JP2001351845A - Application device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an applicator for applying resist solution to be applied to a treatment substrate in uniform film thickness. SOLUTION: When an application solution supply nozzle 46 passes through outer circumferential edge regions G1 to G4, application solution T of low viscosity (shown in black) is applied, and it is applied to a region (white part D) excepting the outer circumferential edge regions G1 to G4 by raising its viscosity. As a result, wettability to a substrate G rises in the outer circumferential edges G1 to G4 of a glass substrate G and rising of application solution in an outer circumferential edge can be restrained. Therefore, resist solution can be applied in uniform thickness all over the glass substrate G.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating apparatus for coating a resist solution on a glass substrate used for, for example, a liquid crystal display (LCD).

[0002]

2. Description of the Related Art In a manufacturing process of an LCD, an ITO (Indium Tin Oxide) is formed on a glass substrate for an LCD to be processed.
In order to form a thin film and an electrode pattern of xide), a photolithography technique similar to that used for manufacturing a semiconductor device is used. In the photolithography technique, a photoresist is applied to a glass substrate, exposed, and further developed. As a method of applying the resist solution,
At present, a spin coating method in which a resist liquid is dropped on the center of a glass substrate while rotating the glass substrate, and the resist liquid is diffused and applied using centrifugal force is mainly used.

However, in the spin coating method, the resist solution scatters outside the glass substrate G, and a considerable amount is wasted. For this reason, as shown in FIG.
Without rotating the holding member for holding the glass substrate G, the resist liquid supply nozzle 110 is scanned so as to move in the vertical and horizontal directions or in the circumferential direction, and the resist liquid 100 is formed into a thin linear shape to form the glass substrate. A means for applying the composition on G (spinless method) has been proposed.

[0004]

However, in the case of the spinless method, as shown in FIG.
There is a problem that the resist solution applied thereon rises more at the outer peripheral edge of the glass substrate G than at other portions due to surface tension. Such a swelling part 100
a, the uniformity of the coating film is impaired, and the processing time in the exposure step or the development step is reduced by the rising portion 1
It is necessary to match the processing time of the exposure and development processing steps at 00a. For example, as shown in FIG. 11B, when the resist is removed from the raised portion 100a to the flat portion 100b, that is, at a predetermined interval L in the drawing, the exposure and development processing time in the flat portion 100b is reduced by the exposure and development time in the raised portion 100a. Since it is necessary to match the development processing time, the processing time of the flat portion 100b becomes longer than a predetermined processing time, and the exposure and development of the flat portion 100b are performed excessively.

[0005] In the resist solution coating process,
Immediately after the application of the resist solution, the raised portion 100a is removed by an edge remover or the like.
As described in No. 96, the glass substrate G immediately after the application of the resist solution may be dried under reduced pressure in order to prevent the occurrence of transfer marks.

However, when the glass substrate G is dried under reduced pressure,
As shown in FIG. 12, the resist liquid on the substrate has a depression 105 in the inner peripheral portion of the raised portion 100a, and even when the raised portion 100a is removed at the position of the broken line 80 by an edge remover or the like in this state. The depression 105 remains, and the coating thickness is not uniform on the glass substrate G. Therefore, it is necessary to match the processing time of exposure and development in the recess 105 with the processing time of the flat portion 100b, so that the exposure and development of the portion of the recess 105 are excessively performed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to prevent a swelling and dent of a coating solution from occurring near an outer peripheral portion of an object to be processed, and to improve the uniformity of a film thickness of the coating solution. It is an object of the present invention to provide a coating apparatus that can perform the coating.

[0008]

An object of the present invention is to provide a holding member for holding an object to be processed and a coating liquid supply for supplying a coating liquid onto the object to be processed while relatively moving with respect to the holding member. The problem is solved by a coating apparatus comprising: a nozzle; and control means for varying the viscosity of the coating liquid discharged from the coating liquid supply nozzle.

As a result, the uniformity of the film thickness of the coating solution can be improved, and excessive exposure and development can be prevented, so that a precise circuit pattern can be formed.

[0010]

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

FIG. 1 is a plan view showing a system for applying and developing resist on an LCD substrate to which the present invention is applied.

This coating / developing processing system includes a cassette station 1 on which a cassette C accommodating a plurality of substrates G is mounted, and a plurality of processing units for performing a series of processing including resist coating and developing on the substrates G. The processing unit 2 includes an interface unit 3 for transferring a substrate G between the exposure unit (not shown) and a cassette station 1 and an interface unit 3 at both ends of the processing unit 2. Are located.

The cassette station 1 has a transport mechanism 10 for transporting an LCD substrate between the cassette C and the processing section 2. And cassette station 1
, A cassette C is loaded and unloaded. The transport mechanism 10 includes a transport arm 11 that can move on a transport path 10 a provided along the direction in which the cassettes are arranged. The transport arm 11 allows the substrate G to be moved between the cassette C and the processing unit 2.
Is carried out.

The processing section 2 is divided into a front section 2a, a middle section 2b, and a rear section 2c.
2, 13 and 14, and each processing unit is disposed on both sides of these transport paths. Then, relay portions 15 and 16 are provided between them.

The front section 2a includes a main transfer device 17 movable along the transfer path 12. On one side of the transfer path 12, two cleaning devices (SCR) 21a and 21b are disposed. On the other side of the transport path 12, an ultraviolet irradiation / cooling unit 25 in which an ultraviolet irradiation device (UV) and a cooling device (COL) are vertically stacked, and two heat treatment devices (HP) are vertically stacked. Heating unit 2
6, and a cooling unit 27 in which two cooling devices (COL) are vertically stacked.

The middle section 2b is provided with a main transfer device 18 that can move along the transfer path 13. On one side of the transfer path 13, a resist coating device (CT) 22 and a reduced-pressure drying device (DP) ) 40 and an edge remover (ER) 23 for removing the resist on the peripheral portion of the substrate G are integrally provided and arranged, and constitute a coating unit group 50. In this coating system processing unit group 50, after the resist is applied to the substrate G by the resist coating device (CT), the substrate G is transported to the reduced-pressure drying device (DP) 40 and dried.
Thereafter, the edge remover (ER) 23 performs a peripheral edge resist removal process. Transport path 13
On the other side, a heat treatment unit 28 in which two heating devices (HP) are vertically stacked, a heat treatment device (HP)
Heating / cooling unit 29 in which a heat treatment / cooling unit (COL) is vertically stacked, and an adhesion / cooling unit 30 in which an adhesion treatment device (AD) and a cooling device (COL) are vertically stacked. Have been.

Further, the rear section 2c is provided with a main transfer device 19 which can move along the transfer path 14.
On one side, three developing devices (DEV) 24a,
24b and 24c are arranged, and on the other side of the transport path 14, a heat treatment unit 31 in which two heat treatment devices (HP) are vertically stacked, and a heat treatment device (HP)
And a cooling device (COL) are vertically stacked, and two heat treatment / cooling units 32 and 33 are arranged.

The main transporting devices 17, 18, and 19 respectively include an X-axis driving mechanism, a Y-axis driving mechanism in two directions in a horizontal plane,
And a vertical Z-axis drive mechanism.
A rotation drive mechanism that rotates about an axis is provided, and has arms 17a, 18a, and 19a that support the substrate G, respectively.

The processing unit 2 includes cleaning devices 21a and 21b, a resist coating device (CT) 22, developing devices 24a, 24b, and 24c on one side of the transport path.
, And only the heat processing units such as the heating processing unit and the cooling processing unit are disposed on the other side.

A chemical solution supply device 34 is provided at a portion of the relay units 15 and 16 on the side where the spinner system unit is disposed, and a space 35 for maintenance is provided.

The interface section 3 includes an extension 36 for temporarily holding the substrate when transferring the substrate to and from the processing section 2, and two buffer stages 37 provided on both sides thereof for disposing a buffer cassette.
And a transport mechanism 38 for loading and unloading the substrate G between these and an exposure apparatus (not shown). Transport mechanism 38
Is provided with a transfer arm 39 movable along a transfer path 38a provided along the direction in which the extension 36 and the buffer stage 37 are arranged. The transfer arm 39 allows the transfer of the substrate G between the processing unit 2 and the exposure apparatus. Done.

FIGS. 2 and 3 show a coating system processing apparatus group 50.
It is the schematic plan view and schematic side view which show. These resist coating device (CT) 22, reduced pressure drying device (DP) 4
0 and the edge remover (ER) 23 are integrally arranged in parallel on the same stage as shown in the figure.

The vacuum drying device (DP) 40 has a lower chamber 61 and an upper chamber 62 provided so as to cover the lower chamber 61 and keeping the processing space therein airtight. The lower chamber 61 is provided with a stage 63 on which the substrate G is mounted. At each corner of the lower chamber 61, four exhaust ports 64 are provided.
Is connected to an exhaust pump (not shown) such as a turbo-molecular exhaust pump. Then, the lower chamber 61 and the upper chamber 62 are configured to be evacuated to a predetermined vacuum degree by evacuating the processing space in a state where the lower chamber 61 and the upper chamber 62 are in close contact with each other.

The edge remover (ER) 23 is provided with a stage 91 on which the glass substrate G is placed.
On each of the four sides of the glass substrate G, four remover heads 93 for removing excess resist from the edges of the four sides of the glass substrate G are provided. Each of the remover heads 93 has a substantially U-shaped cross section so as to discharge thinner from the inside, and is moved by a moving mechanism (not shown) so as to be sandwiched along four sides of the substrate G.
Thus, each remover head 93 can remove excess resist attached to the four edges of the substrate G while moving along each side of the substrate G and discharging thinner.

Next, the resist coating apparatus (C
T) 22 will be described. FIG. 4 is a partial sectional view showing a schematic configuration of the resist coating apparatus (CT) 22, and FIG. 5 is a plan view thereof.

As shown in these figures, a bottomed cylindrical frame 71a is disposed substantially at the center of the resist coating apparatus (CT) 22, and a glass substrate G is provided in the frame 71a.
A substrate suction table 58 which is a holding member for fixing and holding the substrate is disposed. An opening 71c for taking the glass substrate G in and out is provided in the upper part of the frame 71a. An upper lid 79 is put on the opening 71c. The upper lid 79 is movably supported by an opening / closing mechanism (not shown).

A seal member 77 is attached to the lower surface on the outer peripheral side of the substrate suction table 58. When the substrate suction table 58 is lowered to bring the seal member 77 into contact with the bottom of the frame 71a, airtightness is obtained. Processing space 78
Is formed.

The substrate suction table 58 has a glass substrate G
Is connected to a vacuum suction device 72 for holding the vacuum suction. Further, this substrate suction table 58 is
The lifting cylinder 73 allows the lifting cylinder 73 to move up and down. The lifting cylinder 73 has a CP
The operation is controlled by U74. In particular,
The lower side of the rod 75 is disposed in a cylindrical body (not shown), in which the rod 75 can be moved in the vertical direction by driving the elevating cylinder 73 via a vacuum seal 76.

On both sides of the frame 71a, the transport rails 6 are provided.
6 and 66 are arranged, and a scanning mechanism is provided between the transport rails 66 and 66. The scanning mechanism is provided between the transport rails 66, 66 and moves in the Y direction along the transport rails 66, 66. It is movable in the X direction along the longitudinal direction of the slider 67,
The resist liquid supply nozzle 46 has a second slider 43 to which it is fixed. In the vicinity of one traveling end of the transport rail 66, the first slider 67 is moved along the transport rail 66 by a command from the CPU 74,
A drive unit 48 for moving the second slider 43 along the first slider 67 is provided.

FIG. 6 shows a resist / thinner mixture in which the viscosity of the resist solution applied on the glass substrate G is varied by mixing the resist solution and a liquid having a viscosity different from that of the resist solution, for example, thinner. The device is shown. The resist / thinner mixing device 70 includes a resist tank 81 that stores a resist solution, a thinner tank 82 that stores, for example, a thinner as a solvent, and a mixed liquid supply pipe that supplies a mixed liquid of the resist liquid and the thinner to the coating liquid supply nozzle 46. 88,
A resist liquid supply pipe 89 for supplying a resist liquid to the mixed liquid supply pipe 88, a thinner supply pipe 90 which is a solvent supply pipe for supplying a thinner to the mixed liquid supply pipe 88, and a resist tank 81
A resist bellows pump 84 for sucking up the resist solution therein and introducing it into a resist solution supply pipe 89;
A thinner bellows pump 85 for sucking up the thinner inside the thinner supply pipe 90 and a mixer 87 as mixing means for further stirring and mixing the mixed liquid of the resist liquid and the thinner. A sensor 99 for measuring the concentration of the mixed solution passing therethrough and a CPU 74 as control means for controlling the concentration of the mixed solution to a predetermined concentration are provided.

The CPU 74 determines the concentration of the mixture to be obtained,
That is, the bellows pumps 84, 85 according to the desired viscosity.
And the concentration of the mixed solution supplied to the coating solution supply nozzle 46 is measured, and the bellows pumps 84 and 85 discharge the solution based on the measurement result. It has a function of controlling the discharge amounts of the resist solution and the thinner, and a function of controlling the above-described scanning mechanism in FIG.

The operation of the resist coating / developing system configured as described above will be described.

Referring to FIG. 1, substrate G in cassette C
Is transported to the processing unit 2, where the surface modification / cleaning process is first performed by the ultraviolet irradiation device (UV) of the ultraviolet irradiation / cooling unit 25 in the former stage 2a, and then the cooling device of the unit After cooling in (COL), scrubber cleaning is performed in the cleaning units (SCR) 21a and 21b, and heating and drying is performed in one of the heat treatment devices (HP) disposed in the former stage 2a. Is cooled by any one of the cooling devices (COL).

Thereafter, the substrate G is transported to the middle section 2b,
In order to improve the fixability of the resist, a hydrophobic treatment (H) is performed by an adhesion treatment device (AD) in the upper stage of the unit 30.
After being cooled by the lower cooling device (COL), it is carried into the coating system processing device group 50.

In the coating system processing apparatus group 50, first, the substrate suction table 58 is connected to the opening 7 of the frame 71a.
In a state where the glass substrate G is raised above 1c, the glass substrate G is transferred onto the substrate suction table 58 by the main transfer device 18 and held by vacuum suction. Next, the substrate suction table 58 is lowered by driving the elevating cylinder 73, and the glass substrate G is carried into the frame 71a through the opening 71c.

Subsequently, according to the size of the glass substrate G, CP
The drive unit 48 controls the first slider 67
Moves along the transfer rail 66 in the Y direction, and the second slider 43 moves along the first slider 67 in the X direction. As a result, the application liquid supply nozzle 46 fixed to the second slider discharges a predetermined overlapping discharge of the outer peripheral edge area G2 and the outer peripheral edge area G1 of the substrate G surrounded by, for example, a dashed line as shown in FIG. It moves to the start point S, that is, outside the corner of the substrate G.

Next, by moving the second slider 43 in the X direction, the outer peripheral area G
1, the CPU 74 shown in FIG.
Is located on the area G1 near the outer peripheral edge on the substrate G, and the thinner is mixed with the resist liquid by the resist / thinner mixing device 70 shown in FIG. The coating process is performed at a predetermined density. When the application liquid supply nozzle 46 reaches the outer peripheral edge area G4, the resist liquid supply nozzle 46 is moved slightly in the Y direction by moving the first slider 67 along the transport rail 66 (the outer peripheral edge area G4). Area G3), and from that point the second slider 43 is again moved to the outer peripheral area G2.
In the X direction. At this time, if the position of the coating liquid supply nozzle 46 is not already in the outer peripheral edge area G1, the concentration of the coating liquid in the outer peripheral edge areas G1 to G4 is applied to the area other than the outer peripheral edge areas G1 to G4 by a command from the CPU 74. The coating process is performed after changing to a predetermined density to be performed. When the first slider 67 is slightly moved in the Y direction toward the outer peripheral area G3 when the outer peripheral area G2 is reached,
The second slider 43 is moved in the X direction toward the outer peripheral edge area G4.

In this way, as shown in FIG. 7B, the viscosity of the coating liquid supply nozzle 46 differs between when the coating liquid supply nozzle 46 passes through the outer peripheral edge regions G1 to G4 and when it passes through the regions other than the outer peripheral edge regions G1 to G4. Different coating liquids. For example, in the outer peripheral edge regions G1 to G4, the application liquid is applied with a relatively low viscosity (black portion T), and the outer peripheral edge regions G1 to G4 are applied.
In areas other than G4, the coating is applied with a relatively high viscosity (white part D). Thus, in the outer peripheral edge regions G1 to G4 of the glass substrate G, the wettability of the coating liquid to the substrate G is increased, and it is possible to suppress the swelling generated on the outer peripheral edge of the coating liquid. Therefore, it is possible to apply the resist liquid with a uniform thickness over the entire glass substrate G.

As shown schematically in FIG. 8, the distance d when the coating liquid supply nozzle 46 is slightly moved in the Y direction toward the outer peripheral edge area G3 is equal to the distance d.
Distance shorter than the diameter of the discharge hole of No. 6 (usually about half)
By this, the application lines R1, R2,..., Rn of the adjacently discharged resist liquid on the glass substrate G are melted with each other, and are applied with a uniform thickness without gaps. Go.

After the resist is applied by the resist coating device (CT) 22, the resist is dried by a reduced-pressure drying device (DP) 40. Since the entire surface can be made uniform, the dent 105 as shown in FIGS. 12A and 12B does not occur, and the excess resist on the outer peripheral edge of the substrate G is removed by the edge remover (ER) 23. As a result, more uniform resist film thickness can be obtained with higher accuracy.

Thereafter, the substrate G is pre-baked in one of the heat treatment apparatuses (HP) arranged in the middle section 2b.
The cooling unit (COL) at the lower stage of the unit 29 or 30 is cooled, and is conveyed from the relay unit 16 by the main conveying unit 19 to an exposing device (not shown) via the interface unit 3 where a predetermined pattern is exposed. And the substrate G
Is again carried in via the interface unit 3 and, if necessary, is subjected to post-exposure bake processing in any one of the heat processing units (HP) in the post-stage unit 2c, and then is subjected to the development processing units (DEV) 24a, 24b, 24c. Is developed. When the exposure and development processes are performed in this manner, the resist liquid film thickness on the glass substrate G is uniform over the entire substrate G, so that exposure and development are excessively performed only on a specific portion of the substrate G. There is no.

Development units (DEV) 24a, 24
b and 24c, the processed substrate G is subjected to post-baking in one of the heat treatment devices (HP) in the subsequent stage 2c, and then subjected to a cooling device (COL). ), And is cooled by the main transfer devices 19, 18, 17
Then, the sheet is stored in a predetermined cassette on the cassette station 1 by the transport mechanism 10.

FIG. 9 shows a main part of a resist coating apparatus according to another embodiment of the present invention.

The resist coating apparatus 100 operates a heating device 45 (for example, a heating wire or the like) capable of heating a resist solution supplied from a resist solution supply source, and operates the heating device 45 as shown in FIG.
In the same manner as the resist liquid application operation shown in FIGS.
Under the control of No. 4, the supply temperature is higher than the supply temperature of the resist liquid supplied to portions other than the outer peripheral edge regions G1 to G4. By heating the supplied resist solution, the viscosity of the resist solution decreases. As a result, the resist liquid having a low viscosity is supplied to the outer peripheral edge of the glass substrate G, so that the raised portion generated at the outer peripheral edge of the low-temperature resist liquid is dissolved in the high-temperature resist liquid. And swelling can be suppressed. As a result, the thickness of the resist liquid becomes uniform over the entire glass substrate G. Therefore, exposure and development are not excessively performed only on a specific portion on the substrate G.

Further, by replacing the heating device 45 with a cooling device, the viscosity at the outer peripheral edge is relatively increased, or the viscosity of the coating liquid is relatively reduced between the outer peripheral edge of the substrate G and other regions. And the coating pressure can be variably controlled.

The present invention is not limited to the embodiment described above.

For example, the resist / thinner mixing device 70 (FIG. 6) in the first embodiment may be provided with a heating device 45 (FIG. 9) in another embodiment. In this case, a heating device 45 is provided between the sensor 99 and the application liquid supply nozzle 46 shown in FIG. Thereby, the resist tank 81
The concentration of the mixture of the resist solution from the thinner and the thinner from the thinner tank 82 is controlled by the sensor 99, and the mixture is further heated by the heating device 45, so that the viscosity control of the coating solution can be performed more efficiently and with higher precision. Can be done.

In the above embodiments, the present invention is applied to a coating apparatus for applying a resist liquid to an LCD substrate. However, the present invention is also applied to a coating apparatus for applying a resist liquid to a substrate other than the LCD substrate, for example, a semiconductor wafer. Applicable. In this case, since the semiconductor wafer is circular, the viscosity of the coating liquid applied to the peripheral edge of the circular shape is controlled to be lower than the viscosity of the coating liquid applied to portions other than the peripheral edge.

Further, the present invention has been described with respect to a coating apparatus using thinner as a solvent for varying the viscosity of a coating solution. It can also be applied to a coating device using a liquid.

[0050]

As described above, according to the present invention, by making the viscosity of the coating liquid applied to the glass substrate variable, it is possible to suppress the swelling of the coating liquid which occurs on the outer peripheral edge of the glass substrate due to surface tension. Thus, the uniformity of the film thickness of the coating solution can be improved. Therefore, since exposure and development are not excessively performed on only a specific portion on the substrate, a precise circuit pattern can be formed on the substrate.

[Brief description of the drawings]

FIG. 1 is a plan view showing an LCD substrate coating / developing processing system to which the present invention is applied.

FIG. 2 is a schematic plan view of a coating processing unit group including a resist coating device (CT), a reduced-pressure drying device (DP), and an edge remover (ER) shown in FIG.

FIG. 3 is a schematic side view of a coating system processing unit group shown in FIG. 2;

FIG. 4 is a partial cross-sectional view showing a schematic configuration of a resist coating apparatus (CT) according to the embodiment of the present invention shown in FIG. 3;

FIG. 5 is a plan view of the resist coating apparatus (CT) shown in FIG.

FIG. 6 is a view illustrating a main part of a resist coating apparatus (CT) according to an embodiment of the present invention, and is a view illustrating a configuration of a resist / thinner mixing apparatus.

FIG. 7 is a view for explaining a step of applying a coating liquid on a glass substrate in the embodiment of the present invention, wherein A is a drawing in which a coating liquid supply nozzle is located at a coating start point; FIG. 4 is a diagram in which a nozzle is at a position of an application end point.

FIG. 8 is a schematic cross-sectional view for explaining a step of applying a coating liquid on a glass substrate in the embodiment of the present invention.

FIG. 9 shows a main part of a resist coating apparatus (CT) according to another embodiment of the present invention, and is a configuration diagram when a heating apparatus is used.

FIG. 10 is a diagram for explaining a coating method of a conventional resist coating device.

11A and 11B are diagrams for explaining a problem of the conventional resist coating method, in which A is a diagram showing a state in which a coating liquid swells on an outer peripheral edge portion of the glass substrate, and B is a diagram showing the glass substrate shown in A in FIG. FIG. 9 is a diagram for explaining the size of resist removal in the case of exposure and development.

FIG. 12 is a view for explaining a problem of a conventional resist coating method, and FIG. 12A is a view showing a state in which a depression is formed inside an outer peripheral edge of a glass substrate.

[Explanation of symbols]

 G: glass substrate G1 to G4: outer peripheral edge region 22: resist coating device (CT) 23: edge remover (ER) 40: reduced pressure drying device (DP) 45: heating device 46: coating liquid supply nozzle 58: substrate suction table Reference numeral 66: transport rail 70: thinner mixing device 74: CPU 81: resist tank 82: thinner tank 84: bellows pump for resist 85: thinner bellows pump 87: mixer 88: mixed liquid supply pipe 89: resist liquid supply pipe 90: thinner supply Tube 99 ... Sensor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03F 7/16 501 G03F 7/16 502 502 H01L 21/30 564Z F-term (Reference) 2H025 AA18 AB20 EA04 4D075 AC08 AC84 AC92 AC96 BB16Y BB18Y BB22Y CA48 DA06 DB13 DC24 EA45 4F041 AA02 AA06 AB02 BA23 BA35 BA43 BA47 4F042 AA02 AA08 BA08 BA12 BA16 BA19 CA08 CB02 CB08 CB27 DF09 DF34 EB09 EB18 5F046 JA01

Claims (3)

[Claims] A holding member for holding the object to be processed; a coating liquid supply nozzle for supplying a coating liquid onto the object to be processed while moving relative to the holding member; Control means for varying the viscosity of the discharged coating liquid. 2. The coating apparatus according to claim 1, wherein the control unit is configured to control the viscosity of the coating liquid when the coating liquid supply nozzle applies the liquid on the vicinity of an outer peripheral edge of the object to be processed. A coating apparatus, wherein liquids having different viscosities are mixed with the discharged coating liquid. 3. The coating apparatus according to claim 1, wherein the control unit is configured to discharge the coating liquid when the coating liquid supply nozzle applies the coating liquid near an outer peripheral edge of the processing target. Coating or heating apparatus.