JP2658953B2 - Resist baking equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist baking apparatus used for drying and curing a resist applied to a substrate.

[0002]

2. Description of the Related Art Conventionally, in a semiconductor manufacturing process, a baking process is performed to heat a substrate on which a resist is applied and to dry and harden a solvent or the like in the resist.

[0003] As such a baking method, for example, an apparatus for transporting substrates one by one and baking on a hot plate is used.

FIG. 5 is a perspective view for explaining a conventional resist baking apparatus, FIG. 6 is a cross-sectional view taken along line AA 'of the resist baking apparatus of FIG. 5, and FIGS. FIG.

The hot plate 10 has a surface size of the substrate W
It is formed of a square metal plate larger than the size of (see FIG. 6), and is controlled at a predetermined baking temperature by heating means (not shown) such as a heater provided below the metal plate.

A plurality of small pin holes 11 having an inner diameter of about 1.5 mm are provided on the hot plate 10 (four at the center in FIG. 5). 12 (see FIG. 6).

That is, the lifting pins 12 are raised or lowered in the pin holes 11 by driving means (not shown) so as to protrude from the surface of the hot plate 10. And the lifting pin
When the reference numeral 12 rises, the substrate W is supported by the lifting pins 12 as shown by a dashed line in FIG.

On the surface of the hot plate 10, a plurality of small projections 13 for supporting the periphery of the substrate W at points are provided (four in FIG. 5).

Further, the transfer arms 14 and 14 'are moved up and down by driving means (not shown) as shown by arrows in FIGS.
The substrates W placed thereon are sequentially transferred to the forward side in a cycle of forward / backward movement in conjunction with the operation 12.

Next, the operation of the conventional resist baking apparatus will be described.

[0011] First, FIG. 7 (A), as shown in FIG. 7 (B), resist coating cup resist R (Fig. 9 (not shown)
The substrate W coated with the substrate W is transferred to the upper portion of the hot plate 10 via the transfer arm 14.

Next, as shown in FIG. 7 (C), the substrate W is supported by the raised lifting pins 12, and the transfer arm 14 is retracted in the direction of the arrow and stopped at the retracted position.

Then, as shown in FIG. 7 (D), the elevating pins 12 descend and the substrate W is supported by a plurality of projections 13 arranged on the surface of the hot plate 10, and It is baked to a predetermined temperature by radiant heat.

Next, as shown in FIG. 8 (E), after a desired baking time has elapsed, the elevating pins 12 are raised to separate the substrate W from the surface of the hot plate 10.

Finally, as shown in FIGS. 8 (F) to 8 ( H ),
The baked substrate W is sent to the next step via the transfer arm 14.

[0016]

In the conventional resist baking apparatus, while the elevating pins 12 are immersed below the surface of the hot plate 10, the heating is mainly performed by radiant heat from the hot plate 10. Therefore, when the lifting pins 12 rise and support the back surface of the substrate W at four points via the transfer arms 14 and 14 ′, the heat of the lifting pins 12 is transmitted to the substrate W and a local temperature gradient is formed. Would.

Further, when the elevating pins 12 are lowered and the substrate W is supported at four points by the convex portions 13 disposed on the surface of the hot plate 10 and baking is performed by radiant heat from the surface of the hot plate 10, A local temperature gradient is formed at the pin hole 11.

As a result, in the conventional resist baking apparatus, as shown in FIGS. 9A and 9B, the positions of the pin holes 11 and the elevating pins 12 provided on the hot plate 10 are changed. There is a problem that local irregularities in the resist film thickness occur on the surface of the corresponding substrate W. The irregularities in the thickness of the resist film cause variations and deterioration of the characteristics or quality of the substrate (for example, display unevenness in an LCD device).

In particular, in order to cope with the necessity of faithfully controlling the wiring pattern on the substrate, which will be increasingly miniaturized in the future, with high dimensional accuracy, uniformity of the resist film thickness formed on the substrate surface is required. You.

For this purpose, it is essential to uniformly heat the entire surface of the substrate to dry the solvent in the resist.

The present invention has been made in view of the above problems, and makes it possible to uniformly heat the entire surface of a substrate and to avoid the occurrence of irregularities in the resist film thickness due to a local temperature gradient. An object of the present invention is to provide a resist baking apparatus.

[0022]

In order to achieve the above object, the present invention relates to a resist baking apparatus which has a substrate transfer section and heat-treats a resist-coated substrate on a hot plate. A resist baking apparatus is provided, wherein a substrate coated with a resist from a transport unit is placed on the hot plate and a second hot plate that can be raised and lowered is held at a predetermined temperature of the hot plate when the substrate is lowered. I do.

In the resist baking apparatus of the present invention, preferably, a plurality of projections are provided around the surface of the second hot plate, and the substrate is supported by the plurality of projections. 2 is characterized in that the resist on the substrate surface is dried by radiant heat from the surface of the hot plate.

In the resist baking apparatus of the present invention, preferably, a plurality of pin holes are provided on the first hot plate, and the surface of the second hot plate facing the substrate is provided with the pin holes. The second hot plate is provided with a plurality of recesses at positions corresponding to the plurality of pin holes of the first hot plate, respectively, on the back side of the second hot plate. At the time of ascent, the concave portion is supported by being in contact with the ascending and descending pin tip portion which is inserted through the pin hole of the first hot plate and rises,
The second hot plate comes into contact with the surface of the first hot plate when the lifting pin is lowered.

[0025]

According to the present invention, the entire surface of the second hot plate is a flat metal plate having nothing except a plurality of convex portions arranged around the surface of the second hot plate. With this configuration, heat is uniformly transmitted to the entire surface of the substrate placed on the second hot plate, and the substrate is directly held at the tips of the elevating pins during the baking process of the resist film (the conventional example). In this case, a local temperature gradient can be prevented from occurring, and variations in the resist film thickness can be suppressed and a uniform resist film thickness distribution can be formed.

[0026]

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

FIG. 1 is a perspective view for explaining an embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA 'of FIG. 1, and FIGS. 3 and 4 are views for explaining the baking operation in the order of steps. It is.

Referring to FIG. 1, first hot plate 1
Is formed of a square metal plate whose surface is larger than the size of the substrate W (see FIG. 2), and is heated to a predetermined baking temperature by heating means (not shown) such as a heater provided on the lower side. Controlled.

The inner diameter of the first hot plate 1 is about 1.5 mm
A plurality of small pin holes 2 are provided (in FIG. 1, provided at four locations at the center), and a thin elevating pin 3 that passes through the pin hole 2 is provided. That is, the elevating pin 3 moves up or down in the pin hole 2 by driving means (not shown),
The first hot plate 1 is configured so as to protrude from the surface thereof.

Next, the second hot plate 4 placed in contact with the tip of the elevating pin 3 has a surface size of the substrate W.
It is made of a square metal plate that is almost equal to.

On the surface of the second hot plate 4, a substrate W
A plurality of small projections 5 are provided for supporting the periphery within about 10 mm from the end face at a plurality of points (disposed at four places in FIG. 1). A small concave portion 6 for positioning in the left-right direction is provided at a position in contact with the portion. When the elevating pin 3 is lifted, as shown by a dashed line in FIG.
Is supported by the lifting pins 3.

As shown in FIGS. 3 and 4, the transfer arms 7, 7 'advance and retreat in the directions indicated by arrows by driving means (not shown) in conjunction with the operation of the elevating pins 3 and the second hot plate 4. Is driven as one cycle, and the mounted substrates W are sequentially transferred to the forward side.

Next, the operation of this embodiment will be described.

First, as shown in FIGS. 3A and 3B, a substrate W coated with a resist R by a resist coating cup (not shown) is placed on a second hot plate 4 via a transfer arm 7. Transported to

Next, as shown in FIG. 3C, the second hot plate 4 rises with the elevation of the lifting pins 3, and the substrate W is placed on the protrusions 5 provided on the surface of the second hot plate 4.
Are simultaneously supported at four points, and the transfer arm 7 retreats in the direction of the arrow and stops at the retreat position.

Then, the second hot plate 4 is lowered together with the lowering of the elevating pins 3, and as shown in FIG. 3D, the second hot plate 4 comes into close contact with the surface of the first hot plate 1 and at the same time. By direct heating from the first hot plate 1, the entire surface is uniformly heated to a temperature substantially equal to that of the first hot plate 1 with an accuracy of, for example, within ± 1 ° C.

In this state, the substrate W supported at four points on the projections 5 of the second hot plate 4 is baked to a predetermined temperature by radiant heat from the surface of the second hot plate 4.

Next, after a desired baking time has elapsed, the second hot plate 4 is raised together with the lifting pins 3 as shown in FIG.

Finally, as shown in FIGS. 4 (F) to 4 (H),
The baked substrate W is sent to the next step via the transfer arm 7.

According to the present embodiment, the substrate is held on the flat second hot plate having no pin holes or the like for inserting the elevating pins on the front surface side. Heat can be uniformly transmitted to the entire surface of the substrate with an accuracy of approximately ± 1 ° C, and the uniformity of resist film thickness distribution is achieved by eliminating the variation in the drying speed of the solvent of the resist applied on the substrate. can do. For example, 30
When a resist film having a thickness of 2 μm is formed on a glass substrate having a size of 0 × 350 mm, the variation in the film thickness distribution can be reduced to 1/3 or less as compared with the conventional case.

In the above embodiment, the distance between the second hot plate 4 and the substrate W via the surface convex portion 5 is approximately one.
Although the proximity baking method in which heating is performed with a small gap of less than mm is employed, the present invention is not limited to this. For example, the protrusion 5 disposed on the surface of the second hot plate 4 is eliminated. Needless to say, the present invention can also be applied to a contact baking method in which the substrate W is directly heated by contact.

[0042]

As described above, according to the present invention, the substrate is not directly held by the tips of the elevating pins during the baking process of the resist film as in the conventional example, but the surface of the substrate is flat. By adopting the method of holding the substrate on the second hot plate, the heat of the second hot plate can be uniformly transmitted to the entire surface of the substrate with an accuracy of approximately ± 1 ° C. or less. As a result, there is an effect that a uniform resist film thickness distribution can be formed without variations in the drying speed of the solvent of the resist applied on the substrate.

As an example of the quantitative effect of the present invention, for example,
When a resist film having a thickness of 2 μm is formed on a glass substrate having a size of 300 × 350 mm, the variation in the resist film thickness distribution can be reduced to 1/3 or less of the conventional example.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating the configuration of an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA 'of FIG.

FIG. 3 is a diagram for explaining a baking processing operation in an embodiment of the present invention in the order of steps.

FIG. 4 is a view for explaining a baking processing operation in an embodiment of the present invention in the order of steps.

FIG. 5 is a perspective view of a conventional device.

FIG. 6 is a sectional view taken along the line AA ′ of FIG. 5 ;

FIG. 7 is a view for explaining a baking operation in a conventional apparatus in the order of steps.

FIG. 8 is a diagram for explaining a baking operation in a conventional apparatus in the order of steps.

FIG. 9 is a cross-sectional view for explaining local irregularities in resist irregularities.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st hot plate 2, 11 pin hole 3, 12 raising / lowering pin 4 2nd hot plate 5, 13 convex part 6 recessed part 7, 7 ', 14, 14' Transfer arm 10 hot plate W board R resist

Claims (3)

(57) [Claims] 1. A resist baking apparatus having a substrate transfer section, wherein a resist-coated substrate is heat-treated on a hot plate. A resist baking apparatus having a second hot plate that can be raised and lowered and held at a predetermined temperature of the hot plate when the hot baking state is maintained. 2. A plurality of protrusions are provided around the surface of the second hot plate, the substrate is supported by the plurality of protrusions, and the substrate is heated by radiant heat from the surface of the second hot plate. 2. The resist baking apparatus according to claim 1, wherein the resist on the surface is dried. 3. A plurality of pin holes are provided in a first hot plate, and a surface side of the second hot plate facing the substrate has a flat plate shape without pin holes, and the second hot plate has a plate shape. On the back side of the plate, a plurality of recesses are provided at positions corresponding to the plurality of pin holes of the first hot plate, respectively, and when the second hot plate is raised, the recess is formed by the first hot plate. The second hot plate contacts and is supported by being contacted with the tip of an elevating pin that rises by passing through the pin hole, and that the second hot plate contacts the surface of the first hot plate when the elevating pin is lowered. The resist baking apparatus according to claim 1, wherein: