KR102685397B1 - Substrate processing apparatus - Google Patents

Abstract

The present invention relates to a substrate processing apparatus, and more specifically, when processing processes such as drying processes for substrates using supercritical fluid, tilting the substrate in the vertical and/or horizontal directions inside the chamber. It is about a substrate processing device that can detect.

Description

Substrate processing apparatus {Substrate processing apparatus}

The present invention relates to a substrate processing apparatus, and more specifically, when processing processes such as drying processes for substrates using supercritical fluid, tilting the substrate in the vertical and/or horizontal directions inside the chamber. It is about a substrate processing device that can detect.

In general, when manufacturing large-scale/high-density semiconductor devices such as LSI (Large scale integration) on the surface of a semiconductor wafer, it is necessary to form an ultrafine pattern on the surface of the wafer.

These ultrafine patterns can be formed by transferring the resist pattern to the wafer by going through various processes of exposing, developing, and cleaning a wafer coated with resist, patterning the resist, and then etching the wafer.

After this etching, the wafer is cleaned to remove dust or natural oxide film on the wafer surface. The cleaning process is performed by immersing the wafer on which a pattern is formed on the surface in a treatment liquid such as a chemical solution or a rinse liquid, or by supplying the treatment liquid to the wafer surface.

However, as semiconductor devices become more highly integrated, pattern collapse, in which the pattern on the resist or wafer surface collapses, occurs when the treatment liquid is dried after cleaning.

This pattern collapse occurs when the processing liquid 10 remaining on the surface of the substrate S is dried, as shown in FIG. 16, when the processing liquid on the left and right sides of the patterns 11, 12, and 13 dries unevenly. , This corresponds to a phenomenon in which the patterns 11, 12, and 13 collapse in the direction where a large amount of the treatment liquid remains due to an imbalance in the capillary force that stretches the patterns 11, 12, and 13 to the left and right.

In the case of FIG. 16, drying of the processing liquid in the left and right outer regions where the pattern is not formed on the upper surface of the substrate S is completed, while the processing liquid 10 remains in the gap between the patterns 11, 12, and 13. It indicates the status. As a result, the patterns 11 and 13 on both the left and right sides collapse toward the inside due to the capillary force received from the treatment liquid 10 remaining between the patterns 11, 12 and 13.

The capillary force causing the pattern collapse described above is due to the surface tension of the processing liquid acting at the liquid/gas interface between the atmospheric atmosphere surrounding the substrate S after cleaning and the processing liquid remaining between the patterns.

Therefore, recently, a treatment method of drying the treatment liquid using a fluid in a supercritical state (hereinafter referred to as 'supercritical fluid') that does not form an interface between gas or liquid has been attracting attention.

In the conventional drying method using only temperature control in the pressure and temperature phase diagram of Figure 17, the gas-liquid equilibrium line is always passed, and at this time, capillary force is generated at the gas-liquid interface.

On the other hand, when drying via a supercritical state using both temperature and pressure control of the fluid does not pass through the vapor-liquid equilibrium line, it becomes possible to dry the substrate in a state essentially free of capillary force.

Looking at drying using a supercritical fluid with reference to FIG. 17, when the pressure of the liquid is raised from A to B and the temperature is then raised from B to C, it switches to the supercritical state C without passing the vapor-liquid equilibrium line. In addition, when the drying process is completed, the pressure of the supercritical fluid is lowered and converted to gas D without passing the vapor-liquid equilibrium line.

Meanwhile, as described above, in the case of a chamber in which a processing process for a substrate is performed using a supercritical fluid, a tray supporting the substrate may be configured to support the substrate from the outside of the chamber and move into the inside of the chamber.

However, in a chamber having the above-described configuration, when a tray is inserted into the chamber, tilting of the tray may occur in the vertical or horizontal direction. This tilting of the tray can occur for various reasons.

For example, the tray may be tilted by its own weight, or may be tilted by high-pressure fluid supplied into the chamber. Additionally, the tray may be tilted due to thermal expansion during the processing of the substrate, or may be tilted due to internal stress or residual stress.

Tilting the tray changes the thickness of the processing liquid or organic solvent on the top of the substrate, which may cause damage to the pattern on the top of the substrate. In addition, it causes imbalance in the flow of fluid supplied into the chamber, preventing the flow energy of the fluid from being uniformly transmitted toward the substrate. In this case, if the flow energy of the fluid is not transmitted to the upper surface of the substrate or is not transmitted uniformly, the organic solvent such as IPA (Isopropyl alcohol) existing between the patterns of the substrate may not be properly replaced.

In the prior art device, a method of measuring the tilt of the tray from outside the chamber was used to detect the tilt of the tray. That is, the tilt of the tray was measured and corrected from the outside of the chamber, and then the tray was inserted into the chamber.

However, since the method according to the prior art corrects the tilt of the tray from outside the chamber, it is difficult to detect tilt that occurs after the tray is inserted into the chamber.

In order to solve the above problems, the purpose of the present invention is to provide a substrate processing device that can detect tilting of a tray in at least one of the vertical and horizontal directions inside a chamber.

The object of the present invention as described above is to provide a processing space for performing a processing process on a substrate coated with a processing liquid or an organic solvent using a fluid in a supercritical state, a chamber that supports the substrate, and a processing space that supports the substrate through an opening of the chamber. A tray provided to be able to be drawn into the inside of the chamber and withdrawn from the outside of the chamber, and a tilt detection unit that detects tilting of the tray in at least one of the vertical and horizontal directions inside the chamber. This is achieved by a characterized substrate processing device.

Here, the tilting detection unit can measure the electric capacity inside the chamber and detect the tilting of the tray inside the chamber.

In addition, the tilt detection unit may include at least one of a first tilt detection unit that detects a vertical tilt of the tray inside the chamber and a second tilt detection unit that detects a horizontal tilt of the tray inside the chamber. there is.

In this case, the first tilting detection unit includes a first electrode and a second electrode installed to be spaced apart from each other along the vertical direction on the inner wall of the chamber, an electric capacity between the tray and the first electrode, and an electric capacity between the tray and the first electrode. A first comparison unit may be provided to detect vertical tilting of the tray by comparing the capacitance between the two electrodes.

Furthermore, the second tilting detection unit includes a third electrode and a fourth electrode installed to be spaced apart in the horizontal direction on the inner wall of the chamber, a capacitance between the tray and the third electrode, and a capacitance between the tray and the fourth electrode. A second comparison unit may be provided to detect horizontal tilting of the tray by comparing capacity.

Meanwhile, the installation height of the first electrode and the second electrode may be set so that when the tray is not tilted in the vertical direction, the overlapping areas of the tip of the tray and the first electrode and the second electrode are all the same.

Additionally, the heights of the first and second electrodes may be determined so that a line bisecting the vertical distance between the first electrode and the second electrode coincides with a line bisecting the thickness of the tray.

Furthermore, when the distance between the centers of the first electrode and the second electrode is 'L', the distance (L) between the centers of the first electrode and the second electrode satisfies the following equation,

'2G < L < t + 2G '

In the above equation, 'G' may be defined as the distance from the center to the edge of the first and second electrodes, and 't' may be defined as the thickness of the tray.

Meanwhile, when the first electrode and the second electrode are installed, if the areas overlapping with the tray are set differently, the initial capacitance of the first electrode and the second electrode with the tray is stored in the first comparison unit, respectively, and , when the tray is introduced into the chamber, tilting can be detected by comparing changes in capacitance of the first electrode and the second electrode with the tray.

According to the present invention having the above-described configuration, the tilting of the tray can be detected by comparing the respective capacitances between the tray and two or more electrodes installed inside the chamber.

In addition, according to the present invention, the processing process for the substrate can be carried out more effectively by detecting the tilting of the tray inside the chamber, which was difficult to detect in the device according to the prior art.

Furthermore, according to the present invention, the configuration and control method can be simplified by comparing and determining the capacitance values between two or more electrodes installed inside the chamber and the tray without directly calculating them.

1 is a block diagram showing the configuration of a substrate processing apparatus according to an embodiment of the present invention;
Figure 2 is a side cross-sectional view showing the configuration of a chamber according to an embodiment of the present invention;
Figure 3 is a side cross-sectional view showing the tray supporting the substrate in an inclined state;
Figure 4 is a side cross-sectional view of a chamber equipped with a tilting detection unit according to an embodiment of the present invention;
Figure 5 is a top view of the chamber of Figure 4;
Figure 6 is a diagram showing a tilting detection unit according to an embodiment provided on the inner side of the chamber;
Figure 7 is a partial enlarged side view showing the 'VII' area in Figure 4,
Figure 8 is a diagram schematically showing the first tilt detection unit;
Figure 9 is a diagram showing a tilting detection unit according to another embodiment provided on the inner surface of the chamber of the present invention;
Figure 10 is a graph showing the change in dielectric constant of carbon dioxide according to pressure and temperature;
Figure 11 is a graph showing the change in dielectric constant of carbon dioxide according to the pressure of carbon dioxide containing carbon dioxide and a polar solvent;
Figure 12 is a side cross-sectional view showing the configuration of a chamber equipped with a process detection unit according to another embodiment of the present invention;
13 is a diagram schematically showing the process detection unit;
14 is a graph showing changes in the remaining amount of organic solvent inside the chamber, the dielectric constant of the fluid inside the chamber, and the electrostatic capacitance inside the chamber according to the pressure change in the substrate processing process;
15 is a side cross-sectional view showing the configuration of a chamber according to another embodiment of the present invention;
Figure 16 is a diagram schematically showing the state in which the pattern collapses when drying the pattern on the upper part of the substrate according to the prior art;
Figure 17 is a state diagram showing changes in pressure and temperature of the fluid in a treatment process using supercritical fluid.

Hereinafter, the structure of a substrate processing apparatus according to an embodiment of the present invention will be examined in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a substrate processing apparatus 1000 according to an embodiment of the present invention, and FIG. 2 is a side cross-sectional view showing the configuration of the chamber 400.

The substrate processing apparatus 1000 according to the present invention performs a processing process on the substrate S using a fluid in a supercritical state. Here, a fluid in a supercritical state corresponds to a fluid with a phase that is formed when a substance reaches a critical state, that is, a state exceeding the critical temperature and critical pressure. The fluid in this supercritical state has a molecular density close to that of a liquid, but a viscosity close to that of a gas. Therefore, the supercritical fluid has excellent diffusion, penetration, and dissolving power, which is advantageous for chemical reactions. It has almost no surface tension, so it does not apply surface tension to the microstructure, so it not only has excellent drying efficiency during the drying process of semiconductor devices. It can be very useful as it can avoid pattern collapse.

In the present invention, carbon dioxide (CO ₂ ) may be used as the supercritical fluid. Carbon dioxide has a critical temperature of approximately 31.1°C and a relatively low critical pressure of 7.38Mpa, so it is easy to create a supercritical state, easy to control by adjusting the temperature and pressure, and has the advantage of being inexpensive.

In addition, carbon dioxide is non-toxic, harmless to the human body, and has the characteristics of being non-flammable and inert. Furthermore, carbon dioxide in a supercritical state has a diffusion coefficient that is approximately 10 to 100 times higher than that of water or other organic solvents, so it has excellent permeability, allowing rapid replacement of organic solvents, and has almost no surface tension, making it easy to dry during the drying process. It has properties that are advantageous for use in In addition, it is possible to convert the carbon dioxide used in the drying process into a gaseous state, separate the organic solvent, and reuse it, thus reducing the burden in terms of environmental pollution.

Referring to Figures 1 and 2, the substrate processing apparatus 1000 uses a fluid in a supercritical state to apply a processing liquid or an organic solvent 10 (hereinafter referred to as 'organic solvent') to a substrate (S). It may be provided with a chamber 400 that provides a processing space 412 for performing a processing process, and a fluid supply unit 600 that supplies fluid into the chamber 400.

The fluid supply unit 600 may supply fluid to the chamber 400 through the fluid supply port 140 by adjusting at least one of the temperature and pressure of the fluid.

For example, the fluid supply unit 600 includes a fluid storage unit 100 that stores the fluid, and a main supply passage 120 connecting the fluid storage unit 100 and the fluid supply port 140. can do.

In this case, the pressure control unit 200 and the temperature control unit 300 may be disposed along the main supply passage 120. At this time, the pressure control unit 200 may be comprised of, for example, a pressure pump, and the temperature control unit 300 may be comprised of a heater or a heat exchanger that heats the fluid.

Furthermore, the main supply passage 120 may further include a sensing unit (not shown) that detects at least one of the pressure and temperature of the fluid. The pressure and temperature of the fluid flowing in the main supply passage 120 may be adjusted according to the pressure and temperature detected by the sensor. To this end, the substrate processing apparatus 1000 according to an embodiment of the present invention may include a control unit (not shown) that controls the pressure control unit 200 and the temperature control unit 300. The control unit may control the pressure control unit 200 and the temperature control unit 300 based on the pressure and temperature detected by the sensor.

Meanwhile, when performing a processing process on the substrate S, the internal environment of the processing space 412 of the chamber 400, i.e., the temperature and pressure of the processing space 412, are transferred to the inside of the chamber 400. An environment above the critical temperature and critical pressure that can convert the supplied fluid into a supercritical state must be created and maintained during the process.

To this end, while the fluid is moving along the main supply passage 120, the fluid can be pressurized to a critical pressure or higher by the pressure control unit 200, and the temperature control unit 300 The fluid can be heated to a critical temperature or higher.

Meanwhile, the fluid supply port 140 may be composed of an upper supply port 142 connected to the upper part of the chamber 400 and a lower supply port 144 connected to the lower part of the chamber 400.

For example, the above-mentioned main supply passage 120 may be branched and connected to the upper supply port 142 and the lower supply port 144, respectively. In this case, although not shown in the drawing, valves are provided at the front ends of the upper supply port 142 and the lower supply port 144 to control the supply of fluid.

If fluid is supplied from the beginning of the process through the upper part of the chamber 400, high-pressure fluid may be supplied from the upper part of the chamber 400 toward the substrate S. In this case, a pattern (not shown) formed on the top of the substrate S may be damaged by high-pressure fluid. Therefore, at the beginning of the process, fluid is supplied from the lower part of the chamber 400 through the lower supply port 144 to prevent damage to the pattern on the substrate S. If the fluid is accommodated inside the chamber 400 and, for example, the substrate S is submerged by the fluid, the fluid can be supplied from the upper part of the chamber 400 through the upper supply port 142. there is.

Meanwhile, the chamber 400 is provided with a discharge port 146 through which fluid in the processing space 412 can be discharged to the outside. During the processing process for the substrate S or when the processing process is completed, fluid may be discharged from the inside of the chamber 400 to the outside through the discharge port 146.

Meanwhile, the chamber 400 may provide a processing space 412 for performing a processing process such as a drying process on the substrate S using a fluid in a supercritical state.

The chamber 400 has an opening 414 formed on one side, and may be made of a material suitable for processing the substrate S on the inside of the chamber 400 through a high pressure process.

The processing space 412 of the chamber 400 is maintained in a sealed state, so that the pressure of the fluid supplied to the processing space 412 can be maintained above the critical pressure.

Additionally, the chamber 400 may be further equipped with a heating unit (not shown) to maintain the temperature of the processing space 412 above a predetermined temperature. The heating unit may maintain the temperature of the processing space 412 or the temperature of the fluid contained in the processing space 412 above a critical temperature during the process for the substrate S.

Meanwhile, a tray unit 450 is provided in the chamber 400 to support the substrate S and to be able to be introduced into the chamber 400 and withdrawn from the outside of the chamber 400 through the opening 414. ) can be provided.

The tray unit 450 is introduced into the processing space 412 of the chamber 400 through the opening 414, or enters the processing space 412 into the chamber 400 through the opening 414. It can be withdrawn externally.

For example, the tray unit 450 may include a tray 456 supporting the substrate S, and a cover 452 provided at a distal end of the tray 456 to seal the opening 414. You can.

The tray 456 may be supported by seating the substrate S on its upper surface. The cover 452 may be connected to the end of the tray 456.

When the tray 456 is inserted into the processing space 412 through the opening 414, the cover 452 closes the opening 414. In this case, a sealing member 458 may be provided to seal between the cover 452 and the chamber 400.

Meanwhile, when the opening 414 is sealed by the cover 452, a high-pressure process is performed inside the chamber 400 using a supercritical fluid, so the cover 452 is used to close the chamber 400. A configuration is needed to prevent it from being pushed by internal pressure.

For example, the cover 452 may be provided with a shutter 459 that pressurizes the cover 452 to prevent it from being pushed by the internal pressure of the chamber 400. The shutter 459 presses the cover 452 when the tray 456 is inserted into the processing space 412 and the cover 452 blocks the opening 414 to close the cover 452. Make sure it does not slip during the process. The shutter 459 may move vertically from the top or bottom to press the cover 452 toward the chamber 400 from the outer surface of the cover 452. The configuration for pressing the cover 452 in this way has been described as an example, and may be modified and applied in various ways.

When the tray 456 is inserted into the processing space 412 in the chamber 400 having the above-described configuration, tilting of the tray 456 may occur in the vertical or horizontal direction.

Figure 3 is a side view showing a case where the tray 456 is tilted in the vertical direction and vertical tilting occurs.

Referring to FIG. 3, the tray 456 may be tilted for various reasons. For example, the tray 456 may be tilted by its own weight, or may be tilted by high-pressure fluid supplied into the chamber 400. Additionally, the tray 456 may be tilted through thermal expansion during the process for the substrate S, or may be tilted due to internal stress or residual stress. Furthermore, if the shutter 459 described above does not press the cover 452 in an accurate horizontal direction and pushes it at an angle, the tray 456 may be tilted.

Tilting the tray 456 changes the thickness of the organic solvent 10 on the upper surface of the substrate S, which may cause damage to the pattern on the upper surface of the substrate S. Additionally, an imbalance is caused in the flow of fluid supplied into the chamber 400, preventing the flow energy of the fluid from being uniformly transmitted toward the substrate S. In this case, if the flow energy of the fluid is not transmitted or is not transmitted uniformly to the upper surface of the substrate (S), organic substances such as IPA (Isopropyl alcohol) existing between the patterns (not shown) of the substrate (S), etc. The solvent 10 may not be properly replaced.

In the prior art device, a method of measuring the tilt of the tray from outside the chamber was used to detect the tilt of the tray. That is, the tilt of the tray was measured and corrected from the outside of the chamber, and then the tray was inserted into the chamber.

However, since the method according to the prior art corrects the tilt of the tray from outside the chamber, it is difficult to detect tilt that occurs after the tray is inserted into the chamber.

In the present invention, in order to solve the above-described problem, a tilt detection unit 470 is provided inside the chamber 400 to detect tilting of the tray 456 in at least one of the vertical and horizontal directions. You can.

FIG. 4 is a side cross-sectional view of the chamber 400 equipped with a tilting detection unit 470 according to an embodiment of the present invention, FIG. 5 is a top view of the chamber 400, and FIG. 6 is a view of the chamber 400. This is a diagram showing the tilting detection unit 470 provided on the inner side.

4 to 6, the tilting detection unit 470 measures the electric capacity inside the chamber 400 and detects the tilting of the tray 456 inside the chamber 400. I do it.

For example, the capacitance (C) between a pair of electrodes facing each other can be defined as [Equation 1] below.

[Equation 1]

In [Equation 1], 'C' corresponds to capacitance, 'A' corresponds to the overlapping area of a pair of electrodes, and 'd' corresponds to the gap between the two electrodes. Meanwhile, 'ε' is the dielectric constant of the medium between the electrodes and is defined as the dielectric constant of the vacuum multiplied by the dielectric constant.

In [Equation 1] above, the vacuum dielectric constant corresponds to a constant, so the variables that determine the capacitance are the dielectric constant (ε), the overlapping area of the two electrodes (A), and the distance between the two electrodes (d). . In other words, when the dielectric constant (ε) of the medium, the overlapping area (A) of the two electrodes, and the distance (d) between the two electrodes change, the capacitance value changes, allowing detection.

Since this change in capacitance can be measured up to a very small decimal unit change, there is an advantage in that the displacement of the tray 456 in nanometer units can also be measured.

Meanwhile, the tilting detection unit 470 is a first tilting detection unit 4700A that detects the vertical tilting of the tray 456 inside the chamber 400 and the tray 456 inside the chamber 400. It may be provided with at least one of the second tilt detection units 4700B that detect horizontal tilting.

As shown in FIG. 6, electrodes 472, 476, and 482 may be disposed on the inner surface of the chamber 400 opposite the opening 414.

For example, the first tilting detection unit 4700A includes a first electrode 472 and a second electrode 476 installed to be spaced apart in the vertical direction on the inner wall of the chamber 400, the tray 456, and the A first comparison that detects vertical tilting of the tray 456 by comparing the electric capacity between the first electrode 472 and the electrostatic capacity between the tray 456 and the second electrode 476. It may be provided with unit 490 (see FIG. 8).

In addition, the second tilt detection unit 4700B includes a third electrode 472 and a fourth electrode 482 installed to be spaced apart in the horizontal direction on the inner wall of the chamber 400, the tray 456, and the third electrode 470B. A second comparison unit (not shown) may be provided to detect horizontal tilting of the tray 456 by comparing the capacitance between the electrodes and the capacitance between the tray 456 and the fourth electrode 482. there is.

In this case, a common electrode can be used to reduce the number of electrodes installed on the inner wall of the chamber 400. That is, the first electrode 472 of the first tilting detection unit 4700A corresponds to the third electrode of the second tilting detection unit 4700B. In this way, by using a common electrode, the number of electrodes installed on the inner wall of the chamber 400 can be reduced, making work more convenient and the configuration of the sensing unit can be simplified.

FIG. 7 is an enlarged side view of the region 'VII' in FIG. 4 and shows the configuration of the first tilt detection unit 4700A.

Referring to FIGS. 4 and 7, the first tilting detection unit 4700A includes a first electrode 472 and a second electrode 476 installed to be spaced apart in the vertical direction on the inner wall of the chamber 400, as described above. can be provided. The first electrode 472 and the second electrode 476 are respectively connected to insulating members 474 and 478 installed on the inner wall of the chamber 400, and the first electrode 474 and 478 are connected to each other. Wiring connected to the electrode 472 and the second electrode 476 may be brought out to the outside.

Meanwhile, in the above-described configuration, the tray 456 corresponds to an opposing electrode facing the first electrode 472 and the second electrode 476. Therefore, an insulator 454 is placed on the cover 452 connected to the tray 456, and the tray 456 and the first electrode 472 and the tray 456 and the second electrode are connected through the cover 452. The capacitance between the electrodes 476 is detected and compared. Wiring connected to the tray 456 may be connected through the cover 452.

In this case, when the tray 456 is installed normally without sagging, the height of the tip can be known, and thereby the installation height of the first electrode 472 and the second electrode 476 can be determined.

Figure 8 is a diagram schematically showing the first tilt detection unit 4700A. FIG. 8(A) shows the tray 456 installed normally and not sagging, and FIG. 8(B) shows the tray 456 sagging.

Referring to Figures 7 and 8, the installation height of the first electrode 472 and the second electrode 476 is equal to the height between the tip of the tray 456 and the first electrode when the tray 456 is installed normally without sagging. The overlapping areas A ₁ and A ₂ of the electrode 472 and the second electrode 476 may be set to be the same. That is, the first electrode is aligned so that the line C1 dividing the vertical distance between the first electrode 472 and the second electrode 476 into two coincides with the line C2 dividing the thickness of the tray 456 into two. The height of 472 and the second electrode 476 can be set.

At this time, the distance between the centers of the first electrode 472 and the second electrode 476 is referred to as 'L', and the distance from the center to the edge of the first electrode 472 and the second electrode 476 is If the distance is 'G' and the thickness of the tray 456 is 't', the distance (L) between the centers of the first electrode 472 and the second electrode 476 is given by [Equation 2] below. It can be determined within a satisfactory range.

[Equation 2]

2G < L < t + 2G

That is, the distance L between the centers of the first electrode 472 and the second electrode 476 is equal to the thickness t of the tray 456 and the distance from the center to the edge of each electrode 472 and 476 ( If it is more than twice the value of G), there is no overlapping area between the first electrode 472, the second electrode 476, and the tip of the tray 456.

Additionally, the distance L between the centers of the first electrode 472 and the second electrode 476 is set to be greater than twice the distance G from the center to the edge of each electrode 472 and 476. If the distance (L) between the centers of the first electrode 472 and the second electrode 476 is equal to twice the distance (G) from the center to the edge of each electrode (472, 476), This is because the first electrode 472 and the second electrode 476 are in contact with each other.

Meanwhile, the first tilting detection unit 4700A compares the capacitance between the tray 456 and the first electrode 472 and the capacitance between the tray 456 and the second electrode 476. It is provided with a first comparison unit 490 that detects vertical tilting.

That is, the first tilting detection unit 4700A specifically measures the capacitance between the tray 456 and the first electrode 472 and the capacitance between the tray 456 and the second electrode 476. Instead of calculating the capacitance, the capacitance between the tray 456 and the first electrode 472 and the capacitance between the tray 456 and the second electrode 476 are simply compared by the first comparison unit 490. Thus, the vertical tilting of the tray 456 can be detected.

In this way, when the capacitance between the first electrode 472 and the capacitance between the tray 456 and the second electrode 476 are simply compared to detect the configuration, compared to the case where a specific value of the capacitance is obtained. It has the advantage of being able to be configured by compacting the elements and simplifying the control logic.

For example, when the tray 456 is installed normally without sagging as shown in (A) of FIG. 8, the area A ₁ where the tip of the tray 456 overlaps with the first electrode 472 and the tray The overlapping area (A ₂ ) of the tip of 456 and the second electrode 476 becomes the same.

Therefore, in this case, the capacitance between the tray 456 and the first electrode 472 and the capacitance between the tray 456 and the second electrode 476 are equal to each other, so that the tray 456 It can be judged that it is installed normally and not tilted in the vertical direction. Meanwhile, even when the capacitance detected between the tray 456 and the first electrode 472 and between the tray 456 and the second electrode 476 do not completely match, a predetermined margin is applied. You can also set a range and judge it as normal even if it falls within that range.

On the other hand, when the tray 456 sags as shown in (B) of FIG. 8, the area A ₁ where the tip of the tray 456 and the first electrode 472 overlap, and the tip of the tray 456 The overlapping area (A ₂ ) of the second electrode 476 changes.

That is, among the three variables described in [Equation 1] above, the overlapping area (A) of the two electrodes varies, causing the capacitance value to change.

In this case, the areas (A ₁ , A ₂ ) of the first electrode 472 and the second electrode 476 overlapping with the tray 456 are changed, so that the tray 456 and the first electrode 472 ) and between the tray 456 and the second electrode 476 are different from each other. Accordingly, it can be determined that the tray 456 is tilted in the vertical direction.

In addition, the above-described embodiment has the advantage of being able to fix the initial installation position of the tray 456 using electrostatic capacitance, and the tip of the tray 456, the first electrode 472, and Although the explanation assumes that the overlapping areas (A ₁ and A ₂ ) of the second electrodes 476 are set to be equal and the capacitances of the two are compared to detect tilting, it is not limited to this.

For example, when the first electrode 472 and the second electrode 476 are initially installed, even if the areas (A ₁ and A ₂ ) overlapping with the tray 456 are set differently, the first electrode 472 ) and the initial capacitance of the second electrode 476 with the tray 456 may be stored in the first comparison unit 490, respectively. Afterwards, when the tray 456 is introduced into the chamber 400, a method of detecting tilting by comparing changes in capacitance of the first electrode 472 and the second electrode 476 with the tray 456. It is also possible.

Meanwhile, in the above-described FIG. 6, the second tilting detection unit 4700B detects static electricity between the tray 456 and the third electrode 472 and between the tray 456 and the fourth electrode 782. By comparing capacities, horizontal tilting is detected.

The second tilting detection unit 4700B, like the above-described first tilting detection unit 4700A, detects between the tray 456 and the third electrode 472 and between the tray 456 and the second comparison unit. Horizontal tilting can be detected by comparing the capacitance detected between the fourth electrodes 482.

For example, when the tray 456 is tilted in the horizontal direction, the overlapping area between the tray 456 and the third electrode 472 and the fourth electrode 482 may change, causing the measured capacitance to vary. By this, it can be detected that the tray 456 is tilted in the horizontal direction.

The description of the second tilting detection unit 4700B is similar to that of the first tilting detection unit 4700A except that the tilting direction of the tray 456 is changed from vertical to horizontal, so repetitive description is omitted. do.

Meanwhile, FIG. 9 is a diagram illustrating a tilting detection unit 470' disposed on the inner side of the chamber 400 in a substrate processing apparatus according to another embodiment.

Referring to FIG. 9, the tilting detection unit 470' according to this embodiment includes a third tilting detection unit 4700C and a fourth tilting detection unit in addition to the above-described first tilting detection unit 4700A and the second tilting detection unit. A unit 4700D may be further provided.

The third tilt detection unit 4700C is arranged to be horizontally spaced apart from the first tilt detection unit 4700A, and detects the vertical tilt of the tray 456.

Additionally, the fourth tilt detection unit 4700D is arranged to be vertically spaced apart from the second tilt detection unit 4700B, and detects the horizontal tilting of the tray 456.

In this case, an additional electrode 484 is further included in the configuration of FIG. 6 described above, and all electrodes 472, 476, 482, and 484 serve as common electrodes. In other words, one electrode serves as a detection unit that detects horizontal tilting and further functions as a detection unit that detects vertical tilting.

In this way, if all electrodes function as common electrodes, the configuration can be simplified and the control logic that controls each electrode can be configured more simply.

In the configuration shown in FIG. 9, the tilting of the tray 456 can be detected more precisely compared to the above-described embodiment in that it can detect when the tray 456 is tilted in the horizontal direction from the vertical direction. can do.

Meanwhile, when performing a drying process for the substrate S using a supercritical fluid, it is not easy to accurately detect the end point of the process. This is because it is difficult to accurately measure the remaining amount of organic solvent, such as IPA (Isopropyl alcohol), on the substrate S located inside the aforementioned chamber 400.

In order to solve this problem, in another embodiment of the present invention, a process detection unit 500 detects whether the process for the substrate S is completed by measuring at least one parameter inside the chamber 400 (see FIG. 12). ) can be provided.

Figure 10 is a graph showing the change in dielectric constant of carbon dioxide according to pressure and temperature. In Figure 10, the horizontal axis represents pressure, and the vertical axis represents dielectric constant.

As shown in Figure 10, looking at curves ① or ② where the temperature is lower than the critical temperature, the dielectric constant rises too dramatically below the critical point as the pressure rises, and the range of change in dielectric constant according to pressure beyond the critical point is very large. Because it is small, it is difficult to detect changes in the capacitance of carbon dioxide within the chamber 400 in this temperature range.

On the contrary, if you look at curve ③, where the temperature is approximately in the saturation temperature range, it is easy to detect the change in capacitance of carbon dioxide within the chamber 400 because the temperature passes the critical point as the pressure rises and the range of change in dielectric constant according to pressure is relatively large. .

On the other hand, when the temperature becomes too high above the saturation temperature, the range of change in dielectric constant according to pressure becomes small again, as shown in curve ④, making it difficult to detect the change in capacitance of carbon dioxide within the chamber 400.

Meanwhile, Figure 11 is a graph showing the change in dielectric constant of carbon dioxide (curve ①) and carbon dioxide containing a polar organic solvent such as IPA (curve ②) according to the pressure.

Referring to FIG. 11, it can be seen that the change in dielectric constant of carbon dioxide is greater when a polar organic solvent is included (curve ②) compared to pure carbon dioxide (curve ①).

Ultimately, in the graph of FIG. 10, when carbon dioxide is heated to approximately the saturation temperature range or above the saturation temperature and contained within the chamber 400, a change in capacitance can be detected by a change in the dielectric constant of carbon dioxide according to pressure. can be seen. Furthermore, in the graph of FIG. 11, when carbon dioxide contains a polar organic solvent such as IPA, the change in dielectric constant of carbon dioxide becomes larger, resulting in a change in the amount of carbon dioxide including the organic solvent remaining inside the chamber 400, that is, the change in carbon dioxide. It can be seen that the range of change in dielectric constant increases depending on the concentration of the organic solvent included.

Therefore, when a drying process is performed using a supercritical fluid such as carbon dioxide for a substrate (S) coated with a polar organic solvent such as IPA, the electrostatic capacitance that changes depending on the remaining amount of the organic solvent inside the chamber 400 is changed. By detecting this, it becomes possible to determine the end point of the drying process for the substrate (S).

Based on the description of FIGS. 10 and 11 above, the above-described process detection unit 500 measures the capacitance inside the chamber 400 and determines the process in the drying process for the substrate S using supercritical fluid. You can check the progress and end point of the process.

FIG. 12 is a side cross-sectional view showing the configuration of the chamber 400 equipped with a process detection unit 500 according to another embodiment of the present invention, and FIG. 13 is a diagram schematically showing the process detection unit 500. am.

Referring to Figures 12 and 13, the process detection unit 500 measures the electric capacity inside the chamber 400 to determine the progress of the process on the substrate S and whether the process is completed, i.e. , the end point is determined.

In addition, the process detection unit 500 measures the capacitance inside the chamber 400, detects the remaining amount of organic solvent, such as IPA, or the concentration of the organic solvent inside the chamber 400, and detects the substrate ( The end point of the process for S) is determined.

For example, the process detection unit 500 measures the capacitance between the tray 456 and the inner wall of the chamber 400. In this case, the cover 452 and the tray 456 are electrically connected so that an electrical wire can be connected to the cover 452. In addition, in this embodiment, unlike the tilting detection unit described above, a separate electrode is not provided inside the chamber 400, and the entire chamber 400 is used as an electrode.

That is, if one electrode for measuring capacitance is the tray 456, the opposite electrode corresponds to the chamber 400.

If a separate electrode is provided inside the chamber 400 for the process detection unit 500, when measuring capacitance, the capacitance value of the corresponding area where the electrode inside the chamber 400 is installed is reflected. This is because there is a large difference from the capacitance value due to the organic solvent remaining throughout the interior of the chamber 400.

In addition, the process detection unit 500 measures the capacitance between the chamber 400 and the tray 456, and determines the progress and end point of the process for the substrate S according to the measured capacitance value. A measuring unit 495 that makes the judgment may be provided.

The measuring unit 495 may be composed of a separate device installed in the process detection unit 500, or the control unit (not shown) of the substrate processing apparatus 1000 may serve as the measuring unit 495. do.

Meanwhile, Figure 14 shows the remaining amount (B) of the organic solvent inside the chamber 400 according to the pressure change (A) of the process for the substrate (S), and the dielectric constant (C) of the fluid inside the chamber 400. ) and the capacitance (D) inside the chamber 400 measured by the process detection unit 500. In Figure 14, the horizontal axis shows time according to the progress of the process.

Referring to FIG. 14, in the case of a preparation step (P1: 0 to T1) in which the process for the substrate S begins and the tray 456 is inserted and docked inside the chamber 400, the chamber 400 ) The remaining amount (B) of the organic solvent inside is maintained constant.

Meanwhile, the dielectric constant (C) of the fluid inside the chamber 400 is also maintained constant.

The capacitance value (D) inside the chamber 400 increases as the tray 456 is inserted into the chamber 400 and approaches the inner wall of the chamber 400.

Next, a pressurization step (P2: T1 to T3) in which the pressure inside the chamber 400 increases follows.

In the pressurization step, high-pressure fluid is supplied into the chamber 400, and fluid is not discharged from the chamber 400 to the outside. Accordingly, the pressure inside the chamber 400 increases and passes the critical pressure (Pc) to a predetermined pressure.

In the case of the pressurization step, the remaining amount (B) of the organic solvent inside the chamber 400 remains constant.

Meanwhile, the dielectric constant (C) of the fluid inside the chamber 400 increases as the pressure increases. When the pressure inside the chamber 400 passes the critical pressure (T2 to T3), the dielectric constant (C) of the fluid inside the chamber 400 increases with a relatively larger slope.

Additionally, the capacitance value (D) inside the chamber 400 also increases as the dielectric constant increases. When the pressure inside the chamber 400 passes the critical pressure (T2 to T3), the capacitance value (D) of the fluid inside the chamber 400 also increases at a larger slope.

The pressurizing step (P2) is followed by the pressure maintaining step (P3). In the pressure maintenance step (P3), the fluid is continuously supplied into the chamber 400 and the fluid is discharged to the outside of the chamber 400 in an amount equal to the amount of fluid supplied to keep the pressure inside the chamber 400 constant. will be maintained.

In the case of the pressure maintenance step (P3), the fluid containing the organic solvent inside the chamber 400 is discharged to the outside of the chamber 400, so the remaining amount (B) of the organic solvent inside the chamber 400 decreases. do. When the amount of organic solvent inside the chamber 400 reaches a predetermined organic solvent threshold value (I _end ) (T4), the process for the substrate S may be set to be completed.

Meanwhile, in the pressure maintenance step (P3), as the remaining amount of organic solvent inside the chamber 400 decreases, the dielectric constant (C) of the fluid inside the chamber 400 decreases.

Likewise, the capacitance value (D) inside the chamber 400 also decreases.

Following the pressure maintenance step described above, a pressure reduction step (P4) is performed. In the decompression step (P4), the pressure inside the chamber 400 is reduced by discharging the fluid to the outside of the chamber 400 rather than supplying the fluid into the chamber 400.

In the case of the pressure reduction step (P4), the fluid containing the organic solvent inside the chamber 400 is discharged to the outside of the chamber 400, so the remaining amount (B) of the organic solvent inside the chamber 400 continues to decrease. do.

Meanwhile, as the remaining amount of organic solvent inside the chamber 400 decreases, the dielectric constant (C) of the fluid inside the chamber 400 also decreases, and similarly, the capacitance value (D) inside the chamber 400 ) also decreases.

The change in capacitance inside the chamber 400 due to the pressure change in the process for the substrate S described above may be stored in advance in the measurement unit 495 described above. In addition, the capacitance threshold value (C _end ) inside the chamber 400 corresponding to the organic solvent threshold value (I _end ) that can determine whether or not to terminate the process for the substrate (S) is similarly measured in the measuring unit 495. Can be saved in advance.

Therefore, when the drying process for the substrate S progresses and a pressure change occurs, the measuring unit 495 compares the measured capacitance value with the previously stored capacitance value to determine the progress of the process, that is, the process. It is possible to determine which stage has been reached among the preparation stage (P1), pressurization stage (P2), and pressure maintenance stage (P3).

Furthermore, when the measured capacitance value reaches the capacitance threshold value (C _end ), the measuring unit 495 determines that the process is finished and performs the above-described pressure reduction step (P4).

Meanwhile, the substrate processing apparatus according to FIGS. 12 and 13 may be provided with a tilting detection unit 470 according to FIGS. 4 to 9, which is not shown in the drawings, in addition to the process detection unit 500 described above.

Furthermore, the process detection unit 500 described above can be applied to other types of chambers. For example, Figure 15 shows a chamber 600 according to another embodiment.

Referring to FIG. 15, the chamber 600 of this embodiment includes a lower chamber 612, an upper chamber 610 that seals the upper part of the lower chamber 612, and a space between the lower chamber 612 and the upper chamber 610. It may be provided with a sealing portion 630 that seals the.

Inside the chamber 600, a substrate support portion 620 is provided on which the substrate S coated with the organic solvent 10 is seated.

In the above-described configuration, the process detection unit 500' measures the capacitance between the upper chamber 610 and the lower chamber 612 to determine the progress of the process and the completion of the process for the substrate S.

Since the description of the process detection unit 500' is similar to the above-described embodiment, repetitive description will be omitted.

Although the present invention has been described above with reference to preferred embodiments, those skilled in the art may make various modifications and changes to the present invention without departing from the spirit and scope of the present invention as set forth in the claims described below. You can do it. Therefore, if the modified implementation basically includes the elements of the claims of the present invention, it should be considered to be included in the technical scope of the present invention.

10: substrate
100: Fluid storage unit
200: Pressure control unit
300: Temperature control unit
400: Chamber
412: processing space
450: Tray unit
452: cover
456: tray
458: Sealing member
470: Tilting detection unit
500: Process detection unit
600: Fluid supply unit
1000: Substrate processing device
4700A: 1st tilting detection unit
4700B: 2nd tilting detection unit
4700C: 3rd tilting detection unit
4700D: Fourth tilting detection unit

Claims (9)

A chamber that provides a processing space for performing a processing process on a substrate coated with a processing solution or organic solvent using a fluid in a supercritical state;
a tray that supports the substrate and is capable of being introduced into and out of the chamber through an opening of the chamber; and
A tilt detection unit that detects tilting of the tray in at least one of the vertical and horizontal directions within the chamber,
The tilting detection unit has a plurality of electrodes on the inner wall of the chamber, and detects the tilting of the tray by detecting a change in capacitance according to a change in the overlapping area between the plurality of electrodes and the tip of the tray. Substrate processing equipment. According to paragraph 1,
The tilting detection unit measures electric capacity inside the chamber and detects tilting of the tray inside the chamber. According to paragraph 1,
The tilting detection unit
A substrate processing apparatus comprising at least one of a first tilt detection unit that detects a vertical tilt of the tray within the chamber and a second tilt detection unit that detects a horizontal tilt of the tray within the chamber. . According to paragraph 3,
The first tilting detection unit
By comparing the first and second electrodes installed to be spaced apart from each other along the vertical direction on the inner wall of the chamber, the electric capacity between the tray and the first electrode, and the electric capacity between the tray and the second electrode. A substrate processing device comprising a first comparison unit that detects vertical tilting of the tray. According to paragraph 3,
The second tilting detection unit
By comparing the capacitance between the third and fourth electrodes installed to be spaced apart in the horizontal direction on the inner wall of the chamber, the tray and the third electrode, and the capacitance between the tray and the fourth electrode, the tray is horizontally spaced. A substrate processing device comprising a second comparison unit that detects direction tilting. According to paragraph 4,
The installation height of the first electrode and the second electrode is determined so that when the tray is not tilted in the vertical direction, the overlapping areas of the tip of the tray and the first electrode and the second electrode are all the same. Processing device. According to paragraph 4,
A substrate processing apparatus, wherein the heights of the first electrode and the second electrode are determined so that a line bisecting the vertical distance between the first electrode and the second electrode coincides with a line bisecting the thickness of the tray. According to clause 6 or 7,
When the distance between the centers of the first electrode and the second electrode is 'L', the distance (L) between the centers of the first electrode and the second electrode satisfies the following equation,
'2G < L < t + 2G '
In the above equation, 'G' is defined as the distance from the center to the edge of the first electrode and the second electrode, and 't' is defined as the thickness of the tray. According to paragraph 4,
When installing the first electrode and the second electrode, if the areas overlapping with the tray are set differently, the initial capacitance of the first electrode and the second electrode with the tray is stored in the first comparison unit, respectively,
A substrate processing apparatus characterized in that when the tray is introduced into the chamber, tilting is detected by comparing changes in capacitance of the first electrode and the second electrode with the tray.