JP3527459B2 - Coating film forming method and coating processing apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device (L
The present invention relates to a coating film forming method and a coating processing apparatus for coating a surface of a (CD) substrate or a semiconductor substrate with a coating liquid such as a resist liquid.

[0002]

2. Description of the Related Art In manufacturing a liquid crystal display (LCD), a rectangular LCD substrate made of glass is coated with a photoresist solution to form a resist film, and the resist film is exposed in accordance with a circuit pattern. To develop
A circuit pattern is formed by a so-called photolithography technique. Conventionally, a resist coating and developing treatment system including a plurality of treatment units for carrying out such a series of steps has been used.

In such a resist coating and developing system, a rectangular LC is used in the step of coating the resist solution.
The D substrate (hereinafter referred to as the substrate) is subjected to a hydrophobic treatment (HMDS treatment) in the adhesion treatment unit to improve the fixability of the resist, cooled in the cooling unit, and then carried into the resist coating unit.

In the resist coating processing unit, while the substrate is rotated while being held on the spin chuck, a resist liquid is supplied to the surface of the substrate from a nozzle provided above the spin chuck, and the resist is rotated by centrifugal force due to the rotation of the substrate. The liquid is diffused, whereby a resist film is formed on the entire surface of the substrate.

The substrate coated with the resist solution is transferred to a heat treatment unit where prebaking is performed after the excess resist on the peripheral edge is removed by an end face treatment unit (edge remover), and cooled by a cooling unit. ,
The film is conveyed to an exposure device where a predetermined pattern is exposed, and then developed and post-baked to form a predetermined resist pattern.

[0006]

By the way, recently,
With the miniaturization of patterns, it is necessary to make the resist film thickness more uniform, and from the viewpoint of manufacturing cost reduction, etc.
It is desired to reduce the resist consumption amount, that is, to reduce the discharge amount of the resist liquid onto each substrate.

As one of the methods for reducing the resist consumption (resist saving), a so-called dynamic coating method, in which the resist solution is discharged while rotating the substrate, is being studied, and although a certain effect has been confirmed, It is desired to reduce the number of resists. Further, in such a dynamic coating method, the film thickness uniformity of the coating film is not always sufficient under the present circumstances.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a coating film forming method and a coating treatment apparatus capable of further reducing the supply amount of the coating liquid in the dynamic coating method. . In addition, the amount of coating liquid can be reduced in this way,
An object of the present invention is to provide a coating film forming method and a coating treatment apparatus capable of making the coating film thickness uniform.

[0009]

In order to solve the above problems, the present invention is a method for forming a coating film by supplying a coating liquid onto the surface of a substrate contained in a processing container to form a coating film. And a coating liquid discharging step of discharging the coating liquid onto the substrate, and a rotating step of rotating the substrate to spread the coating liquid on the substrate, wherein the coating liquid discharging step and the rotating step are performed at substantially the same time. Provided is a coating film forming method characterized in that a coating liquid discharging speed is reduced after a predetermined time has elapsed from the start of coating liquid discharging in a coating liquid discharging step.

Further, the present invention is a coating film forming method for forming a coating film by supplying a coating liquid onto the surface of a substrate housed in a processing container, wherein the coating liquid is discharged onto the substrate. And a rotating step of rotating the substrate to spread the coating liquid on the substrate, wherein the coating liquid discharging step and the rotating step are performed substantially at the same time, and the coating liquid discharging step starts a predetermined time from the coating liquid discharging step. After the lapse of time, the coating liquid discharge speed is decreased, and the film thickness profile of the coating film is controlled by controlling the ratio of the discharge speed before and after the time when the coating liquid discharge speed is decreased and the time when the discharge speed is changed. A method for forming a coating film is provided.

Furthermore, the present invention is a coating processing apparatus for coating a coating liquid on the surface of a substrate, the processing container having an opening in the upper part and containing the substrate, and the substrate rotating in the processing container. Substrate rotating means for causing the coating liquid to be discharged onto the substrate, discharge driving means for discharging the coating liquid from the coating liquid discharging nozzle, discharge of the coating liquid by the discharging driving means, and substrate by the substrate rotating means Rotation is performed almost at the same time, and the control means controls the substrate rotating means and the discharge driving means so that the coating liquid discharge speed decreases after a lapse of a predetermined time from the start of coating liquid discharge. A coating treatment device is provided.

Furthermore, the present invention is a coating processing apparatus for coating a coating liquid on the surface of a substrate, the processing container having an opening in the upper part and containing the substrate, and the substrate in the processing container. The substrate rotating means for rotating, the coating liquid discharging nozzle for discharging the coating liquid onto the substrate, the discharging driving means for discharging the coating liquid from the coating liquid discharging nozzle, the discharging of the coating liquid by the discharging driving means and the substrate rotating means. The substrate rotation means and the discharge driving means are controlled so that the rotation of the substrate is performed almost at the same time, and the coating liquid discharge speed is decreased after a predetermined time has passed from the start of the coating liquid discharge, and the coating liquid discharge speed is decreased. There is provided a coating processing apparatus comprising: a control unit that controls a ratio of a discharging speed before and after a discharging speed is changed.

According to the present invention, on the premise of a so-called dynamic coating system in which the coating liquid discharging step and the rotating step are performed substantially at the same time, the coating liquid discharging speed is reduced after a predetermined time has elapsed from the start of the coating liquid discharging step in the coating liquid discharging step. . In this way, by lowering the discharge speed during the process, it is possible to reduce the amount of the coating liquid used to form a desired coating film on the substrate.

In addition to this, by controlling the ratio of the discharge speed before and after the time when the discharge speed of the coating liquid is lowered and the time when the discharge speed is changed, the amount of the coating liquid used can be reduced and the coating film can be reduced. The film thickness profile can be controlled, and by appropriately adjusting these, the film thickness can be made more uniform.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a plan view showing a resist coating / developing processing system for an LCD substrate equipped with a resist coating processing unit according to an embodiment of the coating processing apparatus of the present invention.

This coating / developing system includes a cassette station 1 for mounting a cassette C containing a plurality of substrates G, and a plurality of processing units for performing a series of processes including resist coating and development on the substrates G. The processing unit 2 is provided with an interface unit 3 for transferring the substrate G to and from an exposure apparatus (not shown). The cassette station 1 and the interface unit 3 are provided at both ends of the processing unit 2, respectively. It is arranged.

The cassette station 1 is equipped with a transfer mechanism 10 for transferring the LCD substrate G between the cassette C and the processing section 2. Then, the cassette C is carried in and out at the cassette station 1. Further, the transfer mechanism 10 includes a transfer arm 11 that can move on a transfer path 10 a provided along the arrangement direction of the cassettes, and the transfer arm 11 transfers the substrate G between the cassette C and the processing section 2. Done.

The processing section 2 is divided into a front section 2a, a middle section 2b and a rear section 2c, and the transport path 1 is located at the center of each section.
2, 13, and 14, and the processing units are arranged on both sides of these conveyance paths. Further, relay units 15 and 16 are provided between them.

The front stage portion 2a is provided with a main carrier unit 17 which is movable along the carrier path 12, and two cleaning units (SCR) 21a and 21b are arranged on one side of the carrier path 12. A processing block 25 in which an ultraviolet irradiation unit (UV) and a cooling unit (COL) are stacked in two stages on the other side of the transport path 12, a heating processing unit (HP)
A processing block 26 having two layers stacked therein and a processing block 27 having a cooling unit (COL) stacked two layers are arranged.

The middle section 2b is provided with a main transfer device 18 which is movable along the transfer path 13. On one side of the transfer path 13, the resist coating unit (CT) 22 and the peripheral edge of the substrate G are provided. A peripheral edge resist removal unit (ER) 23 that removes the resist in a certain portion is integrally provided,
On the other side of the transport path 13, a processing block 28 in which heat treatment units (HP) are stacked in two stages, and a processing block 29 in which a heat treatment unit (HP) and a cooling treatment unit (COL) are stacked vertically. , And a processing block 30 in which an adhesion processing unit (AD) and a cooling unit (COL) are vertically stacked.

Further, the rear stage portion 2c is provided with a main transfer device 19 which can move along the transfer path 14,
On one side, three development processing units (DEV) 24
a, 24b, and 24c are arranged, and the heat treatment unit (HP) is superposed in two stages on the other side of the transport path 14, and both the heat treatment unit (HP) and the cooling treatment unit (HP). COL) are vertically stacked and processing blocks 32 and 33 are arranged.

As described above, the processing section 2 has only the spinner system units such as the cleaning processing unit 21a, the resist coating processing unit 22 and the developing processing unit 24a arranged on one side across the transport path. It has a structure in which only a thermal processing unit such as a heating processing unit or a cooling processing unit is arranged on the other side.

Further, a chemical liquid supply unit 34 is arranged at the portion of the relay portions 15 and 16 on the side where the spinner system unit is arranged, and further a space 35 for maintaining the main carrier is provided.

The main transfer devices 17, 18 and 19 are respectively provided with a two-direction X-axis drive mechanism, a Y-axis drive mechanism in a horizontal plane,
And a vertical Z-axis drive mechanism.
It has a rotary drive mechanism that rotates about an axis, and has arms 17a, 18a, and 19a that support the substrate G, respectively.

The main transfer device 17 transfers the substrate G to and from the arm 11 of the transfer mechanism 10, transfers the substrate G into and out of each processing unit of the pre-stage portion 2a, and further transfers the substrate G to and from the relay part 15. It has a function of transferring the substrate G between them. In addition, the main carrier 18 is the relay unit 1
The substrate G is transferred to and from the intermediate stage 2
The substrate G has a function of loading / unloading the substrate G to / from each processing unit, and further transferring the substrate G to / from the relay unit 16. Further, the main transfer device 19 transfers the substrate G to and from the relay unit 16, transfers the substrate G to and from each processing unit of the rear stage 2c, and transfers the substrate G to and from the interface unit 3. Has the function of performing. The relay portions 15 and 16 also function as cooling plates.

The interface section 3 has an extension 36 for temporarily holding the substrate when transferring the substrate to and from the processing section 2, and two buffer stages 37 provided on both sides of the extension 36 for arranging a buffer cassette. And the substrate G between these and the exposure apparatus (not shown)
And a transport mechanism 38 for loading and unloading the same. The transport mechanism 38 includes the extension 36 and the buffer stage 3.
A transfer arm 39 that is movable along a transfer path 38a provided along the arrangement direction of 7 is provided, and the transfer arm 39 transfers the substrate G between the processing unit 2 and the exposure apparatus.

By thus integrating and integrating the processing units, it is possible to save space and improve processing efficiency.

In the resist coating / development processing system thus constructed, the substrate G in the cassette C is transported to the processing section 2, and the processing section 2 first irradiates the processing block 25 of the pre-stage section 2a with ultraviolet rays. Surface modification / cleaning processing is performed in the unit (UV), and cooling processing unit (COL)
After being cooled by the cleaning unit (SCR) 21a, 21
After scrubber cleaning in b and heat drying in any of the heat treatment units (HP) of the treatment block 26,
One of the cooling units (COL) of the processing block 27
Is cooled by.

After that, the substrate G is transferred to the middle stage 2b,
In order to improve the fixability of the resist, a hydrophobic treatment (HMDS treatment) is performed in the adhesion processing unit (AD) in the upper stage of the processing block 30 and after cooling in the cooling treatment unit (COL) in the lower stage, the resist coating treatment unit (C).
The resist is applied at (T) 22 and the excess resist at the peripheral edge of the substrate G is removed at the peripheral edge resist removing unit (ER) 23. After that, the substrate G is pre-baked in one of the heat treatment units (HP) in the middle section 2b, and the lower cooling unit (CO in the treatment block 29 or 30).
It is cooled in L).

After that, the substrate G is transferred from the relay section 16 to the exposure apparatus via the interface section 3 by the main transfer apparatus 19 and a predetermined pattern is exposed there. And
The board G is carried in again via the interface unit 3,
If necessary, the processing blocks 31, 32, 3 of the latter part 2c
After performing the post-exposure bake processing in any one of the heat treatment units (HP) of No. 3, the development processing is performed in any of the development processing units (DEV) 24a, 24b, 24c, and a predetermined circuit pattern is formed. The developed substrate G is post-baked by one of the heat treatment units (HP) of the rear stage 2c and then cooled by one of the cooling units (COL), and the main transfer device 19, It is accommodated in a predetermined cassette on the cassette station 1 by 18, 17 and the transport mechanism 10.

Next, the resist coating processing unit (CT) 22 according to one embodiment of the present invention will be described. Figure 2
FIG. 3 is a schematic sectional view of a resist coating processing unit according to an embodiment of the present invention.

As shown in FIG. 2, the resist coating unit (CT) 22 includes a driving device 4 which is a substrate rotating means.
A spin chuck 41 rotated by 0 is provided, and the LCD substrate G is mounted on the spin chuck 41 with its surface horizontal by suction. Also,
A container for housing a substrate, for example, this spin chuck 41
A rotating cup (processing container) having a bottomed cylindrical shape that is rotated together with the spin chuck 41 and surrounds the substrate G from below.
42 are provided. The rotary cup 42 is also rotated by the drive device 40. Drive device 40
Is the stepping motor 40a and the stepping motor 4
The belts 40b and 40c for transmitting the rotation of 0a, the spin chuck 41, and the transmission mechanism 40d for rotating the rotary cup 42 are provided.

On the outer peripheral side of the rotary cup 42, there is arranged a hollow ring-shaped outer cup 43 which covers the outer peripheral side and the lower side of the rotary cup 42, and the drain cup 4 is provided on the outer side thereof.
4 are arranged. The drain cup 44 can guide the resist solution scattered during the resist application downward.

An annular lid 45 having an opening 46 at the center is mounted on the upper opening of the rotary cup 42 by a mounting arm (not shown). The annular lid 45 is adapted to rotate together with the rotary cup 42 when the rotary cup 42 is rotated together with the substrate G. At the opening 46 of the lid 45, a cylindrical tubular member 47 is provided upright to prevent the resist liquid from scattering when the resist liquid is discharged.

An outer lid 60 is mounted above the rotary cup 42 by a mounting arm (not shown), and a support column 50 and a support column 54 are erected on the outer lid. ..

From the support column 50, the arm 4 having a spray head 49 for supplying the resist solution or the solvent to the substrate G is provided at the tip.
8 is extended. A resist liquid discharge nozzle 51 for discharging a resist liquid, which is a coating liquid, is provided on the spray head 49.
And a solvent discharge nozzle 52 for discharging a solvent such as a thinner are provided, which constitutes a multi-system nozzle unit. A resist solution supply pipe 71 is connected to the resist solution discharge nozzle 51, and the resist solution supply pipe 71 is inserted into a resist solution tank 75. The resist solution supply pipe 71 is provided with a suck back valve 72, an air operation valve 73, and a motor pump (discharging drive means) 74. The motor pump 74 provides a discharge driving force for the resist liquid, and the discharge speed of the resist liquid can be adjusted. Further, the pipe 71 is opened and closed by the air operation valve 73 to supply / stop the resist liquid, and the suck back valve 72 sucks the resist liquid so as not to drip after the resist liquid is stopped. On the other hand, the solvent discharge nozzle 5
A solvent supply pipe 76 is connected to 2 and a solvent is discharged from a solvent tank (not shown) from the solvent discharge nozzle 52 via the solvent supply pipe 76.

Further, the arm 48 is constructed so as to be swingable and movable up and down by a mechanism (not shown) in the support column 50, and at the time of discharging the resist liquid or the solvent, as shown in FIG. 51 and the solvent discharge nozzle 52 are located above the substrate G and above the opening 46 of the annular lid 45. On the other hand, after discharging the resist liquid or the like, it is moved to the retracted position.

This resist coating unit (CT) 2
2 is provided with a controller 80 which controls this unit. The controller 80 is a suck back valve 7 provided in the resist liquid supply pipe 71.
2. A resist coating unit (CT) such as controlling the air operation valve 73 and the motor pump 75 to control the stepping motor 40a for rotating the spin chuck 41 and the rotary cup 42, and also controlling the arms 48 and 55. All 22 drive systems are controlled.

A small lid 53 is provided in the opening 46 of the annular lid 45.
Is configured to be mounted. This small lid 53
A transfer arm 5 provided so as to extend from the support column 54.
5 is to be transported. The transfer arm 55 is configured to be movable up and down by a mechanism (not shown) in the support column 54, and has a locking claw 57 for locking the locking portion 56 of the small lid 53 at the tip thereof. There is. Then, the transfer arm 55 suspends the small lid 53 and opens the opening 4 as shown in FIG.
A small lid 53 is attached to the unit 6. The small lid 53 is provided with an appropriate sealing mechanism (not shown) so that it can be sealed.

Further, a plurality of air outflow holes 58 are provided on the circumference at the outer peripheral side portion of the bottom of the rotary cup 42, and the outer peripheral side portion of the annular lid 45 is provided on the outer peripheral side portion. A plurality of air inflow holes 59 are provided. By rotating the rotary cup 42, a centrifugal force acts on the air inside the rotary cup 42, and as shown by the arrow in FIG. An airflow is formed such that air is introduced from the outside through the inflow hole 59 of the. That is, this air inflow hole 5
9 and the outflow hole 58 also function as an air flow forming means. The airflow can be adjusted by changing the sizes of the outflow hole 58 and the inflow hole 59.

Next, the operation of forming a resist film on the surface of the substrate G by the resist coating processing unit (COT) having the above structure will be described. FIG. 3 is a flow chart for explaining such a coating process operation, and FIG.
3 is a graph showing the relationship between the rotation speed of the LCD substrate and the processing time.

First, the annular lid 45 is removed from the rotary cup 42 by a transfer arm (not shown), and the substrate G is transferred onto the spin chuck 41 by a transfer arm (not shown) and vacuum-adsorbed (ST1).

An annular lid 45 is attached to the upper opening of the rotary cup 42 by a transfer arm (not shown) (ST2),
Next, the resist solution discharge nozzle 51 and the solvent discharge nozzle 52 are located above the substrate G and above the opening 46 of the annular lid 45, and before the rotation of the substrate G is started, the solvent discharge nozzle 52 and the thinner are discharged. The solvent such as an annular lid 45
Is discharged onto the substrate G through the opening 46 (ST3). Next, the resist solution is ejected from the resist solution ejection nozzle 51 to the substrate G through the opening 46 of the lid 45 at the first ejection speed (ST4), and the rotation of the substrate G and the rotary cup 42 is started almost at the same time (ST5). ). The rotation of the substrate at this time is, as shown in FIG.
pm, hold at 1500 rpm for a predetermined time, and then decelerate.

Next, while the substrate G is being rotated in this way, the motor pump 74 is controlled to reduce the discharge speed of the resist liquid to the second discharge speed lower than the first discharge speed (ST6). By rotating the substrate G while discharging the resist liquid in this manner, the resist liquid is diffused on the substrate G, and a substrate G resist film (coating film) is formed.

Thus, the so-called dynamic coating for discharging the resist liquid while rotating the substrate G and the pre-wetting treatment of the substrate with a solvent such as thinner can form a resist film with a smaller amount of resist used, thus saving resist. However, in addition to this, by further reducing the discharge speed during the rotation of the substrate G as in ST6 described above, a further resist saving effect can be obtained.

After forming the resist film in this way,
Discharge of resist solution and substrate G and rotating cup 42
Is stopped (ST7), and the small lid 5 is moved by the transfer arm 55.
3 is conveyed and attached to the opening 46 of the annular lid 45 (ST8). Thereafter, as shown in FIG. 4, the substrate G and the rotating cup 42 are rotated again, and the rotation speed is 1340 rp.
The film is held at m for a predetermined time, and the thickness of the resist film is adjusted (ST9). When adjusting the thickness of the resist film in this way,
Since the small lid 53 is attached to the opening 46 of the annular lid 45, it is possible to reliably prevent the resist solution from splashing to the outside. Further, air can be prevented from entering through the openings 46, an air flow that adversely affects processing is not generated around the substrate, and the film thickness of the resist film is prevented from becoming nonuniform.

Then, the substrate G and the rotary cup 42 are stopped (ST10), the outer lid 60 and the lid 45 are removed (ST11), and the substrate G is unloaded (ST12).

Next, the discharge speed of the resist solution during the dynamic coating will be described in detail. FIG. 5 is a diagram showing the relationship between the rotation speed of the substrate and the discharge speed of the resist solution during dynamic coating. Here, the first ejection speed is R1 and the second ejection speed is R2, and the ejection speed is reduced at T1 after the start of ejection. By lowering the discharge speed while rotating the substrate in this way,
As described above, the coating film can be formed with a smaller amount of resist, and a large resist-saving effect can be obtained. At this time, by controlling the values of T1 and R1 / R2, the resist solution In addition to reducing the amount used, the film thickness profile of the resist film can be controlled, and by appropriately adjusting these, the film thickness can be made more uniform. Specifically, when T1 is increased, the film thickness in the portion between the central portion and the peripheral portion becomes smaller, and accordingly, the film thickness in the peripheral portion also tends to become smaller, while R1 / R2 is As the thickness increases, the thickness of the portion between the central portion and the peripheral portion increases, and the thickness of the peripheral portion tends to increase due to the increase in the thickness. Therefore, it is possible to surely make the film thickness uniform by grasping the film thickness profile and controlling the motor pump 74 by the controller 80 so that the profile becomes uniform and setting T1 and R1 / R2 to appropriate values. The preferable range of the ratio of the discharge time up to T1 to the total discharge time is 0.4 to 0.6, particularly preferably 0.47 to 0.56.
The preferable range of the value of R1 / R2 is 1.5 to 9, and the film thickness of the resist film can be made more uniform in these ranges.

The steady rotation speed of the substrate G (here, 1500
The film thickness profile can also be controlled by controlling the time Tc of (rpm), which contributes to uniformization of the film thickness. Specifically, increasing the Tc time tends to increase the film thickness of the portion between the central portion and the peripheral portion.

Further, as described above, the discharge of the resist solution and the rotation of the substrate G are almost at the same time, but the discharge of the resist solution is slightly advanced, and the time from the discharge of the resist solution to the rotation of the substrate G is started. (Timing of starting discharge of resist solution) Ts is preferably 0.2 sec or more. T
If s is less than 0.2 sec, a good coating film may not be formed. It is preferable that the end of discharge of the resist solution and the end of rotation of the substrate G be substantially the same, and specifically, the difference between these times (resist discharge end timing) Te
Of -0.2 to 0.2 sec is preferable because it has almost no effect on the film thickness profile.

Next, description will be made on the results of grasping the film thickness uniformity by performing resist coating while changing the resist discharge speed condition or the substrate rotation condition variously. Here, as described above, after performing pre-wetting with thinner, the resist solution was discharged onto the substrate G and the substrate G was rotated to perform dynamic coating. The total discharge time was 3.4 sec.

First, in the first experiment, the total amount of resist solution was set to 1 × 10 ⁻² L (10 cc) and R2 was set to 1.
The discharge speed switching time point T1 was changed while fixing the discharge speed to 2 × 10 ⁻³ L / s. The conditions in that case are shown in Table 1. In addition,
In Table 1, T2 is a total discharge time of 3.4 sec.
Is a value obtained by subtracting T1 from.

[0053]

[Table 1]

After forming the resist film under each condition of Table 1,
The film thickness was measured using a non-contact type film thickness measuring device. As shown in FIG. 6, the film thickness was measured at 51 points on a diagonal line of the sample substrate, excluding the periphery of 10 mm. The result is shown in FIG. 7.

As shown in FIG. 7, as the timing of T1 is delayed, the thickness of the shoulder portion between the central portion and the peripheral portion decreases, and the thickness of the peripheral portion tends to decrease accordingly. T1 that satisfies the preferable range of the ratio of the ejection time up to T1 to the entire ejection time is 0.4 to 0.6.
= 1.4 to 2.0 sec. 4 to 10 showed good film thickness uniformity, but among them, T1 = 1.6 to 1.9se in which the ratio satisfies 0.47 to 0.56.
No. c. 6-9 are good, and as shown in FIG.
No. 1 = 1.8 sec. In No. 8, particularly good film thickness uniformity was obtained.

In the second experiment, the total amount of resist solution was 1
The discharge speed switching timing T was fixed at 1.8 sec, and R1 / R2 was changed at × 10 ⁻² L (10 cc). The conditions at that time are shown in Table 2.

[0057]

[Table 2]

As in the first experiment, the film thickness was measured at 51 points on one diagonal line of the sample substrate except for the periphery 10 mm. The result is shown in FIG. As shown in FIG. 9, as the value of R1 / R2 increases, the film thickness of the shoulder portion between the central portion and the peripheral portion tends to increase, and R1
/ R2 satisfies 1.5 to 9 Sample No. 14, 15
Good film thickness uniformity was obtained in No. 4, among which No. 1
No. 5 showed particularly good film thickness uniformity.

In the third experiment, the total amount of resist solution was set to 1
× 10 ⁻² L (10 cc), T1 is fixed to 1.8 sec, and the time Tc at the steady rotation speed is 0.2 sec, 0.
It was changed to 4 seconds and 0.6 seconds. Therefore, T
The total ejection time was increased by the increase in c. The conditions in that case are shown in Table 3. Note that T2 in Table 3 is the time obtained by subtracting T1 from the total ejection time.

[0060]

[Table 3]

As in the first experiment, the film thickness was measured at 51 points on one diagonal line of the sample substrate except for the periphery 10 mm. The result is shown in FIG. As shown in FIG. 10, it was confirmed that when Tc was lengthened, the film thickness of the shoulder portion between the central portion and the peripheral portion tended to increase.

In the fourth experiment, the discharge start timing of the resist solution was changed. Specifically, the value of the discharge start timing Ts shown in FIG. 5 was changed in the range of 0 to 0.5 sec. The conditions in that case are shown in Table 4. The value of Ts indicates the time before the start of substrate rotation.

[0063]

[Table 4]

Similar to the first experiment, the film thickness was measured at 51 points on the one-sided diagonal line of the sample substrate except the periphery 10 mm. The result is shown in FIG. As shown in FIG. 11, the coating start timing has almost no effect on the film thickness profile. However, when the coating state was confirmed, sample No. with Ts of less than 0.2 sec. Two
It was confirmed that the coating state of Nos. 2 and 23 was poor over the entire surface.

In the fifth experiment, the discharge end timing of the resist solution was changed. Specifically, the value of the discharge end timing Te shown in FIG. 5 was changed in the range of −0.2 to 0.4 sec. The conditions at that time are shown in Table 5. The value of Te indicates the time before the rotation of the substrate is stopped. Therefore, -0.2
sec means 0.2 seconds after the rotation is stopped.

[0066]

[Table 5]

Similar to the first experiment, the film thickness was measured at 51 points on one diagonal line of the sample substrate except the periphery 10 mm. The result is shown in FIG. As shown in FIG. 12, the application end timing Te is -0.2 to 0.2.
It can be seen that if sec, it has almost no effect on the film thickness profile.

The present invention is not limited to the above embodiment, and various modifications can be made. For example, although the case where the present invention is applied to the resist coating / developing system has been described in the above embodiment, the present invention is not limited to this. Further, although the case where the resist solution is applied has been described, another application solution can be applied if the application film is formed by spin coating. Further, in the above embodiment, the case where the LCD substrate is used as the substrate to be processed has been described, but the present invention is not limited to this, and the invention can be applied to the formation of a coating film on another substrate such as a semiconductor wafer.

[0069]

As described above, according to the present invention,
Assuming a so-called dynamic coating method in which the coating liquid discharging step and the rotating step are performed almost at the same time, the coating liquid discharging speed is reduced after a predetermined time has elapsed from the start of the coating liquid discharging step in the coating liquid discharging step. It is possible to reduce the amount of the coating liquid used for forming the film.

In addition to this, by controlling the ratio of the discharge speed before and after changing the discharge speed of the coating liquid and the time at which the discharge speed is changed, the amount of the coating liquid used can be reduced and the coating film can be used. The film thickness profile can be controlled, and by appropriately adjusting these, the film thickness can be made more uniform.

[Brief description of drawings]

FIG. 1 is a plan view showing a resist coating / developing processing system for an LCD substrate equipped with a resist coating processing unit according to an embodiment of a coating processing apparatus of the present invention.

FIG. 2 is a sectional view showing a resist coating processing unit according to an embodiment of the present invention, which is mounted on the resist coating and developing system.

FIG. 3 is a flowchart for explaining an operation when forming a resist film on the surface of a substrate G by a resist coating processing unit.

FIG. 4 is a graph showing the relationship between the rotation speed of the LCD substrate and the processing time.

FIG. 5 is a graph showing the rotation speed of the LCD substrate and the discharge speed of the resist liquid during dynamic coating.

FIG. 6 is a schematic diagram showing measurement points when measuring the film thickness of a resist film.

FIG. 7 is a diagram showing a first example in which a discharge timing switching time point T1 is changed.
6 is a diagram showing the film thickness distribution of each sample in the experiment of FIG.

FIG. 8 is a diagram showing a first example in which a discharge speed switching time point T1 is changed.
6 is a diagram showing the film thickness distribution of each sample in the experiment of FIG.

FIG. 9 is a diagram showing a film thickness distribution of each sample in a second experiment in which R1 / R2 was changed.

FIG. 10 is a diagram showing a film thickness distribution in each sample in the third experiment in which the time Tc at the steady rotation speed was changed.

FIG. 11 is a diagram showing a film thickness distribution in each sample in the fourth experiment in which the ejection start timing Ts is changed.

FIG. 12 is a diagram showing a film thickness distribution in each sample in a fifth experiment in which the discharge end timing Te is changed.

[Explanation of symbols]

22 ... Resist coating processing unit (coating processing apparatus) 40 ... Driving device (substrate rotating means) 40a ... Stepping motor (substrate rotating means) 41 ... Spin chuck 42 ... Rotating cup (processing container) 45 ... An annular lid 46 ... Opening 51 ... Resist discharge nozzle (coating liquid discharge nozzle) 52 ... Solvent discharge nozzle 53 ... Small lid 74 ... Motor pump 80 ... Controller (control means) G ... LCD substrate

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI G03F 7/16 502 H01L 21/30 564D (72) Inventor Dr. Hashimoto Otsu-machi, Kumamoto-ken Oo-cho Takano-no 4 Tokyo 272 Electron Kyushu Co., Ltd. Otsu Works (56) Reference JP 2000-33320 (JP, A) JP 11-297589 (JP, A) JP 10-151407 (JP, A) JP 11-169773 (JP, A) JP-A-11-128815 (JP, A) JP-A-10-106918 (JP, A) JP-A-11-44957 (JP, A) (58) Fields investigated (Int.Cl. ⁷⁾ , DB name) H01L 21/027 B05C 11/08 B05C 11/10 B05D 1/40 B05D 3/00 G03F 7/16

Claims (10)

(57) [Claims] 1. A coating film forming method for forming a coating film by supplying a coating liquid onto the surface of a substrate housed in a processing container, comprising: a coating liquid discharging step of discharging the coating liquid onto the substrate; And a rotating step of spreading the coating liquid on the substrate by rotating the coating liquid, the coating liquid discharging step and the rotating step are performed substantially at the same time, and the coating liquid is discharged after a predetermined time has elapsed from the coating liquid discharging step in the coating liquid discharging step. A method for forming a coating film, which comprises reducing the discharge speed. 2. A coating film forming method for forming a coating film by supplying a coating liquid onto the surface of a substrate housed in a processing container, comprising: a coating liquid discharging step of discharging the coating liquid onto the substrate; And a rotating step of spreading the coating liquid on the substrate by rotating the coating liquid, the coating liquid discharging step and the rotating step are performed substantially at the same time, and the coating liquid is discharged after a predetermined time has elapsed from the coating liquid discharging step in the coating liquid discharging step. Forming a coating film characterized by controlling the film thickness profile of the coating film by decreasing the discharge speed and controlling the ratio of the discharge speed before and after changing the discharge speed and the time at which the discharge speed is changed. Method. 3. In the step of discharging the coating liquid, when the discharge speed before lowering the discharge speed of the coating liquid is R1 and the discharge speed after lowering is R2, the value of R1 / R2 is 1. It is the range of 5-9, The coating film forming method of Claim 1 or Claim 2 characterized by the above-mentioned. 4. The ratio of the time until the point at which the discharge speed of the coating liquid is reduced to the total discharge time is 0.4 to
It is 0.6, The coating film forming method of any one of Claim 1 to 3 characterized by the above-mentioned. 5. The substrate according to claim 1, wherein the substrate is rotated in the rotating step after 0.2 seconds or more has elapsed after the discharging of the coating solution in the coating solution discharging step is started. The method for forming a coating film according to item 1. 6. The time from the end of discharging the coating liquid in the coating liquid discharging step to the end of rotating the substrate in the rotating step is −0.2 to 2.0 seconds.
To the coating film forming method according to claim 5. 7. In the rotating step, the rotation speed is increased from the start of rotation to a predetermined value, the rotation speed is held for a certain period of time, then the rotation speed is decreased, and the holding time is changed to form a film of a coating film. The coating film forming method according to any one of claims 1 to 6, wherein the thickness profile is controlled. 8. The coating film forming method according to claim 1, wherein a step of discharging a solvent onto the substrate is performed prior to the step of discharging the coating liquid. 9. A coating processing apparatus for coating a coating liquid on the surface of a substrate, the processing container having an opening at the top and housing the substrate, and a substrate rotating means for rotating the substrate in the processing container. A coating liquid discharge nozzle for discharging the coating liquid onto the substrate; a discharge driving unit for discharging the coating liquid from the coating liquid discharge nozzle; a discharge of the coating liquid by the discharge driving unit and a rotation of the substrate by the substrate rotating unit; A coating process, which is performed at the same time, and includes a control unit that controls the substrate rotating unit and the discharge driving unit so that the coating liquid discharge speed decreases after a lapse of a predetermined time from the start of coating liquid discharge. apparatus. 10. A coating processing apparatus for coating a coating liquid on the surface of a substrate, the processing container having an opening at the top and containing the substrate, and a substrate rotating means for rotating the substrate in the processing container. A coating liquid discharge nozzle for discharging the coating liquid onto the substrate; a discharge driving unit for discharging the coating liquid from the coating liquid discharge nozzle; a discharge of the coating liquid by the discharge driving unit and a rotation of the substrate by the substrate rotating unit; Simultaneously, so that the coating liquid discharge speed decreases after a predetermined time has elapsed from the start of coating liquid discharge,
Control means for controlling the substrate rotating means and the ejection drive means, and for controlling the ratio of the ejection speed before and after the time when the coating liquid ejection speed is lowered and before and after the time when the ejection speed is changed are provided. And a coating treatment device.