JP3800291B2 - Coating method and coating apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique of a coating method and a coating apparatus, and in particular, uniformly applies a liquid coating film by a solvent such as a resist film on a substrate to be processed such as a semiconductor wafer or a mask substrate or on a layer formed thereon. The present invention relates to a coating method and a device therefor.
[0002]
[Prior art]
Conventionally, a coating solution is dropped onto a substrate for precision pattern formation (hereinafter referred to as “substrate”) such as a semiconductor wafer for semiconductor manufacturing equipment, a glass substrate for manufacturing various displays and photomasks, and then rotating centrifuge. A coating technique using a so-called spin coating apparatus is known in which a coating liquid is spread and applied to the entire surface of a substrate to be processed by force.
[0003]
As is well known, in the field of semiconductor technology, when a semiconductor layer, an insulator layer, and an electrode layer formed on a semiconductor wafer are selectively etched into a predetermined pattern, the pattern portion is masked on the surface of the layer. A resist film is formed.
[0004]
As a method for forming this resist film, a resist solution composed of a solvent and a photosensitive resin is dropped onto the central portion of the upper surface of the wafer by the coating method using the above-described spin coating device, and the resist solution is applied by the rotational force and centrifugal force of the wafer. Coating is performed by diffusing from the center of the wafer toward the periphery.
[0005]
In this method, the solvent in the resist solution evaporates in the process in which the resist solution diffuses from the center position of the wafer toward the peripheral portion. For this reason, the viscosity of the resist solution differs in the direction of diffusion, and the thickness of the formed resist film differs between the central portion and the peripheral portion. That is, there was a limit to uniform coating.
[0006]
For this reason, conventionally, a method has been proposed in which a solvent of the resist solution is dropped onto the wafer surface before the resist solution is applied. Further, a spray-type coating apparatus using a two-fluid nozzle that performs coating by mixing a solvent with a gas and spraying uniformly on the wafer so as to uniformly apply the solvent is used.
[0007]
[Problems to be solved by the invention]
By the way, since the solvent used as the solvent has volatility, when the nozzle is left for a long time, the liquid level of the downstream end of the solvent in the nozzle pipe recedes due to the volatilization of the solvent, and the amount of solvent in the pipe fluctuates. End up. Therefore, there is a problem that the next solvent discharge amount fluctuates. As a result of variations in the amount of the solvent discharged, resist coating was uneven.
[0008]
This state becomes prominent when the application standby time from the stop of the application of the solvent to the start of the application becomes relatively long. This means that even if the amount of fluctuation is small, the solvent application before the application of the resist solution is carried out with a small amount of solvent, and the proportion of the total amount of the solvent increases. .
[0009]
An object of the present invention is to provide a coating method and a coating apparatus that can discharge an optimum amount of coating liquid in a highly volatile liquid regardless of the length of the coating standby time, and can achieve uniform coating.
[0010]
[Means for solving the problems and their functions and effects]
In order to achieve such an object, the present invention has the following configuration. In other words, the invention according to claim 1 is a coating method in which a liquid and a gas are simultaneously supplied and mixed at the tip of the spray nozzle and spray-applied to a substrate to be processed, immediately before the spray-coating step. gas only after a predetermined time feeding step, have rows spray coating step of the substrate to be processed, and the accumulated liquid to the spray nozzles only liquid is supplied a predetermined time before the supplying step of the gas only the process step of discharging waste, characterized in row Ukoto.
[0011]
(Delete)
[0012]
The invention according to claim 2 is the coating method according to claim 1 , wherein the liquid has volatility.
[0014]
According to a third aspect of the present invention, there is provided a coating apparatus that supplies a liquid and a gas at the same time, mixes them at the tip of the spray nozzle, and spray-applies to a substrate to be processed, and supplies the liquid to the spray nozzle. A system, a gas supply system that supplies a gas that merges with the liquid supply system, and a control unit that controls the operation of the liquid supply system and the gas supply system, the control unit immediately before performing spray coating. The spray nozzle is controlled to supply only gas from the gas supply system to the spray nozzle for a predetermined time, and before supplying only gas from the gas supply system, only the liquid is supplied from the liquid supply system for a predetermined time. Control is performed so that the liquid accumulated in the liquid is discharged and discarded.
[0015]
The invention according to claim 4 is the coating apparatus according to claim 3 , wherein the control means is a timing instruction means for instructing operation timings of the liquid supply system and the gas supply system, and the timing instruction means. In response to a signal from the liquid supply system and a discharge control means for controlling the discharge of the liquid or gas from the gas supply system, and a gas supply completion signal from the gas supply system from the timing instruction means. The spray control means performs spray coating.
[0016]
(Delete)
[0017]
The operation of the present invention is as follows. In the coating method according to the first aspect of the present invention, the step of supplying only the gas for a predetermined time is performed immediately before the step of spraying and applying the gas and the liquid simultaneously. And the spraying process is performed through the process. Therefore, immediately before the spraying process, the liquid is blown off by the gas on the downstream side of the gas / liquid mixing portion of the spray nozzle. Therefore, the liquid level at the downstream end of the liquid in the spraying process is always located at the mixing site, and the liquid discharge amount is constant.
[0018]
Further, in the method of applying the invention according to claim 1, the liquid accumulated only liquid is supplied a predetermined time to the spray nozzle before the previous crisis body only supply step is discharged discarded. For this reason, even when a characteristic change occurs in the liquid accumulated in the spray nozzle, such liquid is discarded, so that uniform application can be performed. Moreover, even if the liquid is discharged and discarded and the liquid remains up to the tip in the spray nozzle, only the gas is supplied thereafter, and the liquid is discharged by the gas downstream of the spray nozzle gas and liquid mixing portion. Blown away. Therefore, the liquid level at the downstream end of the liquid in the spraying process is always located at the mixing site, and the liquid discharge amount is constant.
[0019]
In the coating method of the invention according to claim 2 , the liquid used in the coating method according to claim 1 is volatile. In the case of a liquid having volatility, the fluctuation of the liquid amount in the spray nozzle is significant due to volatilization. However, in the gas-only supply step, the liquid level at the downstream end of the liquid is always defined as the mixing site, and the liquid discharge amount is constant.
[0021]
In the coating apparatus of the invention according to claim 3 , the liquid supply system and the gas supply system are controlled by the control means, and the gas and the liquid are supplied at the same time and the gas is supplied for a predetermined time immediately before the spray coating is performed. Do. Therefore, immediately before the spray application, the liquid remaining by the gas is blown off at the downstream side of the gas / liquid mixing portion of the spray nozzle. Therefore, the liquid level at the downstream end of the liquid in spray application is always located at the mixing site, and the liquid discharge amount is constant. Furthermore, in the invention according to claim 3 , before supplying only the gas from the gas supply system, only the liquid is supplied from the liquid supply system for a predetermined time, and the liquid accumulated in the spray nozzle is discharged and discarded. For this reason, even when a characteristic change occurs in the liquid accumulated in the spray nozzle, such liquid is discarded, so that uniform application can be performed. Further, even when the liquid is discharged and discarded and the liquid remains up to the tip in the spray nozzle, only the gas is supplied thereafter and remains in the downstream of the spray nozzle gas and liquid mixing portion. Liquid is blown away.
[0022]
In the coating apparatus according to the fourth aspect of the present invention, the ejection control means supplies the gas and the liquid at the same time and performs the spray application in response to the signal of completion of the gas supply from the gas supply system from the timing instruction means. That is, since the spraying process is performed after the liquid level of the downstream end of the liquid is set to the liquid and gas mixing portion by supplying only the gas, it is possible to prevent the liquid from further volatilizing and the liquid level position from fluctuating.
[0023]
(Delete)
[0024]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of a rotary substrate coating apparatus using the apparatus of the present invention to which the method of the present invention is applied.
[0025]
In the figure, reference numeral 1 denotes a suction type spin chuck that sucks and supports the substrate W in a substantially horizontal posture. The suction type spin chuck 1 is driven by a rotary motor 3 through a hollow rotary shaft 2, and is rotated around a vertical axis together with the substrate W by the drive of the rotary motor 3. Around the suction type spin chuck 1, a scattering prevention cup 5 for preventing scattering of a photoresist liquid as a coating liquid is disposed. Although not shown in the drawings, the anti-scattering cup 5 and the rotary shaft 2 are configured to move up and down relative to each other, and the unprocessed substrate W can be carried into the anti-scattering cup 5 in a state where these are raised and lowered relative to each other. The processed substrate W is carried out of the anti-scattering cup 5.
[0026]
A coating liquid discharge nozzle 11 that discharges a photoresist liquid onto the substrate W is disposed above the scattering prevention cup 5 and substantially above the center of rotation of the substrate W. The coating liquid discharge nozzle 11 is supplied with a photoresist liquid, which is a coating liquid, from a coating liquid supply unit 13, and the tip of the driving unit 15 is supplied to the supply position shown in FIG. 5 is swung over a standby position (not shown) that is distant from the side of 5.
[0027]
Further, a solvent spraying nozzle (hereinafter referred to as a spray nozzle) 17 for spraying the solvent (liquid) in the form of a mist onto the substrate W is provided in parallel with the coating liquid discharge nozzle 11 to constitute the solvent supply mechanism 6. The solvent supply mechanism 6 includes a solvent (liquid) supply system 8 for supplying a solvent connected to the spray nozzle 17 and a gas supply system 7 for supplying a gas such as N ₂ mixed to make the solvent mist. And.
[0028]
The spray nozzle 17 is composed of a two-fluid nozzle, which will be described later, for spraying the solvent from the solvent supply source 19, and applies the solvent by discharging the solvent onto the upper surface of the substrate W held by the spin chuck 1 in the processing chamber. . The spray nozzle 17 is supplied with pressurized N ₂ gas through the electromagnetic on-off valve 21. Therefore, as shown by a dotted line in FIG. 1, when the electromagnetic on-off valve 21 is opened, the solvent is sprayed from the spray gun 17a attached to the tip of the spray nozzle 17, and the solvent is sprayed in a range almost covering the radius of the substrate W. It has come to be. The spray gun 17a may have a spray range that covers the entire surface of the substrate W.
[0029]
Further, the spray nozzle 17 is configured to be oscillated and moved between the supply position shown in FIG. 1 and a standby position located on the side of the anti-scattering cup 5 by the drive unit 23. At the same time, when the solvent is sprayed in a state where the substrate W is not rotated, the solvent is sprayed over the entire surface of the substrate W so that the solvent can be sprayed to scan a certain range. In the standby position, a container that receives the solvent to be discharged and discarded may be disposed.
[0030]
Next, the spray gun 17a, the solvent supply system 8, and the gas supply system 7 will be described with reference to FIG. The solvent supply system 8 includes a solvent supply source 19 including a container 81 for storing a solvent, a pressurizer for pressurizing and storing a stored solvent (not shown), a flow meter 82, a filter (filter) 83, and an electromagnetic on-off valve 19a. The pipe 19b is connected to the spray gun 17a.
[0031]
The gas supply system includes a gas supply body 71 of a gas such as N ₂ for making the solvent liquid in a mist form, a flow system 72, and a filter 73 in the pipe 7a, and is connected to the spray gun 17a via the electromagnetic on-off valve 21. Is done.
[0032]
As shown in FIG. 2, the spray gun 17a includes a liquid supply nozzle 17b connected to the solvent supply system 8 and a gas supply nozzle 17c connected to the gas supply system 7 in the vicinity of the tip of the liquid supply nozzle 17b. This junction is defined at the mixing site where the solvent and gas are mixed. The solvent and N2 are mixed between the cavity of the diffusion hole 17d provided in the inner wall of the tip hole of the spray gun 17a and the above-described mixing portion, and the solvent is ejected in a mist form. If the opening angle of the diffusion hole 17d is too small, it does not form a mist, and if it is too large, there is a wasteful ejection in the lateral direction.
[0033]
The rotation motor 3, the coating liquid supply unit 13, the drive unit 15, the solvent supply mechanism 6, the electromagnetic open / close valves 19 a and 21, and the drive unit 23 are controlled by the control unit 31. . The control unit 31 controls each of the above units by a processing program stored in advance in the memory 33 according to a time chart described later. That is, the control unit 31 and the memory 33 constitute the control unit of the present invention, the function of the control unit 31 that gives a timing instruction by the time chart is the timing instruction unit, and the function that controls the discharge operation from the spray nozzle 17 is the discharge control. Corresponds to means.
[0034]
In the coating apparatus having the above-described configuration, the photoresist solution supplied from the coating solution supply unit 13 includes, for example, a positive type composed of a quinonediazide-based photosensitive material, an alkali-soluble phenolic resin, and an organic solvent. Examples of the organic solvent to be used include those containing ECA (ethyl cellosolve acetate), EL (ethyl lactate), PGMEA (propylene glycol monomethyl ether acetate) as a main component.
[0035]
In addition, as a solvent which said solvent supply source 19 stores, what is necessary is just to use the same kind of organic solvent as the solvent contained in the photoresist liquid. For example, PGMEA (propylene glycol monomethyl ether acetate) and EL (ethyl lactate), which are used as the main solvent of the photoresist solution, can be used.
[0036]
Next, the photoresist liquid coating process will be described with reference to the time chart of FIG. A processing program corresponding to this time chart is stored in advance in the memory 33 shown in FIG. 1 and executed by the control unit 31. In addition, it is assumed that the substrate W to be processed is already placed on the suction spin chuck 1 and sucked and held, and the spray nozzle 17 is waiting at the standby position.
[0037]
First, the rotational drive of the rotary motor 3 is started. Specifically, the control unit 31 drives the rotation motor 3 to rotate forward so that the spin chuck 1 reaches a rotation speed R1 (for example, 100 rpm) at time t1. On the other hand, the spray nozzle 17 opens the electromagnetic on-off valve 19a at time t11 and performs a process of discharging and discarding only a small amount of solvent (hereinafter, pre-dispensing) until time t12. This is performed for the purpose of maintaining the uniformity of the coating liquid by discharging and discarding the portion of the spray gun 17a that has changed its characteristics with the solvent that has been waiting for a certain period of time at the tip.
[0038]
Next, at time t12, the electromagnetic on-off valve 19a is closed, the electromagnetic on-off valve 21 is opened, and N ₂ is supplied. This supply of N ₂ continues until t13. Thereby, the solvent which remains downstream from the mixing part of the spray gun 17a is blown off by the above-mentioned pre-dispensing. The liquid level at the downstream end of the solvent is defined at the mixing site by blowing off the gas. It should be noted that the process from the pre-dispense to the gas-only supply process may be continued with a time lag even if not at the same time.
[0039]
When the electromagnetic on-off valve 21 is closed at time t13, the spray nozzle 17 is moved from the standby position to the supply position by the drive unit 23. When the spray nozzle 17 is positioned at the supply position at time t14, a solvent spray coating process is performed.
[0040]
When the rotation speed of the substrate W is stabilized at the rotation speed R1, at time t14, the electromagnetic on-off valves 19a and 21 are opened to start supplying the solvent from the spray nozzle 17 in the form of a mist, and at time t15, first, the electromagnetic on-off valve 19a. The electromagnetic on-off valve 21 is closed with a slight delay, and the supply is stopped. That is, the time from the time t14 to the time t15 is the solvent spraying time, and the amount of the solvent supplied during this time is, for example, 0.3 ml. Here, the reason why the electromagnetic on-off valve 21 is closed with a delay is to prevent dripping from the tip of the spray gun 17a.
[0041]
Here, in order to close the electromagnetic on-off valve 21 with a delay, the liquid level at the downstream end of the solvent is defined at the mixing site in the same manner as in the steps (t12 to t13). Then, there is a waiting period until the next solvent application, in which the solvent volatilizes and the liquid level may recede from the mixing site. If the liquid level at the downstream end recedes from the mixing site, the pre-dispensing process (t11 to t12) is carried out in the first embodiment, although it does not act to regulate the liquid level even if only gas is supplied. Therefore, the liquid level regulating action is not impaired.
[0042]
In addition, after the time point t15 when the supply of the solvent is stopped, the drive unit 23 moves the spray nozzle 17 to the standby position, and instead, the drive unit 15 moves the coating liquid discharge nozzle 11 to the supply position.
[0043]
Next, the rotational speed is increased at time t2 so that the rotational speed of the substrate W reaches the rotational speed R2 (for example, 1000 rpm) at time t3. Then, at the time ts when the rotational speed R2 is stabilized, the supply of the photoresist liquid from the coating liquid discharge nozzle 11 is started at a constant flow rate, and the supply of the photoresist liquid is stopped at the time te when the supply time Tse comes from that time.
[0044]
Therefore, before the entire surface of the substrate W is covered with the photoresist solution R supplied to the surface of the substrate W, the rotation speed starts to be increased to a rotation speed R3 (for example, 2500 rpm) higher than the rotation speed R2 (1000 rpm) ( t4). At this time, the rotation speed is controlled to start increasing from the time point t4 and reach the rotation speed R3 at the time point t5, and this time is, for example, about 0.1 sec.
[0045]
In addition, since the solvent is previously applied to the entire surface of the substrate W as described above, the contact angle between the photoresist liquid and the surface of the substrate W is extremely small. Accordingly, the diameter of the photoresist liquid is rapidly increased, and the time until the entire surface of the substrate W is covered with the photoresist liquid is significantly shortened as compared with the prior art.
[0046]
In this way, the entire surface of the substrate W is covered with the photoresist solution, and the rotational speed of the substrate W is reduced to the rotational speed R4 (for example, 1500 rpm) at time t7, and this rotational speed R4 is held from time t7 to time t8. As a result, a slight excess of the photoresist solution covering the entire surface of the substrate W is shaken off. As a result, a photoresist film having a desired film thickness is formed on the surface of the substrate W.
[0047]
As described above, the solvent is applied before supplying the photoresist solution of the substrate W, and the contact angle between the photoresist solution and the surface of the substrate W is reduced, so that the diameter of the photoresist solution supplied thereafter is reduced. Can be easily expanded. In addition, since the solvent supplied prior to the photoresist solution is sprayed, it can be supplied over a wide range in a short time, and even if unevenness such as a circuit pattern is formed on the surface of the substrate W, the solvent is applied to that portion. Since it can be made difficult to stay, unevenness due to the solvent can be prevented from occurring in the photoresist film.
[0048]
Furthermore, the amount of solvent discharged is always constant because the downstream surface of the solvent in the spray nozzle 17 is defined at a fixed position in the gas-only supply step (t12 to t13) performed immediately before solvent application. It becomes. That is, the amount of solvent in the spray nozzle 17 varies as the solvent moves backward in the spray nozzle 17 due to its volatility, but the discharge amount can be made constant.
[0049]
In addition, since the gas-only supply process is performed immediately before the solvent spray application process (t14 to t15) with the movement period (t13 to t14) of the spray nozzle 17 in between, the solvent after the liquid level is defined Volatility fluctuations are minimized.
[0050]
Next, a photoresist solution coating process according to a reference example will be described with reference to the time chart of FIG. The apparatus for performing the coating process is the same as that shown in FIG. 1, and the processing program stored in the memory 33 is different as follows.
[0051]
First, unlike the first embodiment, the solvent is not pre-dispensed in the reference example . Therefore, the spray nozzle 17 performs a gas-only supply process (t22 to t23) at the standby position, and after the spray nozzle 17 is moved (t24), the substrate W is sucked and held by the suction spin chuck 1 and the rotary motor 3 is moved. Without being driven, that is, the solvent is sprayed while the substrate W is stationary (t24 to t25). Specifically, the drive unit 23 starts the spraying of the solvent from the spray nozzle 17 onto the surface of the substrate W at the time t24 and starts supplying the solvent within the solvent spraying time up to the time t25. To move the spray gun 17a.
[0052]
When stopping the spraying of the solvent at the time t25, the supply of the solvent by the solvent supply system 8 is stopped after the supply of N ₂ by the gas supply system 7 is stopped. The timing of this stop procedure may be a slight shift of the solvent supply system 8 and only a small amount of solvent is supplied after stopping the supply of N ₂ , and the liquid level at the downstream end of the solvent is always kept at the spray gun 17a. Will be defined downstream from the mixing site.
[0053]
Next, the supply of the photoresist liquid from the coating liquid discharge nozzle 11 is started at the time ts, and the supply is stopped at the time te when the supply time Tse elapses. That is, the supply of the photoresist solution is completed with the substrate W being stationary.
[0054]
At the time te, the supply of the photoresist solution is stopped and the rotation speed of the substrate W is increased toward the rotation speed R2, and this is maintained from the time t1 to the time t2, and then the rotation speed of the substrate W is rotated at the time t3. Acceleration is started from time t2 so as to reach the number R3. This time point t2 is set before the entire surface of the substrate W is covered.
[0055]
As described above, in the above reference example , pre-dispensing is not performed, but the liquid level at the downstream end of the solvent is positively positioned downstream from the mixing site when the spray application of the solvent is stopped. By doing so, the liquid level is defined by always blowing the solvent present downstream from the mixing site when the gas-only supply process is carried out next time.
[0056]
Further, as the control at the time of stopping the spray application, the supply of the solvent and N ₂ may be stopped simultaneously. By doing so, not a little of the solvent blown off remains on the downstream side of the mixing part of the spray gun 17a, and it will be blown off in the next gas-only supply step (t11 to t12).
[0057]
In the first embodiment and the reference example , a photoresist solution is taken as an example of the coating solution. However, the method of the present invention is applicable to SOG solution (Spin On Glass, also called silica-based film forming material), polyimide resin, etc. Even a coating solution is applicable.
[0058]
In the above description, the spraying of the solvent is performed in the coating apparatus. However, only the solvent spraying may be performed in a separate apparatus, and then the coating liquid may be applied in the coating apparatus. .
[0059]
【The invention's effect】
According to the first aspect of the present invention, there is provided a coating method in which a liquid and a gas are simultaneously supplied, mixed at the tip of the spray nozzle and spray-coated on the substrate to be processed, and only the gas is supplied for a predetermined time immediately before the spray-coating step. The step of spraying the substrate to be processed is performed through the step of performing the step of supplying the gas only for a predetermined time immediately before the step of spraying and applying the gas and the liquid simultaneously. And the spraying process is performed through the process. Therefore, immediately before the spraying process, the residual liquid is blown away by the gas on the downstream side of the gas / liquid mixing portion of the spray nozzle. Therefore, the liquid level at the downstream end of the liquid in the spraying process is always located at the mixing site, and the liquid discharge amount is constant. In addition, since only the liquid is supplied for a predetermined time before the gas-only supply step and the liquid accumulated in the spray nozzle is discharged and discarded, even if the characteristic change occurs in the liquid accumulated in the spray nozzle, The liquid can be discarded for uniform application.
[0060]
According to a third aspect of the present invention, there is provided a coating apparatus that supplies a liquid and a gas at the same time, mixes them at the tip of the spray nozzle, and spray-applies to a substrate to be processed, and supplies the liquid to the spray nozzle. A system, a gas supply system that supplies a gas that merges with the liquid supply system, and a control unit that controls the operation of the liquid supply system and the gas supply system, the control unit immediately before spray application By controlling the gas supply system to supply the gas to the spray nozzle for a predetermined time, only the gas is supplied for a predetermined time immediately before the gas and the liquid are simultaneously supplied and spray coating is performed. Therefore, immediately before spray application, the liquid is blown off by the gas at the downstream side of the spray nozzle gas and liquid mixture. Therefore, the liquid level at the downstream end of the liquid in spray coating is always located at the mixing site, and a coating apparatus is provided in which the liquid discharge amount is constant. In addition, before supplying only the gas from the gas supply system, only the liquid is supplied from the liquid supply system for a predetermined time and the liquid accumulated in the spray nozzle is discharged and discarded, so that a characteristic change occurs in the liquid accumulated in the spray nozzle. In such a case, such a liquid can be discarded for uniform application.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of a rotary substrate coating apparatus to which a method of the present invention is applied.
FIG. 2 is a schematic configuration diagram showing a configuration of a spray nozzle.
FIG. 3 is a time chart showing a photoresist liquid coating method according to the first embodiment.
FIG. 4 is a time chart showing a photoresist liquid coating method according to a reference example .
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Suction type spin chuck 5 Spatter prevention cup 6 Solvent supply mechanism 7 Gas supply system 8 Solvent (gas) supply system 11 Coating liquid discharge nozzle 13 Coating liquid supply parts 15 and 23 Drive part 17 Spray nozzle 17a Spray gun 19 Solvent supply source 19a , 21 Electromagnetic on-off valve 31 Control unit 33 Memory W Substrate

Claims (4)

It is an application method in which liquid and gas are simultaneously supplied and mixed at the tip of the spray nozzle, and spray applied to the substrate to be processed.
Through the process of supplying only gas for a predetermined time immediately before the spray application process, the spray application process to the substrate to be processed is performed,
And before the gas-only supply step, perform a processing step of supplying only liquid for a predetermined time and discharging and discarding the liquid accumulated in the spray nozzle.
The coating method characterized by the above-mentioned. The coating method according to claim 1,
The coating method, wherein the liquid has volatility. It is a coating apparatus that supplies liquid and gas at the same time, mixes at the tip of the spray nozzle, and spray-coats the substrate to be processed.
A liquid supply system for supplying liquid to the spray nozzle;
A gas supply system for supplying a gas that joins the liquid supply system;
Control means for controlling the operation of the liquid supply system and the gas supply system;
With
The control means controls to supply only the gas from the gas supply system to the spray nozzle for a predetermined time immediately before spray application, and before supplying only the gas from the gas supply system, from the liquid supply system. A coating apparatus, wherein only a liquid is supplied for a predetermined time and control is performed to discharge and discard the liquid accumulated in the spray nozzle. The coating apparatus according to claim 3 , wherein
The control means is a timing instruction means for instructing the operation timing of the liquid supply system and the gas supply system;
Discharge control means for controlling discharge of liquid or gas from the liquid supply system and the gas supply system in response to a signal from the timing instruction means;
With
The coating apparatus according to claim 1, wherein spraying is performed by the discharge control means in response to a gas supply completion signal from the gas supply system from the timing instruction means.

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