JP2966231B2 - Resist thin film forming equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method of applying a resist solution to the surface of a substrate such as a semiconductor wafer or a glass square substrate for liquid crystal (hereinafter simply referred to as "substrate"), and then subjecting the substrate to a heat treatment. about the resist film forming equipment for forming a resist film on the substrate surface.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram showing a schematic configuration of a conventional resist thin film forming apparatus. As shown in FIG. 1, the resist thin film forming apparatus includes a resist coating unit 10 for coating a resist solution on the surface of a substrate, and a heating unit 20 for heating the substrate.

The resist coating unit 10 includes a resist coating unit 11 such as a spin coater or a roll coater, and an unloading mechanism 12 for unloading a substrate to a next processing station (heating unit 20). When the application of the resist liquid to the substrate surface (resist coating process) by the substrate 11 is completed, the substrate is carried out to the heating unit 20 side by the carry-out mechanism 12.

On the other hand, a loading mechanism 2 for loading a substrate from the resist coating unit 10 into the heating unit 20.
The substrate 1 is provided to carry the substrate from the resist coating unit 10 into the heating unit 20 in cooperation with the unloading mechanism 12 of the resist coating unit 10, and then to the proximity bake unit 22. The heating unit 20 is provided with a contact bake unit 23 in addition to the proximity bake unit 22. After being conveyed to the unit 23, a heating process (contact baking) is performed by the contact baking unit 23. The reason why the proximity bake is performed prior to the contact bake is that if the contact bake is immediately performed on the substrate coated with the resist solution at room temperature, the substrate is rapidly heated and warped, This is because the proximity baking prevents the substrate from warping and uniformly dry the resist solution.

[0005]

When a resist liquid is applied to the surface of a substrate by a spin coater (resist coating unit 10), radial streaks may be formed in the radial direction from the center of rotation of the substrate. Also, when a resist solution is applied by a roll coater (resist application unit 10), streaks parallel to the substrate transport direction may occur. In the conventional apparatus, the resist coating unit 10
Therefore, even if a streak is formed in the resist solution applied to the substrate, the substrate is conveyed to the heating unit 20 in a state where the streak is formed, and then heat treatment is performed. Therefore, streaky marks may be left on the resist thin film. In this vicinity, the thickness of the resist thin film is not uniform, which adversely affects the subsequent steps. In particular, in recent years, the shortening of the tact time (the processing time per substrate) has been progressing, and the heating process has been performed immediately after the resist coating process, so that the problem of streak marks remaining is remarkable. It is becoming.

In the proximity bake section 22, heat treatment is performed while supporting the substrate conveyed from the resist coating unit 10 with a plurality of pins erected from the hot plate surface. Therefore, when examining the in-plane temperature distribution of the substrate, the temperature of the portion in contact with the heated pin becomes higher than the other portions, and the resist thickness near the contact portion with the pin may become non-uniform.

[0007] The close baking section 23 also has a similar problem. That is, in the close contact baking section 23, it is necessary to hold the substrate in close contact with the hot plate surface.
Suction holes are provided in the hot plate to hold the back surface of the substrate by suction. Therefore, the temperature in the vicinity of the suction hole is lower than that in the other region, and the in-plane temperature of the substrate is not uniform. As a result, similarly to the case of the proximity bake, there is a problem that the resist thickness near the suction holes becomes uneven.

Further, since the substrate is transferred from the resist coating unit 10 to the heating unit 20 by the carry-out mechanism 12 and the carry-in mechanism 21, the same problem as in the proximity bake may occur. This is because the loading mechanism 21 is provided in the vicinity of the proximity bake unit 22 and thus has a relatively high temperature, and a part of the loading mechanism 21 (for example, the transfer arm) is used for loading the substrate. A part of the resist film, the temperature of the contact part becomes higher than the temperature of the other part (normally, room temperature), which is one of the causes of the nonuniformity of the thickness of the resist thin film.

[0009] The present invention was made in view of the problems as described above, and aims to provide a resist film forming equipment which is capable of forming a resist thin film of uniform thickness on a substrate I do.

[0010]

According to a first aspect of the present invention, there is provided an application unit for applying a resist solution to a substrate surface, and a heating unit for heating the substrate on which the resist solution is applied. A resist thin film forming apparatus for forming a thin film, wherein a plurality of substrates can be accommodated vertically between said coating means and said heating means in order to achieve the above object.
The substrates, each having a surface coated with a resist solution by the coating means, are stored at standby positions for a predetermined time or longer.
And a standby means for conveying the resist solution to the heating means after the resist solution is homogenized and pre-dried .

According to a second aspect of the present invention, the standby means includes a cassette capable of storing a plurality of substrates at the standby position.

[0012]

[0013]

According to the first aspect of the present invention, the substrate having the resist liquid applied to the surface thereof by the coating means is kept on standby for a predetermined time or more between the coating means and the heating means. During this wait,
The resist solution applied to the substrate is made uniform (leveling) and preliminarily dried. Therefore, even if the thickness of the resist solution applied to the substrate surface by the applying means is not uniform, it is made uniform by leveling. Also,
Even if the temperature distribution in the substrate surface becomes non-uniform in the subsequent processing by the preliminary drying, the influence can be suppressed. In addition, the standby means can store multiple substrates vertically
Therefore, when processing a plurality of substrates continuously,
The waiting time for each substrate is reduced by making the resist solution uniform.
And can be long enough to pre-dry
You.

According to the second aspect of the present invention, the standby means is provided with a cassette capable of storing a plurality of substrates at the standby position, and stores the substrate from the application means in the cassette.

[0015]

[0016]

FIG. 1 is a block diagram showing one embodiment of a resist thin film forming apparatus according to the present invention. This embodiment is significantly different from the conventional example (FIG. 3) in that a standby unit 30 is provided between the resist coating unit 10 and the heating unit 20 in this embodiment. The resist coating unit 10 and the heating unit 20
Are well known in the related art, and a detailed description of their configuration and operation will be omitted here.

Next, referring to FIG.
An example of 0 will be described. FIG. 2 shows the standby unit 30.
FIG. 3 is a diagram showing the configuration of FIG. The standby unit 30 includes a loading mechanism 40 for loading the substrate W from the resist coating unit 10 into the unit, and a plurality of substrates W at a predetermined standby position.
50, an unloading mechanism 60 for appropriately taking out the substrate W stored in the cassette 50, and unloading the substrate W toward the heating unit 20, a loading mechanism 40, and an unloading mechanism 60.
And a control unit 70 for controlling.

As shown in FIG. 2, the carry-in mechanism 40 is provided with a carry-in section 41 composed of a plurality of rollers. These rollers are connected to the motor M1 and the control unit 7
By driving the motor M1 in response to a control signal from 0, the substrate W carried by the carry-out mechanism 12 of the resist coating unit 10 can be carried in the carrying direction X and positioned at a predetermined position. ing.

Further, in the loading mechanism 40, the transfer arm 43 having the substrate holder 42 for holding the substrate W is mounted on the arm support block 44 so as to be able to advance and retreat toward the cassette 50 (that is, in the direction X). It is supported and connected to the rotary actuator 45. Also,
An air cylinder 46 is connected to the transfer arm 43. For this reason, by driving the rotary actuator 45 in response to a control signal from the control unit 70, the substrate holder 42 and the transfer arm 43 can be integrally advanced and retracted in the direction X, while the By driving the air cylinder 46 in response to the control signal, the substrate holder 42 and the transfer arm 43 can be integrally moved up and down slowly in the vertical direction Z with a constant stroke.

Further, the loading mechanism 40 is provided with a driving screw 47 extending in the direction Z. An arm support block 44 is screwed into the center of the driving screw 47, and a pulse motor PM1 is connected to the lower end thereof. I have. Therefore, the arm support block 44 can be accurately positioned in the up-down direction Z by driving the pulse motor PM1 by a signal from the control unit 70.

The cassette 50 is provided with a plurality of substrate accommodation grooves (not shown) formed in multiple stages in the direction Z. The substrate W from the resist coating unit 10 is
Can be temporarily accommodated.

The unloading mechanism 60 is composed of the same components as the loading mechanism 40, and is arranged substantially symmetrically with the loading mechanism 40 with the cassette 50 interposed therebetween. Therefore,
Here, components corresponding to the components of the loading mechanism 40 are denoted by corresponding reference numerals, and description thereof will be omitted.

As shown in FIG. 2, the control unit 70 includes a central processing control unit 71 and a ROM 7 for storing an operation program and the like.
2 and a RAM 73 for temporarily storing data such as data stored in the cassette 50. Sensors S1 to S4 for detecting whether or not the substrate W exists in each part of the apparatus are arranged in each part of the apparatus.
The signals from 1 to S4 are input to the control unit 70.

A transport section R comprising a plurality of rollers is provided at a position below the cassette 50. The transport section R is provided without temporarily holding the substrate W in the cassette 50.
This is a mechanism for directly transporting to the heating unit 20. That is, the motor M3 is synchronized with the carry-in section 41 and the carry-out section 61.
Is driven to rotate the rollers, so that the loading section 41
The substrate W from the resist coating unit 10 can be directly conveyed to the heating unit 20 through the path of the conveying unit R and the unloading unit 61.

Next, the operation of the resist thin film forming apparatus according to this embodiment will be described.

When the application of the resist solution to the substrate surface (resist coating process) by the resist application unit 10 is completed, the substrate (the substrate having the surface coated with the resist solution) is transferred to the standby unit by the unloading mechanism 12 and the loading mechanism 40. 30
It is carried in. At this time, the arm support block 4
4 is positioned at the lowest position (origin position).

When the substrate W is positioned and stopped at a predetermined position on the carry-in section 41 by the carry-in mechanism 40, a collecting program stored in the ROM 72 is read out, and a substrate collecting process is executed according to the program. That is, first, the substrate holder 42 and the transfer arm 43 are slowly raised by extending the air cylinder 46, and the substrate W is softened up from the loading section 41. Next, the pulse motor PM1 is driven to move the arm support block 44 to an appropriate height position. Then, by moving the transfer arm 43 forward, the substrate holder 42 is inserted into the cassette 50 while holding the substrate W. Thereafter, the substrate W is softened down by contracting the air cylinder 46, and the substrate W is placed in the accommodation groove. Subsequently, after retreating the transfer arm 43,
The arm support block 44 is lowered to return to the home position.

In this way, the collection of the substrate W into the cassette 50 is completed, but the substrate collection process is continuously performed while the resist coating process by the resist coating unit 10 is continuously performed.

On the other hand, when the substrates W are stored in the cassette 50, the time for which the substrates W are stored in the cassette 50 is measured by the control unit 70 for each substrate W, and when a predetermined time (for example, 5 minutes) elapses, the ROM 72 is used. The substrate unloading program is read out from, and the substrate unloading process is executed according to the program. That is, first, the arm support block 64 located at the origin position is raised, and positioned at a height position corresponding to the substrate accommodation groove accommodating the substrate W to be carried out. Then, the transfer arm 63 is advanced, and the substrate holder 6 is moved.
2 is inserted into the cassette 50, and then the air cylinder 66
The substrate W is softened by expanding the substrate W, and the substrate W is mounted on the substrate holder 62. Subsequently, after the transfer arm 63 is retracted, the arm support block 64 is further lowered to position the substrate W directly above the unloading section 61. Next, the air cylinder 66 is contracted, and the substrate W is placed on the rollers of the unloading section 61. Then, the substrate W is unloaded to the heating unit 20 side by the unloading section 61.

In this way, the substrate W which has been waiting for a certain time in the cassette 50 is carried out to the heating unit 20. The substrate W carried out to the heating unit 20 is sequentially subjected to proximity baking and close contact baking by the heating unit 20 to form a resist thin film.

As described above, according to the resist thin film forming apparatus according to this embodiment, the substrate W having the surface coated with the resist liquid by the resist coating unit (coating means) 10 is collected in the cassette 50 of the standby unit 30. Then, the resist solution is kept at a low viscosity state for a relatively long time by standing by at room temperature for a certain period of time. Therefore, even if stripes are formed in the resist liquid by the resist coating unit 10, the resist liquid on the substrate surface is made uniform (leveling), and the resist liquid by the resist coating unit 10 becomes non-uniform. The problem is solved.

In the above embodiment, when the substrate W is stored in the cassette 50, the time is measured, and when the time reaches a predetermined time, the substrate W is unloaded from the cassette 50. The present invention is not limited to this,
It is sufficient if the substrate W is configured to be always stored in the cassette 50 for a certain period of time or more. Further, when the resist solution is a color resist solution containing a pigment, by waiting, not only the leveling but also the pigment contained therein can be uniformly dispersed throughout the thin film.

During standby in the cassette 50, preliminary drying of the resist solution proceeds in parallel with leveling of the resist solution. Therefore, even if the in-plane temperature of the substrate W becomes non-uniform during the proximity bake, the close bake, and the transfer of the substrate W to the proximity bake unit 22 by the carry-in mechanism 21 as described above, even if the in-plane temperature of the substrate W becomes uneven, Compared to the case where the resist solution is transported to the heating unit 20 immediately after the application (conventional example), the resist solution is appropriately dried, so that it is less susceptible to the influence (non-uniformity of the in-plane temperature) and has a uniform film thickness. A resist thin film is obtained. In addition,
The unit 50 can store a plurality of substrates in a vertical direction.
Therefore, when processing multiple substrates continuously,
The waiting time is reduced by equalizing the resist solution and pre-drying.
Can be long enough to dry
A compact device can be provided.

When the same component as the solvent component contained in the resist solution is supplied into the cassette 50 to form an appropriate atmosphere, the leveling in the cassette 50 can be promoted.

When an airflow such as a downflow flows into the cassette 50, drying unevenness easily occurs due to the influence of the airflow. For example, by providing an airflow blocking member on the outer peripheral portion of the cassette 50, the drying unevenness is reduced. Can be prevented.

Further, in the above embodiment, the leveling and the preliminary drying are performed in parallel in the same cassette 50. However, two types of cassettes are prepared, and the substrate from the resist coating unit 10 is first processed. After allowing the leveling to proceed while waiting in the belling cassette, the pre-drying may be performed by allowing the sufficiently leveled substrate to wait in the preliminary drying cassette.

[0037]

As described above, according to the first and second aspects of the present invention, the standby means is provided between the coating means and the heating means, and the substrate having the surface coated with the resist liquid by the coating means is provided. Since the standby position is maintained at the standby position for a predetermined time or more, a resist thin film having a uniform thickness can be formed on the substrate. In addition, the standby means collects a plurality of substrates in the vertical direction.
It is possible to process multiple substrates continuously
In this case, the waiting time for each substrate is
Time that is long enough for
The device can be made compact as well as possible.

[0038]

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a resist thin film forming apparatus according to the present invention.

FIG. 2 is a diagram illustrating a configuration of a standby unit.

FIG. 3 is a block diagram showing a schematic configuration of a conventional resist thin film forming apparatus.

[Explanation of symbols]

 Reference Signs List 10 resist coating unit (coating means) 20 heating unit (heating means) 30 standby unit (standby means) W substrate

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Go Okumura 1 at 480 Takamiya-cho, Hikone City, Shiga Prefecture, Japan. A) JP-A-5-309301 (JP, A) JP-A-3-84424 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01L 21/027 G03F 7/16 501

Claims (2)

(57) [Claims] A resist film forming apparatus for forming a resist thin film on the substrate surface, comprising: a coating means for coating a resist liquid on a substrate surface; and a heating means for heating a substrate coated with the resist liquid. Between the coating means and the heating means, a plurality of
Substrates can be stored, and the substrates having the surface coated with the resist liquid by the coating means are placed in a standby position for at least a predetermined time.
To make the resist solution uniform and ready
An apparatus for forming a resist thin film, further comprising a standby unit for transferring to the heating unit after drying . 2. The resist thin film forming apparatus according to claim 1, wherein said standby means has a cassette capable of storing a plurality of substrates at said standby position.