JP2003168643A - Vacuum dryer and method of forming coated film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum dryer that is used when a coated film composed of, for example, a resist film is formed on a semiconductor wafer and can improve the thickness uniformity of the coated film by controlling the flow of coating liquid. <P>SOLUTION: The semiconductor wafer W to which the coating liquid prepared by mixing the component of the coated film with a solvent has been applied in a preceding step is placed on a placing base 41 provided in a closed container 4, and the solvent is vaporized from the liquid applied to the surface of the wafer W by reducing pressure in the container 4 by means of a vacuum pump 46. Then a rectifying plate 5 is provided to face the surface of the wafer W placed on the placing base 41, and the pressure in the container 4 is detected by means of a pressure sensor 55. When the pressure detected by means of the sensor 55 becomes a prescribed value or lower, the rectifying plate 5 is raised from the first position to a second position higher than the first position. Consequently, the film thickness of the coating liquid can be controlled and the in-plane uniformity of the film thickness is improved, because the outwardly expanding flow of the coating liquid is controlled between the wafer W and the plate 5. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a semiconductor wafer and L
In forming a coating film by coating a coating liquid, for example, a resist liquid, on a substrate such as a CD substrate (glass substrate for liquid crystal display) with a solvent, the solvent is volatilized from the coating liquid. The present invention relates to a reduced pressure drying device and a coating film forming method.

[0002]

2. Description of the Related Art In the manufacturing process of semiconductor devices and LCDs, a resist process is performed on a substrate to be processed by a technique called photolithography. In this technique, for example, a resist solution is applied to a semiconductor wafer (hereinafter referred to as a wafer) to form a liquid film on the surface, the resist film is exposed using a photomask, and then a development process is performed to obtain a desired pattern. Is carried out by a series of steps.

As one of the methods for coating the resist solution described above, a coating solution (resist solution) formed by mixing a resist and a solvent, which are components of the coating film, is used as a wafer W as shown in FIG. While the nozzle 10 provided above the nozzle is reciprocated in the X direction and the wafer W is intermittently fed in the Y direction, the coating liquid is discharged from the nozzle 10 onto the surface of the wafer W, and the coating liquid is coated in a so-called one-stroke manner. There is a way to go. In the figure, 12 is a circuit formation region 11 of the wafer W.
It is a mask that covers regions other than the above.

As the solvent contained in the coating liquid, a solvent having low volatility is used, and the solvent is promptly removed from the surface of the wafer W to ensure the film thickness uniformity of the coating film. In carrying out the above method, it is considered preferable to apply the coating liquid on the wafer W and then immediately carry it into a reduced pressure drying unit to perform reduced pressure drying. FIG. 31 is a diagram showing a conventional vacuum drying unit.
Reference numeral 13 in the drawing is a closed container including a lid 14 and a mounting portion 15, and an opening 14a is formed in a ceiling portion of the lid 14. The opening 14a communicates with the vacuum pump 16 via the exhaust pipe 14b so that the pressure inside the closed container 13 can be reduced. In such an apparatus, the wafer W is placed on the placing portion 15, the wafer W is heated by a heating means (not shown), and the vacuum pump 16 is operated to depressurize the inside of the hermetic container 11 to thereby reduce the wafer W.
Solvents such as thinner that remain on the surface volatilize (dry)
Then, the volatilized solvent is sucked to the vacuum pump 16 side, and the resist component in the coating liquid remains on the surface of the wafer W.

[0005]

By the way, the state of the coating liquid 17 on the surface of the wafer W when it is conveyed to the reduced pressure drying unit is, for example, as shown in FIG. In a predetermined distance, for example, an area of about 20 mm inside), it is rounded by the surface tension of the coating liquid itself. Therefore, as shown by the dotted line in FIG. 29, the wafer W is placed above the wafer W placed on the placing portion 15.
It is considered to provide the straightening plate 18 so as to face with. When the rectifying plate 18 is provided in this manner and the inside of the closed container 13 is decompressed, an air flow spreading outward is formed between the rectifying plate 18 and the wafer W, whereby the coating liquid spreads toward the peripheral side on the surface of the wafer W. Go.

For this reason, when the straightening plate 18 is provided and drying under reduced pressure is performed, the coating liquid is attracted to the peripheral side as shown in FIG. 32 (b), and the thickness of the coating film in the peripheral region becomes extremely large. I will end up. When the peripheral region of the coating film is rounded or raised in this way, the peripheral region of the coating film is greatly different from the central portion in thickness, and therefore the peripheral region cannot be used as a circuit formation region. There is a demand to increase the chip acquisition rate per wafer W by making the circuit formation region as wide as possible, and controlling the film thickness of the central portion and the peripheral region in the coating film formed on the surface of the wafer W. It is a serious issue.

The present invention has been made in view of the above circumstances, and an object thereof is to control the thickness of a coating film at the time of drying under reduced pressure in a vacuum drying apparatus for a substrate provided in a coating film forming apparatus, It is an object of the present invention to provide a technique capable of ensuring high in-plane uniformity of film thickness.

[0008]

The vacuum drying apparatus according to the present invention is provided with a mounting portion for mounting a substrate coated with a coating liquid obtained by mixing the components of a coating film and a solvent. A closed container, which is connected to the closed container via an exhaust passage, and the inside of the closed container is in a reduced pressure atmosphere, and a vacuum exhaust means for volatilizing the solvent from the coating liquid on the substrate, and the placement part. A rectifying member provided so as to face the surface of the placed substrate, and a rectifying member elevating mechanism for elevating and lowering the rectifying member. The rectifying member is moved up and down by a rectifying member elevating mechanism while the solvent is volatilized from the liquid, and the height position of the rectifying member is changed. At this time, a pressure detection unit for detecting the pressure in the closed container is provided, and when the detection value from the pressure detection unit becomes equal to or lower than a predetermined pressure, the height position of the rectifying member is set to the first position. From the second
It is preferable to change the position to.

In such a structure, an exhaust gas flow from the center to the outside is formed between the straightening member and the substrate during the reduced pressure drying processing, but the height position of the straightening member is reduced during the reduced pressure drying processing. The flow rate of the coating liquid is controlled by changing the value of, and thus the thickness of the coating film on the substrate surface can be controlled. Therefore, the roundness and swelling of the coating liquid in the peripheral region of the substrate can be suppressed, the film thicknesses of the central portion of the coating film and the peripheral region can be made uniform, and the uniformity of the film thickness can be improved.

Another aspect of the present invention is a closed container in which a mounting portion for mounting a substrate coated with a coating liquid obtained by mixing components of a coating film and a solvent is provided, The heating means for heating the substrate provided in the above-mentioned placing part and the sealed container are connected via an exhaust passage, and the inside of the sealed container is under a reduced pressure atmosphere to volatilize the solvent from the coating liquid on the substrate. For evacuation means, for the above-mentioned mounting portion, provided on the mounting portion, the mounting member configured by a material having a different thermal conductivity, an annular member in contact with the back surface side peripheral region of the substrate,
It is characterized by having.

In such a structure, the substrate is heated by the heating means provided in the mounting portion, but since the peripheral region of the substrate is in contact with the annular member having a different thermal conductivity from that of the mounting portion, The temperature is different between the central region and the peripheral region of the substrate, which causes a different evaporation rate of the solvent contained in the coating liquid. As a result, the film thickness of the coating film on the substrate surface can be controlled, and the film thickness of the central portion and the peripheral region of the coating film can be made uniform to improve the uniformity of the film thickness.

Still another aspect of the present invention is to provide an airtight container having the above-mentioned mounting portion provided therein, and the airtight container connected to the airtight container via an exhaust passage, to create a decompressed atmosphere in the airtight container.
The vacuum evacuation means for volatilizing the solvent from the coating liquid on the substrate and the outer side of the substrate are provided at a position outside the center of the mounting part, which is radially equidistant from the center of the mounting part. A plurality of positioning members that move in a substantially horizontal direction in a synchronized state from a position on the side to a position in contact with the edge of the substrate to align the central position of the mounting portion with the central position of the substrate. It is characterized in that the substrate can be mounted on the mounting part in a state where the central positions of the both are aligned, so that a uniform reduced-pressure drying process can be performed.

Still another aspect of the present invention is a hermetically sealed container in which a mounting portion for mounting a substrate coated with a coating liquid prepared by mixing components of a coating film and a solvent is provided,
Connected to the closed container via an exhaust path, a vacuum atmosphere in the closed container, a vacuum exhaust means for volatilizing the solvent from the coating liquid on the substrate, provided in the placement section,
A support member for supporting the substrate in a state of slightly floating from the mounting portion surface, and a ventilation passage formed in the mounting portion, which communicates with the outside of the closed container,
As a result, when the airtight container is returned from the depressurized atmosphere to the atmospheric pressure, the atmospheric pressure leaks from the air passage and the depressurized state is quickly released even on the back surface side of the substrate placed on the placing portion. It is possible to prevent the central portion on the back surface side of the substrate from being adsorbed to the mounting portion, and it is possible to prevent the substrate from warping.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION First, the overall structure of a coating film forming apparatus incorporating a reduced pressure drying apparatus of the present invention will be described below with reference to FIG.
-A brief description will be given with reference to FIG. In the figure, reference numeral 21 denotes a cassette station, for example, a cassette mounting portion 22 for mounting a cassette C containing 25 wafers W and a transfer for transferring the wafer W between the mounted cassettes C. The arm 23 is provided, and the processing unit S1 is connected to the back side of the transfer arm 23. A main transport means 24 is provided at the center of the processing section S1, and a coating / developing system unit 25 including a plurality of coating units 25A and a developing unit 25B is provided on the right side of the main section 24 so as to surround the main transport means 24. However, shelf units U1, U2, U3 in which heating / cooling system units and the like are stacked in multiple stages are arranged on the left side, the front side, and the back side, respectively.

The shelf units U1, U2, U3 are constructed by combining various units for performing pretreatment and posttreatment of the coating unit 25A, and the combination thereof is, for example, the shelf units U2, U3 shown in FIG. As a representative example, the wafer W having the surface coated with the coating liquid in the coating unit 25A is dried under a reduced pressure atmosphere to evaporate the solvent contained in the coating liquid.
A heating unit for heating (baking) the wafer W, a cooling unit for cooling the wafer W, a hydrophobization processing unit, and the like. Note that the shelf units U2 and U3 also incorporate a delivery unit including a delivery table for delivering the wafer W. Further, the main transport means 24 described above is configured to be movable up and down, moved back and forth, and rotatable about a vertical axis, and is a unit forming the coating unit 25A, the developing unit 25B, and the shelf units U1, U2, U3. It is possible to transfer the wafer W between them.

An interface is provided on the back side of the processing section S1.
The exposure device S3 is connected via the face portion S2. The interface part S2 can be moved up and down, left and right,
The wafer W is transferred between the processing section S1 and the exposure apparatus S3 by a transfer arm 27 configured to be movable back and forth and rotatable about a vertical axis.

The flow of the wafer W in the coating film forming apparatus will be briefly described. First, when the cassette C is loaded into the cassette station 21, the wafer W is taken out by the transfer arm 23. Then, the wafer W is transferred from the transfer arm 23 to the main transfer means 24 via the transfer unit in the shelf unit U2, subjected to the hydrophobic treatment by the hydrophobic unit, and then carried into the coating unit 25A. Here, a resist solution which is a coating solution is applied. Next, the wafer W coated with the coating liquid is transferred to the reduced pressure drying unit 26 by the main transfer means 24, where the solvent contained in the coating liquid on the surface of the wafer W is evaporated and dried by a predetermined method, and the wafer W after the treatment is processed. The wafer W is unloaded by the main transfer means 24 through the steps reverse to the step of loading the wafer W into the reduced pressure drying unit 26, and is transferred to the cooling unit which is the next step. After this, the interface section S2, the transfer arm 2
It is sent to the exposure apparatus S3 through the exposure device 7, and exposure is performed there through a mask corresponding to the pattern. The wafer W after the exposure processing is conveyed to the processing section S1 through the reverse path, is sent to the developing unit 25B through the cooling unit and is subjected to the developing processing, and a resist mask is formed. Thereafter, the wafer W is returned to the original cassette C by the reverse path.

Next, the coating unit 25 will be described with reference to FIGS. Here, the casing that forms the exterior body of the coating unit 25 is omitted, but in the casing (not shown),
For example, an opening (not shown) for loading / unloading the wafer W to the side
A hollow case body 30 in which is formed is provided, and a substrate holding portion 31 that holds the wafer W by vacuum suction from the back surface side and horizontally holds it, and supports the substrate holding portion 31 from the lower side. An elevating mechanism 32 for elevating the substrate holding unit 31 is provided. X on the ceiling of the case body 30
A slit 33 extending in the direction is formed. Above this slit 33, a nozzle 34 for supplying a resist liquid as a coating liquid, and a discharge hole 34a at the lower end are provided via the slit 33 and the case body 30. It is configured so that it can be moved in the X direction by the drive unit 35 in a state of protruding inward.

On the other hand, the substrate holder 31 and the lifting mechanism 32
Is integrally formed with a flat plate-shaped support body 36 provided below the wafer W held by the substrate holding unit 31 so as to face the back surface side of the wafer W. On the bottom surface of the support 36, for example, two rails 37 extending in the Y direction are provided.
a is provided, and a ball screw 37b is provided in the vicinity of the bottom face in parallel with the rail 37a,
When the motor 38 rotates the ball screw 37b, the support 36 is guided by the rail 37a to move in the Y direction.

In such a coating unit 25A, the wafer W carried into the unit 25A by the main carrier means 24 is adsorbed on the back surface side by the substrate holder 31 and held substantially horizontally. Then, after the nozzle 34 is positioned above the wafer W, it is moved in the X direction while ejecting the coating liquid from the nozzle 34, while the wafer W is supported by the support 36.
Is intermittently fed in the Y direction, and thus the coating liquid is applied in the manner of one-stroke writing.

Next, an embodiment of the reduced pressure drying unit 26 which constitutes the reduced pressure drying apparatus according to the present invention will be described with reference to FIG. Reference numeral 41 in the drawing denotes a mounting portion for mounting the wafer W, which is made of, for example, an aluminum material, and the wafer W has a support pin 41 slightly protruding from the mounting portion.
It is slightly floated from the surface of the mounting portion 41 at a and is held, and a lid body 42 made of, for example, an aluminum material is provided on the mounting portion 41. This lid 4
2 is movable up and down by the action of an elevating mechanism 43 composed of a holding arm 43a, a drive unit 43b, and the like, and at the time of lowering, the peripheral portion of the mounting unit 41 and the O-ring 40 serving as a sealing material.
The airtight container 4 is airtightly bonded to form a closed container 4 in which the atmosphere in which the wafer W is placed is a closed atmosphere.

In the vicinity of the surface of the mounting portion 41, a heater H which is a heating means for heating the wafer W at the time of drying under reduced pressure and is composed of, for example, a resistance heater is embedded.
Inside the mounting portion 41, three lift pins 44 are provided so as to pass the wafer W to and from the main transfer means 24. The lift pins 44 are provided in the first lift plate 4.
First elevating part 4 such as an air cylinder via 4a
It can be moved up and down by 4b.

An opening 45a is formed in the ceiling 42a of the lid 42 so that the atmosphere in the closed container 4 can be sucked,
An exhaust pipe 45, which is made of, for example, stainless steel and constitutes an exhaust passage, is connected to the opening 45a, and the other end of the exhaust pipe 45 is not shown in the casing of the reduced pressure drying unit 26 and the processing unit S1. It penetrates through the housing and is connected to a vacuum pump 46, which is a vacuum evacuation unit provided in a clean room, for example, through an opening / closing valve V1.

In the space facing the wafer W in the lid 42, the space facing the wafer W placed on the placing section 41 and having a gap between the ceiling 42a and the side wall 42b of the lid 42 is provided. A rectifying plate 5, which is a plate-shaped rectifying member, is provided in the inside of the wafer W. For example, a plurality of substantially vertical rectifying plates 5 provided so as to penetrate the mounting portion 41 on the outer side of the wafer W are provided. The three support rods 51 are connected to the connecting member 52. The support rod 51 is the second lifting plate 5
3a or a second elevating part 53b such as an air cylinder, for example, can be moved up and down by a current plate elevating mechanism 53 that forms a current elevating member elevating mechanism.
Is configured to be movable up and down on the upper side of the wafer W, and its height position can be changed with respect to the wafer W.

At this time, in order to prevent the atmosphere in which the wafer W is placed from communicating with the atmosphere side through the through hole 47a of the lift pin 44 and the through hole 54a of the support rod 51, the first and second elevating plates 44a, 53a. Bellows 47b and 44b are provided between the peripheral portion and the mounting portion 41, respectively. By providing the straightening vane 5 in this manner, a uniform exhaust flow is formed along the inner wall surface of the lid 42 during the reduced pressure drying.

Further, the closed container 4 has a pressure sensor 55 serving as a pressure detecting portion for detecting the pressure in the container 4.
Is provided on the inner wall of the lid 42, and is configured such that the control unit 56 can change the height position of the straightening plate 5 via the straightening plate elevating mechanism 53 based on the detection value of the pressure sensor 55. There is.

Next, a vacuum drying method carried out by the vacuum drying unit 26 will be described. First, the wafer W on which the resist liquid as the coating liquid has been applied in the previous step
Is transported to the reduced-pressure drying unit 26 by the main transport means 24. To carry the wafer W into the reduced-pressure drying unit 26, first, the arm (not shown) of the main transfer means 24 enters the upper side of the mounting portion 41 with the lid 42 and the rectifying plate 5 raised, and the lift pins 44 are raised. After receiving the wafer W from the arm, the lift pins 44 are lowered.

Thereafter, the flow regulating plate 5 is lowered to an initial position, for example, a position where the distance between the front surface of the wafer W and the back face of the flow regulating plate 5 is 5 mm, and then the lid 42 is lowered to form the hermetically sealed container 4. For example, the flow straightening plate 5 is once lowered to a position of 3 mm, the on-off valve V1 is opened, and the vacuum pump 46 starts depressurization. Next, the current plate 5 is lowered to a first position, for example, a position where the distance between the front surface of the wafer W and the back surface of the current plate 5 is 1 mm, and the first distance (gap) is set between the front surface of the wafer W and the back surface of the current plate. The pressure is reduced for a predetermined time.

The coating liquid (resist liquid) coated on the surface of the wafer W is a mixture of the components of the registration film, which is the coating film, and a solvent such as a thinner liquid or water, and the closed container 4 When the inside is placed under a reduced pressure atmosphere, the solvent and water of the coating liquid are volatilized, and the exhaust pipe 4 passes through the opening 45a.
5 is sucked. At this time, the exhaust flow in the closed container 4 is
Since it is formed so as to bypass the straightening vanes 5, the solvent vapor volatilized from the wafer W collides with the straightening vanes 5 and turns outward, and spreads uniformly in the radial direction along with this exhaust flow to the openings 45a. Go to

In this way, between the wafer W and the flow straightening plate 5, an air flow is generated from the center side of the wafer W toward the outer side, and the flow of this air flow causes a gap between the flow straightening plate 5 and the wafer W. The smaller it is, the stronger it is, and the larger the gap, the weaker it is. Therefore, if the gap between the flow straightening plate 5 and the wafer W is reduced to 1 mm to reduce the pressure, the flow straightening plate 5 and the wafer W will be reduced.
The coating liquid spreads due to the strong airflow spreading outside between
The coating liquid is sufficiently distributed to the peripheral area of the wafer W. In this way, when the coating liquid is spread to the peripheral area of the wafer W in order to suppress the roundness of the coating film in the peripheral area of the wafer W, the rectifying plate 5 is moved from the first position to a position higher than the first position at a predetermined timing. Position, for example, the distance between the front surface of the wafer W and the back surface of the rectifying plate 5 is raised to 5 mm, and a second distance (gap) larger than the first distance is provided between the front surface of the wafer W and the back surface of the rectifying plate 5. Continue drying under reduced pressure for a predetermined time.

In this way, the gap between the rectifying plate 5 and the wafer W becomes large and the air flow toward the outside is weakened, so that the liquid flow of the coating liquid is suppressed. Therefore, the thickness of the coating film in the peripheral region of the wafer W is prevented from increasing, and the in-plane uniformity of the thickness of the coating film is improved. In this way, reduced pressure drying is performed to evaporate the solvent and water from the coating liquid on the surface of the wafer W to dry the coating film, and then, for example, air is supplied into the hermetically sealed container 4 by, for example, an air supply unit (not shown) to seal it. The inside of the container 4 is returned from the depressurized state to the normal pressure, the lid 42 and the current plate 5 are raised, and then the lift pins 44 are raised, and the wafer W is transferred to the main transfer means 24.

As described above, in this embodiment, by changing the height position of the straightening vanes 5 during the reduced pressure drying process, the size of the gap between the straightening vanes 5 and the wafer W is changed, whereby the coating liquid is applied. It is characterized by controlling the liquid flow of the coating film to improve the uniformity of the film thickness of the coating film. The timing of changing the height position of the straightening vane 5 is determined based on the pressure in the closed container 4. The height position of the current plate 5 is changed via the control unit 56.

That is, when the pressure in the closed container 4 is reduced, the pressure in the container 4 changes as shown by the pressure curve in FIG. That is, the air in the container 4 is discharged from time 0 to time t1, and the pressure in the container 4 is from P0 to P1.
It is decompressed with a steep gradient. Subsequently, time t1 is when the thinner liquid, which is a solvent, starts to volatilize from the coating liquid on the surface of the wafer W, and from time t1 to time t3, the thinner liquid continues to volatilize. The pressure is gradually reduced from P1 to P3. Next, at time t3, the water contained in the coating liquid on the surface of the wafer W starts to evaporate. From time t3 to time t4, the thinner liquid remaining in the coating liquid and the water are in a state of being evaporated. At this time, the pressure in the container 4 is again reduced steeply from P3 to P4.

Here, when the temperature in the closed container 4 is constant, the thinner liquid is volatilized (evaporated) even when the inside of the container 4 is not depressurized. However, if the pressure in the container 4 is lowered at once, it will reach the boiling point immediately. It reaches and becomes a state of volatilizing from inside the thinner liquid. However, when the solvent is volatilized from the inside of the thinner liquid, the coating film becomes rough. Therefore, in the above-described embodiment, the exhaust amount of the vacuum pump 46 is determined so that the pressure in the container 4 decreases a little. When the evacuation rate by the vacuum pump 46 is set to be a little small in this way, the thinner liquid vigorously volatilizes just before the boiling point, and the pressure in the container 4 changes from the pressure P1 due to the presence of the vaporized gas and the balance of the evacuation rate. The pressure gradually inclines downward like the pressure P3.
As described above, the “state in which the thinner liquid volatilizes violently” is called “volatilization of the thinner liquid” in the present invention, and this state includes a boiling point and a state before the boiling point.

The state of the coating liquid on the surface of the wafer W depends on the fluidity of the coating liquid due to the volatilization of the thinner liquid which is the solvent. Further, since the amount of the solvent is large at the initial stage of the volatilization and the fluidity becomes large, the solvent volatilizes. At times, it is necessary to change the height position of the current plate 5. Specifically, from time 0 when the air in the container 4 is discharged to time t1, the wafer W
From the time t3 to the time t4 when the water evaporates from the coating liquid on the surface, the height of the straightening plate 5 may be any position, and the time from the time t1 when the thinner liquid as the solvent evaporates from the coating liquid to the time t4. During t3, it is required to control the height position of the current plate 5.

During the volatilization of the solvent, it is necessary to increase the fluidity of the coating liquid at first to sufficiently spread the coating liquid to the peripheral region of the wafer W. After that, the fluidity of the coating liquid is suppressed and the wafer W is suppressed. It is necessary to prevent the height of the coating liquid in the peripheral region of the above from becoming too large. Here, the fluidity of the coating liquid changes depending on the size of the air flow generated between the wafer W and the current plate 5, and as described above, if the gap between the wafer W and the current plate 5 is small, the air flow is increased. Is stronger, and the larger the gap, the weaker the air flow.

At this time, as described above, from time t1 to time t3
In the above, since the pressure in the container 4 gradually decreases from P1 to P3, the pressure is set to the preset pressure P2 which is obtained in advance.
When (time t2) has been reached, the current plate 5 is raised from the first position to the second position. Before the time t1 and after the time t3, the height of the straightening vane does not affect the coating film, and thus may be set to any height, but in this example, the labor of moving the straightening vane 5 is omitted. , The first position is set from time t1 to time t2, and the second position is set from time t2 to time t4. Here, the set pressure P2 and the first
Position (first gap) and second position (second gap) are appropriately selected depending on the size of the wafer W, processing conditions such as temperature and pressure in the closed container 4, components of the coating liquid, and the like. It is something.

According to the above-described embodiment, the height position of the straightening plate 5 is changed during the reduced pressure drying process, and the size of the gap between the straightening plate 5 and the wafer W is changed, whereby the liquid of the coating liquid is changed. Since the flow is controlled, the film thickness of the coating film on the surface of the wafer W can be controlled, the roundness and swelling of the coating liquid in the peripheral region of the wafer W can be suppressed, and the central portion and the peripheral region of the coating film can be suppressed. And the film thickness can be made uniform, and the uniformity of the film thickness can be improved. As a result, chips can be manufactured (a circuit formation region) near the outer peripheral edge of the wafer W, and the chip acquisition rate per wafer W is improved.
Further, by improving the uniformity of the film thickness of the coating film, the film thickness is stabilized, stable production of devices is possible, and the throughput is increased.

Further, at this time, since the height of the straightening vanes 5 is controlled based on the pressure in the closed container 4, the timing of changing the height position of the straightening vanes 5 is highly reliable. Since it is possible to always perform the treatment with a highly uniform coating film thickness, a high throughput can be obtained.

In this embodiment, the wafer W is placed on the mounting portion 4
1 and then the lid 42 is lowered to form the closed container 4, the straightening vane 5 is first lowered to the first position, the opening / closing valve V1 is opened, and decompression is started by the vacuum pump 46. Then, the pressure is reduced for a predetermined time. Next, when the pressure in the container 4 reaches the pressure P2, the rectifying plate 5 is moved from the first position to the second position.
Alternatively, the vacuum drying may be continued for a predetermined time by elevating to the position.

Next, other embodiments of the reduced pressure drying unit 26 will be individually described, but the same members are denoted by the same reference numerals in the subsequent drawings. Further, the following examples may be combined with the above-described reduced pressure drying unit 26, or other embodiments may be combined with each other.

In the example of FIG. 8, the height of the current plate 5 is set to the closed container 4
Instead of controlling based on the internal pressure, the film thickness of the coating liquid A on the surface of the wafer W is measured by, for example, a film thickness sensor 57 which is a film thickness measuring means using CCD or light, and based on this, the rectifying plate. The height of 5 is controlled. In this case, for example, the film thickness of the central part and the film thickness of the peripheral part of the coating liquid on the surface of the wafer W are measured, and the difference between these film thicknesses is calculated. The height is controlled to rise from the first position to the second position. Even in this case, it is possible to stably ensure high uniformity of the film thickness of the coating film and obtain high throughput.

The volatilization time of the solvent may be controlled as follows. In the example shown in FIG. 9, a pressure adjusting unit 58 including, for example, a pressure adjusting valve is provided between the exhaust pipe 45 and the vacuum pump 46, the pressure inside the closed container 4 is detected by the pressure sensor 55, and based on the detected value. The control unit 56 adjusts the pressure adjusting unit 58 to control the exhaust amount (exhaust speed) in the closed container 4, thereby adjusting the evaporation time of the solvent of the coating liquid. For example, the pressure adjusting unit 5
When a pressure adjusting valve is used as 8, the exhaust amount can be controlled by adjusting the opening degree of the valve. In this case, as shown in FIG. 10, the slope of the pressure curve from time t1 to time t3 does not change even if the exhaust amount is changed, but if the exhaust speed is increased or decreased between time t1 and time t3. The evaporation time of the solvent can be adjusted. That is, when the exhaust amount is increased, the evaporation time of the solvent is shortened as shown by the dashed line in the figure, and when the exhaust amount is decreased, the evaporation time of the solvent is extended as shown by the dotted line in the figure.

Here, for example, when a coating liquid using a thinner, which is a solvent, is applied to the surface of the wafer W, the spreading speed of the coating liquid is high, and therefore the height of the rectifying plate 5 is controlled to control the coating liquid. Although it may be difficult to control the diffusion state with high precision, if the evaporation time of the solvent of the coating liquid is lengthened as in this example, the spreading speed of the coating liquid can be slowed as a result, so volatilization is performed. Even if the coating liquid uses a thinner as a solvent, the diffusion position of the coating liquid can be sufficiently controlled by controlling the height position of the straightening plate 5, and the thickness of the coating liquid can be easily controlled. It can be carried out.

Next, in the example shown in FIG. 11, heating means for heating the wafer W is provided inside the closed container 4 at the time t3 in the pressure curve in the closed container 4 shown in FIG. The heating means may be provided at any place in the closed container 4, such as the inside of the mounting portion 41 or the lid 42, but in this example, the heating means 59 formed of, for example, a resistance heating element is used. It is provided inside the current plate 5.

As described above, in the pressure curve in the closed container 4 shown in FIG. 7, when the wafer W is heated at the time t3, the thinner liquid or the coating liquid remaining in the coating liquid on the surface of the wafer W is heated by the heating. The rate of evaporation of contained water increases. Therefore, for example, even when a coating liquid using a thinner volatilization thinner as a solvent is coated on the surface of the wafer W and the time required for volatilization of all the thinner liquid is long, the thinner Is quickly volatilized. Therefore, the time required for the reduced pressure drying treatment is shortened as compared with the case where heating is not performed. In addition, heating is started at time t3, because in the step of controlling the film thickness of the coating liquid from time t1 to time t3, the film thickness can be controlled more accurately when the solvent volatilization rate is lower. Is.

In this case, the depressurization in the closed container 4 may or may not be stopped while heating by the heating means 59. Further, the timing of turning on the heating means 59 may be determined based on the detected value of the pressure in the closed container 4, or may be determined based on the detected value of the film thickness of the coating liquid. Further, the heating of the wafer W and the adjustment of the exhaust amount in the closed container 4 as shown in FIG. 9 are performed in combination, the time from time t1 to time t3 is lengthened to accurately control the film thickness, and after time t3. Alternatively, the total processing time required for the reduced pressure drying step may be adjusted by shortening the time.

In the above, the method of spreading the coating liquid is determined by the wafer W.
It is important to arrange the flow straightening plate 5 so as to be parallel to the wafer W in order to make the flow straightening plate 5 uniform in the plane. An example will be described based on FIGS. 12 to 15.

In FIG. 12, reference numeral 60 denotes a suspending support portion for suspending and holding the flow straightening plate 5 with the lid 42. The support portions 60 are, for example, as shown in FIG. The rectifying plate 5 is connected to three places, and the rectifying plate 5 is suspended and supported by, for example, three supporting portions 60. As shown in FIG. 14, the support portion 60 includes a substantially vertical holding rod 61 and a collar portion 6 provided on the upper end side of the holding rod 61.
2 and a spring portion 63 wound around the holding rod 61, and the lower end side of the holding rod 61 has a spherical joint portion 6
4 is joined to the surface of the current plate 5 facing the lid 42.

On the inner wall (ceiling part) 42a of the lid 42 facing the straightening plate 5, a recess 42b of a size capable of moving the collar 62 is formed at a position facing the holding rod 61. The opening 42c of the recess 42b is formed on the holding rod 61.
Can be passed, but the collar portion 62 is narrowed so that it cannot pass. As a result, the holding rod 61 can be moved up and down by the height of the recess 42b while the flow straightening plate 5 is suspended and held when the flow straightening plate 5 is moved up and down by the flow straightening plate elevating mechanism to be described later.

Next, the flow straightening plate raising / lowering mechanism 65 which constitutes the flow straightening member raising / lowering mechanism will be described. First, the rectifying plate 5 is shown in FIG.
As shown in FIG. 15, the wafer W placed on the placing section 41.
A plurality of, for example, three foot portions 50 are provided at positions on the outer side of the foot portion 50. The foot portions 50 are formed so as to extend substantially vertically inside the surface of the mounting portion 41 on the lower side, and the lower end thereof. The side is connected to the lifting rod described later.

As shown in FIGS. 12 and 15, the current plate lifting mechanism 65 includes a plurality of, for example, three lifting rods 66 for pressing the current plate 5 from the back side via the foot portions 50, and all the lifting rods 66. An elevating plate 67 connected to the lower end of the elevating plate 67 and an elevating part 68 for elevating the elevating plate 67 are provided. The elevating rod 66 is provided so as to elevate and lower at a position corresponding to the foot portion 50 of the rectifying plate 5, and when the elevating rod 66 is elevated and lowered, the elevating rod 66 is elevated and lowered. The foot portion 50, the lifting bar 66, and the lifting plate 67 of the rectifying plate 5 are configured so that the rectifying plate 5 can maintain a high degree of parallelism with the wafer W placed on the mounting part 41.

A hole diameter of, for example, 2 is provided inside the elevating rod 66.
A ventilation hole 66a of mm penetrates through, and a region near the upper end side of the elevating rod 66 is formed so that the lower end side of the foot portion 50 of the current plate 5 can be inserted. The other end of the elevating rod 66, which is not in contact with the flow straightening plate 5, is connected to the first exhaust means 66b through an opening / closing valve V2. 66c is a lifting rod 66
An O-ring 66d serving as a seal member is provided between the through hole 66c and the elevating rod 66. Further, a bellows 66e is provided between the mounting portion 41 around the elevating rod 66 and the elevating plate 67 to prevent the inside of the closed container 4 from communicating with the atmosphere side through the through hole 66c.

As shown in FIG. 12, the elevating part 68 is
It includes a substantially vertical ball screw 68a, a support portion 68b connected to one end of the elevating plate 67, and a motor M1 that rotates the ball screw 68a. The motor M1 rotates the ball screw 68a to provide a support portion. 68b is a ball screw 6
8a, so that the lifting plate 67 and the lifting rod 6
The rectifying plate 5 is moved up and down at an accurate height via 6 and the rectifying plate 5 thus moved up and down by the elevating rod 66 is kept highly parallel to the wafer W mounted on the mounting portion 41. It is configured to be raised and lowered.

Further, in the closed container 4 of this example, O-rings 69a and 69b forming two sealing members having different inner diameters are provided at the connecting portion between the mounting portion 41 and the lid 42, and these O-rings 69a and 69b are also provided. A groove 41b is formed between the two, and the groove 41b is connected to the second exhaust means 69c via the opening / closing valve V3, as shown in FIG.

In such a structure, the rectifying plate 5 has the foot portion 50.
While in contact with the lifting mechanism 65 via the lid 42
Is suspended and supported by the support portion 60, and the current plate 5 moves up and down as the lid 42 moves up and down. Further, when the height position of the straightening vane 5 is changed during the reduced pressure drying process, the straightening vane 5 of the straightening vane lifting mechanism 65 pushes the straightening vane 5 from the back side via the foot portion 50. In this case, for example, in the above-described example, the height of the current plate 5 is changed between the first position 1 mm above the wafer W surface and the second position 5 mm above the wafer W during the depressurization process. First, when the lift bar 66 is placed in the first position, the tip side of the lift bar 66 is brought into contact with the foot portion 50 of the current plate 5, and the opening / closing valve V2 is opened inside the lift bar 66 by the first exhaust means 66b. Aspirate.

As a result, the flow straightening plate 5 and the elevating rod 66 come into contact with each other inside the mounting portion 41, so that particles generated in the vicinity of the connecting portion between the foot portion 50 of the flow straightening plate 5 and the elevating rod 66 during up and down movement. Has a small effect on the processing in the container 4. Furthermore, since particles generated near the connecting portions of the two are discharged through the inside of the elevating rod 66 by the suction of the connecting portions of the both, it is possible to further prevent particle contamination.
At this time, the flow straightening plate 5 and the elevating rod 66 may be configured to be in direct contact with each other, but in this case, since both are in contact with each other at a position higher than the mounting portion 41, a large amount of particles are generated. Become.

Further, the parallelism of the straightening vanes 5 is determined by the three lifting rods 66.
Since the current plate 5 itself is suspended and supported by the lid portion 42, a slight tilt may occur in the current plate 5 when the current plate 5 is moved up and down. However, since the rectifying plate 5 and the holding rod 61 are connected by the spherical joint portion 64, the inclination of the rectifying plate 5 is absorbed by the spherical joint portion 64, and the rectifying plate 5 is moved up and down by the elevating rod 66.
Is moved up and down while maintaining high parallelism with respect to the wafer W placed on the placing section 41. Therefore, the wafer W
The spread of the coating liquid on the surface becomes uniform, and it is possible to secure the uniformity with a higher film thickness.

Further, in this example, the double O-ring 69
a and 69b are provided, the on-off valve V3 is opened between them, and the reduced-pressure drying process is performed while sucking by the second exhaust means 69c. In this way, the space between the mounting portion 41 and the lid 42 is more adsorbed. Therefore, when the inside of the closed container 4 is exhausted by the vacuum pump 46, it is possible to prevent outside air from entering the inside of the container 4 from between the mounting portion 41 and the lid 42.

In the reduced-pressure drying unit 26 of the present invention, a flow straightening plate lifting mechanism which constitutes a flow straightening member lifting mechanism may be constructed as shown in FIG. In FIG. 16, 71 is a substantially horizontal ball screw,
Reference numeral 72 denotes a support portion, and the support portion 72 is configured to move in the horizontal direction along the ball screw 71 by rotating the ball screw 71 by the motor M2.

On the other hand, a joint connecting portion 73 is provided on the rear surface side of the second elevating plate indicated by 53a in the figure, and the joint connecting portion 73 and the supporting portion 72 are formed by a long plate-like joint portion 74. The rotating shaft portions 75a and 75b are provided at both ends, respectively.
Connected by. As a result, when the supporting portion 72 is located away from the joint connecting portion 73, the length direction of the joint portion 74 is located in a state in which the length direction is nearly horizontal, and the current plate 5 is arranged in a position close to the wafer W. Then, when the ball screw 71 is rotated to move the support portion 72 to a position close to the joint connecting portion 73, the length direction of the joint portion 73 gradually becomes closer to the vertical direction, and the straightening plate 5 is removed from the wafer W. Ascend (to increase the height) so that they are separated from each other. As described above, in this example, the height position of the current plate 5 is appropriately determined by adjusting the length of the joint portion 74 in the length direction and the angle between the length direction of the joint portion 74 and the wafer W. It

In such a structure, the mechanism for moving the supporting portion 72 in the horizontal direction with high accuracy by the ball screw 71 and the joint portion 7 for connecting the supporting portion 72 and the second elevating plate 53a.
4, the height position of the straightening vane 5 is changed through the joint portion 74 by moving the support portion 72 in combination with the mechanism to be connected. At times, the height of the current plate 5 can be gently changed by reducing the rotation speed of the ball screw 71. Therefore, it is possible to suppress the turbulence of the air flow when the solvent contained in the coating liquid on the surface of the wafer W is being evaporated, and thus it is possible to further improve the uniformity of the thickness of the coating film.

Next, still another embodiment of the reduced pressure drying unit 26 of the present invention will be described with reference to FIGS. In this embodiment, a member that comes into contact with the peripheral region on the back surface side of the wafer W is provided on the mounting portion 41 in which the heater H is built in, and heat is applied to the peripheral region of the wafer W. Specifically, for example, a ring member 8 that forms an annular member having an L-shaped cross section is provided on the mounting portion 41 that constitutes the closed container 4, and the upper surface of the ring member 8 supports the peripheral portion of the back surface of the wafer W. Is configured. The ring member 8 is made of a material having a thermal conductivity different from that of the mounting portion 41 selected from, for example, aluminum, stainless steel, ceramics or the like.

In such a structure, the heat conduction from the mounting portion 41 changes depending on the material of the ring member 8 and the gap 81 formed between the ring member 8 and the back surface of the wafer W. Therefore, in the wafer W, the central region and the ring member 8
1. The temperature changes between the region near the portion in contact with 1 (the peripheral region of the wafer W), and the volatilization rate of the solvent of the coating liquid changes between the central region and the peripheral region of the wafer W. . Specifically, when the temperature of the wafer W becomes higher, the solvent in that region has a higher volatilization rate, and when the temperature becomes lower, the solvent in that region has a smaller volatilization rate. When controlled so as to change in the plane, the volatilization rate of the solvent is different in the plane, and thus the film thickness can be controlled in the plane of the wafer W.

In this example, as described above, the volatilization of the solvent of the coating liquid is controlled by the combination of the change of the height position of the rectifying plate 5 and the temperature change of the wafer W surface.
It is possible to uniformly control the film thickness of the coating film up to the vicinity of the outer edge of the wafer W. For this reason, even if the outer edge region to be discarded outside the circuit formation region of the wafer W is narrowed within 5 mm from the outer edge, the coating film can be formed with a sufficiently uniform film thickness up to this outer edge vicinity region.

In this case, the ring member 8 may have a L-shaped cross section, or may be of a type in which the entire upper surface of the ring member 8 contacts the back surface side of the peripheral region of the wafer W. At this time, the temperature of the wafer W is adjusted in-plane by the thermal conductivity in the vicinity of the contact portion between the ring member 8 and the wafer W, but depending on the type of coating film to be formed and other processing conditions,
The shape and material of the ring member 8 and the position and size of the contact portion with the wafer W are appropriately selected.

Further, in this embodiment, the ring member 8 is provided to change the heat conduction between the central region and the peripheral region of the wafer W, whereby the temperature of the wafer W is adjusted in the plane and the coating film is formed. Since the film thickness is controlled, the above-described straightening plate 5 may not be provided, or the height position may not be changed even if the straightening plate 5 is provided.

As described above, in this embodiment, the wafer W is transferred to the ring member 8. In this case, when the wafer W is placed on the ring member 8, the center position between the ring member 8 and the wafer W is set. Is easily misaligned. When the center position of the wafer W shifts in this way, the uniformity of the film thickness of the coating film deteriorates. Therefore, the wafer W is transferred onto the ring member 8 with the center positions of the ring member 8 and the wafer W aligned. Is important, and a method of aligning the center positions of the ring member 8 and the wafer W will be described next.

In this method, first, the wafer W is transferred onto the ring member 8 and then, as shown in FIG.
A plurality of, for example, three alignment members 82, which are positioning members provided at positions on the outer side of the wafer W that are equidistantly separated from the center position of the ring member 8, are arranged from the standby position on the outer side of the wafer W, respectively. The wafer W is hunted down by moving the wafer W in a synchronized state to a positioning position where it contacts the outer edge of W, and thus the alignment is performed.

These alignment members 82 are plate-like members 82a.
And a part of the outer edge of the wafer W is pressed by a side edge part of the plate-shaped body 82a. One end of the plate-shaped body 82a is connected to a substantially vertical rotating shaft 83b, and the pulley 83 is connected to the other end of the rotating shaft 83b.
a is connected, and a belt is stretched between the pulleys 83a of each rotating shaft 83b. As a result, when any of the rotary shafts 83b is rotated by a motor (not shown), all the rotary shafts 83b rotate in a synchronized state.

Thus, the plate-like members 82a of the positioning members 82 are rotationally driven from the standby position to the positioning position in a synchronized state.
When the two alignment members 82 are moved to the positioning position and brought into contact with the outer edge of the wafer W, the wafer W is squeezed to a position where the center position of the ring member 81 and the center position of the wafer W are aligned and positioned. ing. Figure 20
The middle 83c is a bearing.

When the wafer W is placed on the ring member 8 in this way and then the alignment member 82 is moved to align the wafer W, the center positions of the wafer W and the ring member 8 are always aligned. The uniformity of the coating film thickness can be increased in a stable state, and the throughput is improved.

In this embodiment, in addition to the case where the wafer W is transferred onto the ring member 8, the wafer W is transferred onto the mounting portion 41.
The present invention can be applied to the case where the wafer W is delivered, and the case where the wafer W is delivered to the support pin 41a of the mounting portion 41.
Is mounted on the ring member 8 and the mounting portion 41 in a state where their central positions are aligned with each other, so that highly uniform reduced-pressure drying treatment can be performed. Furthermore, this embodiment can also be applied to a reduced-pressure drying device having a configuration in which the flow straightening plate 5 and the ring member 8 are not provided. Further, the "mounting portion" in the claims corresponds to all members on which the wafer W is mounted, and also includes a ring member and the like.

FIG. 21 shows a reduced pressure drying unit 26 of the present invention.
Is another example of the present invention, and this example is characterized by the mounting portion on which the wafer W is mounted. In the mounting portion 41 of this example, for example, a first ventilation passage 84a is formed immediately outside the region where the ring member 8 is provided so as to penetrate the mounting portion 41 in the longitudinal direction. The second air passage 84 communicating from the first air passage 84a to the through hole 47a of the lift pin 44.
b is formed, and outside air enters into the closed container 4 through the ventilation passages 84a and 84b at a position closer to the atmosphere side than the position where the first ventilation passage 84a branches into the second ventilation passage 84b. An O-ring 84c is provided to prevent this.

Here, ventilation paths 84a and 84b are provided in the mounting portion 41.
If the inside of the closed container 4 is depressurized, the back surface side of the wafer W and the upper surface of the ring member 8 are attracted to each other, and even if the inside of the container 4 is returned to the atmospheric pressure from the depressurized atmosphere, the wafer W is not formed. The back surface side is still in a depressurized state, and the wafer W may be warped because the central area of the back surface side of the wafer W is adsorbed to the mounting portion 41 side. In the configuration in which the air passages 84a and 84b are provided, when the pressure inside the closed container 4 is returned from the reduced pressure atmosphere to the normal pressure atmosphere, the back surface side of the wafer W easily leaks and the back surface side of the wafer W easily becomes atmospheric pressure. The warp of the wafer W can be suppressed by suppressing the suction between the mounting area 41 and the central region on the back surface side of W.

This structure can also be applied to a reduced-pressure drying device having a structure in which the current plate 5 and the ring member 8 are not provided. Even in the mounting portion 41 having such a structure in which the ring member 8 is not provided, the mounting pin 41a is not supported. The wafer W is mounted on the wafer W, and a space is formed between the central region of the wafer W and the mounting portion 41, so that it can be applied. At this time, the "support member" in the claims
Includes the ring member 8 and the support pin 41a.

FIG. 22 shows a reduced pressure drying unit 26 of the present invention.
This is another example of the present invention, in which the rectifying plate 5 is provided so as to be parallel to the wafer W. More specifically, for example, as shown in the figure, a mounting unit 41 is provided with a digimatic indicator 85 that serves as a parallelism measuring unit for measuring the parallelism of the rectifying plate 5. Rectifying plate 5 through the elevating plate 53a and the supporting rod 51
Are moved up and down to adjust the straightening plate 5 to be parallel to the wafer W. In this case, since the rectifying plate 5 can be accurately aligned so as to be parallel to the wafer W, a coating film having a more uniform film thickness can be formed.

Next, still another example of the reduced pressure drying unit 26 of the present invention will be described with reference to FIG. This example
Instead of the plate-shaped rectifying plate 5, a rectifying member 86 having a reverse concave shape is provided so as to surround the surface and the outer edge of the wafer W. The rectifying member 86 has a substantially horizontal surface 86a formed so as to face the surface of the wafer W, and extends substantially vertically downward from this surface in a region in the vicinity of the outer side of the wafer W to form an outer end of the wafer W. It has a substantially vertical surface 86b that covers the edge while forming a very small gap with the outer edge, and in the substantially horizontal surface 86a, a large number of vent holes 86c are provided in the peripheral region of the wafer W in the circumferential direction. Are formed at equal intervals. Here, the gap between the side surface of the wafer W and the substantially vertical surface 86a is set to, for example, about 0.1 mm, and a large pressure loss is generated here.

In this example, the diameter of the mounting portion 87 for mounting the wafer W, for example, is set to be substantially the same as the diameter of the wafer W, and the substantially vertical surface 86b is mounted on the lower side of the wafer W. This placing portion 8 extends to the side of the placing portion 87.
The side surface of 7 is covered with a very small gap. Here, the gap between the side surface of the wafer W and the side surface of the mounting portion 87 and the substantially vertical surface 86b is set to about 0.1 mm, for example, and a large pressure loss is generated here. In this example, the closed container 4 </ b> A is configured by the lid 42 and the lower container 88, and the placing portion 87 is disposed inside the lower container 88.

In such a structure, when the closed container 4A is placed in a reduced pressure atmosphere, the exhaust flow in the container 4A is formed so as to bypass the rectifying member 86, and the solvent vapor volatilized from the wafer W is rectified by the rectifying member. It hits 86 and turns to the outside, and flows along the inside of the flow regulating member 86. At this time, since a very small gap is formed between the outer edge of the wafer W and the side surface of the mounting portion 87 and the rectifying member 86, a large pressure loss occurs here. Therefore, the solvent vapor volatilized from the wafer W flows out from the vent hole 86c toward the exhaust pipe 45, thereby forming a stable airflow that uniformly spreads in the radial direction. Since the solvent vapor spreads uniformly in the radial direction in this manner, the film thickness in the peripheral region of the coating film can be further improved, and the film thickness uniformity can be further enhanced.

At this time, for example, as shown in FIG. 24, the lid 42 is vertically divided above the rectifying member 86 inside the closed container 4A so as to face the substantially horizontal surface 86a of the rectifying member 86. It is also possible to provide a second rectifying plate 89 which is a second rectifying member, and form the vent hole 89a at a position corresponding to the vicinity of the outer edge of the wafer W of the second rectifying plate 89. In the configuration of FIG. 24, the ventilation hole 86 of the flow regulating member 86
c is formed on a substantially vertical surface 86b near the outer edge of the wafer W.

In such a structure, when the closed container 4A is placed in a reduced pressure atmosphere, the solvent vapor volatilized from the wafer W flows out from the ventilation hole 86c toward the exhaust pipe 45 and is formed on the second straightening plate 89. Exhaust pipe 4 through the vent hole 89a
It flows toward 5. By thus forming the double structure of the rectifying member 86 and the second rectifying plate 89, it is possible to form a stable airflow that spreads more uniformly in the radial direction of the wafer W, whereby the solvent vapor spreads more uniformly in the radial direction. Therefore, the film thickness in the peripheral region of the coating film can be further improved, and the uniformity of the film thickness can be further enhanced.

The rectifying member 86 and the second rectifying plate 89
Can also be applied to the case where the wafer W is placed on the placing section 41 having the configuration shown in FIG. 6, and in this case, the substantially vertical surface 86b extends to the position where the side surface of the wafer W is covered with a slight gap. With this configuration, the film thickness of the peripheral region of the coating film formed on the surface of the wafer W can be improved.

Further, the reduced pressure drying unit 26 may be constructed as shown in FIG. The present embodiment is adjacent to the closed container 9A for performing the reduced pressure drying process, and
A transfer chamber 9B provided with a dedicated auxiliary transfer means 91 for transferring the wafer W is provided for the closed container 9A and the transfer chamber 9.
A gate valve 90, which is an opening / closing member, is configured to open and close a space between B and B.

The auxiliary transfer means 91 transfers the wafer W to and from the main transfer means 24 described above.
For example, as shown in the figure, two arms 91a are individually configured to be capable of advancing and retreating with respect to the closed container 9A and being able to move up and down. Further, in the transfer chamber 9B, for transferring the wafer W between the auxiliary transfer means 91 and the main transfer means 24,
The transfer table 92 is equipped with a transfer pin 92a that can be moved up and down by an elevating mechanism 92b. In the figure, 93a is a mounting portion for the wafer W, and 93b is an exhaust pipe. For example, as shown in FIG. 26, the delivery table 92 has a delivery pin 92.
a of the auxiliary transport means 91 so as not to interfere with a.
And the arm of the main transfer means 24 are accessible so that the wafer W can be transferred between them.

In such a structure, with the gate valve 90 closed, the wafer W is carried into the carrier chamber 9B by the main carrier means 24 through the wafer carrier port (not shown) of the carrier chamber 9B, and the transfer pin 92a is transferred. The wafer W is transferred to the auxiliary transfer means 91 via the. Then, the main transport means 24 is withdrawn, the transport port is closed, and then the gate valve 9
When 0 is opened, the wafer W is transferred by the auxiliary transfer means 91 into the closed container 9A.

In the present embodiment, the wafer W is first transferred to the transfer chamber 9B, the transfer chamber 9B is closed, and then the gate valve 90 is opened to transfer the wafer W into the closed container 9A. When W is carried into the closed container 9A, it is possible to prevent atmospheric air from entering the container 9A.

Further, in the reduced pressure drying unit 26, as shown in FIG. 27, for example, a part of the side wall of the closed container 9A may be formed of a transparent body 94 made of, for example, transparent vinyl chloride. For example, the transparent body 94 is the side wall 95a of the closed container 9A.
An opening 95b is formed on the side wall 95a and is attached to the side wall 95a via an O-ring 95c so as to close the opening 95b. By doing so, there is an advantage that the state of the reduced pressure drying process performed in the closed container 9A can be visually confirmed.

The reduced pressure drying unit 26 is mounted on, for example, the shelf units U2 and U3. In such a case, the wafer W is loaded into the reduced pressure drying unit 26 and the reduced pressure drying unit 2 is used.
The unloading of the wafer W from 6 is performed in a predetermined process.
The transfer arm 23, the main transfer means 24, and the transfer arm 27 shown in FIG.

In consideration of the convenience of access to the inside of the reduced pressure drying unit 26 by each of these conveying means in that case, the reduced pressure drying unit 26 shown in FIG. 28 can be proposed.
That is, in the reduced pressure drying unit 26 shown in FIG. 28, openings 101 and 102 are formed on both sides of the transfer chamber 9B. Therefore, each of the above-mentioned transfer means can carry the wafer W in and out of the reduced pressure drying unit 26 through these openings 101 and 102.

Although the mounting portion 41 has a structure in which the heater H is built in, as shown in FIG. 29, the mounting portion 112 having the temperature adjusting means, for example, the Peltier element 111 is used. May be.

The mounting portion 112 has a recess 117 on the upper surface side.
The main body 110 formed with a seal member 114 such as an O-ring so as to airtightly close the concave portion 117.
And a plate 113 provided on the upper part of the table 10. The plate 113 is a portion on which a substrate such as the wafer W is directly placed. In the recess 117, a Peltier element 111, whose upper surface side is in contact with the lower surface of the plate 113 so as to control the temperature of the plate 113, and a cooling flow path 115 for cooling the lower surface side of the Peltier element 111. It is provided. Cooling water flows through the cooling flow path 115, for example. The cooling fluid flows between the cooling fluid supply source (not shown) arranged outside and the cooling flow passage 115.
Circulate through.

According to the mounting portion 112 having the above-described structure, the temperature of the substrate such as the wafer W mounted on the plate 113 can be adjusted in the range of, for example, 10 ° C to 40 ° C. Therefore, by using the mounting portion 112, the temperature of the wafer W is initially maintained at a low temperature, for example, around 15 ° C. during the vacuum drying, and the solvent is evaporated from the coating liquid such as the resist liquid on the wafer W. For example, when the rectifying plate 5 is brought close to the wafer W and dried while controlling the liquid flow of the coating liquid, the temperature of the wafer W is maintained at room temperature, for example, 23 ° C. Can be properly executed.

In the above, the substrate used in the present invention is L
It may be a CD substrate or a photomask reticle substrate. The coating liquid is not limited to the resist liquid, and an interlayer insulating material, a low dielectric material, a ferroelectric material, a wiring material, an organic metal material, a metal paste, or the like may be used. Furthermore, the coating liquid of the present invention may be applied by a so-called spin coating method, or may be applied by supplying the coating liquid in a spiral shape to the substrate surface.

[0095]

As described above, according to the present invention, in a reduced pressure drying apparatus for a substrate used for forming a coating film, the drying under reduced pressure is performed while ensuring high uniformity of the thickness of the coating film. You can

[Brief description of drawings]

FIG. 1 is a plan view showing the overall structure of an embodiment of a coating film forming apparatus incorporating a reduced pressure drying unit according to the present invention.

FIG. 2 is a perspective view showing the overall structure of the above embodiment.

FIG. 3 is a schematic cross-sectional view showing a configuration of a shelf unit used in the above embodiment.

FIG. 4 is a vertical cross-sectional view for explaining a coating unit used in the above embodiment.

FIG. 5 is a plan view for explaining the coating unit.

FIG. 6 is a vertical cross-sectional view showing a reduced pressure drying unit incorporated in the shelf unit.

FIG. 7 is a characteristic diagram showing a pressure curve in the reduced pressure drying unit.

FIG. 8 is a side view for explaining another embodiment of the reduced pressure drying unit according to the present invention.

FIG. 9 is a cross-sectional view for explaining still another embodiment of the reduced pressure drying unit according to the present invention.

FIG. 10 is a characteristic diagram showing a pressure curve in the reduced pressure drying unit.

FIG. 11 is a cross-sectional view for explaining still another embodiment of the reduced pressure drying unit according to the present invention.

FIG. 12 is a cross-sectional view for explaining still another embodiment of the reduced pressure drying unit according to the present invention.

FIG. 13 is a plan view for explaining still another embodiment of the reduced pressure drying unit according to the present invention.

FIG. 14 is a sectional view for explaining still another embodiment of the reduced pressure drying unit according to the present invention.

FIG. 15 is a cross-sectional view for explaining still another embodiment of the reduced pressure drying unit according to the present invention.

FIG. 16 is a cross-sectional view for explaining still another embodiment of the reduced pressure drying unit according to the present invention.

FIG. 17 is a side view for explaining still another embodiment of the reduced pressure drying unit according to the present invention.

FIG. 18 is a perspective view showing a part of the further another embodiment.

FIG. 19 is a plan view for explaining a method for aligning the wafer with the mounting table.

FIG. 20 is a cross-sectional view for explaining the above method.

FIG. 21 is a cross-sectional view for explaining still another embodiment of the reduced pressure drying unit according to the present invention.

FIG. 22 is a sectional view for explaining still another embodiment of the reduced pressure drying unit according to the present invention.

FIG. 23 is a sectional view for explaining still another embodiment of the reduced pressure drying unit according to the present invention.

FIG. 24 is a cross-sectional view for explaining still another embodiment of the reduced pressure drying unit according to the present invention.

FIG. 25 is a cross-sectional view for explaining still another embodiment of the reduced pressure drying unit according to the present invention.

FIG. 26 is a plan view for explaining the still another embodiment.

FIG. 27 is a cross-sectional view for explaining still another embodiment of the reduced pressure drying unit according to the present invention.

FIG. 28 is a cross-sectional view showing another example of the reduced pressure drying unit.

FIG. 29 is a cross-sectional view showing an example of the internal configuration of another mounting portion.

FIG. 30 is a perspective view for explaining a method for applying a resist solution.

FIG. 31 is a cross-sectional view for explaining a conventional vacuum drying unit.

FIG. 32 is a cross-sectional view showing a state of a coating film when a reduced pressure drying process is performed in a conventional reduced pressure drying unit.

[Explanation of symbols]

24 Main transport means 25A coating unit 26 Vacuum drying unit 4,4A, 9A closed container 41 Placement section 42 Lid 45 Exhaust pipe 46 vacuum pump 5 current plate 53,65,7 Rectifier plate lifting mechanism 55 Pressure sensor 58 Pressure regulator 59 Heating means 60 holding part 66 Lifting rod 8 ring members 82 Alignment member 84a, 84b air passage 85 Digimatic Indicator 86 straightening member 89 Second straightening plate 9B Transport room 90 gate valve 91 auxiliary transport means 94 transparent body

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F26B 5/04 G03F 7/16 501 G03F 7/16 501 H01L 21/30 565 564Z (72) Inventor Naoya Hirakawa 5-3-6 Akasaka, Minato-ku, Tokyo TBS Broadcast Center, Tokyo Electron Co., Ltd. (72) Inventor, Hama Gaku 5-3-6 Akasaka, Minato-ku, Tokyo TBS Broadcast Center, F-term (Tokyo Electron Co., Ltd.) (Reference) 2H025 AA18 AB14 AB16 EA04 3L113 AA05 AB02 AC24 AC67 BA34 DA24 4D075 BB24Z BB56Z CA47 DA06 DB13 DB14 DC22 DC24 EA07 EA45 4F042 AA02 AA07 AB00 BA06 BA08 BA25 DB04 DB21 DB29 DB30 DB39 DC01 EB17 5F5 EB17 5F22

Claims (28)

[Claims] 1. A hermetically sealed container having a mounting portion for mounting a substrate coated with a coating liquid, which is a mixture of a coating film component and a solvent, and an exhaust passage in the hermetically sealed container. And a vacuum evacuation means for evaporating the solvent from the coating liquid on the substrate and a surface of the substrate mounted on the mounting part, which are connected to each other via a vacuum atmosphere in the closed container. A rectifying member, and a rectifying member lifting mechanism for moving the rectifying member up and down,
In a vacuum atmosphere in the closed container, while evaporating the solvent from the coating liquid on the substrate, the rectifying member is moved up and down by a rectifying member elevating mechanism to change the height position of the rectifying member. Vacuum drying device. 2. The rectifying member is changed from the first position to a second position different from the first position while the solvent is volatilized from the coating liquid on the substrate.
The reduced pressure drying apparatus described. 3. A pressure detecting unit for detecting the pressure in the closed container is provided, and when the detected value from the pressure detecting unit becomes equal to or lower than a predetermined pressure, the height position of the rectifying member is set to the first position. The reduced pressure drying apparatus according to claim 1 or 2, wherein the position is changed from the first position to the second position. 4. A film thickness measuring means for measuring the thickness of the coating film formed on the surface of the substrate is provided, and the height position of the rectifying member is changed based on the measured value from the film thickness measuring means. The reduced pressure drying apparatus according to claim 1 or 2, characterized in that: 5. A pressure adjusting unit for adjusting an exhaust amount is provided between the exhaust passage and the vacuum exhaust unit, and the pressure adjusting unit is provided on the basis of the pressure in the closed container and / or the film thickness of the coating film. By controlling the exhaust volume in the closed container by the pressure adjusting unit,
The reduced pressure drying apparatus according to any one of claims 2 to 4, wherein a volatilization time of the solvent is controlled. 6. A temperature adjusting means for adjusting the temperature of the substrate placed on the placing part is provided inside the closed container, and the inside of the closed container is decompressed to reduce the solvent contained in the coating liquid on the substrate surface. 6. The reduced pressure drying apparatus according to claim 1, wherein the temperature of the substrate is adjusted while the moisture is being evaporated. 7. The reduced-pressure drying apparatus according to claim 6, wherein depressurization in the closed container by the vacuum evacuation means is stopped while the temperature of the substrate is adjusted by the temperature adjustment means. 8. The reduced pressure drying apparatus according to claim 6, wherein the temperature adjusting means is provided in the rectifying member. 9. The reduced pressure drying apparatus according to claim 6, wherein the temperature adjusting means is provided in the placing section. 10. The reduced pressure drying apparatus according to claim 6, wherein the temperature adjusting means is capable of adjusting the temperature of the substrate within a range of at least 10 ° C. to 23 ° C. 11. The reduced pressure drying apparatus according to claim 6, wherein the temperature adjusting unit includes a heater. 12. The reduced pressure drying apparatus according to claim 6, wherein the temperature adjusting unit includes a Peltier element. 13. The pressure in the closed container and / or the film thickness of the coating film is detected, and the temperature of the substrate is adjusted by the temperature adjusting means based on the detected value. 13. The reduced pressure drying apparatus according to any one of 1 to 12. 14. The reduced pressure drying apparatus according to claim 1, wherein the rectifying member is a plate-shaped member. 15. The rectifying member is configured to cover the surface and the outer edge of the substrate.
15. The reduced pressure drying apparatus according to any one of 1 to 14. 16. A suspending support portion which is connected to a front surface side of the rectifying member and is attached to a lid of a closed container so as to be movably suspended in a vertical direction, the rectifying member. 16. The reduced pressure drying apparatus according to claim 1, further comprising: a rectifying member elevating mechanism that is provided on a back surface side of the rectifying member and presses the rectifying member to change a height position of the rectifying member. . 17. The reduced pressure drying apparatus according to claim 16, wherein the rectifying member and the suspending support portion are connected by a spherical joint. 18. The rectifying member elevating / lowering mechanism includes an elevating rod having a back surface side and one end side of the rectifying member in contact with each other, the other end side being connected to an exhaust means, and an air vent inside, and the rectifying member and the elevating / lowering member. 18. The reduced pressure drying apparatus according to claim 16 or 17, wherein one end side of the rod is brought into contact with the elevating rod and the rectifying member is pressed by the elevating rod while the inside of the elevating rod is sucked by exhaust means. 19. The hermetically sealed container includes a lid and a lower container, and is formed by closely adhering peripheral portions of the lid and the lower container. Sealing members of two sizes are provided at the contact portion between the lid and the lower container. The reduced pressure drying apparatus according to any one of claims 1 to 18, wherein the vacuum drying apparatus is provided, and a region between these sealing members is exhausted by an exhaust unit to adsorb a contact portion between the lid and the lower container. . 20. The annular member, which is in contact with the peripheral region on the back surface side of the substrate and has a thermal conductivity different from that of the mounting portion, is provided in the mounting portion. Vacuum dryer. 21. The reduced pressure drying apparatus according to claim 1, further comprising a second rectifying member inside the airtight container at a position closer to an exhaust passage than the rectifying member. 22. A hermetically sealed container having a mounting part for mounting a substrate coated with a coating liquid, which is a mixture of a coating film component and a solvent, and the mounting part. A heating means for heating the substrate, a vacuum exhaust means connected to the airtight container via an exhaust passage, a reduced pressure atmosphere in the airtight container, for evaporating the solvent from the coating liquid on the substrate, A reduced pressure drying apparatus, comprising: an annular member that is provided on the placing unit and that is made of a material having a thermal conductivity different from that of the placing unit and that is in contact with the peripheral region on the back surface side of the substrate. . 23. An airtight container having therein a mounting portion for mounting a substrate coated with a coating liquid, which is a mixture of a coating film component and a solvent, and an exhaust passage in the sealed container. Connected via a vacuum evacuation means for evaporating the solvent from the coating liquid on the substrate in a reduced pressure atmosphere in the closed container, and a radial direction from the center position of the placement part outside the placement part. Are provided at positions equidistant from each other, and are moved in a substantially horizontal direction in a synchronized state from a position on the outer side of the substrate to a position in contact with the edge of the substrate, and A reduced pressure drying apparatus, comprising: a plurality of positioning members that perform alignment with a central position. 24. An airtight container having therein a mounting portion for mounting a substrate coated with a coating liquid, which is a mixture of a coating film component and a solvent, and an exhaust passage in the sealed container. Connected to the inside of the sealed container in a reduced pressure atmosphere to evaporate the solvent from the coating liquid on the substrate by vacuum evacuation means, and the mounting part provided on the mounting part to slightly move the substrate from the surface of the mounting part. A reduced pressure drying apparatus, comprising: a supporting member that supports a floating state; and a ventilation path that is formed in the mounting portion and that communicates with the outside of the closed container. 25. A transfer chamber provided adjacent to the airtight container, an opening / closing member for opening and closing between the airtight container and the transfer chamber, and a mounting portion of the airtight container provided in the transfer chamber. 25. The reduced-pressure drying apparatus according to claim 1, further comprising: a transporting unit that transfers the substrate to and from the substrate. 26. The reduced pressure drying apparatus according to claim 1, wherein at least a part of a wall portion of the closed container is formed of a transparent body. 27. A step of applying a coating liquid, which is a mixture of components of a coating film and a solvent, onto a substrate surface; a step of placing the substrate coated with the coating liquid in a closed container; Is evacuated through an exhaust path by a vacuum exhaust means to create a reduced pressure atmosphere, and is placed between a reduced pressure drying step of evaporating the solvent of the coating liquid applied to the substrate and the reduced pressure drying step, and placed in a closed container. A first step of providing a rectifying member at a first position on the upper side of the formed substrate so as to face the substrate, and a first step between the reduced-pressure drying step, and the rectifying member is And a second step of changing the second position different from the first position so as to face the substrate, the method for forming a coating film. 28. A step of applying a coating liquid, which is a mixture of components of a coating film and a solvent, onto the surface of a substrate, and a step of placing the substrate coated with the coating liquid on the upper surface of a mounting portion in a closed container. Then, a step of aligning the substrate with the center position of the placing part by a positioning member, and evacuating the inside of the closed container by an evacuation means by an evacuation means to create a reduced pressure atmosphere, A reduced-pressure drying step of volatilizing a solvent, and a coating film forming method.