JP2002252163A - Method and device for manufacturing image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve yield as much as possible. SOLUTION: This method/device is provided with a process for applying a photoresist on a substrate to be treated whereupon a film to be treated is formed thereon, a process for pre-baking the photoresist in a pre-baking room and a process for allowing the substrate to be treated to stay for a prescribed period or longer in the pre-baking room.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for manufacturing an image display device.

[0002]

2. Description of the Related Art Conventionally, TFTs using a polycrystalline silicon film
In manufacturing a liquid crystal panel having a (Thin Film Transistor), a part of a driver circuit (eg, a transistor) such as an analog switch or a shift register is simultaneously formed on the same substrate. Until now, it has been sufficient if a device width (particularly TFT gate width) of about 5 μm can be processed. However, D / A, which was an external circuit
When a converter or the like is made of a TFT using polycrystalline silicon on the same substrate, it is necessary to improve the characteristics of the TFT, and a fine processing of 1.5 μm to 3 μm is required. When wiring is miniaturized, variations in wiring width will cause TFT
Since the influence on the characteristics becomes large, unless the variation in the wiring width is suppressed, a failure such as a circuit operation failure will occur.

In mass production of liquid crystal panels, cost reduction is the biggest problem. For cost reduction, it is important to improve yield and throughput. Therefore, in a photolithography process for manufacturing a liquid crystal panel, a resist material having high sensitivity is often used in order to improve throughput. Usually, a stepper is used for exposure, and as the substrate size increases, it is necessary to increase the exposure area per shot in order to increase throughput. At this time, since the exposure energy per unit area is reduced, the sensitivity of the resist is increased so that a pattern can be formed even at a low exposure dose, thereby increasing the throughput. However, when the sensitivity is increased, the unexposed portion is also easily dissolved in the developer. As described above, in the case of a high-sensitivity resist, variations in the processing conditions of each step such as pre-exposure bake (hereinafter, also referred to as pre-bake) and development, exposure, and post-exposure bake (hereinafter, also referred to as post-bake) in the photolithography process. It is very sensitive and the pattern width varies. In the manufacture of a semiconductor device using an 8-inch silicon wafer, it is not necessary to reduce the exposure energy, so a low-sensitivity photoresist is used, and it is insensitive to variations in processing conditions such as prebaking. Problems are less likely to occur. Incidentally, in the manufacture of a semiconductor device, the exposure energy per unit area is 100 mJ.
/ Cm ² is used.

Conventionally, in order to realize a high throughput in the production of an image display device (for example, a liquid crystal display device or an EL (Electro Luminesense) device), wiring is patterned with a high-sensitivity resist using an in-line type production device. Was. FIG. 7 shows a general configuration of an in-line type manufacturing apparatus. This manufacturing apparatus includes a resist coating chamber 20 and
It includes a pre-bake chamber 30, a cooling chamber 40, an exposure chamber 50, a developing chamber 60, a post-bake chamber 70, a cooling chamber 80, and a transfer arm 100.

[0005] A method of manufacturing a liquid crystal display device using this manufacturing apparatus will be described with reference to FIG. This manufacturing apparatus has a configuration in which a substrate can be processed in a single-wafer process in the order of cleaning, resist coating, pre-baking, cooling, exposure, development, post-baking, and cooling steps. First, as shown in FIG. 8A, an undercoat film 12 made of a nitride film or an oxide film is formed on a glass substrate 11. Thereafter, a polycrystalline semiconductor film 13 serving as a channel layer is formed on the undercoat film 12, and the polycrystalline semiconductor film 12 is patterned using a photolithography technique. Then, a gate insulating film 14 is formed on the polycrystalline semiconductor film 13, and a gate electrode film 15 is formed on the gate insulating film 14. The formation of these various films is performed in a chamber (not shown).

Next, the substrate 10 on which various films are formed as described above is transferred to the resist coating chamber 20 by the transfer arm 100. Then, the substrate to be processed 10 is placed on the mounting table 21 of the spin coating apparatus, and a photoresist 16 is coated on the gate electrode film 15 of the substrate to be processed 10 by using a spin method (see FIG. 8B). Thereafter, the substrate 10 is transferred from the resist coating chamber 20 to the pre-bake chamber 30 by using the transfer arm 100, and the pusher pins 34 of the pre-bake device 31 provided in the pre-bake chamber.
The substrate to be processed 10 is placed thereon (see FIG. 8C). Subsequently, the pusher pin 34 is lowered to bring the target substrate 10 close to the heater 32 to start baking (FIG. 8).
(D)). The heater 32 is controlled so as to be kept at 110 ° C.

Next, after a predetermined baking time has elapsed in the pre-bake chamber 30, the substrate 10 to be processed is lifted by the pusher pins 34 so that it can be taken out by the transfer arm 100 (see FIG. 8 (e)). Then, the substrate 10 to be processed
Is transferred from the pre-bake chamber 30 to the cooling chamber 40 by the transfer arm 100, and is arranged close to the cooling plate 42 of the cooling device 41 provided in the cooling chamber 40 to perform a cooling step (FIG. 8F). reference). In addition, the cooling plate 42 is 23 ° C.
It is controlled to be kept at.

Next, when the cooling step is completed, the substrate 10 to be processed is transferred from the cooling chamber 40 to the exposure chamber 50 by the transfer arm 100, and the photoresist 16 on the substrate 10 is removed using the photomask 52 as a mask. It is exposed (see FIG. 8 (g)). And when the exposure process is completed,
The substrate to be processed 10 is transferred from the exposure chamber 50 to the developing chamber 60 by the transfer arm 100, and the photoresist 16
Is carried out. When the developing step is completed, the substrate 10 is transferred from the developing chamber 60 to the post-bake chamber 70 by the transfer arm 100, and post-baked. When the post-baking process is completed, the substrate 10 is transferred from the post-baking chamber 70 to the cooling chamber 80 by the transfer arm 100 and cooled.
Thereafter, the gate electrode film 15 is transferred to a chamber (not shown) by the transfer arm 100 and is patterned using the developed photoresist 16 as a mask to form a gate electrode. Thus, a liquid crystal display device is manufactured.

[0009]

In the above-described manufacturing apparatus, one or two transfer arms 100 are provided in one manufacturing apparatus instead of a structure in which a transfer arm is provided for each process. I have. For this reason, when the continuous processing is performed, the processing target substrate 10 is subjected to the baking process according to the transfer system of the processing target substrate 10 and the timing of each processing step.
In the state of (e), stagnation occurs in the pre-bake chamber 30. In particular, when an operation such as coater cup cleaning or mask replacement is performed, the timing of the transfer system is shifted, so that the substrate stays in the pre-bake chamber 30 and is then transferred to the cooling chamber 40 (FIG. 8C → FIG. 8 (C)). d) → FIG. 8 (e) → FIG.
(F)), it is immediately conveyed to the cooling chamber 40 without staying after baking (FIG. 8D → FIG. 8F).

As described above, in the conventional manufacturing apparatus, the residence time of the substrate to be processed 10 in the pre-bake chamber varies from substrate to substrate, and the residence time varies from approximately 0 seconds to 200 seconds.

Due to the variation in the residence time, the resist width after development varies. In particular, when a high-sensitivity resist is used, the variation becomes large. When you measure,
The variation 3σ for each of the 130 substrates was 0.6 μm. When a conventional manufacturing method is applied to processing of a TFT gate wiring of a liquid crystal display device using a TFT, the gate length varies, and as a result, TFT characteristics vary. In particular, since the off-state current increases as the gate length becomes shorter, a leak is liable to occur if the gate length greatly touches the shorter side. As described above, there is a problem that the margin of the ON current and the OFF current of the TFT is narrowed, the circuit operation is defective, and the yield is reduced.

The present invention has been made in view of the above circumstances, and has as its object to provide a method and apparatus for manufacturing an image display device capable of improving the yield as much as possible.

[0013]

A method of manufacturing an image display device according to the present invention comprises the steps of applying a photoresist on a substrate to be processed on which a film to be processed is formed, and prebaking the photoresist in a prebaking chamber. And a step of retaining the substrate to be processed in the pre-bake chamber for a predetermined time or more after the pre-bake.

It is preferable that the time during which the substrate to be processed stays in the pre-bake chamber is constant.

The photoresist has such a characteristic that the variation in the resist width after development is substantially constant even if the retention time varies when the photoresist is retained in the pre-bake chamber for the predetermined time or more. preferable.

An apparatus for manufacturing an image display device according to the present invention comprises:
A pre-bake chamber is provided for pre-baking a substrate to be processed in which a film to be processed is formed on a substrate, and a photoresist layer is formed on the film to be processed. For more than a predetermined time.

It is preferable that the substrate to be processed is kept in the pre-bake chamber after the pre-bake so as to have a substantially constant time.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

First, before describing an embodiment of the present invention,
The experimental results obtained for the first time by the present inventors will be described.

The relationship between the residence time of the substrate to be processed in the pre-baking chamber after the pre-baking process and the resist width after the development will be described. FIG. 1 shows the measurement results of the resist width when the exposure and development were performed while changing the residence time of the substrate to be processed in the prebaking chamber after the prebaking process. The experiment was performed using the manufacturing apparatus described in the related art, and the heater temperature of the prebaking chamber was 110 ° C., and the pin-up distance from the heater to the substrate to be processed was 50 mm. The photoresist may be a high-sensitivity resist such as TFR-970.
(Manufactured by Tokyo Ohka Kogyo). The target value of the resist width after development is 3.30 μm. It can be seen from FIG. 1 that as the residence time after the pre-bake treatment becomes longer, the developing speed of the resist becomes slower, so that the resist width becomes larger. However, the residence time is a predetermined value (for example, 120
1), it can be seen from FIG. 1 that the resist width after development becomes substantially constant even if the residence time varies. FIG. 1 shows that when the residence time is less than 120 seconds, the resist width after development varies greatly when the residence time varies.

Therefore, when an image display device is manufactured using the in-line manufacturing apparatus described in the prior art, the residence time of the substrate to be processed in the pre-baking chamber after the pre-baking process is a predetermined value (for example, 120 seconds). It can be seen that it is preferable to manufacture so as to be as described above. In this case, since the resist width after development is larger than the target value, it is necessary to adjust the development time in anticipation of the increase.

Next, the relationship between the residence time of the substrate to be processed in the pre-baking chamber after the pre-baking process and the variation (3σ) of the resist width in the surface of the substrate to be processed will be described with reference to FIG. FIG. 2 is a graph showing a measurement result of a variation in a resist width in the surface of the substrate when the substrate is exposed and developed by changing the residence time of the substrate in the prebaking chamber after the prebaking process. This experiment was performed using the manufacturing apparatus described in the related art, and the heater temperature in the pre-bake chamber was 110 ° C., and the pin-up distance from the heater to the substrate to be processed was 50 mm. The photoresist may be a high-sensitivity resist such as TFR-970.
(Manufactured by Tokyo Ohka Kogyo).

As can be seen from FIG. 2, as the residence time after the pre-bake process increases, the variation in the resist width in the surface of the substrate tends to increase. This is because the substrate to be processed is pinned up when staying after the pre-baking process and is held at a position about 50 mm away from the heater. However, a substrate for an image display device, for example, a substrate for a liquid crystal display device is a semiconductor device. Unlike 400m board size
It is thought that the cooling rate is different between the central part of the substrate and the peripheral part of the substrate as shown in FIG. FIG. 3 shows the measurement results of the substrate surface temperature at the edge and the center of the substrate when the substrate is placed in the prebaking chamber and the prebaking process is performed. The graph shows the change in substrate surface temperature at the edge of the substrate, and the graph g2 shows the change in substrate surface temperature at the center of the substrate to be processed. The horizontal axis in FIG. 3 indicates the elapsed time from when the substrate to be processed is placed on the pusher pins of the pre-bake device provided in the pre-bake chamber. As soon as the substrate to be processed is placed on the pusher pin, a difference in substrate surface temperature occurs between the end and the center of the substrate to be processed. Then, when about 50 seconds have elapsed after being placed on the pusher pin, the pusher pin is lowered, and the substrate to be processed is arranged close to the heater of the pre-bake device. For this reason, the surface temperature of the substrate to be processed also rises rapidly. And about 1
Prebaking is performed at 10 ° C. About 120 seconds after the substrate to be processed is placed on the pusher pin, the pusher pin is raised to start cooling the substrate to be processed. The cooling rate at the start of the cooling was 0.4 ° C./sec at the center of the substrate to be processed, whereas the cooling rate was 1.1 to 2.0 ° C./sec at the edge of the substrate. This is considered to be because the heater has a size slightly larger than the substrate, so that the edge of the substrate to be processed is cooled more easily than the center. Thereby, the resist width at the edge of the substrate to be processed is smaller than that at the center.

Next, the effect of the substrate cooling rate after prebaking on the resist width will be described with reference to FIG.
FIG. 4 is a graph showing the relationship between the cooling rate of the substrate to be processed and the resist width. As can be seen from FIG. 4, when the cooling rate is high, the resist width becomes small. Therefore, in order to reduce the variation in the resist width, it is necessary to control the cooling rate for each substrate and in the plane of the substrate to be constant. In particular, when the substrate size is large, if the substrate stays in the pre-bake apparatus as described above, the cooling rate in the substrate surface varies due to the influence of heat from the heater.

Next, an embodiment of a method for manufacturing an image display device according to the present invention will be described with reference to FIGS. FIG. 5 is a process cross-sectional view showing a manufacturing process of the liquid crystal display device manufactured by the manufacturing method of the present embodiment. The manufacturing method of this embodiment is performed using the manufacturing apparatus shown in FIG.

First, as shown in FIG.
After an undercoat film 12 and a polycrystalline silicon film 13 are sequentially formed on a glass substrate 11 of 00 mm × 500 mm, a gate insulating film 14 is formed on the polycrystalline silicon film 13, and a gate electrode is formed on the gate insulating film 14. Is formed. As a metal film, for example, Mo or MoW
Are formed by sputtering.

Next, the metal film 15 is washed to remove particles attached during sputtering or the like, and then the substrate 10 on which the metal film 15 is formed is transferred to the transfer arm 1.
In step 00, the wafer is transferred to the resist coating chamber 20. Then, as shown in FIG. 1B, the substrate 10 to be processed is placed on a mounting table 21 of a spin coating apparatus, and a positive type photoresist 16 such as TFR-970 is formed on the metal film 15 of the substrate to be processed by a spin method. Apply. As the photoresist, a high-sensitivity resist that can be exposed to light of 20 mJ / cm ² was used. Usually, in consideration of throughput, a photoresist having a sensitivity of 40 mJ / cm ² or less is used.

Next, the substrate 10 to which the photoresist has been applied is transferred to the resist coating chamber 2 using the transfer arm 100.
From 0, the substrate 10 is transferred to the pre-bake chamber 30, and the substrate to be processed 10 is placed on the pusher pins 34 of the pre-bake device 31 as shown in FIG. At this time, the pusher pin 34 is located 50 mm away from the heater 32,
The temperature of the heater 32 of the pre-bake device 31 is controlled to be kept at 110 ° C.

Next, as shown in FIG. 5D, the pusher pin 34 is lowered to bring the substrate 10 close to the heater 32 to perform a pre-bake process. Temperature control is important because the temperature distribution of the heater also affects the variation of the resist width.
The temperature of the heater was controlled at 110 ± 1 ° C. Heater temperature ±
The surface temperature of the substrate to be processed 10 fluctuated at ± 2 ° C. with respect to 1 ° C. As can be seen from the above experimental results, the amount of change in resist width with respect to temperature is 0.04 μm / ° C.
The resist width can be suppressed to ± 0.08 μm. In the pre-baking process, the pins are lowered, stopped once at a position 4 mm above the heater 32, and baked for 50 seconds. The purpose is to prevent the glass substrate from warping due to rapid heating. Then, heater 3
A bake is performed for 70 seconds while the substrate is brought into close contact with the vacuum. Note that a method may be used in which the substrate to be processed 10 is vacuum-chucked at a distance of 0.2 mm without completely contacting the heater 32. This can suppress the occurrence of defects due to static electricity on the substrate.

Then, the pre-baking chamber 3 is kept until a predetermined time (for example, 120 seconds) elapses after the completion of the pre-baking process.
The target substrate 10 stays at 0. When the pre-bake process is completed, as shown in FIG. 5E, the substrate to be processed 10 is pinned up by pusher pins 34 and is held at a position separated from the heater 32 by a predetermined distance (for example, 50 mm). As described above, by making the residence time of the substrate 10 after the pre-baking process in the pre-baking chamber 30 equal to or longer than the predetermined time (for example, 120 seconds), the resist width after the development can be made substantially constant. Note that the residence time is desirably a constant value in order to suppress variations in the resist width in the surface of the substrate to be processed.

Next, the pre-bake chamber 30 of the substrate 10 to be processed is
As soon as the dwell time after the pre-baking process in the step elapses for a predetermined time, the substrate 10 to be processed is taken out of the pre-baking chamber 30 by the transport arm 100 and transported to the cooling chamber 40. Then, as shown in FIG. 5F, the substrate 10 to be processed is placed on a cooling plate 42 of a cooling device 41 provided in the cooling chamber 40.
Are brought into close contact. The temperature of the cooling plate 42 is room temperature 23 ° C. ± 2.
Cooling is performed at 60 ° C. for 60 seconds. In the present embodiment, it takes 10 seconds from the removal of the substrate to be processed from the pre-bake chamber 30 to the placement of the substrate to be processed 10 on the cooling plate 42. As described above, since the substrate is not exposed to the heater, the transfer is hardly affected, and the substrate is uniformly cooled in the plane. By the way, when measured, the cooling rate was 8 ± 0.2 ° C./sec in the plane of the substrate.

Next, when the cooling step is completed, the substrate to be processed 10 is transferred from the cooling chamber 40 to the exposure chamber 50 by the transfer arm 100. Then, as shown in FIG. 5G, the resist 16 on the substrate 10 to be processed is exposed using the photomask 52 as a mask. When the exposure processing is completed, the substrate 10 to be processed is transferred from the exposure chamber 50 to the developing chamber 60 by the transfer arm 100, and the developing processing is performed as shown in FIG. This development processing is performed with TMAH 2.4%
The developing solution is applied on the substrate by, for example, a paddle method to dissolve the exposed resist portion, and thereafter, the developing solution is replaced and washed with pure water, and the resist is formed on the metal film 15 of the substrate 10 to be processed. The pattern 16a is left (see FIG. 5H).

Next, when the development processing is completed, the substrate 10 to be processed is transported from the development chamber 60 to the post-baking chamber 70 by the transport arm 100, and the post-baking processing is performed. As shown in FIG. 5 (i), this post-baking process is performed in a state where the heater 72 of the post-baking device 71 provided in the post-baking chamber 70 is kept at 130 ° C.

Next, when the post-bake processing is completed, the substrate to be processed 10 is transferred from the post-bake chamber 70 to the cooling chamber 80 by the transfer arm 100, where the cooling processing is performed. The cooling in the post-baking may be the same as that in the pre-baking, but after the post-baking, it does not significantly affect the variation in the resist width, so that it is not necessary to control the cooling process so much.

Next, when the cooling process is completed, the substrate 10 to be processed is transferred to an etching chamber (not shown) by the transfer arm 100, and as shown in FIG. The film 15 is etched to form a gate electrode 15a. Then, using the gate electrode 15a as a mask, the polycrystalline silicon film 1 is formed.
By introducing an impurity into the substrate 3, a low concentration source / drain region 13a is formed. Then, a not-shown resist pattern is formed on the side and top surfaces of the gate electrode 15a, and impurities are introduced using the resist pattern as a mask, thereby forming a high-concentration source / drain region 13b (see FIG. 5 (l)). ). After that, the resist pattern is removed. And plasma CV on the whole surface
After the interlayer insulating film 92 is formed using D, a contact hole for making contact with the high concentration source / drain region 13b is formed in the interlayer insulating film 92 (see FIG. 5 (l)). Thereafter, a film of an electrode material is deposited on the entire surface so as to fill the contact hole, and the source / drain electrodes 94 are formed by patterning the film of the electrode material, thereby producing a thin film transistor (see FIG. 5 (l)). .

The effect of the present embodiment was examined by measuring the resist width for 100 substrates to be processed and calculating the resist width variation 3σ. Conventionally, the variation between the substrates is 0.1.
Although it was 6 μm, it could be reduced to 0.2 μm by using the manufacturing method of the present embodiment. When the thin film transistor shown in FIG. 5 (l) is manufactured using the above process, and finally a liquid crystal display device including a thin film transistor having a built-in drive circuit is manufactured, the line width variation 3σ of the gate line having a line width of 3.0 μm is , Within 0.5 μm. On the other hand, in the conventional manufacturing method, the line width variation 3σ of the gate line having the line width of 3.0 μm was 0.9 μm. Thus, by using the manufacturing method of the present embodiment, display defects due to TFT characteristics caused by line width variations were reduced.

As described above, in this embodiment, the resist width after development is made substantially constant by setting the residence time of the substrate 10 after the pre-bake processing in the pre-bake chamber 30 to a predetermined time or more. Is possible,
The yield can be improved as much as possible. Note that the residence time is desirably a constant value in order to suppress variations in the resist width in the surface of the substrate to be processed.

In the above-described embodiment, the residence time of the substrate 10 after the pre-baking process in the pre-baking chamber 30 is equal to or longer than the predetermined time.
The pre-bake may be configured so as not to stay in the pre-bake chamber 30 at all. With such a configuration, it is possible to make the cooling rate of each substrate 10 to be constant, and to make the cooling rate in the surface of the substrate to be uniform. As a result, even when a high-sensitivity resist capable of maintaining a high throughput is used, it is possible to reduce variations in the resist width for each substrate and within the substrate surface.

Next, a specific example in which the residence time in the pre-baking chamber 30 after the pre-baking is set to zero or a constant value will be described.

First, the case of adjusting by software will be described. As a first specific example, the transfer arm 100 waits in front of the pre-bake chamber 30 before the baking process is completed, so that the substrate to be processed can be taken out immediately after the substrate 10 is pinned up. Thereby, the residence time in the pre-baking chamber 30 after the pre-baking can be made zero.
As a second specific example, a sequence is set such that the cooling time is shorter than the pre-bake time, and the substrate 10 to be processed is transferred to the cooling chamber 40 as soon as the substrate 10 is taken out of the pre-bake chamber 30 after the pre-bake processing. And
When, for example, 15 seconds before the completion of the baking process, a signal is sent to the transfer arm 100 to preferentially cause the transfer arm 100 to wait in front of the pre-bake chamber 30. Note that the above-mentioned 15 seconds is a time required for the transfer arm 100 to move to the position before the pre-bake chamber 30 after the operation being performed when the transfer arm 100 receives the above signal. To make such a sequence possible, the pre-bake processing time is set as long as possible (for example, 200 seconds) and the processing time of other steps is reduced to about 50 to 70 seconds as long as the pre-bake processing can be sufficiently performed. It is necessary to set. By doing so, basically, the transfer arm 100 is in a standby state before the end of the pre-bake, so that the residence time after the pre-bake processing can be made substantially zero.

Next, it will be described that the residence time after the pre-bake processing can be made zero or constant by modifying the manufacturing apparatus.

First, as a first specific example, the baking chamber 30
The purpose of the present invention is to provide a device structure having a dedicated transfer arm from the first to the cooling chamber 40 so that the substrate to be processed can be taken out immediately. With this configuration, the residence time after the pre-bake processing can be made substantially zero.

Further, as a second specific example, as shown in FIG. 6, the pre-bake chamber 30 is provided with a cooling device. FIG. 6A is a top view of the heater 32 and the cooling devices 36a and 36b of the pre-bake device when the substrate to be processed is pre-baked, and FIG.
FIG. 3 shows a top view of the heater 32 of the pre-baking device and the cooling devices 36a and 36b during cooling. This cooling device 36
The parts a and 36b are divided on the right and left sides of the heater 32 and at a predetermined height from the heater 32 except when the cooling operation is performed (see FIG. 6A). Then, when the pre-bake processing of the processing target substrate 10 is completed, the processing target substrate 10
Is raised by the pusher pin 34 and is held at a predetermined position from the heater 32 (for example, a position at a height of 300 mm or more from the heater 32). At this time, the cooling devices 36a and 36b provided in the pre-bake chamber are in the center direction (FIG. 6).
Then, the cooling plates of the cooling devices 36a and 36b are inserted between the heater 32 and the substrate to be processed. For this reason, each cooling plate of the cooling devices 36a and 36b is provided with a notch 37 for avoiding collision with the pusher pin 34. Cooling device 36a,
When the cooling plate 36b is inserted between the heater 32 and the substrate to be processed, the pusher pins 34 descend, and the substrate 10
Is placed on the cooling plate and cooled. It is necessary that the cooling plate is not heated by the influence of the heat from the heater 32. For this reason, the cooling plate has a large capacity (thickness: 50 mm) and circulates a refrigerant at 23 ° C. to maintain a constant temperature (23 ± 5 ° C.). Further, it is preferable to coat a heat reflection film on the lower surface (heater side) of the cooling plate. When the cooling is completed, the pusher pin 34
Is raised, the substrate to be processed is pinned up, and the substrate to be processed 10 is taken out of the pre-bake chamber 30 using the transfer arm 100. In the second specific example, the cooling chamber 4 of the manufacturing apparatus
0 becomes unnecessary.

As described above, by making the residence time after the pre-bake process almost zero, the variation in the resist width among the substrates can be reduced, and the in-plane variation of the substrate has been 0.5 μm in comparison with the conventional case. It was confirmed that it could be reduced to 0.3 μm.

It goes without saying that the manufacturing apparatus of the present invention may be used for all patterning used for forming TFTs.

[0046]

As described above, according to the present invention, the variation in the resist width after development can be reduced as much as possible, and the yield can be improved as much as possible.

[Brief description of the drawings]

FIG. 1 is a graph showing a relationship between a residence time of a substrate to be processed after prebaking and a resist width.

FIG. 2 is a graph showing a relationship between a residence time after prebaking and a variation in a resist width in a substrate surface.

FIG. 3 is a graph showing a time change of a surface temperature of a substrate to be processed in a pre-bake process.

FIG. 4 is a graph showing a relationship between a cooling rate after prebaking and a resist width.

FIG. 5 is a process sectional view showing a configuration of an embodiment of a method for manufacturing an image display device according to the present invention.

FIG. 6 is a top view showing the configuration of a pre-bake chamber according to the image display device manufacturing apparatus according to the present invention.

FIG. 7 is a block diagram showing a general configuration of an in-line type manufacturing apparatus.

FIG. 8 is a cross-sectional view illustrating a manufacturing process of a conventional method for manufacturing an image display device.

[Explanation of symbols]

 Reference Signs List 11 glass substrate 12 undercoat (nitride film, oxide film) 13 channel layer (polycrystalline semiconductor film) 13a low-concentration source / drain region 13b high-concentration source / drain region 14 gate insulating film 15 gate electrode film 15a gate electrode 16 photoresist Reference Signs List 16a photoresist 20 resist coating chamber 21 mounting table of spin coating apparatus 30 pre-bake chamber 31 pre-bake apparatus 32 heater 34 pusher pin 36a, 36b cooling apparatus 40 cooling chamber 41 cooling apparatus 42 cooling plate 50 exposure chamber 52 photomask 60 developing chamber 70 post Bake chamber 80 Cooling chamber 82 Heater 92 Interlayer insulating film 94 Source / drain electrode

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Claims (5)

[Claims] A step of applying a photoresist on a substrate to be processed on which a film to be processed is formed; a step of pre-baking the photoresist in a pre-bake chamber; A method of manufacturing the image display device, the method comprising: 2. The method according to claim 1, wherein the time during which the substrate to be processed stays in the pre-bake chamber is constant. 3. The method according to claim 1, wherein the photoresist has a characteristic that the variation in the resist width after development is substantially constant even if the residence time varies when the photoresist is retained in the pre-bake chamber for the predetermined time or more. The method for manufacturing an image display device according to claim 1 or 2, wherein: 4. A pre-bake chamber for pre-baking a substrate on which a film to be processed is formed on a substrate and having a photoresist layer formed on the film to be processed, wherein the pre-baking of the substrate to be processed is performed after the pre-baking of the substrate to be processed. An apparatus for manufacturing an image display device, wherein a substrate is retained in the pre-bake chamber for a predetermined time or more. 5. The apparatus for manufacturing an image display device according to claim 4, wherein after the pre-baking, the time for which the substrate to be processed stays in the pre-baking chamber is substantially constant.