JP2002083855A - Liquid material coater and organic contamination preventing method in liquid material coating process - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent substrates which are carried in a state to be housed in a pot such as an FOUP and an SMIF from organic contamination, regarding a liquid material coater for forming a thin film on a semiconductor wafer or the like. SOLUTION: By using a pot 18 capable of housing a plurality of substrates in a state to be isolated from external environment, the substrates are carried in the liquid material coater. The coater is provided with a carrying in and out region 10 for housing the pot 18, and a treatment region 14 which is used for forming a thin film on a surface of the substrate by using liquid material containing organic solvent. All the substrates in the pot 18 are transferred previously to a substrate housing unit 22. Substrates which have been treated in the treatment region 14 are housed sequentially in the emptied pot 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid material applying apparatus and a method for preventing organic contamination in a liquid material applying step, and more particularly to a liquid material applying apparatus and a semiconductor wafer suitable for forming a thin film on a semiconductor wafer or the like. The present invention relates to a method for preventing organic contamination which is effective in forming a thin film with a high yield.

[0002]

2. Description of the Related Art In the manufacturing process of semiconductor devices and liquid crystal devices,
2. Description of the Related Art A liquid material coating apparatus that forms a thin film by spin coating a liquid material is used. BACKGROUND ART A liquid material application apparatus spin-coats a liquid material on a substrate such as a semiconductor wafer and then volatilizes an organic solvent contained in the liquid material to form a thin film.

In recent years, when a substrate is carried into such a liquid material coating apparatus, a FOUP (Front Opening Unifie) is required.
d Pod) and SMIF (Standard Mechanical Inter Fac)
e) Pods are being used. FO
According to UP or SMIF, a plurality of substrates are carried into a liquid material application device in a state of being shielded from an external environment such as a clean room, and those substrates are carried out of the liquid material application device without touching the external environment. be able to.
Therefore, the use of a pod such as a FOUP or a SMIF can cope with high integration of a semiconductor device and increase the yield.

[0004]

The substrates carried into the liquid material applying apparatus while being housed in a FOUP or SMIF are taken out one by one inside the apparatus and subjected to a thin film forming process. Then, the processed substrate (hereinafter referred to as “substrate with thin film”) is stored in the pod in a state where the organic solvent contained in the thin film is not completely volatilized. Therefore, a relatively high concentration of organic solvent gas is generated inside the pod.

When the substrate with a thin film is stored in the pod, there is a substrate inside the pod that has not yet been subjected to the thin film forming process. Organic solvent gases generated inside the pods adhere to the surface of those untreated substrates, causing organic contamination of the substrates. When a thin film is formed on a substrate on which such organic contamination has occurred, a foreign substance composition abnormality is likely to be formed at a boundary portion between the thin film and the substrate or inside the thin film. As described above, the conventional method using the FOUP or the SMIF has a problem that an abnormality caused by organic contamination of the substrate is easily caused.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and can prevent organic contamination of a substrate carried in a state of being housed in a pod such as a FOUP or SMIF. A first object is to provide a liquid material application device. In addition, the present invention provides FOUP and S
It is a second object of the present invention to provide an organic contamination prevention method for preventing a substrate carried in a pod such as a MIF from being organically contaminated.

[0007]

According to the first aspect of the present invention,
A liquid material application device for carrying in and out of the substrate using a pod capable of storing a plurality of substrates in a state of being shielded from an external environment, a carry-in / out area for storing the pod, and an organic solvent. A processing region for forming a thin film on the surface of the substrate using a liquid material containing, a transfer device that stores the processed substrate processed in the processing region in a pod in which the unprocessed substrate is not stored, It is characterized by having.

According to a second aspect of the present invention, there is provided the liquid material applying apparatus according to the first aspect, further comprising a substrate storage unit capable of storing all substrates stored in a single pod, wherein the transfer device is provided. After all the substrates in the pod are transferred to the substrate storage unit, the processed containers are stored in the pod.

According to a third aspect of the present invention, there is provided the liquid material applying apparatus according to the second aspect, wherein the substrate storage unit circulates clean air or an inert gas around the substrate stored therein. It is characterized by having an air purifier.

According to a fourth aspect of the present invention, there is provided a method for preventing an unprocessed substrate from being organically contaminated during a step of applying a liquid material containing an organic solvent onto the substrate, wherein the unprocessed substrate is contained in a pod. A first step of loading a plurality of substrates into the liquid material application apparatus, a second step of removing the substrates from the pod, and a step of forming a thin film on the surface of the substrates removed from the pods using the liquid material. The method is characterized by including three steps and a fourth step of storing the processed substrate having the thin film formed on the surface in a pod in which the unprocessed substrate is not stored.

According to a fifth aspect of the present invention, there is provided the organic contamination preventing method according to the fourth aspect, wherein in the second step, all the substrates in the pod are transferred to a substrate storage unit in the liquid material application device. In the third step, a thin film is sequentially formed on the substrate transferred to the substrate storage unit,
In the fourth step, the pod emptied by transferring all the substrates to the substrate storage unit,
The processed substrate is returned.

According to a sixth aspect of the present invention, there is provided the organic contamination preventing method according to the fifth aspect, wherein the substrate accommodating unit circulates clean air or an inert gas around the substrate stored therein. An air cleaner is provided, and in the fourth step, the processed substrate is returned to the pod after being temporarily held in the substrate storage unit.

According to a seventh aspect of the present invention, there is provided the method for preventing organic contamination according to the sixth aspect, wherein all the substrates taken out from a single pod are processed at the stage where the last substrate is a processed substrate. And returned to the pod sequentially or collectively.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. Elements common to the drawings are denoted by the same reference numerals, and redundant description will be omitted.

Embodiment 1 FIG. 1 is a plan perspective view of the liquid material application device according to the first embodiment of the present invention. The liquid material application apparatus according to the present embodiment is an apparatus suitable for forming an interlayer insulating film of a semiconductor device or forming an organic thin film of a liquid crystal device. According to the liquid material applying apparatus, for example, an interlayer insulating film having excellent flatness and filling properties can be formed as compared with an interlayer insulating film formed by plasma CVD or thermal CVD.

A substrate loading / unloading area 10, a substrate waiting area 12, and a substrate processing area 14 are provided inside the liquid material application apparatus. These areas are shielded from an external environment such as a clean room by an outer wall 16. A pod 18 such as a FOUP or SMIF can be carried into the carry-in / out area 10 from outside the liquid material application device. A plurality of substrates are housed in the pod 18 in a state of being shielded from an external environment such as a clean room.

In the waiting area 12, a first transfer device 20 for loading and unloading the substrate in the pod 18 is provided. Beside the first transfer device 20, the substrate storage unit 2
2 are provided. The substrate storage unit 22 includes a storage space 24 for temporarily storing all the substrates stored in one pod 18 and an air purifier 26. The plurality of substrates are stored in the storage space 24 in parallel with each other at a predetermined interval. The air purifier 26 includes air purified by a HEPA filter or the like,
Alternatively, an inert gas such as a nitrogen gas or an argon gas can flow in a direction parallel to the substrate in the storage space 24.

In the processing area 14, a first cooling plate 28, a coating processing section 30, first to third heat treatment plates 32, 34, 36,
And a second cooling plate 38, and a second transfer device 40 for transferring the substrate in the processing area 14. The substrates temporarily stored in the standby area 12 are carried one by one into the processing area 14 by the first and second transfer devices 20 and 40, and after being cooled to an appropriate temperature on the first cooling plate 28, It is carried into the coating processing section 30.

The coating unit 30 includes a rotating mechanism for holding the substrate by suction and a mechanism for coating the liquid material on the substrate. The liquid material is applied to the surface of the substrate while rotating the substrate at a speed of about 500 to 5000 rpm. Is applied. Due to the rotation of the substrate, the applied liquid material is spread in the form of a thin film, and the excess is removed from the substrate. The organic solvent evaporates to a certain extent from the liquid material extended to the front surface of the substrate, whereby a thin film is formed on the substrate.

The substrates processed in the coating processing section 30 are sequentially transferred onto the first to third heat-treating plates 32, 34 and 36 by the second transfer device 40, and are sequentially transferred to the first and second heat treatment plates 32, 34 and 36.
It is subjected to a heat treatment at about 350 ° C. These heat treatments are performed for the purpose of volatilizing the organic solvent in the thin film and preliminarily thermosetting the thin film to stabilize the thin film.

The substrate processed by the third heat-treating plate 36, that is, the processed substrate is cooled to an appropriate temperature on the second cooling plate 38, and then is carried out of the processing area 14 and is subjected to the first processing.
It is stored in the pod 18 by the transport device 20.

The thin film formed by the coating section 30 is subjected to a final curing process outside the liquid material coating apparatus. Therefore, at the stage of processing by the third heat treatment plate 3, that is, at the stage of being unloaded from the processing region 14, some organic solvent remains in the thin film. Therefore, when an unprocessed substrate is present in the pod 18, a gaseous organic solvent emitted from the processed substrate may adhere to the unprocessed substrate.

As described above, in the present embodiment, the pod 18
After all of the substrates are transferred to the substrate storage unit 22, the thin film forming process is started. Therefore, when the processed substrate is loaded into the pod 18, no unprocessed substrate exists in the pod 18. Therefore, according to the liquid material applying apparatus of the present embodiment, even if the gas of the organic solvent is generated from the processed substrate, the organic contamination of the unprocessed substrate does not occur due to the influence.

FIG. 2 is a view for explaining the effect of the liquid material coating apparatus according to the present embodiment. In FIG. 2, the horizontal axis represents time, and the vertical axis represents the number of samples in which an abnormality was recognized after the thin film forming process. In FIG. 2, the broken line connecting ■ indicates the relationship between the time during which the unprocessed substrate is exposed to the organic solvent gas in the pod 18 and the abnormal number, and the broken line connecting 、 indicates
The relationship between the time during which an unprocessed substrate is held in the substrate storage unit 22 and the number of abnormalities is shown.

As shown in FIG. 2, the unprocessed substrate is a pod 1
When exposed to the organic solvent gas within 8, the abnormal number increases with time. On the other hand, when the unprocessed substrate is held in the substrate storage unit 22, almost no abnormality is recognized regardless of the length of time. As can be seen from these relationships, according to the liquid material application apparatus of the present embodiment, the number of abnormalities in the thin film forming process is significantly reduced as compared with the case where the processed substrate is returned to the pod where the unprocessed substrate exists. Can be done.

In the first embodiment described above, the processed substrate is transported directly from the processing area 14 to the pod 18, but the present invention is not limited to this. That is, the processed substrates are unloaded from the processing area 14 and stored in the substrate storage unit 22 until the processing of all the substrates is completed. 18 may be stored.

In the liquid material application device of the present embodiment,
In the vicinity of the substrate stored in the substrate storage unit 22,
Clean air (or inert gas) is always supplied by the air purifier 26. Therefore, even if the processed substrate and the unprocessed substrate are mixed in the substrate storage unit 22, the unprocessed substrate is not contaminated by organic. If the processed substrate is stored in the substrate storage unit 22 and then stored in the pod 18, the pod 18
The amount of the organic solvent brought into the inside can be reduced.
Therefore, according to the above-described modified example, the amount of contamination of the pod 18 itself can be suppressed while effectively preventing organic contamination of the unprocessed substrate.

In the first embodiment described above, the processed substrate is returned to the pod 18 used for carrying in the substrate. However, the present invention is not limited to this, and is used for carrying in the substrate. An empty pod 18 may be prepared in the loading / unloading area 10 separately from the pod 18, and the substrates carried out and processed from the pod 18 may be sequentially stored in the empty pod 18. In this case, the substrate storage unit 22 is not necessarily required.

[0029]

Since the present invention is configured as described above, it has the following effects. Claim 1
According to the fourth aspect, the processed substrate can be stored in a pod in which the unprocessed substrate is not stored.
Therefore, according to the present invention, it is possible to reliably prevent the unprocessed substrate from being contaminated due to the organic solvent gas emitted from the processed substrate.

According to the second or fifth aspect of the present invention, all the substrates stored in the pod are transferred to the substrate storage unit, so that the pod is emptied, and the processed substrate is removed.
You can return to the empty pods sequentially. ADVANTAGE OF THE INVENTION According to this invention, organic contamination of an unprocessed board | substrate can be reliably prevented, using only one pod.

According to the third, sixth or seventh aspect of the present invention, the processed substrate is temporarily stored in the substrate storage unit, and after the organic solvent is volatilized to some extent in the processed substrate, the processed substrate is returned to the pod. be able to. Therefore, according to the present invention, the organic contamination of the unprocessed substrate can be prevented, and
Organic pollution of the pod itself can also be prevented.

[Brief description of the drawings]

FIG. 1 is a plan perspective view of a liquid material application device according to a first embodiment of the present invention.

FIG. 2 is a diagram for describing an effect of the liquid material application device according to the first embodiment.

[Explanation of symbols]

10 loading / unloading area, 12 standby area, 14 processing area, 16 outer wall, 18 pod, 20
1st transfer device, 22 substrate storage unit, 2
4 storage space, 26 air purifier.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/31 H01L 21/31 Z F term (Reference) 2H025 AB16 EA05 4D075 AC64 AC71 DC22 4F042 AA07 DF15 EB21 EB24 5F031 CA02 CA05 DA17 FA01 FA02 FA11 FA12 FA15 GA48 MA24 MA26 MA28 NA02 NA04 5F045 BB14 EB19 EE10 EN04

Claims (7)

[Claims] 1. A liquid material application apparatus for carrying in and out a substrate using a pod capable of storing a plurality of substrates in a state of being shielded from an external environment, wherein a carry-in / out area for storing the pod. And a processing area for forming a thin film on the surface of the substrate using a liquid material containing an organic solvent; and storing the processed substrate processed in the processing area in a pod in which an unprocessed substrate is not stored. A liquid material application device, comprising: 2. The apparatus according to claim 1, further comprising: a substrate storage unit capable of storing all substrates stored in a single pod, wherein the transfer device is configured to transfer all the substrates in the pod to the substrate storage unit. The liquid material application device according to claim 1, wherein the processed material is stored in the pod. 3. The substrate storage unit according to claim 2, further comprising an air purifier that circulates clean air or an inert gas around the substrate stored in the unit.
The liquid material application device according to claim. 4. A method for preventing an unprocessed substrate from being contaminated organically during a step of applying a liquid material containing an organic solvent on a substrate, comprising the steps of: A first step of bringing the substrate into the coating device, a second step of taking out the substrate from the pod, a third step of forming a thin film on the surface of the substrate taken out of the pod using the liquid material, A fourth step of storing the processed substrate on which the thin film is formed in a pod in which the unprocessed substrate is not stored. 5. In the second step, all the substrates in the pod are transferred to a substrate storage unit in the liquid material coating device. In the third step, the substrates transferred to the substrate storage unit are sequentially thinned. Is formed. In the fourth step, all the substrates are transferred to the substrate storage unit, and the pod is emptied.
5. The method according to claim 4, wherein the processed substrate is returned.
The organic pollution prevention method described in the above. 6. The substrate accommodating unit includes an air purifier that circulates clean air or an inert gas around a substrate stored in the substrate accommodating unit. In the fourth step, the processed substrate is The method according to claim 5, wherein the pod is returned to the pod after being temporarily held in the substrate storage unit. 7. The method according to claim 1, wherein all of the substrates removed from a single pod are sequentially or collectively returned to the pod when the last substrate is a processed substrate. 6. The method for preventing organic contamination according to 6.