JP2024016558A - Substrate drying device, substrate processing device, and substrate drying method - Google Patents

Abstract

To provide a substrate drying device, a substrate processing device, and a substrate drying method that can reduce occurrence of pattern blockage on the entire surface layer of a substrate.SOLUTION: A drying device (substrate drying device) 300 includes a drying chamber 31 into which a substrate W having a liquid film of a processing liquid formed on a processing target surface thereof is conveyed, a support portion 34 for supporting the substrate W conveyed into the drying chamber 31, a flash lamp 321 that is provided in the drying chamber 31 and heats the surface layer of the processing target surface of the substrate W to a temperature equal to or higher than a temperature at which a gas layer is generated due to the Leidenfrost phenomenon in the entire area between the liquid film and the surface layer, a temperature maintenance unit (halogen lamp 322) that maintains the temperature of the surface layer by heating so as to maintain the gas layer by the heating of the flash lamp 321, and a drive mechanism 35 for rotating the substrate W together with the support portion 34 so that the liquid film having the gas layer generated between the liquid film and the surface layer is discharged by centrifugal force caused by the rotation of the substrate W.SELECTED DRAWING: Figure 2

Description

The present invention relates to a substrate drying apparatus, a substrate processing apparatus, and a substrate drying method.

In the manufacturing process of manufacturing semiconductors, liquid crystal panels, etc., substrate processing involves supplying a processing liquid to the surface to be processed of a substrate such as a wafer or liquid crystal substrate, processing the surface to be processed, and cleaning and drying the surface after processing. A device is used. In the drying process of this substrate processing equipment, fine uneven patterns such as those around memory cells and gates may be formed due to the spacing and structure of the patterns formed on the surface layer of the processing surface, the surface tension of the processing liquid, etc. may collapse and become blocked. This tendency has become more pronounced as semiconductors have become increasingly finer in recent years due to higher integration and higher capacity.

In order to suppress pattern collapse, a substrate drying method using IPA (2-propanol: isopropyl alcohol), which has a lower surface tension than ultrapure water, has been proposed. In this substrate drying method, DIW (ultra pure water) on the surface of the substrate is replaced with a mixed solution of IPA and DIW, and the substrate is dried. However, semiconductors are becoming increasingly finer, and even when drying is performed using a highly volatile organic solvent such as IPA, the wafer pattern may collapse due to the surface tension of the liquid.

For example, if the drying rate of the substrate surface becomes uneven during the drying process of the liquid, and liquid remains between some patterns, the pattern collapses due to the surface tension of the liquid in that part. Specifically, the patterns in the areas where the liquid remains collapse due to elastic deformation due to the surface tension of the liquid, and the residue slightly dissolved in the liquid aggregates. When the liquid completely evaporates, the fallen patterns stick together.

To deal with this, after supplying the cleaning liquid, the surface layer of the surface to be processed of the rotating substrate is rapidly heated to a temperature at which the Leidenfrost phenomenon occurs, and a gas layer is created between the surface layer and the liquid film of the cleaning liquid. A drying method has been proposed in which collapse of fine patterns due to surface tension is suppressed by turning a liquid film into liquid beads and discharging them outside the substrate by centrifugal force of rotation (see Patent Document 1). In this drying method, a nucleate boiling state in which microscopic bubbles are generated inside the liquid film that is in direct contact with the heating surface is not sufficient, but a vapor film is interposed between the liquid and the heating surface, and steam is removed from the heating surface. It is necessary to create a film boiling state in which evaporation occurs in the vapor film by heat transfer through the film.

Patent No. 6400919

As described above, even in drying that uses the Leidenfrost phenomenon to turn a liquid film into liquid beads and remove them, a part of the substrate may have a portion where the pattern is occluded. This is because part of the liquid film in contact with the surface layer of the substrate remains in a nucleate boiling state rather than a film boiling state, and the liquid film does not turn into liquid beads but remains between the unevenness of the pattern, resulting in the final It is thought that pattern occlusion occurs due to surface tension acting on that part.

In order to bring the liquid film to a film boiling state over the entire surface layer of the substrate in order to prevent such partial pattern blockage, it is necessary to instantaneously heat the entire surface layer of the substrate to a high temperature. More specifically, it is necessary to instantaneously heat the surface layer of the substrate to a temperature difference of more than 100° C. with respect to the boiling point temperature of the liquid film in contact with the surface layer. Furthermore, it is necessary to maintain the film boiling temperature until the liquid beads are discharged from the substrate.

Heat sources conventionally used in the semiconductor field include flash lamps and halogen lamps. However, although flash lamps can instantaneously heat the surface layer of a substrate in a few milliseconds, they cannot maintain film boiling temperature until the liquid beads are expelled from the substrate. On the other hand, halogen lamps take several seconds to heat the surface layer of the substrate, so the heating speed is slower than flash lamps, but once the temperature of the substrate reaches film boiling, it is possible to maintain that temperature. become. However, in order to more stably turn a liquid film into a liquid ball, it is necessary to increase the rate at which the halogen lamp heats the film to the boiling temperature to several milliseconds, which requires an enormous amount of output. In other words, it would be impractical to install a power source that can produce a large output, and repeated heating would result in excessive power consumption.

An object of the present invention is to provide a substrate drying apparatus, a substrate processing apparatus, and a substrate drying method that can reduce the occurrence of pattern blockage on the entire surface layer of a substrate.

The substrate drying apparatus of the present invention includes a drying chamber into which a substrate with a liquid film formed by a processing liquid formed on a surface to be processed is carried in, a support part that supports the substrate carried into the drying chamber, and a support part that supports the substrate carried into the drying chamber; a flash lamp provided in a drying chamber and heating the surface layer of the surface to be processed of the substrate to a temperature higher than a temperature at which a gas layer due to the Leidenfrost phenomenon is formed between the liquid film and the surface layer; A temperature maintaining section that maintains the temperature of the surface layer by heating, and a temperature maintaining section that rotates the substrate together with the support section so as to maintain the air layer due to heating, thereby forming the air layer between the surface layer and the surface layer. and a drive mechanism that discharges the liquid film by centrifugal force caused by rotation of the substrate.

The substrate processing apparatus of the present invention includes a processing apparatus that processes a substrate by supplying a processing liquid while rotating the substrate, a cleaning apparatus that cleans the processed substrate by supplying a processing liquid while rotating the substrate, and a cleaning apparatus that processes the substrate by supplying a processing liquid while rotating the substrate. The present invention includes a drying device, and a transporting device that carries out the substrate cleaned in the cleaning device with a liquid film formed by the cleaning liquid and carries it into the substrate drying device.

In the substrate drying method of the present invention, the support section supports the substrate carried into the drying chamber with a liquid film formed by the processing liquid on the surface to be processed, and the drive mechanism supports the substrate together with the support section. the flash lamp heats the surface layer of the surface to be processed of the substrate to a temperature higher than a temperature at which a gas layer due to the Leidenfrost phenomenon is formed between the liquid film and the surface layer, and the temperature maintaining section The temperature of the surface layer is maintained by heating so as to maintain the gas layer by heating with a flash lamp, and the liquid film is discharged by centrifugal force caused by rotation of the substrate.

The present invention can provide a substrate drying device, a substrate processing device, and a substrate drying method that can reduce the occurrence of pattern occlusion on the entire surface layer of a substrate.

FIG. 1 is a simplified configuration diagram showing a substrate processing apparatus according to an embodiment. 2 is a configuration diagram showing a cleaning device and a drying device of the substrate processing apparatus in FIG. 1. FIG. FIG. 3 is an internal configuration diagram showing the drying device when the substrate is carried in (A) and when the film thickness is measured (B). FIG. 4 is an internal configuration diagram showing the drying device when a cleaning liquid is being supplied (A) and when the drying device is on standby (B). It is an internal configuration diagram showing the drying device when drying the substrate (C) and when lowering the substrate (B). It is a flowchart which shows the procedure of a substrate drying process of an embodiment. FIG. 3 is an explanatory diagram showing the flow of drying processing using the Leidenfrost phenomenon. FIG. 3 is an explanatory diagram showing a liquid film remaining within a pattern. It is a graph showing temperature changes of a flash lamp, a halogen lamp, and a substrate. It is a block diagram which shows the modification of a temperature maintenance part.

Embodiments of the present invention will be described below with reference to the drawings.
[overview]
As shown in FIG. 1, the substrate processing apparatus 1 of this embodiment includes a plurality of chambers 1a that house devices for performing various types of processing, and a plurality of substrates are stored in a cassette (FOUP) 1b and transported in a pre-process. This is a single-wafer processing apparatus in which one substrate W is processed in each chamber 1a. Unprocessed substrates W are taken out one by one by the transfer robot 1c from the cassette 1b, and after being temporarily placed on the buffer unit 1d, the unprocessed substrates W are transferred to each chamber 1a and processed by various devices described below. It will be done.

The substrate processing apparatus 1 includes a processing apparatus 110, a cleaning apparatus 120, a transport apparatus 200, a drying apparatus 300, and a control apparatus 400. For example, the processing apparatus 110 applies a processing liquid (for example, a phosphoric acid aqueous solution, a mixture of hydrofluoric acid and nitric acid, a mixture of acetic acid, sulfuric acid, and hydrogen peroxide (SPM)), etc. to the rotating substrate W. ) is used to remove unnecessary films and leave circuit patterns. The cleaning device 120 cleans the substrate W that has been etched by the etching device using a processing liquid (cleaning liquid).

The transport device 200 transports the substrate W between the buffer unit 1d and each chamber 1a, and between each chamber 1a. For example, the transport device 200 transports the substrate W processed in the processing device 110 to the cleaning device 120, and transports the substrate W cleaned in the cleaning device 120 to the drying device 300. The drying device (substrate drying device) 300 performs a drying process by rotating and heating the substrate W that has been cleaned with the cleaning liquid. Control device 400 controls each of the above devices.

Note that the substrate W processed according to this embodiment is, for example, a semiconductor wafer. Hereinafter, the surface of the substrate W on which the pattern etc. are formed will be referred to as the surface to be processed. Further, on the surface to be processed of the substrate, the outermost surface of the pattern that is in contact with the liquid film of the processing liquid is defined as the surface layer.

As the cleaning liquid, which is a processing liquid for the cleaning process, an alkaline cleaning liquid (APM), ultrapure water (DIW), and a volatile solvent (IPA) are used. APM is a chemical mixture of aqueous ammonia and hydrogen peroxide, and is used to remove residual organic matter. DIW is used to wash away APM remaining on the surface of the substrate W to be processed after the APM processing. Since IPA has a lower surface tension than DIW and higher volatility, IPA is used to replace DIW and reduce pattern collapse due to surface tension.

[Cleaning device]
As shown in FIG. 2, the cleaning device 120 includes a cleaning chamber 11 which is a container in which a cleaning process is performed, a support part 12 that supports a substrate W, a rotation mechanism 13 that rotates the support part 12, and a cleaning liquid L that is scattered around the substrate. It has a cup 14 that receives from the periphery of W, and a supply section 15 that supplies cleaning liquid L. The supply unit 15 is provided with a nozzle 15a for dropping the cleaning liquid L and a moving mechanism 15b for moving the nozzle 15a.

The cleaning process is performed by supplying the cleaning liquid L from the nozzle 15a to the processing surface of the substrate W, which is supported by the support part 12 and rotated by the rotation mechanism 13. The cleaning process is performed by supplying APM to the surface to be processed of the substrate W that has been subjected to the etching process in the processing apparatus 110 to perform APM cleaning, and after the APM cleaning, by performing a pure water rinsing process using DIW, the surface to be processed of the substrate W is cleaned. Wash away remaining APM with pure water. As a result, the surface to be processed of the substrate W is filled with the DIW cleaning liquid L. Furthermore, DIW will eventually be replaced by IPA. The cleaning chamber 11 is provided with an opening 11a through which substrates W are carried in and out, and the opening 11a is configured to be openable and closable by a door 11b.

[Transport device]
The transport device 200 includes a handling device 20. The handling device 20 includes a robot hand 21 that grips the substrate W and a moving mechanism 22. The robot hand 21 grips the substrate W. The moving mechanism 22 moves the robot hand 21. The transport device 200 transports the substrate W between the buffer unit 1d and various devices, and between the various devices. For example, the substrate W that has undergone the etching process is carried out from the processing apparatus 110 and carried into the cleaning apparatus 120 with a liquid film of the cleaning liquid L formed on the surface of the substrate W to be processed.

Furthermore, the moving mechanism 22 moves the handling device 20 and the robot hand 21 to transport the substrate W that has been cleaned from the cleaning device 120, so that a liquid film of the cleaning liquid L is formed on the surface of the substrate W to be processed. The formed state is carried into the drying device 300. Note that the reason why the substrate W is transported with a liquid film of the cleaning liquid L formed on the surface to be processed is to prevent particles from adhering to the surface to be processed of the substrate W while the substrate W is being transported. be.

[Drying device]
As shown in FIG. 1, the drying device 300 includes a drying chamber 31, a heating section 32, a window section 33, a support section 34, a drive mechanism 35, a cup 36, a measurement section 37, and a supply section 38. The drying chamber 31 is a container for drying the substrate W therein. A substrate W on which a liquid film of a processing liquid is formed on the surface to be processed is carried into the drying chamber 31 . The drying chamber 31 has a box shape such as a rectangular parallelepiped or a cube, for example. The inner wall of the drying chamber 31 is coated with silica to improve dust resistance. The drying chamber 31 is provided with an opening 31a through which the substrate W is carried in and out. The opening 31a is provided so that it can be opened and closed by a door 31b.

Further, the drying chamber 31 is provided with an inlet 31c and an exhaust port 31d. An air supply section 31e that includes piping, an intake valve, and an air supply device that supplies clean gas ( _N2, etc.) is connected to the introduction port 31c. An exhaust section 31f including piping, an exhaust valve, and an exhaust device for exhausting gas is connected to the exhaust port 31d. By supplying clean gas into the drying chamber 31 from the inlet 31c, a clean atmosphere can be created inside the drying chamber 31. Further, by creating a configuration in which gas is supplied into the drying chamber 31 through the inlet 31c and gas within the drying chamber 31 is discharged through the exhaust port 31d, a flow of gas within the drying chamber 31 is created. Thereby, the vapor of the processing liquid generated when heating the substrate W can be discharged from the drying chamber 31 without filling the inside of the drying chamber 31. Note that the exhaust section 31f may be provided with a quick exhaust valve that lowers the pressure caused by the rapidly expanding atmosphere using a flash of light emitted from a flash lamp 321, which will be described later.

The heating unit 32 is a device that heats the substrate W. The heating unit 32 is provided in the upper part of the drying chamber 31 . The heating section 32 includes a flash lamp 321 and a halogen lamp 322. Note that a partition window 32a made of a plate-like material such as quartz is provided between the flash lamp 321 and the halogen lamp 322. The flash lamps 321 have a straight tube shape, and a plurality of flash lamps 321 are arranged in parallel in a horizontal state. A power supply and a capacitor (not shown) are connected to the flash lamp 321, and the flash lamp 321 instantly emits light and can be heated to a high temperature by the energy stored in the capacitor. The flash lamp 321 of this embodiment heats the surface layer of the substrate W to a temperature equal to or higher than the temperature at which a gas layer due to the Leidenfrost phenomenon occurs between the liquid film and the surface layer (hereinafter referred to as the Leidenfrost temperature). Note that the Leidenfrost temperature is a temperature range that has different widths depending on the type and thickness of the liquid film.

The halogen lamp 322 is a temperature maintenance unit that maintains the temperature of the surface layer by heating so as to maintain the gas layer due to the heating by the flash lamp 321 . The halogen lamps 322 are of a straight tube type, and a plurality of halogen lamps 322 are arranged horizontally above the flash lamp 321 in a direction perpendicular to the flash lamp 321. A power source (not shown) is connected to the halogen lamp 322. Note that for both the flash lamp 321 and the halogen lamp 322, a general factory power source of 200 V or less can be used as a power source.

Since the directions of the flash lamp 321 and the halogen lamp 322 are perpendicular to each other, the entire structure has a lattice shape. The flash lamp 321 and the halogen lamp 322 promote the generation of a gas layer due to the heat of the substrate W by using electromagnetic waves (infrared rays) having a wavelength that heats the surface layer of the substrate W more easily than the cleaning liquid L itself.

More specifically, the entire surface layer of the substrate W on which the IPA liquid film is present is heated to 200° C. or higher within several milliseconds. As a result, the liquid film enters a film boiling state, and the contact portion of the liquid film with the substrate W is instantaneously and uniformly vaporized to generate a gas layer, thereby making it possible to float the liquid film. Since the flash lamp 321 cannot be lit for a long time, the surface layer of the substrate W is heated by the halogen lamp 322 to continue vaporizing the floating liquid near the substrate W, thereby preventing re-adhesion to the surface layer of the substrate W. , the liquid film can be removed without applying surface tension.

The window portion 33 is a member that transmits electromagnetic waves from the heating portion 32. As the window portion 33, for example, a plate-shaped body such as quartz can be used. The window part 33 is provided directly under the heating part 32 in the drying chamber 31, and by partitioning the heating part 32 and the support part 34, the connector part is heated by repeatedly turning on the flash lamp 321 and the halogen lamp 322. This prevents particles generated due to expansion and contraction of the member from adhering to the substrate W from above and causing metal contamination.

The support part 34 supports the substrate W carried into the drying chamber 31. The support section 34 includes a rotating table 34a, a plurality of holding members 34b, and a rotating shaft 34c. The rotary table 34a has a cylindrical shape with a diameter larger than that of the substrate W, and has a flat circular top surface. The plurality of holding members 34b are arranged at equal intervals along the outer periphery of the substrate W, and hold the substrate W in a horizontal state with an interval between the substrate W and the upper surface of the rotary table 34a. The plurality of holding members 34b are provided so as to be movable between a closed position in contact with the edge of the substrate W and an open position away from the edge of the substrate W by an opening/closing mechanism (not shown). The rotating shaft 34c is a vertical axis that supports the rotating table 34a from below and serves as the center of rotation.

The drive mechanism 35 is a mechanism that rotates the substrate W supported by the support section 34 and raises and lowers it. The drive mechanism 35 has a rotating part 35a and an elevating part 35b. The rotating part 35a has a drive source such as a motor, and rotates the support part 34 via the rotating shaft 34c. The elevating part 35b has a mechanism in which a slider is raised and lowered by a ball screw rotated by a motor, and together with the rotating part 35a, the support part 34 is moved up and down.

In this embodiment, the standby position D and the drying position U are set as the positions of the support part 34 that are changed by the drive mechanism 35. The standby position D is a position that receives the substrate W carried into the drying chamber 31 with a liquid film formed by the cleaning liquid L separated from the heating unit 32 .

More specifically, the standby position D is a position lower than a detection unit 37a and a nozzle 38a, which will be described later. The reason why the substrate W is thus received and supported at a position separated from the heating section 32 is as follows. In other words, even if the heating section 32 performs heating (lamp lighting) only during the drying process, the heat generated by the heating section 32 accumulates in the window section 33 . In particular, since the window part 33 is located directly below where the heating part 32 is installed and is made of quartz, which has poor thermal conductivity, it is easy to accumulate heat. Therefore, as the drying process is repeated, heat accumulation in the window portion 33 progresses.

If the substrate W on which the liquid film of the cleaning liquid L is formed is carried in under such an environment, the liquid film on the substrate W will start to evaporate due to the radiant heat from the window portion 33 that has accumulated heat. However, the entire liquid film does not evaporate instantaneously, but only a portion of the liquid film evaporates, resulting in an uneven drying state, and pattern blockage occurs due to the surface tension of the remaining cleaning liquid L. Therefore, it is necessary to support the device at a position apart from the heating section 32 so as not to be affected by such radiant heat.

Therefore, the standby position D is located at the window 33 where the processing liquid deposited on the surface to be processed of the substrate W (the processing liquid at the time of being carried into the drying chamber 31) is repeatedly heated by the heating unit 32 and stored heat. This position is kept away from the window portion 33 until there is no risk of evaporation (less influence of heat) due to radiant heat. The drying position U is a position where the substrate W, which is close to the heating unit 32 and heated by the heating unit 32, generates a gas layer between it and the liquid film. The standby position D of this embodiment is below the upper edge E of the opening 31a, and the drying position U is above the upper edge E of the opening 31a.

The cup 36 is formed into a cylindrical shape so as to surround the support portion 34 (see FIG. 2). The upper part of the peripheral wall of the cup 36 is inclined radially inward and is open so that the substrate W on the support part 34 is exposed. The cup 36 receives the cleaning liquid L scattered from the rotating substrate W and flows it downward. A discharge port (not shown) is formed at the bottom of the cup 36 to discharge the cleaning liquid L flowing down. Note that the cup 36 is connected to the drive mechanism 35 and is provided so as to be movable up and down together with the support section 34.

The measurement unit 37 is carried into the drying chamber 31 and measures the thickness of the liquid film on the substrate W at the standby position D. The measuring section 37 includes a detecting section 37a, a swinging arm 37b, and a swinging mechanism 37c. As the detection unit 37a, for example, a laser displacement meter, a camera, or the like is used. The swinging arm 37b is provided with a detection section 37a at its tip, and has a measurement position in which the detection section 37a faces near the center between the center and the outer peripheral edge of the surface to be processed of the substrate W on the support section 34; It is evacuated from the measurement position and moved to a standby position where the substrate W can be loaded or unloaded. The swing mechanism 37c is a mechanism that swings the swing arm 37b.

As the film thickness measurement method by the measurement unit 37, for example, an optical interference principle can be used. In addition, as another example, it is possible to use a weight scale within the support part 34. When using this weighing scale, the weight of the liquid film on the substrate W (weight of the liquid film = weight of the substrate including the liquid film - weight of the substrate) can be calculated theoretically or experimentally to determine the thickness of the liquid film. Convert.

The supply unit 38 is carried into the drying chamber 31 and supplies the cleaning liquid L onto the substrate W at the standby position D. The supply section 38 includes a nozzle 38a, a swing arm 38b, and a swing mechanism 38c. The nozzle 38a supplies the cleaning liquid L toward the vicinity of the center of the surface to be processed of the substrate W. The cleaning liquid L is supplied to the nozzle 38a from a storage section outside the drying chamber 31 via piping (none of which is shown).

The type of cleaning liquid L supplied by the supply unit 38 is determined by the type of liquid finally deposited on the substrate W in the rinsing process after alkaline cleaning in the cleaning process in the cleaning device 120. That is, when the rinsing process is completed with DIW, the liquid is transported from the cleaning device 120 to the drying device 300 in a state where it is filled with DIW. In the case of DIW, the supply section 38 supplies DIW. When DIW is finally replaced with IPA, it is transported from the cleaning device 120 to the drying device 300 in a state where it is filled with IPA. In the case of IPA, the supply unit 38 newly supplies IPA because it volatilizes during transportation or absorbs moisture in the atmosphere during transportation.

The swinging arm 38b is provided with a nozzle 38a at its tip, and the nozzle 38a can be moved between a supply position facing the vicinity of the center of the surface to be processed of the substrate W on the support part 34, and a position where the nozzle 38a is evacuated from the supply position to carry in the substrate W. or move it to an evacuation position where it can be carried out. The swing mechanism 38c is a mechanism that swings the swing arm 38b. Note that the drying position U is located above the supply unit 38 which is at the supply position for supplying the cleaning liquid L to the substrate W.

[Control device]
The control device 400 is a computer that controls each part of the substrate processing apparatus 1. The control device 400 includes a processor that executes programs, a memory that stores various information such as programs and operating conditions, and a drive circuit that drives each element. That is, the control device 400 controls the processing device 110, the cleaning device 120, the transport device 200, and the drying device 300. Note that the control device 400 includes an input device for inputting information and a display device for displaying information.

The control device 400 includes a mechanism control section 41, a film thickness analysis section 42, and a heating control section 43. The mechanism control section 41 controls the mechanisms of each section. For example, the mechanism control unit 41 controls the rotation speed, rotation start, and rotation stop timing of the support unit 34 by controlling the rotation unit 35a of the drive mechanism 35. Furthermore, the mechanism control section 41 controls the distance (gap) between the heating section 32 and the support section 34 by controlling the elevating section 35b of the drive mechanism 35.

More specifically, after holding the substrate W on the support part 34 at the standby position D, the control device 400 adjusts the film thickness of the cleaning liquid L deposited on the processing surface of the substrate W. The substrate W is raised to the drying position U while being rotated, and the flash lamp 321 and the halogen lamp 322 are turned on to dry it for a predetermined period of time. Thereafter, the substrate W is lowered to the standby position D while maintaining rotation. It also controls operations such as the swinging of the nozzle 38a, the discharge of the cleaning liquid L, and the swinging and measurement of the detection unit 37a.

The film thickness analysis section 42 analyzes the thickness of the liquid film of the cleaning liquid L measured by the measurement section 37. The film thickness analysis unit 42 determines whether the thickness of the liquid film of the cleaning liquid L (liquid film thickness value) measured by the measurement unit 37 is within a predetermined threshold value. When the film thickness analysis unit 42 determines that the measured thickness of the liquid film is within a predetermined threshold, the film thickness analysis unit 42 determines that the thickness of the liquid film is appropriate and rotates and raises the substrate W. A permission signal is sent to the mechanism control unit 41. Upon receiving the permission signal, the mechanism control section 41 transmits a signal to the drive mechanism 35 to instruct the support section 34 to rotate and rise.

Note that the appropriate film thickness is, for example, 10 μm or less in the case of DIW, and 100 μm or less in the case of IPA. These film thicknesses are such that the liquid film does not evaporate from the substrate W when approaching the heating section 32 (when approaching the window section 33), and is suitable for performing drying processing by the Leidenfrost phenomenon. The liquid film thickness is such that it can be dried well. However, these numerical values are just examples, and in reality, an appropriate liquid film thickness can be determined in advance through experiments and the like. Further, the rotational speed of the substrate W is, for example, about 200 to 300 rpm, and even if the liquid film is adjusted, the liquid film thickness can be maintained at a predetermined thickness within such a rotational speed range.

The heating control section 43 controls the heating section 32 according to commands from the mechanism control section 41 . When the heating control unit 43 receives a command signal output from the mechanism control unit 41 when the support unit 34 comes to the drying position U and stops, the heating unit 32 controls the processing surface of the substrate W on the support unit 34 by the heating unit 32. Execute heating.

The heating control unit 43 causes the flash lamp 321 and the halogen lamp 322 to emit light at the same time. Then, due to the light emission from the flash lamp 321, the entire area between the liquid film and the surface layer on the surface to be processed of the substrate W is rapidly heated to the Leidenfrost temperature or higher. For example, by heating at a temperature of 200° C. or higher, the entire surface layer of the substrate W is heated to a temperature higher than the temperature at which the liquid film reaches a film boiling state within several milliseconds. Note that the halogen lamp 322 may emit light before the flash lamp 321 emits light. That is, the temperature maintenance section may start heating before the flash lamp 321 emits light.

Then, as the temperature of the halogen lamp 322 that continues to emit light increases, the surface layer of the substrate W is maintained at a temperature equal to or higher than the Leidenfrost temperature, and a film boiling state is maintained. As a result, the cleaning liquid L on the surface layer of the surface to be processed of the substrate W becomes a liquid droplet.

If the film thickness analysis unit 42 determines that the thickness of the measured liquid film of the cleaning liquid L is thinner than the lower limit of the predetermined threshold range, the film thickness analysis unit 42 determines that the liquid film is too thin and stops the supply from the mechanism control unit 41. A supply instruction for the processing liquid (cleaning liquid L) is output to the unit 38 . Thereby, the cleaning liquid L is supplied from the nozzle 38a to the surface to be processed of the substrate W in a predetermined amount (for a predetermined time), and the thickness of the liquid film is kept within a predetermined threshold value. Thereafter, drying is performed by rotating and lifting the substrate W as described above. When replenishing the cleaning liquid L, the substrate W may be stopped without being rotated, but the substrate W may be rotated.

When the film thickness analysis unit 42 determines that the measured thickness of the liquid film of the cleaning liquid L is thicker than the upper limit of the predetermined threshold range, the film thickness analysis unit 42 determines that the liquid film is too thick and causes the mechanism control unit 41 to drive the liquid film. An instruction to rotate the support portion 34 is output to the mechanism 35 . Thereby, the cleaning liquid L for the substrate W rotating together with the support part 34 is scattered by centrifugal force, and the thickness of the liquid film is made to be within a predetermined threshold value. Thereafter, drying is performed by rotating and lifting the substrate W as described above.

[motion]
The operation of the substrate processing apparatus 1 of this embodiment as described above will be described with reference to the explanatory diagrams of FIGS. 3 to 5, the flowchart of FIG. 6, and the explanatory diagram of FIG. 7 in addition to FIGS. 1 and 2 above. explain. Note that a substrate manufacturing method for manufacturing a substrate W by the following procedure, a substrate W drying method for drying a substrate W, and a substrate processing method for processing a substrate W are also aspects of this embodiment. Further, in FIGS. 3 to 5, illustration of the cup 36 is omitted.

As shown in FIG. 2, the substrate W subjected to the etching process in the processing apparatus 110 is carried into the cleaning apparatus 120 by the transport apparatus 200. In the cleaning device 120, while the support section 12 holding the substrate W rotates, the supply section 15 supplies APM to the surface to be processed of the substrate W to perform alkaline cleaning, and then supplies pure water by supplying DIW. Perform cleaning. Further, after finishing the pure water cleaning, IPA is supplied to the surface of the substrate W to be processed.

As a result, centrifugal force due to the rotation of the substrate W causes IPA to spread over the entire surface of the substrate W to be processed, and alcohol rinsing processing is performed in which DIW that has been deposited on the surface of the substrate W to be processed is replaced with IPA. . Note that here, since IPA, which has a lower surface tension than DIW, is substituted, the surface tension that acts between patterns formed on the surface to be processed of the substrate W is reduced.

The transport device 200 carries out the cleaned substrate W from the cleaning device 120 and carries it into the drying device 300. Note that after the pure water cleaning is completed, it is not always necessary to replace the surface of the substrate W to be treated with DIW with IPA. In other words, the cleaning process may be completed only by cleaning with pure water using DIW.

As shown in FIG. 3A, the substrate W carried in from the opening 31a of the drying chamber 31 of the drying apparatus 300 is moved to the standby position D with a liquid film (IPA) formed by the cleaning liquid L on the surface to be processed. The holding member 34b of the support section 34 located at the holder 34b holds the holding member 34b (step S01). As shown in FIG. 3B, the detection unit 37a of the measurement unit 37 measures the film thickness on the substrate W (step S02).

If the film thickness is thin (less than the predetermined range in step S03), the supply unit 38 adjusts the film thickness by further supplying the cleaning liquid L to the liquid film on the substrate W, as shown in FIG. Step S04). If the film thickness is thick (exceeding the predetermined range in step S03), the supporting part 34 rotates to blow the cleaning liquid L from the rotating substrate W to adjust the film thickness (step S05).

When the film thickness is appropriate or when the film thickness becomes appropriate after adjustment (within the predetermined range in step S03), as shown in FIG. Step S06), as shown in FIG. 5A, the substrate W is brought closer to the heating unit 32 by rising to the drying position U (Step S07). By rotating the substrate W before it is heated by the heating section 32, the liquid film of the cleaning liquid L on the surface to be processed of the substrate W is rotated together with the substrate W. Even after an air layer is generated between the cleaning liquid L and the surface to be treated, the liquid film of the cleaning liquid L continues to rotate due to inertial force, so that centrifugal force is exerted.

The flash lamp 321 and the halogen lamp 322 of the heating section 32 simultaneously emit light to heat the surface layer of the substrate W (step S08). At this time, the flash lamp 321 emits light for several milliseconds to rapidly heat the entire surface layer of the substrate W to a temperature higher than the Leidenfrost temperature, causing a Leidenfrost phenomenon to occur at the interface between the surface layer of the substrate W and the liquid film. A liquid film is floated from the surface layer through an air layer. The halogen lamp 322 continues to emit light for several seconds and then turns off, thereby heating the entire surface layer of the substrate W to maintain the temperature above the Leidenfrost temperature even after the flash lamp 321 turns off.

As a result, the floating state of the liquid film from the entire surface layer of the substrate W is maintained, and the liquid film becomes a liquid ball, and the cleaning liquid L is blown off by centrifugal force and dried (step S09). That is, as shown in FIG. 7(A), the cleaning liquid L in contact with the pattern P on the surface to be processed of the substrate W is removed only by the lighting of the flash lamp 321, as shown in FIG. 7(B). is heated instantaneously, and the interface between the surface layer of the substrate W and the cleaning liquid L starts to vaporize earlier than the cleaning liquid L in other parts. , that is, an air layer G is generated. By keeping the halogen lamp 322 lit, the temperature of the surface layer of the substrate W is maintained, so the gas layer G is maintained. In addition, in FIGS. 7(B), (C), and (D), the pattern P of the substrate W is hatched with fine diagonal lines to indicate that the substrate W is rapidly heated and maintained. There is.

As shown in FIG. 7(C), the liquid (cleaning liquid L) between adjacent patterns P is instantly lifted up from between the patterns P by the gas layer G, and as shown in FIG. 7(D), the liquid immediately rises from between the patterns P due to the Leidenfrost phenomenon. Beaded (Leidenfrost phenomenon). As shown by the black arrow in the figure, centrifugal force is applied to the cleaning liquid L due to rotation, and each generated liquid droplet is blown off from above the substrate W by the centrifugal force. As shown, the surface of the substrate W to be processed is dried.

In this way, the cleaning liquid L existing between the patterns P is caused to float up from between the patterns P on the entire surface to be processed of the substrate W, and by preventing re-adhesion, the cleaning liquid L between some of the patterns P is lifted up. It is possible to prevent L from remaining and the drying rate of the liquid on the processed surface of the substrate W becomes uniform, thereby suppressing the pattern P from collapsing due to the collapsing force (for example, surface tension, etc.) caused by the residual liquid. be able to.

Note that if the liquid film is insufficiently thick and the liquid film dries by normal drying before the Leidenfrost phenomenon occurs, as shown in FIG. The pattern collapses due to the applied surface tension. In this embodiment, since the liquid film thickness of the cleaning liquid L on the surface to be processed of the substrate W is adjusted to an appropriate thickness, the liquid film is maintained while the Leidenfrost phenomenon occurs, and the gas layer Since the floating liquid film is removed from between the patterns P by centrifugal force, collapse of the pattern due to surface tension is prevented.

Thereafter, as shown in FIG. 5(B), the support section 34 descends to the standby position D while maintaining the rotation of the substrate W (step S10). After the support unit 34 stops rotating the substrate W (step S11), the transport device 200 carries out the substrate W from the opening 31a (step S12).

[effect]
(1) The drying apparatus (substrate drying apparatus) 300 of this embodiment as described above includes a drying chamber 31 into which a substrate W with a liquid film formed by a processing liquid on the surface to be processed is carried, and a drying chamber A supporting part 34 that supports the substrate W carried into the drying chamber 31 is provided in the drying chamber 31, and a gas layer due to the Leidenfrost phenomenon is formed between the liquid film and the surface layer of the surface layer of the surface to be processed of the substrate W. The substrate W is heated together with a flash lamp 321 that heats the temperature above the generated temperature, a temperature maintenance section (halogen lamp 322) that maintains the temperature of the surface layer by heating, and a support section 34 so as to maintain the gas layer due to the heating of the flash lamp 321. It has a drive mechanism 35 that discharges a liquid film in which an air layer is formed between the substrate W and the surface layer by centrifugal force caused by the rotation of the substrate W.

The substrate processing apparatus 1 of this embodiment includes a processing apparatus 110 that supplies a processing liquid while rotating a substrate W, a cleaning apparatus 120 that cleans a processed substrate by supplying a processing liquid while rotating it, It includes a transport device 200 that transports the substrate W cleaned in the cleaning device 120 with a liquid film formed by the processing liquid and transports it into the drying device 300.

In the substrate drying method of the present embodiment, the support section 34 supports the substrate W carried into the drying chamber 31 with a liquid film formed by the processing liquid on the surface to be processed, and the drive mechanism 35 34, the flash lamp 321 instantaneously heats the surface layer of the surface to be processed of the substrate W to a temperature higher than the temperature at which a gas layer due to the Leidenfrost phenomenon is formed between the liquid film and the surface layer. The maintenance section (halogen lamp 322) maintains the temperature of the surface layer by heating so as to maintain the gas layer due to the heating by the flash lamp 321, and discharges the liquid film by centrifugal force caused by the rotation of the substrate W.

In this way, the surface layer of the substrate W is heated to the Leidenfrost temperature or higher by the flash lamp 321, which can only emit light for a short time but can instantaneously heat up to a high temperature, and the liquid film is floated, and the temperature maintenance section (halogen lamp 322) Since the Leidenfrost temperature can be maintained, the liquid film floated by the gas layer can be removed from the substrate W without re-adhering to the surface layer, and pattern collapse due to the remaining liquid can be prevented. Moreover, compared to the case where the liquid film is brought into a film boiling state using only the halogen lamp 322, it is possible to stably bring the liquid film into a film boiling state and turn it into a liquid ball without using an enormous amount of electric power.

FIG. 9 schematically shows temperature changes of the flash lamp 321, the halogen lamp 322, and the substrate W in a graph in which the horizontal axis is time and the vertical axis is temperature. In the case of heating only with the flash lamp 321, the surface layer of the substrate can be instantly heated to the Leidenfrost temperature (double-dashed line in the figure) or higher, as shown by the broken line in the figure, but the liquid beads are not discharged. The film boiling temperature cannot be maintained until the temperature reaches the boiling point. On the other hand, when heating only with the halogen lamp 322, as shown by the dashed line in the figure, it takes longer to raise the temperature than with the flash lamp 321, so it is not possible to instantly raise the entire surface layer to the Leidenfrost temperature or higher. This may cause the liquid beads to re-adhere to the surface layer.

In this embodiment, the heating of the halogen lamp 322 continues even after the flash lamp 321 is turned off, so that the average temperature of the substrate W can be maintained at or above the Leidenfrost temperature, as shown by the solid line in the figure. can. In other words, it is possible to instantaneously bring the liquid film to a film boiling temperature and then maintain that temperature. The instant referred to here, that is, the time required to reach the film boiling state, is preferably 3 msec or less. Thereby, only the surface layer of the liquid film can be brought into a film boiling state in a very short time. In this way, the surface layer of the liquid film on the entire surface of the substrate W does not stay in the nucleate boiling state but instantly enters the film boiling state, so that the liquid film is easily turned into liquid beads. In addition, after instantaneously achieving a film boiling state, the film boiling state can be maintained. More specifically, by setting the temperature of the substrate W to a temperature higher than the Leidenfrost temperature (for example, 100° C. or higher), the liquid film on the entire surface of the substrate W can be stably maintained in a film boiling state. Therefore, in the figure, after transitioning from the state in which the liquid film adheres to the surface layer in the region α to the region β in which the liquid film has risen from the surface layer due to the Leidenfrost phenomenon, re-adhesion of the liquid film is prevented. . Therefore, while preventing the temperature of the substrate W from decreasing due to turning off the flash lamp 321, there is no need to heat the halogen lamp 322 to an extremely high temperature, and drying processing using the Leidenfrost phenomenon can be realized.

In addition, if the flash lamp 321 can heat the substrate W to a temperature of approximately 300° C. in less than 1 second, the liquid film on the surface layer of the substrate W will undergo a nucleate boiling state (without remaining in a nucleate boiling state). , can quickly reach a film boiling state. Also, based on FIG. 9, if the maximum heating temperature of the flash lamp 321 is set to be about twice to about three times the Leidenfrost temperature, the liquid on the surface layer of the substrate W can be The film can reach a film boiling state without remaining in a nucleate boiling state.

Here, the flash lamp 321 needs to be instantly heated to the Leidenfrost temperature, so high energy is required. When creating this state, by reducing the pulse width, it is possible to instantaneously emit light with high energy.

As shown in FIG. 9, the heating temperature of the halogen lamp 322 reaches the Leidenfrost temperature in about 1 second. That is, after the flash lamp 321 finishes emitting light, the average substrate temperature decreases, but since the halogen lamp 322 reaches the Leidenfrost temperature in about 1 second, the average substrate temperature can maintain the Leidenfrost temperature.

(2) The temperature maintaining unit (halogen lamp 322) starts heating before or at the same time as the flash lamp 321 emits light. Therefore, even if the temperature rise in the temperature maintenance section is slow, heating to a temperature higher than the Leidenfrost temperature is possible when the flash lamp 321 is turned off.

(3) The temperature maintenance section (halogen lamp 322) continues heating even after the flash lamp 321 is turned off. Therefore, cooling due to turning off the flash lamp 321 is prevented, and the Leidenfrost temperature can be maintained.

(Modified example)
(1) The flash lamp 321 and the temperature maintenance section may be placed on opposite sides of the substrate W. For example, as shown in FIG. 10, a flash lamp 321 may be provided on the ceiling side of the drying chamber 31, and a halogen lamp 322 may be provided on the floor side with the substrate W in between. In this embodiment, the halogen lamp 322 is fixedly supported on a support base 322a. An annular hollow motor 341 is installed on the floor of the drying chamber 31. The fixed side of the hollow motor 341 is configured with a stator 341a made of coils, and the rotating side is provided with a rotor 341b made of magnets.

The rotor 341b is provided with a plurality of holding members 34b. As a result, the substrate W held by the holding member 34b is spaced apart from the support base 322a and rotates with the rotation of the rotor 341b. The surface of the substrate W to be processed faces the flash lamp 321 .

During drying, similarly to the above, the substrate W rotated by the hollow motor 341 is heated by causing the flash lamp 321 and the halogen lamp 322 to emit light. In this way, by heating one side and the other side of the substrate W, it is possible to reduce the difference in stress applied to both sides, so thermal expansion occurs in the substrate W, excessive stress is applied, and cracks etc. can be prevented from occurring.

(2) The temperature maintaining section is not limited to the halogen lamp 322. It may also be an infrared lamp. If the heating speed of the temperature maintaining section is slow, heating may be started before the flash lamp 321 starts emitting light. Further, if the heating speed of the temperature maintaining section is fast, heating may be started after the flash lamp 321 emits light. If it is possible to maintain the temperature using residual heat, the lamp used as the temperature maintaining section may stop emitting light at the same time as the flash lamp 321 emits light.

(3) As long as the processing performed by the processing apparatus 110 ultimately requires cleaning and drying, the contents of the processing and the processing liquid are not limited to those exemplified above. The substrate W to be processed and the processing liquid are also not limited to those exemplified above. The cleaning liquid L that is applied to the substrate W after cleaning in the cleaning device 120 is not limited to IPA. For example, the liquid may be filled by DIW.

[Other embodiments]
The embodiments of the present invention and modifications of each part have been described above, but these embodiments and modifications of each part are presented as examples, and are not intended to limit the scope of the invention. These novel embodiments described above can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention, and are also included in the invention described in the claims.

1 Substrate processing apparatus 1a Chamber 1b Cassette 1c Transfer robot 1d Buffer unit 11 Cleaning chamber 11a Opening 11b Door 12 Support part 13 Rotating mechanism 14 Cup 15 Supply part 15a Nozzle 15b Moving mechanism 20 Handling device 21 Robot hand 22 Moving mechanism 31 Drying chamber 31a Opening 31b Door 31c Inlet 31d Exhaust port 31e Air supply section 31f Exhaust section 32 Heating section 32a Partition window 33 Window section 34 Support section 34a Rotating table 34b Holding member 34c Rotating shaft 35 Drive mechanism 35a Rotating section 35b Elevating section 36 Cup 37 Measurement Section 37a Detection section 37b Swinging arm 37c Swinging mechanism 38 Supply section 38a Nozzle 38b Swinging arm 38c Swinging mechanism 41 Mechanism control section 42 Film thickness analysis section 43 Heating control section 110 Processing device 120 Cleaning device 200 Transfer device 300 Drying device 321 Flash lamp 322 Halogen lamp 322a Support stand 341 Hollow motor 341a Stator 341b Rotor 400 Control device

Claims (6)

a drying chamber into which the substrate with a liquid film formed by the processing liquid on the surface to be processed is carried;
a support part that supports the substrate carried into the drying chamber;
a flash lamp that is provided in the drying chamber and heats the surface layer of the surface to be processed of the substrate to a temperature higher than a temperature at which a gas layer due to the Leidenfrost phenomenon is generated throughout between the liquid film and the surface layer;
a temperature maintenance unit that maintains the temperature of the surface layer by heating so as to maintain the air layer due to the heating of the flash lamp;
a drive mechanism that rotates the substrate together with the support part to discharge the liquid film in which the gas layer is generated between the substrate and the surface layer by centrifugal force caused by the rotation of the substrate;
A substrate drying device comprising: 2. The substrate drying apparatus according to claim 1, wherein the temperature maintaining unit starts heating before or at the same time as the flash lamp emits light. The substrate drying apparatus according to claim 1, wherein the temperature maintaining section continues heating even after the flash lamp is turned off. 2. The substrate processing apparatus according to claim 1, wherein the flash lamp and the temperature maintenance section are disposed on opposite sides of the substrate. a processing device that processes a substrate by supplying a processing liquid while rotating the substrate;
a cleaning device that cleans the processed substrate by supplying a processing liquid while rotating the substrate;
A substrate drying device according to any one of claims 1 to 4,
a transport device that transports the substrate cleaned in the cleaning device with a liquid film formed by the processing liquid and transports it into the substrate drying device;
A substrate processing apparatus comprising: The support part supports the substrate carried into the drying chamber with a liquid film formed by the processing liquid on the surface to be processed,
a drive mechanism rotates the substrate together with the support part;
a flash lamp heats the surface layer of the surface to be processed of the substrate to a temperature higher than a temperature at which a gas layer due to the Leidenfrost phenomenon is generated throughout between the liquid film and the surface layer;
a temperature maintenance unit maintains the temperature of the surface layer by heating so as to maintain the gas layer by heating the flash lamp;
discharging the liquid film by centrifugal force caused by rotation of the substrate;
A substrate drying method characterized by:

Images