JP2003262464A - Method and apparatus for drying thin film, and method for manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for drying a thin film, making the obtained thin film uniform and fine by preventing the thin film before a drying process from being unevenly dried, and to provide a method for manufacturing a device. <P>SOLUTION: This apparatus for drying the thin film 11 formed by applying a liquid material to a substrate 8 is provided with a stage 7 for holding the substrate 8; a drying cover 2 forming a storage space 12 for storing the substrate 8 between the stage 7 and the cover 2; and a pressure reducing means 5 connected to the drying cover 2 to reduce pressure in the storage space 12. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of drying a thin film, a drying apparatus, and a device manufacturing method, which allow a thin film applied with a liquid material to be dried well without being unevenly dried.

[0002]

2. Description of the Related Art Semiconductor elements, liquid crystal elements, organic EL elements,
In various electronic devices such as image pickup devices (CCD) and optical devices, various films such as films that are constituent elements and films used in processes are formed during manufacturing. In such a film, the liquid material is sprayed or spin coated,
In many cases, it is applied by an inkjet method or the like to form a thin film, which is further dried by heating and solidifying to be formed. Specifically, it is a film formed of a liquid material mainly using an organic solvent, such as a resist film, a color filter, an interlayer insulating film, a protective film, an alignment film in a liquid crystal element, and a passivation film.

Such a film is usually formed by applying a liquid material onto a substrate to form a thin film, and then the film is conveyed to the next process of drying (or baking) together with the substrate, where it is heated (or reduced pressure) to be dried. To obtain a desired film. Further, although the thin film formation, that is, the application of the liquid material is usually performed on the upper surface of the substrate, the liquid material may be applied on the lower surface of the substrate depending on the type of the forming material and the state of the substrate surface. . For example, when various components are already provided on the surface of the substrate and unevenness is formed by this, it is better to apply this surface to the lower surface and apply it to the unevenness due to surface tension. The embeddability may be improved. In addition, in order to make the film thickness uniform, it is advantageous to apply the liquid material to the lower surface.

[0004]

By the way, depending on the kind of film to be formed, there is a case where an organic solvent having a particularly high volatility is used as a liquid material. When applying such a liquid material, it is necessary to apply it to the substrate. In some cases, the thin film may be nonuniformly dried after the application of the coating and before the drying, and even if the thin film is dried in the subsequent drying step, the obtained film may be nonuniform in thickness and the like. The non-uniform drying of the thin film before the drying process may be because it takes time for the substrate to be transported to the drying process, dried, and then waited for the substrate to be dried and transferred to the drying furnace. It is considered to be a major cause.

In particular, when the liquid material is applied to the lower surface of the substrate, when the liquid material is conveyed to the drying step after application, the substrate is first swirled so that the thin film forming surface faces up, and the drying step is performed in that state. Transfer to. However, when such a rotation is performed, the thin film is near the rotation axis especially when the substrate has a relatively long dimension of 400 mm to 500 mm or a large dimension having a long dimension exceeding 1 m. However, the influence of the air flow and centrifugal force generated by the swirl is small, but the influence becomes large as the distance from the swirl axis increases, and as a result, the thin film dries unevenly and uneven film thickness occurs. In addition, when the thickness of the thin film formed by coating is comparatively large, when the substrate stands vertically when swirling, the liquid drips and becomes uneven, and the resulting thin film becomes uneven in thickness. There is also a problem.

The present invention has been made in view of the above circumstances, and an object thereof is to prevent uneven drying of a thin film before a drying step, and to obtain a uniform and good film obtained by this. Another object of the present invention is to provide a thin film drying method and a drying apparatus, and a device manufacturing method.

[0007]

In order to achieve the above object, the thin film drying method of the present invention is a thin film drying method for drying a thin film formed by applying a liquid material to a substrate. The substrate is held and the liquid material is applied, and while the holding of the substrate by the stage is maintained, the drying cover is covered on the stage to accommodate the substrate in the space between the drying cover and the stage. The thin film is dried by reducing the pressure in the space between the drying cover and the stage. According to this thin film drying method, the space between the drying cover and the stage is depressurized to dry the thin film, so that the time from the coating process to the drying process can be significantly shortened compared to the conventional case. This makes it possible to prevent the thin film from drying unevenly before the drying step.

Further, in this thin film drying method, when the liquid material is applied by a method of applying the liquid material to the lower surface of the substrate, the drying cover is placed on the lower side of the stage to cover the substrate. Is preferably housed. In this way, the substrate coated with the thin film is dried under reduced pressure before the thin film is turned to the upper side. It is possible to prevent the film from being evenly dried or having uneven film thickness.

Further, in this thin film drying method, it is preferable that the pressure between the drying cover and the stage is reduced and the thin film is also heated. In this way, since the pressure reduction and the heating are performed in combination, the thin film can be dried more quickly and surely, and thereby a good thin film can be formed.

The thin film drying apparatus of the present invention is a drying apparatus for drying a thin film formed by applying a liquid material to a substrate, wherein the substrate is held between a stage holding the substrate and the stage. It is characterized in that it is provided with a drying cover forming an accommodation space for accommodating and a decompression means connected to the drying cover to decompress the inside of the accommodation space. According to this thin film drying apparatus, by depressurizing the accommodating space for accommodating the substrate by the depressurizing means, the time from the coating step to the drying step can be remarkably shortened as compared with the conventional case. It is possible to prevent the thin film from drying unevenly before the drying step.

Further, in this thin film drying apparatus, it is preferable that the stage is provided with an adsorption means for adsorbing the substrate. With this configuration, the substrate can be securely held and fixed on the stage, and thus, for example, the substrate can be sucked and held with the substrate facing downward.

Further, in this thin film drying apparatus, it is preferable that the drying cover or the stage is provided with heating means for heating the thin film. By doing so, decompression and heating can be performed in combination, and therefore, the thin film can be dried more quickly and reliably, whereby a good thin film can be formed.

The device manufacturing method of the present invention is a device manufacturing method manufactured by drying a thin film applied to a substrate, which comprises a mounting step of mounting the substrate on a stage, and a mounting step on the stage. A coating step of coating the thin film on the placed substrate, and a drying step of drying the coating film, the drying step being performed after the coating step, and the state where the substrate is placed on the stage. Is covered with a drying cover, and the pressure is reduced by a pressure reducing means. According to the method of manufacturing this device,
Since the pressure inside the drying cover is reduced to dry the thin film,
The time from the coating process to the drying process can be significantly shortened as compared with the conventional case, and thus it is possible to prevent the thin film from being unevenly dried before the drying process.

Another method of manufacturing a device according to the present invention is a method of manufacturing a device, which is manufactured by drying a thin film applied to a substrate, which comprises a mounting step of mounting the substrate on a stage, and the stage. A coating step of coating the thin film on the substrate placed on the substrate, and a drying step of drying the coating film, the drying step is performed after the coating step, and the substrate is placed on the stage. It is characterized in that it is carried out by covering the drying cover in this state and heating by a heating means. According to this device manufacturing method, since the inside of the drying cover is heated to dry the thin film, the time from the coating process to the drying process can be significantly shortened compared to the conventional case. Thereby, it is possible to prevent the thin film from being unevenly dried before the drying step.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
1 (a) to 1 (c) are views for explaining an embodiment of a thin film drying apparatus of the present invention. In this embodiment, a method of applying the liquid material to the lower surface of the substrate is adopted as the method of applying the liquid material in the applying step which is a step before the drying step. The liquid material described in the present embodiment is not particularly limited to a liquid, and includes a liquid material containing fine particles such as metal.

In FIGS. 1A to 1C, reference numeral 1 is a drying device, and the drying device 1 includes a drying cover 2, an elevating mechanism 3 for elevating the drying cover 2, and a drying device. A pressure reducing means 5 such as a vacuum pump provided via a flexible pipe 4 connected to the cover 2 and communicating with the inside thereof, and a heating means 6 provided inside the drying cover 2 are configured. It is a thing.

The drying cover 2 covers the substrate 8 held by the suction stage 7 shown in FIG. 1A, and is constructed so as to cover the suction stage 7 in this state. The cover 2 has a rectangular plate shape. 2a and side plates 2b ... Which are provided orthogonally to the cover body 2a from the four sides of the cover body 2a. The drying cover 2 is arranged such that the side plate 2b side thereof faces upward and the cover body 2a faces downward. By being arranged in this manner, the side plate 2b on the lower surface side of the suction stage 7 ... Is easy to hit. Also, this drying cover 2
Is formed of metal, hard resin, or the like, and a packing material 9 made of rubber, soft resin, or the like is attached to the end surface of the side plate 2b, that is, the contact surface with the suction stage 7. Based on this structure, the drying cover 2
As will be described later, when the side plates 2b ... Abut against the substrate holding surface of the suction stage 7 and cover the suction stage 7, an airtight accommodation space is formed between the drying cover 2 and the suction stage 7. It will be done.

The lifting mechanism 3 comprises a plurality of arms 3a for supporting the drying cover 2 and a lifting device 3b such as an air cylinder connected to the arms 3a. The lifting device 3b operates to lift the arms 3a. The drying cover 2 is configured to be raised and lowered via the above. The flexible pipe 4 communicates with the through hole 2c formed in the central portion of the cover body 2a of the drying cover 2, and when the pressure reducing means 5 is operated to reduce the pressure, the flexible pipe 4 is not partially biased. The inside of the cover body 2a is sucked almost uniformly to reduce the pressure.

The heating means 6 is arranged on the inner surface of the cover body 2a of the drying cover 2 so as to avoid the through holes 2c, and is constituted by an electric heater or an infrared heater generally used conventionally. It is something. A temperature detecting means (not shown) such as a thermocouple is provided on the inner surface of the drying cover 1.
Is provided, and heating by the heating means 6 is controlled based on the temperature inside the drying cover 2 detected by the temperature detecting means. The drying device 1 having such a configuration is arranged near a position where a coating process described later is performed.

Next, an example of the drying method of the thin film of the present invention will be described based on the drying method by the drying apparatus 1 having such a configuration. First, as a pre-process of the drying process, the substrate 8 is placed on the adsorption stage 7 and held and fixed, and then the adsorption stage 7 is swiveled to turn the substrate 8 upside down, as shown in FIG. This is held on the suction stage 7 in the state of being lowered. As a mechanism for rotating the suction stage 7, for example, a holding arm (not shown) connected to the suction stage and a motor (not shown) connected to the holding arm via a ball screw (not shown). A swivel device (not shown) is used. According to the turning device having such a configuration, the holding arm can be turned via the ball screw by operating the motor, whereby the suction stage 7 can be turned.

When the suction stage 7 is swung by such a swiveling means and the substrate 8 is directed downward, the liquid material is applied to the substrate 1 by the coating head 10 arranged in advance on the lower side.
To form a thin film 11. Then, the suction stage 7 is moved toward the drying device 1 arranged near this coating position while the substrate 8 is being held, and FIG.
The substrate 8 is positioned immediately above the drying cover 2 as shown in FIG.

Next, the elevating mechanism 3 of the drying device 1 is operated to raise the drying cover 2, and the packing material 9 provided on the side plate 2b of the drying cover 2 is sucked by the suction stage 7 as shown in FIG. 1 (c). It abuts against the substrate 8 holding surface. Then, the drying cover 2 is covered with the suction stage 7 to form an airtight housing space 12 between the drying cover 2 and the suction stage 7, and the substrate 8 is housed in the housing space 12.

After covering the drying stage 2 on the adsorption stage 7 in this manner, the decompression means 5 is operated to decompress the accommodation space 12 to, for example, about 100 Torr to 1 Torr. Then, the decompression treatment accelerates the volatilization of the liquid component such as the organic solvent in the thin film 11 and forcibly removes it, and the thin film 11 is dried. When the accommodation space 12 is decompressed as described above, the packing material 9 of the drying cover 2 is kept in close contact with the suction stage 7 to maintain the airtightness of the accommodation space 12. Therefore, the raising of the drying cover 2 by the elevating mechanism 3 is stopped, and the drying cover 2 may be fixed to the stopped raised position.

When the depressurizing process is performed for a preset time as described above, or when the housing space 12 is depressurized to a predetermined pressure, the heating means 6 heats the thin film 1
The drying of 1 is further promoted to form the dried and solidified thin film 11. Next, the heating by the heating means 6 is stopped, the decompression by the decompression means 5 is stopped, and the accommodation space 12 is returned to normal pressure. Then, the elevating mechanism 3 is activated to lower the drying cover 2 this time. Further, the substrate 8 is moved together with the adsorption stage 7, and the substrate 8 is swung again by the swiveling device so that the dried and solidified thin film 11 faces upward. After that, the substrate 8 on which the thin film 11 is formed is carried to the next step after the drying step by a suitable carrying means.

In such a drying method, the suction cover 7 is covered with the drying cover 2 while covering the substrate 8.
After that, since the pressure between the drying cover 2 and the suction stage 7 is reduced, it is possible to cover the drying cover 2 on the suction stage 7 immediately after applying the liquid material in the coating step and perform vacuum drying. Therefore, the time from the coating process to the drying process can be remarkably shortened as compared with the conventional case, whereby the thin film 11 can be prevented from being unevenly dried before the drying process, and a good thin film can be obtained. Can be formed.

Although the liquid material is applied by the method of applying the liquid material to the lower surface of the substrate 8, the substrate 8 coated with the thin film 11 is swung to reduce the pressure before the thin film 11 is placed on the upper side. Since the drying process is performed, due to the air flow and centrifugal force generated by the turning, and further due to the sagging at the time of turning,
It is possible to reliably prevent the thin film 11 from being unevenly dried or from having uneven film thickness. Therefore, since it is possible to prevent such an inconvenience due to the swirling, it is not necessary to pay attention to the state and properties of the thin film 11 formed by coating, and thus the thin film 1
The degree of freedom in designing 1 can be increased. Further, since the depressurization treatment and the heat treatment are performed in combination, the thin film 11 can be dried more quickly and surely, and thus the good thin film 11 can be formed.

The present invention is not limited to the above examples, and various modifications can be made without departing from the gist of the present invention. For example, the present invention can be applied even in the case where the liquid material is applied from the upper side to the upper surface of the substrate 8 in the applying step which is a step before the drying step. In that case, the posture of the drying cover 2 shown in FIGS. 1A to 1C is reversed in advance, and the side plate 2b side faces downward and the cover body 2a faces upward. Then, the suction stage 7 holding and fixing the substrate 8 on the upper side is lowered by the elevating mechanism 3, and the side plates 2b ... Are made to abut against the upper surface side of the suction stage 7, thereby forming the accommodation space 12. Thereafter, in the same manner as in the case shown in FIGS. 1A to 1C, decompression and further heating are performed to perform a drying process.

Even when the drying process is performed in this manner, the drying cover 2 is attached to the suction stage 7 immediately after the coating process.
Then, the time from the coating process to the drying process can be significantly shortened as compared with the conventional case, and the thin film 11 can be dried before the drying process.
Can be prevented from drying unevenly and a good thin film can be formed. When the liquid material is applied to the upper surface of the substrate 8 from the upper side as described above, the stage 8 holds the substrate 8 in place of the suction stage 7 and simply functions as a table. You may use the stage which has only.

Further, in the above example, the heating means 6 is provided on the drying cover 2, but, for example, a function of a hot plate is added to the adsorption stage (or the above-mentioned simple stage), so that the substrate 8 is provided. The thin film 11 may be heated and dried. Further, the heating means 6 may not be provided, and the drying may be performed only by the depressurization process. Further, the elevating mechanism 3 is not provided in the drying device 1, and the suction stage 7
It is also possible to add an elevating function to the side that conveys the so that the drying cover 2 abuts against the suction stage 7. Examples of devices manufactured by the drying method of the present invention include various electronic elements such as semiconductor elements, liquid crystal elements, organic EL elements, and image pickup elements (CCD), and optical elements. When manufacturing these devices, the drying method of the present invention is applied to various films such as a film used as a constituent element and a film used in a process.

[0030]

As described above, according to the thin film drying method and the drying apparatus of the present invention, the drying cover is covered on the stage while the substrate is covered, and then the pressure between the drying cover and the stage is reduced. As a result, it is possible to cover the stage with a drying cover immediately after applying the liquid material and dry under reduced pressure.
Therefore, the time from the coating process to the drying process can be significantly shortened compared to the conventional case, which prevents the thin film from drying unevenly before the drying process and forms a good thin film. be able to.

According to the device manufacturing method of the present invention, the inside of the drying cover is depressurized or heated to dry the thin film, so that the time from the coating step to the drying step is significantly longer than in the past. It can be shortened, which can prevent the thin film from drying unevenly before the drying process.

[Brief description of drawings]

FIG. 1A to FIG. 1C are side cross-sectional views of an essential part for explaining an embodiment of an apparatus for drying a thin film of the present invention and for explaining a drying method by this drying apparatus in the order of steps.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Drying device, 2 ... Drying cover, 5 ... Decompression means, 6 ...
Heating means, 7 ... adsorption stage, 8 ... substrate, 11 ... thin film,
12 ... accommodation space

Claims (8)

[Claims] 1. A method of drying a thin film, which comprises drying a thin film formed by applying a liquid material to a substrate, comprising: holding the substrate on a stage to apply the liquid material;
While maintaining the holding of the substrate by the stage, the drying cover is covered on the stage to accommodate the substrate in the space between the drying cover and the stage, and the space between the drying cover and the stage is depressurized, A method for drying a thin film, which comprises drying the thin film. 2. The liquid material is applied by a method of applying the liquid material to the lower surface of the substrate, and the drying cover is placed under the stage to accommodate the substrate. The method for drying a thin film according to claim 1. 3. The method for drying a thin film according to claim 1, wherein the space between the drying cover and the stage is decompressed and the thin film is heated. 4. A drying device for drying a thin film formed by applying a liquid material to a substrate, wherein a stage for holding the substrate and an accommodation space for accommodating the substrate are formed between the stage and the stage. A drying cover,
A thin film drying apparatus comprising: a decompression unit connected to the drying cover to decompress the inside of the accommodation space. 5. The thin film drying apparatus according to claim 4, wherein the stage is provided with a suction means for sucking the substrate. 6. The thin film drying apparatus according to claim 4, wherein the drying cover or the stage is provided with heating means for heating the thin film. 7. A method of manufacturing a device, which is manufactured by drying a thin film applied to a substrate, comprising: a mounting step of mounting the substrate on a stage; and a step of mounting the substrate on the stage on the substrate. There is a coating step of coating a thin film, and a drying step of drying the coating film, the drying step is performed after the coating step, and covers the drying cover in a state where the substrate is placed on the stage,
A method for manufacturing a device, which is performed by reducing the pressure by a pressure reducing means. 8. A method of manufacturing a device, which is manufactured by drying a thin film applied to a substrate, comprising: a mounting step of mounting the substrate on a stage; and a step of mounting the substrate on the stage on the substrate. There is a coating step of coating a thin film, and a drying step of drying the coating film, the drying step is performed after the coating step, and covers the drying cover in a state where the substrate is placed on the stage,
A method for manufacturing a device, which is performed by heating by a heating means.