrifluoroethylene (PCTFE), polypropylene (PP), and Polyetheretherketone (PEEK).

6. The substrate drying apparatus according to claim 3, wherein the pipe heating body is made of any one material of Ni, Cr, Ni-Cr, and tungsten (W).

7. The substrate drying apparatus of claim 1, wherein the substrate drying chamber further comprises a heater embedded in at least one of the upper housing and the lower housing.

8. The substrate drying apparatus of claim 7, wherein the heater comprises a plurality of heating bodies symmetrically disposed in the form of concentric circles in at least one of the upper case and the lower case.

9. The substrate drying apparatus of claim 8, wherein the heater is operative to maintain the temperature of the supercritical fluid for initial pressurization supplied through the integrated supply/exhaust port and the supercritical fluid for drying supplied through the upper supply port at greater than or equal to a critical point.

10. The substrate drying apparatus according to claim 8, wherein a plurality of heating bodies constituting the heater extend to an aperture formed in at least one side wall of the upper case and the lower case to be electrically connected to an external power source.

11. The substrate drying apparatus of claim 1, wherein the integrated supply/exhaust port comprises:

a common conduit line formed from a side surface of the lower case to a middle region of the lower case; and

a common port configured in the intermediate region of the lower case to communicate with the common conduit line and formed to face the substrate placement board.

12. The substrate drying apparatus according to claim 11, wherein:

the supercritical fluid for initial pressurization is supplied from the outside to the drying space sealed by the upper case and the lower case through the common conduit line and the common port, and

wherein the mixed fluid in which the organic solvent is dissolved in the supercritical fluid for drying is discharged from the drying space to the outside through the common port and the common conduit line.

13. The substrate drying apparatus according to claim 1, wherein:

the substrate drying chamber further includes a sealing part disposed on a coupling surface of the lower case and the upper case; and is

The base plate is disposed on the base plate placing plate to be positioned higher than the coupling surfaces of the lower case and the upper case, and when a drying process is terminated and the lower case and the upper case are opened, particles disposed around the sealing part on the coupling surfaces are prevented from being introduced onto the base plate due to gravity caused by a height difference between the base plate and the coupling surfaces.

14. The substrate drying apparatus according to claim 12, wherein the supercritical fluid for initial pressurization supplied through the common conduit line and the common port is blocked by the substrate placing plate, thereby preventing the supercritical fluid for initial pressurization from being directly injected onto the substrate.

15. The substrate drying apparatus of claim 1, wherein the substrate drying chamber further comprises a substrate placing plate supporting part having one end coupled to the bottom surface of the lower case and the other end coupled to the substrate placing plate and configured to separate the substrate placing plate from the bottom surface of the lower case while supporting the substrate placing plate.

16. The substrate drying apparatus according to claim 15, wherein the supercritical fluid for initial pressurization supplied through the integrated supply/discharge port is guided to move along a bottom surface of the substrate placing plate by a first separation space existing between the bottom surface of the lower housing and the substrate placing plate due to the substrate placing plate supporting part to gradually diffuse into a processing region in which the substrate is arranged.

17. The substrate drying apparatus of claim 1, wherein the substrate drying chamber further comprises a substrate supporting part having one end coupled to a top surface of the substrate placing plate and the other end coupled to the substrate and configured to separate the substrate from the top surface of the substrate placing plate while supporting the substrate.

18. The substrate drying apparatus according to claim 17, wherein a second separation space existing between the top surface of the substrate placing plate and the substrate due to the substrate supporting part exposes a bottom surface of the substrate to the supercritical fluid for initial pressurization supplied through the integrated supply/discharge port and the supercritical fluid for drying supplied through the upper supply port, thereby reducing a drying process time.