KR20090118820A - Coating apparatus, coating method and storage medium - Google Patents

Abstract

PURPOSE: A coating apparatus, a coating method, and a memory medium are provided to reduce use amount of solvent by reducing attachment of particles in a rear surface of a substrate. CONSTITUTION: A coating apparatus includes a preventing part, a partition part, an opening part, an opening amount control unit, an exhaust amount control unit, and a control part. The preventing part is formed in a circumference direction of a substrate with a ring shape. The partition part(22) is extended from the preventing part to the center of the substrate. The opening part(25) is formed in the partition part. The opening amount control unit controls an opening amount of the opening part. The exhaust amount control unit is installed in an exhaust duct, and controls an exhaust amount of the exhaust duct. The control part controls the opening amount control unit and the exhaust amount control unit according to the number of rotations of the substrate.

Description

Coating device, coating method and storage medium {COATING APPARATUS, COATING METHOD AND STORAGE MEDIUM}

The present invention relates to a coating apparatus and a coating method for applying a coating liquid to a substrate.

In a semiconductor manufacturing process, there is a process of apply | coating a coating liquid on a board | substrate, As a method of apply | coating, a spin coating method is mentioned, for example. This spin coating method absorbs a substrate such as a semiconductor wafer or a glass substrate for LCD onto a spin chuck, which is a substrate holding unit, supplies the coating liquid to the center of the substrate, and rotates the substrate at a high speed so that the coating liquid is applied to the surface of the substrate. It is a method of telegraph. As the coating liquid, a resist liquid is typical, and other chemical liquids for insulating films containing precursors of silicon oxide are used.

In the coating apparatus used in the spin coating method, as shown in FIG. 9, the spin chuck 11 is provided in the cup 10 having the wastewater passage 15 and the exhaust passage 16 at the bottom thereof. The liquid is formed by forming a ring-shaped preventive return portion 2 in a ring shape so as to be close to the edge around the back surface of the wafer W, which is the substrate on the spin chuck 11, and the wafer W by the spin chuck 11. ), The mist dropped when it is rotated is attracted to the lower side of the cup 10 by suction of the exhaust passage 16, and is discharged from the wastewater passage 15. The space near the spin chuck 11 from the spring return prevention part 2 is partitioned from the outside by the partition part 22 continuous to the said prevention part 2. Moreover, clean air is supplied from the fan filter unit (FFU) 33 provided in the upper side of this coating apparatus to the lower side, and therefore mist of the coating liquid dropped by the centrifugal force by the rotation of the wafer W. The gas is transported downward by the air flow of the clean air formed in the cup 10 by the suction of the exhaust path 16, and gas-liquid is separated and discharged from the wastewater channel 15.

By the way, although the splashing prevention part 2 is provided so that the coating liquid which collided with the inner wall of the cup 10 may not splash and return to the back surface side of a board | substrate, it prevents splashing and returning when rotating the wafer W at high speed. The space 23 on the inner `` spin chuck 11 side '' becomes negative pressure (reduced pressure) from the part 2, thereby causing the fine particles (mist) of the coating liquid to be dispersed into the space 23 under reduced pressure. It adheres to the back surface of the wafer W, and becomes a particle. In order to remove this particle, the process (bleaching) of supplying a solvent to the back surface of the wafer W from the nozzle provided on the back surface side of the wafer W is performed following the spin coating. Since the amount of use per sheet is several tens of ml, this rinse is the process which consumes the solvent most among the liquid treatment which added a series of coating processes or image development. For this reason, the total amount of monthly solvent used becomes a considerable amount, and it is preferable to reduce the amount of the solvent used for rinse.

On the other hand, in Patent Document 1, a gap is formed in a partition around the spin chuck shaft, and a shutter for opening and closing the gap is provided, and gas is introduced into the negative pressure space on the back surface of the substrate by opening and closing the shutter to eliminate the negative pressure state. Thus, an apparatus for reducing the adhesion of particles to a substrate is described. However, since the degree of negative pressure varies depending on the rotational speed of the substrate, for example, when the rotational speed is low, the degree of negative pressure is small. When the shutter is opened largely, more gas than necessary flows into the cup from the outside of the cup through the gap. In addition, the airflow on the surface of the substrate is disturbed by the influence of the downdraft, and as a result, the in-plane uniformity of the liquid film formed on the substrate may be impaired. On the contrary, when the rotational speed is high, the degree of negative pressure is large, so that the opening of the shutter is small, the inflow of gas is small. Therefore, it is difficult to say that the negative pressure is not solved and the particle reduction is effective.

[Patent Document 1] Japanese Patent Laid-Open Publication Pyeongseong 5-6855

SUMMARY OF THE INVENTION An object of the present invention is to provide a coating apparatus and a coating method which can reduce adhesion of particles to the back surface of a substrate in applying the coating liquid to the substrate by spin coating, thereby reducing the amount of solvent used. It is in doing it.

An applicator of the present invention includes a cup placed in an atmosphere in which a downdraft is formed, and an exhaust path connected to a lower portion of the cup to suck and exhaust the atmosphere in the cup, and the substrate holding portion surrounded by the cup. In the coating apparatus which maintains horizontally and supplies a coating liquid to the center part of this board | substrate, and spreads a coating liquid on the surface of a board | substrate by rotating a board | substrate about the vertical axis | shaft across the said board | substrate holding part,

In order to prevent the liquid from splashing back to the back side of the substrate, it is provided close to the circumferential edge of the back side of the substrate, and protrudes to the back side of the substrate, and is formed in an annular shape in the circumferential direction of the substrate to prevent the return. Wealth,

A partition portion continuous from the splash prevention portion near the center of the substrate and defining a space partitioned with respect to the outer space below the cup on the back side of the substrate;

An opening which is formed in the partition portion and connects the space on the rear surface side of the substrate surrounded by the partition portion with the outer space below the cup;

An opening amount adjusting means for adjusting the opening amount of the opening portion,

An exhaust amount adjusting means provided in the exhaust path, for adjusting an exhaust amount of the exhaust path;

And a control unit for controlling the opening amount adjusting means and the exhaust amount adjusting means in accordance with the rotational speed of the substrate.

The control unit includes: a storage unit for storing data corresponding to the opening amount of the opening and data corresponding to the displacement amount for each rotational speed of the substrate; reading data according to the rotational speed of the substrate from the storage unit; It can be set as the structure provided with the means which outputs each control signal of a displacement adjustment means.

The control unit may further include: a storage unit storing time series data of data corresponding to the opening amount of the opening and data corresponding to the displacement amount for each application recipe; and based on the data read out from the storage unit; It is good also as a structure provided with the means which outputs each control signal of a displacement adjustment means.

The coating method of the present invention is provided so as to face the substrate holding portion surrounded by the cup and close to the periphery of the rear surface of the substrate in order to prevent the liquid from splashing back to the back side of the substrate held by the substrate holding portion. A protruding bounce prevention portion formed in an annular shape in the circumferential direction of the substrate so as to protrude toward the back surface side of the substrate, and continuous from the bouncing back prevention portion near the center of the substrate and in the outer space below the cup on the back side of the substrate; A partition which forms a space partitioned with respect to the space, an opening which is connected to the space on the back side of the substrate surrounded by the partition and the outer space below the cup, and connected to a lower portion of the cup, Using the coating apparatus provided with the exhaust path for suction,

Forming a downdraft in the atmosphere in which the cup is placed;

Holding the substrate horizontally in the substrate holding portion;

Supplying the coating liquid to the center of the substrate, and rotating the substrate around the vertical axis with the substrate holding portion interposed therebetween to spread the coating liquid onto the surface of the substrate;

And controlling an opening amount of the opening portion and an exhaust amount by an exhaust amount adjusting means provided in the exhaust passage in accordance with the rotation speed of the substrate.

The coating method refers to a storage unit in which data corresponding to the opening amount of the opening and data corresponding to the displacement amount are stored for each rotational speed of the substrate, and the data corresponding to the opening amount and the displacement according to the rotational speed of the substrate. Reading data corresponding to the data from the storage unit by a computer;

The configuration may include a step of controlling the opening amount and the exhaust amount based on the read data.

In addition, the coating method includes a step of reading the time series data by a computer from a storage unit that stores respective time series data of data corresponding to the opening amount of the opening and data corresponding to the displacement amount for each coating recipe;

It is good also as a structure containing the process of controlling an opening amount and an exhaust volume based on the read time series data.

Another invention is a storage medium for storing a computer program used in a coating apparatus for applying a coating liquid to a rotating substrate,

The computer program is characterized in that a group of steps for carrying out the coating method of the present invention is incorporated.

According to the present invention, the amount of gas sucked from the outside of the cup into the negative pressure space on the back surface of the substrate is controlled by adjusting the opening amount of the opening of the partition portion that partitions the space on the back surface side of the substrate based on the rotation speed of the substrate. Therefore, the particle | grains which generate | occur | produce by the mist of the coating liquid attracted to the back surface side of a board | substrate can be reduced. As a result, the amount of particles adhering to the back surface of the substrate can be reduced, and the amount of the back rinse can be reduced. In addition, since the adjustment of the exhaust amount in the exhaust path is also performed in conjunction with the adjustment of the opening amount, confusion of airflow around the substrate based on congestion of gas from the outside to the negative pressure space on the back side of the substrate is suppressed. In addition, since the influence on the film thickness profile of the film formed in the board | substrate is small, and the gap of the film thickness profile between board | substrates is small, a stable process can be performed.

1 is a longitudinal sectional view showing an embodiment of a coating device according to the present invention. This coating device is provided with the spin chuck 11 which is a board | substrate holding | maintenance part which hold | maintains the wafer W which is a board | substrate horizontally, and vacuum-suctions, and can be lifted and lowered by the rotation drive part 12 with the axial part 11a interposed, It is also rotatable around the vertical axis. The cup 10 is provided so as to surround the wafer W on the spin chuck, and the upper portion of the cup 10 has a circumference more than the wafer W so that the opening 18 can exchange the wafer W. It is formed in a large circular shape. At the circumferential edge of the opening 18, an annular recess 19 formed by cutting out to the outer side horizontally from the inner circumferential surface is formed, and the bottom surface 13 of the recess 19 is formed. ) Is set at approximately the same height as the wafer W held by the spin chuck 11. The bottom surface 13 has a role of controlling the air flow generated by the rotating wafer W to make the resist film thickness of the peripheral portion of the wafer W uniform. In addition, a communication path 13a is formed vertically and downwardly from the bottom surface 13 so as to be connected to the liquid receiving part 14 described later.

Moreover, the bottom part of the cup 10 is comprised as the liquid receiving part 14, and the liquid receiving part 14 is connected with the waste water path 15 for discharging wastewater. In addition, exhaust pipes 16a and 16b constituting two exhaust passages are provided in the center side of the cup 10 from the liquid receiving portion 14, and gas-liquid separation is performed by this intrusion portion. These two exhaust pipes 16a and 16b respectively join downstream and are connected to an exhaust duct in a factory (not shown) with a damper 17 interposed therebetween. Therefore, the gas in the cup 10 is attracted by opening this damper 17, and it is possible to control the displacement by adjusting the opening degree.

Inside the cup 10, a guide part 2 is provided near the edge of the back surface of the wafer W held by the spin chuck 11. The guide portion 2 is formed in the shape of a mountain by the inner inclined surface 21 and the outer inclined surface 26 and is formed in an annular shape along the circumferential direction of the wafer W. It consists. At the outer end of the guide portion 2, a vertical wall 24 extending vertically and downwardly is provided so as to intrude into the liquid receiving portion 14. The guide portion 2 guides the coating liquid separated from the wafer W to the liquid receiving portion 14 with its surface interposed therebetween, and prevents the coating liquid from splashing back to the back surface of the wafer W. It is for. A horizontal surface 22 is provided inside the inclined surface 21 of the guide portion 2, and the inclined surface 21 and the horizontal surface 22 constitute a partition portion. By this partition, a space partitioned from the lower outer space of the cup 10 is formed on the back surface side of the wafer W. As shown in FIG. That is, the annular space surrounded by the inclined surface 21, the horizontal surface 22, the wafer W, and the spin chuck 11 becomes the rear space 23 of the wafer W. As shown in FIG. Since the shaft portion 11a of the spin chuck 11 penetrates, a small gap is formed between the outer circumference of the spin chuck 11 and the horizontal plane 22. The rear space 23 is a space in which the atmosphere is reduced by the rotation of the wafer W and the suction effect of the exhaust pipes 16a and 16b. On the other hand, since the guide part 2 is equivalent to a rebound prevention part, it can also be understood that the part forming the empty "back space 23" partitioned on the back side of the wafer W also includes a rebound prevention part. However, since there is no problem in the technical description, it is assumed that the inclined surface 21 continuous to the upper end of the guide portion 2 and the horizontal surface 22 following this correspond to the partition portion. Moreover, the back rinse nozzle 40 is provided in the vicinity of the outer edge of the horizontal surface 22, The front end part is comprised toward the outer periphery edge of the wafer W. As shown in FIG. This rinse nozzle 40 is connected to a rinse supply source via a supply path not shown.

The said cup 10 is put in the box 30, The conveyance port 31 of the wafer W is provided in this box 30, and this conveyance port 31 is carried out by the conveyance mechanism which is not shown in figure. ), The wafer W can be exchanged. 31a in the figure is a shutter which opens and closes the conveyance port 31. As shown in FIG. The shutter 31a is closed except that the wafer W is carried in and out of the box 30 by the transfer mechanism. In addition, a fan filter unit (FFU) 33 is provided at the upper part of the box 30, and the FFU 33 uses a clean gas, for example, clean air flowing in through the gas supply passage 32, as a downflow. It has a role to supply the box 30. In the drawings, a fan provided in the FFU 33 is omitted. At the bottom of the box 30, a suction exhaust path 35 for exhausting the gas in the box 30 is provided. The downdraft from the FFU 33 and the suction by the exhaust pipes 16a and 16b described above, together with the downdraft are formed in the opening 18 of the cup 10.

In the box 30, a solvent nozzle 41 for discharging the solvent, a coating nozzle 42 for discharging the coating liquid, and a rinse nozzle 43 for discharging the rinse liquid are provided in the upper portion of the cup 10. These nozzles 41, 42 and 43 are connected to the solvent supply source 51, the coating liquid supply source 52 and the rinse liquid supply source 53 via the supply pipes 41a, 42a and 43a, respectively, and the wafer W It is comprised so that it may move by the carrier arm which is not shown in figure between the upper predetermined position and the standby position of the side of the cup 10. As shown in FIG.

An opening 25 penetrating downward is formed in the horizontal surface 22 of the guide part 2. This opening part 25 is comprised by the slit formed in circular arc shape along the circle centered on the rotation center of the spin chuck 11, for example, as shown in FIG. Four places are provided along the said circle at equal intervals. As for the opening part 25, since the above-mentioned back space 23 becomes a negative pressure state, gas flows into the said space 23 through this opening part 25 from the space below the cup 10, and the magnitude | size of a negative pressure It is to have a role to mitigate. In addition, the replaceable filter 26 is detachably provided so that the gas which flows in does not contain garbage etc. In addition, four shutter holding pedestals 63 are provided below the four openings 25, respectively, and the shutters 6 are held on the holding pedestals 63, respectively. It is comprised so that the opening amount of 25) may be adjusted. In addition, 61 is a support rod and 62 is the drive part 62. FIG. This shutter 6 has an arc shape and a strip | belt-shaped form, and has the structure larger than the said opening part 25 so that the said opening part 25 may be covered from below. The drive part 62 can move the shutter 6 horizontally in the radial direction of the wafer W with the support rod 61 interposed therebetween, and by this operation, the shutter 6 is moved to the opening 25. The aperture amount can be adjusted.

3 schematically illustrates the control unit 7. The control unit 7 is composed of a computer and includes a data bus 70. In this computer, a computer program for operating the coating apparatus according to the embodiment of the present invention is installed via a storage medium such as a flexible disk, a hard disk, an MD, a memory card, a compact disk, and the like. The data bus 70 includes a CPU 71, a program 72 stored in a storage unit 72a, a storage unit 73, a spin chuck motor 12, a shutter driver 62, a damper driver 76 ), A resist supply system 77, a side rinse supply system 78, and the like are connected. On the other hand, the resist supply system 77 and the side rinse supply system 78 are comprised with the valve and pump for adjusting liquid amount. The storage unit 73 stores the data of the opening amount of the opening portion 25 and the displacement amount of the gas for each rotational speed of the wafer W or the application recipe. For example, when the program 72 acquires data on the rotational speed of the wafer W, the data of the opening amount of the opening portion 25 and the displacement amount of the gas can also be acquired along with the data bus 70. Through this configuration, each data can be output to the shutter driver 62 and the damper driver 76, respectively.

Next, the operation of the above-described embodiment will be described. The wafer W is loaded into the box 30 using a conveyance mechanism (not shown), for example, the spin chuck 11 is lifted by the rotation driver 12, and the wafer is placed on the spin chuck 11. Put (W) on and let it adsorb in vacuum. Thereafter, the spin chuck 11 is lowered so that the wafer W is placed in the cup 10. For example, three lifting pins may be provided to penetrate the horizontal surface 22, and the three lifting pins may transfer the wafer W to each other. On the other hand, as described above, the air flow is formed in the box 30, and as shown in Fig. 4A, the wafer W is exemplified by the spin chuck 11 at time t1. For example, it rotates at a speed of 2000 (rpm). Then, the above-mentioned downdraft spreads in a vortex toward the circumferential edge by the centrifugal force of the rotating wafer W. As shown in FIG. Then, the solvent nozzle 41 is moved from the standby position to the center upper portion of the wafer W by using a moving mechanism (not shown), and thinner is supplied from the solvent nozzle 41 to the wafer W so that the wafer W is used. The surface of the surface is moistened with thinner and trimmed to an environment where the resist liquid is easy to extend (prewet). Thereafter, the rotation of the wafer W is temporarily stopped at time t2, the solvent nozzle 41 is evacuated to the standby position, and the coating nozzle 42 is moved to the upper center of the wafer W.

At the time t3, the rotation speed is increased to 1500 (rpm), and this state is maintained for 1 to 5 seconds, during which the resist liquid is supplied from the coating nozzle 42 to the center portion of the wafer W. As shown in FIG. 5A, the resist liquid R is extended outward by centrifugal force due to the rotation of the wafer W, and the excess resist liquid R is formed on the surface of the wafer W. As shown in FIG. Falling off. This dropped resist liquid R flows between the communication path 13a, the cup 10, and the guide part 2 in the above-mentioned downdraft, and is temporarily stored in the above-mentioned liquid receiving part 14. And is discharged from the waste water passage 15 to the outside of the cup 10. Then, the coating nozzle 42 which has finished the application of the resist liquid R is evacuated to the standby position. After maintaining the rotation speed 1500 (rpm), the rotation speed of the wafer W is dropped to 1190 (rpm) at time t4, and the resist liquid R on the surface of the wafer W is dried for 20 seconds to form a resist film. do.

Thereafter, the rotation speed of the wafer W is dropped to 1000 (rpm) at time t5, and the side rinse nozzle 43 is moved onto the circumferential edge of the wafer W, as shown in Fig. 5B. As described above, the solvent, which is a rinse liquid, is discharged from the nozzle 43 toward the peripheral edge of the surface of the wafer W, and the peripheral edge of the liquid film of the resist liquid is cut to a predetermined width, and the back rinse nozzle 40 is provided. The rinse liquid is supplied from the circumferential edge portion of the back surface of the wafer W to remove the resist liquid returned to the back surface side of the wafer W. Then, the wafer W is continuously rotated, the resist liquid is dried for 20 seconds, the rotation is stopped at time t6, and the wafer W is moved in the reverse order to that of the wafer W described above. It is exchanged with the conveyance mechanism and taken out from the box 30.

On the other hand, the control part 7 reads out the data corresponding to the opening degree of the shutter 6 and the damper 17 corresponding to the rotation speed of the wafer W from the memory | storage part 73, and based on this data, the shutter 6 And control signals are output to the driving units 62 and 76 of the damper 17, respectively. Thereby, the opening degree of the shutter 6 and the damper 17 is controlled according to the rotation speed of the wafer W. As shown in FIG. On the other hand, since the control part 7 reads the time chart of the rotation speed from the memory | storage part 73 according to a recipe when controlling the rotation speed of the wafer W, the memory | storage part 73 is based on this read rotation speed. Although the data corresponding to the opening degree of the shutter 6 and the damper 17 may be read from, the detection part which detects the rotation speed of the spin chuck 11 is provided, and based on the detection value of the rotation speed from this detection part, Data corresponding to the opening degree may be read out.

An example of the operation of the shutter 6 and damper 17 is shown in Figs. 4B and 4C, respectively. From the time t1 to t2, since the rotation speed is as high as 2000 (rpm), the gas near the wafer W falls out by the centrifugal force by rotation, and the degree of negative pressure in the rear space 23 is large. Therefore, in response to this, the shutter 6 is largely opened, for example, so that the slit width of the opening 25 is set to 4 mm, so that the amount of gas sucked into the decompressed rear space 23 increases. For this reason, in the atmosphere of the rear space 23, the degree of negative pressure is relaxed by the gas which flowed in. In addition, the damper 17 is opened large so as to suck the airflow dropped outward by the rotation of the wafer W and the above-mentioned downdraft, and is adjusted to, for example, 90% of the opening degree.

Since the rotation of the wafer W is stopped from time t2 to t3, the atmosphere of the rear space 23 is atmospheric pressure, the shutter 6 is closed, and the damper 17 is, for example, opened at 50%. It is open. Next, since the rotation speed of the wafer W is 1500 (rpm) from the time t3 to t4, the atmosphere of the rear space 23 becomes negative pressure, for example, the slit width is 3 mm and the opening degree of the damper 17 is 75 degrees. Since the rotation speed of the wafer W is 1190 (rpm) from time t4 to t5 similarly, the said slit width is 2.4 mm and the opening degree of the damper 17 is adjusted to 67%, for example. In addition, since the rotation speed of the wafer W is 1000 (rpm) from time t5 to t6, for example, the slit width is 2.0 mm and the opening degree of the damper 17 is adjusted to 58%. Since the wafer W is carried out from the cup 10 afterwards, while closing the shutter 6, the opening degree of the damper 17 is controlled to 50%, and the downward airflow inside the cup 10 is sucked.

Next, the flow of the gas inside the cup 10 is demonstrated using FIG. FIG. 6A is a diagram illustrating a state in which the shutter 6 is half open. In this case, the rotation speed of the wafer W is 1000 (rpm) from the time chart of FIG. 4, the slit width is 2 mm and the opening degree of the damper 17 is 58%. The gas (air) D lowered in the cup 10 expands outward while swirling by the rotation of the wafer W. As shown in FIG. In addition, the gas (air) G present in the rear space 23 is pushed out by the rotation of the wafer W and flows downward to the bottom of the cup 10 together with the gas D constituting the downdraft. It is discharged from 16a. For this reason, although the atmosphere of the rear space 23 tries to become a negative pressure, the quantity of gas U suitable for the quantity which the gas G discharge | emits from the rear space 23 disengages the opening ( Flowing into the space 23 through 25, the negative pressure is relaxed.

6B is a view showing a state in which the shutter 6 is deployed. At this time, the rotation speed of the wafer W is 2000 (rpm) from the time chart of FIG. 4, the slit width is 4 mm and the opening degree of the damper 17 is 90%. Since the gas D has a high rotational speed of the wafer W, it expands outward with a strong vortex than the case described above, and the gas G present in the rear space 23 is more outward than the previous case. It is pushed out and flows below the cup 10 with the gas D, and is discharged | emitted from the exhaust pipe 16a. And since the discharge | emission of the gas G of the rear space 23 is large compared with the time of rotation speed 1000 (rpm), the atmosphere of the said space 23 is large and tries to become negative pressure, but since the said slit width is large open to 4 mm. The gas U in an amount corresponding to the amount of the gas G discharged from the rear space 23 flows from the opening 25 into the space 23, so that the negative pressure state is alleviated. At this time, although the total amount of the gas U flowing into the cup 10 becomes larger than the former case, the rotational speed of the wafer W is 1000 (rpm) for the opening degree of the damper 17 in the exhaust passages 16a and b. ), The amount of gas drawn from the periphery of the wafer W into the exhaust paths 16a and b is substantially the same, and therefore the state of the airflow on the surface of the wafer W is the same. On the other hand, the numerical value of the opening degree of the damper 17 is a numerical value for convenience, and it is drawn into exhaust path 16a, b regardless of the rotation speed of the wafer W "regardless of the magnitude | size of the slit width of the opening part 25". Is set such that an amount of gas is provided.

7 is a figure which shows the airflow inside the cup 10 in the case where the opening degree of the damper 17 is fixed to 90% without interlocking the opening and closing of the shutter 6 and the damper 17. As shown in FIG. In this case, for example, when the rotation speed of the wafer W is high and the opening degree of the shutter 6 is large, the gas G of the rear space 23 dropped to the outside by the rotation of the wafer W is released. The gas G and the gas D are attracted from the exhaust pipe 16a in a large amount. This is the same case as in the case of Fig. 6 (b). However, when the rotation speed of the wafer W is low and the opening degree of the shutter 6 is small, the amount of the gas G in the rear space 23 dropped outward by the rotation of the wafer W is the wafer W. Is smaller than the case where the number of revolutions is high, and this gas (G) and gas (D) are sucked from the exhaust pipe 16a. Therefore, in this case, the effect of suction acts excessively on the gas D. As a result, the airflow in the vicinity of the surface of the wafer W is disturbed, which may affect the in-plane profile of the film thickness of the resist film.

According to the embodiment of the present invention described above, the opening and closing of the shutter 6 is controlled based on the rotational speed of the wafer W, and the space behind the wafer W is decompressed so that the space is reduced. The amount of gas flowing into (23) can be adjusted. Therefore, the airflow toward the space 23 from the circumferential edge of the wafer W is suppressed or the airflow does not occur, so the amount of particles adhering to the wafer W can be reduced. It is possible to reduce the amount of rinse used. In addition, by controlling the opening and closing of the shutter 6 and the damper 17 in conjunction with each other, the change in the airflow on the surface of the wafer W according to the size of the opening degree of the shutter 6 is suppressed, so that the airflow in the process Is stabilized, and as a result, the influence of the profile of the film thickness of the resist film by changing the opening degree of the opening portion 25 by the shutter 6 is small, and stable processing can be performed. On the other hand, it is sufficient to adjust the damper 17 only in the process related to the film thickness profile, and therefore, it is not necessary to adjust the prewet to the wafer W.

Moreover, the shutter 6 can also take the structure which adjusts the opening amount of the opening part 25 by moving up and down. In this case, as shown in FIG. 8A, the shutter 6 has a lift unit 64 instead of the drive unit 62, and the support rod 61 is inserted into the lift unit 64. Is taking. The lifting unit 64 can move the shutter 6 up and down by raising and lowering the inserted support rod 61. This moving state is schematically shown in Fig. 8B.

1 is a longitudinal sectional view showing a coating device according to an embodiment of the present invention.

2 is a perspective view schematically showing an opening formed in a horizontal plane and a shutter for adjusting the opening amount thereof.

3 is a diagram illustrating a control unit.

4 is a diagram showing an example of time charts of the rotation speed, the opening amount, and the exhaust amount of the wafer in the embodiment of the present invention.

FIG. 5 is an explanatory diagram schematically showing the application of the resist liquid to the wafer and the supply of side rinse. FIG.

It is explanatory drawing which shows typically the flow of airflow inside a cup.

FIG. 7 is an explanatory diagram schematically showing the flow of airflow inside the cup when the movement of the shutter and the damper are not linked.

8 is an explanatory diagram schematically showing another embodiment of the shutter.

9 shows a schematic cross-sectional view of a conventional coating apparatus.

<Description of the symbols for the main parts of the drawings>

W: Wafer

10: cup

11: spin chuck

12: rotary drive unit

16a, b: exhaust pipe

17: damper

2: guide part

23: rear space

25: opening

34 gas supply unit

42: coating nozzle

6: shutter

7: control unit

R: resist liquid

Claims (7)

A cup placed in an atmosphere in which the downdraft is formed, and an exhaust path connected to a lower portion of the cup to suck and exhaust the atmosphere in the cup, the substrate being held horizontally in a substrate holding portion surrounded by the cup, A coating apparatus for supplying a coating liquid to a central portion of the apparatus, and spreading the coating liquid on the surface of the substrate by rotating the substrate around the vertical axis with the substrate holding portion interposed therebetween. In order to prevent the liquid from splashing back to the back side of the substrate, it is provided close to the edge portion of the back side of the substrate, and is prevented from being splashed and formed in an annular shape in the circumferential direction of the substrate so as to protrude toward the back side of the substrate. Wealth, A partition portion continuous from the splash prevention portion near the center of the substrate and defining a space partitioned with respect to the outer space below the cup on the back side of the substrate; An opening formed in the compartment and communicating between the space on the back side of the substrate surrounded by the compartment and the outer space below the cup; An opening amount adjusting means for adjusting the opening amount of the opening portion, An exhaust amount adjusting means provided in the exhaust path, for adjusting an exhaust amount of the exhaust path; And a control unit for controlling the opening amount adjusting means and the exhaust amount adjusting means in accordance with the rotational speed of the substrate. The said control part is a memory | storage part which stored the data corresponding to the opening amount of the said opening part for every rotation speed of a board | substrate, and the data corresponding to the displacement amount, and the data according to the rotation speed of a board | substrate from this memory | storage part. And a means for reading out and outputting respective control signals of the aperture adjustment means and the displacement adjustment means. The said control part is a memory | storage part which memorize | stored each time series data of the data corresponding to the opening amount of the said opening part, and the data corresponding to the displacement amount for every application | coating recipe, and the data read from this memory | storage part. And a means for outputting respective control signals of the aperture amount adjusting means and the displacement amount adjusting means. It is provided so as to face the edge of the substrate holding portion surrounded by the cup and close to the edge portion of the substrate in order to suppress the splashing of the liquid back to the rear surface side of the substrate held by the substrate holding portion, and to protrude toward the rear surface side of the substrate. A bouncing-back portion which is formed in an annular shape in the circumferential direction of the substrate, and continuous from the bouncing-back portion to near the center of the substrate, and forming a space partitioned with respect to the outer space below the cup on the back side of the substrate; A partition portion, an opening formed in the partition portion to connect the space on the rear surface side of the substrate surrounded by the partition portion with the outer space below the cup, and an exhaust passage connected to the lower portion of the cup to suck in the atmosphere inside the cup. Using one applicator, Forming a downdraft in the atmosphere in which the cup is placed; Holding the substrate horizontally in the substrate holding portion; Supplying the coating liquid to the center of the substrate, and rotating the substrate around the vertical axis with the substrate holding portion interposed therebetween to spread the coating liquid onto the surface of the substrate; And a step of controlling the opening amount of the opening portion and the exhaust amount by the exhaust amount adjusting means provided in the exhaust passage in accordance with the rotational speed of the substrate. The data corresponding to the opening amount according to the rotational speed of the substrate and the data according to claim 4, wherein the data corresponding to the opening amount of the opening and the data corresponding to the displacement amount are stored for each rotational speed of the substrate. A process of reading data corresponding to the displacement from a storage unit by a computer; And a step of controlling the opening amount and the exhaust amount based on the read data. The method of claim 4, further comprising: reading out the time series data by a computer from a storage unit storing respective time series data of data corresponding to the opening amount of the opening portion and data corresponding to the displacement amount for each coating recipe; And a step of controlling the opening amount and the exhaust amount based on the read time series data. A storage medium for storing a computer program used in a coating apparatus for applying a coating liquid to a rotating substrate, The computer program comprises a group of steps for carrying out the coating method according to any one of claims 4 to 6.

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