WO2018020863A1

WO2018020863A1 - Method for forming coating film, apparatus for forming coating film and computer-readable recording medium

Info

Publication number: WO2018020863A1
Application number: PCT/JP2017/021596
Authority: WO
Inventors: 岡本　芳樹; 哲嗣宮本; 和久大村
Original assignee: 東京エレクトロン株式会社
Priority date: 2016-07-27
Filing date: 2017-06-12
Publication date: 2018-02-01
Also published as: KR102424630B1; TW201816518A; CN109478501A; KR20190037237A; TWI775762B; JP6771034B2; JPWO2018020863A1; TW202211995A; CN109478501B; TWI776749B

Abstract

This method for producing a coating film comprises: a first step for heating a body W to be processed, which comprises a substrate W1 and a projected part W2 provided on the surface of the substrate W1; a second step for obtaining a heated liquid by heating a coating liquid; and a third step for spraying the heated liquid in the form of droplets from a nozzle N onto the surface of the body W to be processed, which has been heated in the first step.

Description

Coating film forming method, coating film forming apparatus, and computer-readable recording medium

The present disclosure relates to a coating film forming method, a coating film forming apparatus, and a computer-readable recording medium.

Patent Document 1 discloses a method of forming a coating liquid (for example, a resist film) on an object to be processed in which convex portions (projections, protrusions, etc.) are provided on the surface of a substrate (wafer). The method includes heating the object by heating means when spraying the coating liquid droplets from the nozzle while meandering the nozzle above the surface of the object.

JP 2005-019560 A

In the method disclosed in Patent Document 1, the coating film is formed substantially uniformly along the surface of the object to be processed (including the surface of the convex portion) without filling the space between the convex portions with the coating liquid material. The purpose is that. However, according to the method, the next coating liquid can be sprayed before the solvent of the coating liquid completely evaporates on the surface of the object to be processed where the spray areas overlap as the nozzle moves. Therefore, even if the object to be processed is heated by the heating means, the coating liquid droplet (solvent) flows before the solute of the coating liquid droplet (coating liquid material particles) is fixed on the side wall surface of the convex portion. In particular, the film thickness of the coating film may increase on the base end side of the convex portion.

Thus, the present disclosure describes a coating film forming method, a coating film forming apparatus, and a computer-readable recording medium that can form a coating film more uniformly along the surface of the object to be processed including the protrusions. .

[1] A coating film forming method according to one aspect of the present disclosure includes a first step of heating an object to be processed including a substrate and a convex portion provided on the surface of the substrate, and heating the coating liquid. A second step of obtaining the first heated liquid, and a third step of spraying the first heated liquid from the nozzle in the form of droplets on the surface of the object to be processed after being heated in the first step Process.

In the coating film forming method according to one aspect of the present disclosure, when the coating liquid is sprayed on the surface of the object to be processed, the coating liquid is heated to be the first heating liquid in the second step. Therefore, when the first heated liquid is blown from the nozzle, the solvent (solvent) is volatilized immediately after that, and the concentration of the material particles (solute) in the coating liquid is increased, so that the coating liquid (first heated liquid) The fluidity of is reduced. Therefore, it is suppressed that droplets aggregate and flow on the surface (uneven surface) of the object to be processed. As a result, the material particles of the coating liquid easily adhere uniformly to the surface of the object to be processed. As described above, the coating film can be more uniformly formed along the surface of the object to be processed including the convex portion.

In addition, in the coating film forming method according to one aspect of the present disclosure, in the third step, the first heating liquid is dropped on the surface of the object to be processed after being heated in the first step. In the state of spraying from the nozzle. Therefore, since the object to be processed is heated before the third process, the solvent (solvent) of the coating liquid sprayed in the third process receives heat from the object to be processed over the entire surface of the object to be processed. Volatilizes. Therefore, it is further suppressed that droplets aggregate and flow on the surface (uneven surface) of the object to be processed. Therefore, the coating film can be formed more uniformly along the surface of the object to be processed including the convex portion.

[2] In the method described in [1] above, in the second step, the coating liquid is set so that the temperature of the first heated liquid at the nozzle outlet is ½ or less of the boiling point of the solvent contained in the coating liquid. May be heated. Volatilization is promoted as the temperature of the coating solution solvent (solvent) increases. However, if the amount of volatilization increases too much, the droplets blown from the nozzle may solidify before reaching the surface of the object to be processed. On the other hand, when the coating liquid is heated so that the temperature of the first heating liquid at the outlet of the nozzle is ½ or less of the boiling point of the solvent contained in the coating liquid, the liquid droplets blown out from the nozzle become the surface of the workpiece. It becomes difficult to solidify before reaching.

[3] In the method described in the

above item

1 or 2, in the second step, the coating liquid is heated so that the temperature of the first heating liquid at the nozzle outlet is 35 ° C. to 60 ° C. Also good. In this case, the liquid droplets blown out from the nozzle are more difficult to solidify before reaching the surface of the object to be processed.

[4] In the method according to any one of items 1 to 3, in the second step, the coating liquid is heated by mixing the coating liquid and the heated gas in the nozzle. A first heated liquid may be obtained. In this case, the fluidity of the coating liquid remains high until just before the coating liquid is discharged from the nozzle. Therefore, it becomes easy to blow out the coating liquid from the nozzle in the form of droplets. Therefore, before discharging from the nozzle, it is desired to increase the fluidity of the coating liquid to generate droplets, but after discharging from the nozzle, the fluidity of the coating liquid is reduced to reduce the amount of the coating liquid on the surface of the object to be processed. It is possible to meet the conflicting demands for uniformly attaching the material particles by a simple method.

[5] In the method according to any one of items 1 to 3, in the second step, the coating liquid is heated by a heater on the upstream side of the nozzle to obtain a first heating liquid. Also good. In this case, the fluidity of the coating liquid can be maintained until immediately before the coating liquid is discharged from the nozzle. Therefore, it becomes easy to blow out the coating liquid from the nozzle in the form of droplets. Therefore, before discharging from the nozzle, it is desired to increase the fluidity of the coating liquid to generate droplets, but after discharging from the nozzle, the fluidity of the coating liquid is reduced to reduce the amount of the coating liquid on the surface of the object to be processed. It is possible to meet the conflicting demands for the material particles to adhere uniformly by a simple method.

[6] The method according to any one of Items 1 to 5 includes a fourth step of heating the coating liquid to obtain a second heated liquid after the third step; After the step, the method further includes a fifth step of spraying the second heated liquid in a droplet state from the nozzle onto the surface of the target object on which the coating film is formed, and the second step in the fourth step. The temperature of the heated liquid may be set higher than the temperature of the first heated liquid in the second step. In this case, since the temperature of the first heated liquid is relatively low and the fluidity of the droplets ejected from the nozzle tends to be high, the droplets sprayed on the surface of the object to be processed in the third step are: It becomes easy to enter a narrow concave portion of the workpiece. On the other hand, since the temperature of the second heated liquid tends to be relatively high and the fluidity of the droplets ejected from the nozzle tends to be low, the droplets sprayed on the surface of the object to be treated in the fifth step It becomes easy to adhere to the side surface of the convex portion of the processing body. Therefore, the coating film can be formed more uniformly along the surface of the object to be processed including the convex portion.

[7] In the method described in any one of [1] to [6] above, in the third step, a droplet is blown from the nozzle to the surface of the object to be processed, and a gas nozzle different from the nozzle The nitrogen gas heated with respect to the spraying location of the droplets on the surface of the object to be processed may be sprayed from the gas nozzle while following the nozzle. In this case, since the solvent is dried during the spraying of the droplets, the time required for forming the coating film on the surface of the object to be processed can be shortened.

[8] A coating film forming apparatus according to another aspect of the present disclosure includes a first heating unit configured to heat a coating solution, a substrate, and a convex portion provided on a surface of the substrate. A second heating unit configured to heat the processing body, a supply unit having a nozzle, and a control unit are provided, and the control unit controls the second heating unit to heat the object to be processed. The coating liquid heated by the first heating unit with respect to the surface of the object to be processed after being heated by the first processing by controlling the first processing and the first heating unit and the supply unit A second process is performed in which the first heated liquid is ejected from the nozzle in the form of droplets. The coating film forming apparatus according to another aspect of the present disclosure has the same effects as the method according to the first item.

[9] In the apparatus described in [8] above, the first heating unit is applied so that the temperature of the first heating liquid at the nozzle outlet is equal to or less than ½ of the boiling point of the solvent contained in the application liquid. The liquid may be heated. In this case, the same effect as the method according to the second item can be obtained.

[10] In the apparatus according to item 8 or 9, the first heating unit heats the coating liquid so that the temperature of the first heating liquid at the outlet of the nozzle is 35 ° C. to 60 ° C. May be. In this case, the same effect as the method according to the third item can be obtained.

[11] In the apparatus according to any one of items 8 to 10, the first heating unit supplies the heated gas to the nozzle and mixes the gas and the coating liquid in the nozzle. It may be configured to heat the coating solution. In this case, the same effect as the method according to the fourth item can be obtained.

[12] In the apparatus according to any one of Items 8 to 10, the first heating unit may be a heater that heats the coating liquid upstream of the nozzle. In this case, the same effect as the method according to the fifth aspect can be obtained.

[13] In the apparatus according to any one of items 8 to 12, the control unit controls the first heating unit and the supply unit after the second process to control the object to be processed. A third process is further performed on the surface, in which a second heating liquid, which is a coating liquid heated by the first heating unit, is ejected from the nozzle in the form of droplets, and the second process in the third process is performed. The temperature of the heated liquid may be set higher than the temperature of the first heated liquid in the second process. In this case, the same effect as the method according to the sixth aspect can be obtained.

[14] The apparatus according to any one of items 8 to 13, further including a gas supply unit configured to discharge heated nitrogen gas from the gas nozzle, and the control unit includes: In this process, the first heating unit and the supply unit are controlled to spray droplets from the nozzles, and the gas supply unit is controlled to cause the gas nozzles to follow the nozzles, while the droplets on the surface of the object to be processed. The nitrogen gas heated with respect to the spray location may be sprayed from the gas nozzle. In this case, the same effect as the method according to the seventh aspect can be obtained.

[15] A computer-readable recording medium according to another aspect of the present disclosure records a program for causing a coating film forming apparatus to execute the method according to any one of items 1 to 7 above. ing. In the computer-readable recording medium according to another aspect of the present disclosure, it is possible to form the coating film more uniformly along the surface of the object to be processed including the convex portion, as in the above-described coating film forming method. Become. In this specification, a computer-readable recording medium includes a non-transitory computer recording medium (for example, various main storage devices or auxiliary storage devices) and a propagation signal (transitory computer recording medium). (E.g., a data signal that can be provided over a network).

According to the coating film forming method, the coating film forming apparatus, and the computer-readable recording medium according to the present disclosure, the coating film can be more uniformly formed along the surface of the target object including the convex portion. .

FIG. 1 is a perspective view showing a coating film forming apparatus. 2 is a cross-sectional view taken along line II-II in FIG. 3 is a cross-sectional view taken along line III-III in FIG. FIG. 4 is a block diagram showing the coating film forming apparatus. FIG. 5 is a schematic diagram illustrating a hardware configuration of the controller. FIG. 6 is a schematic diagram showing a liquid processing unit. FIG. 7 is a partial cross-sectional view showing the vicinity of the nozzle. FIG. 8 is a cross-sectional view of the heat treatment unit as viewed from the side. 9 is a cross-sectional view taken along line IX-IX in FIG. FIG. 10 is a flowchart for explaining a coating film forming procedure. FIG. 11 is a schematic diagram for explaining a procedure for forming a coating film. FIG. 12 is a schematic diagram partially showing another example of the liquid processing unit. FIG. 13 is a schematic diagram illustrating another example of the liquid processing unit. FIG. 14 is a schematic diagram illustrating another example of the liquid processing unit. FIG. 15 is a schematic diagram illustrating another example of the liquid processing unit. FIG. 16 is a diagram for explaining the embodiment.

The embodiments according to the present disclosure described below are examples for explaining the present invention, and the present invention should not be limited to the following contents. In the following description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted.

[Coating film forming device]
First, an outline of the coating film forming apparatus 1 will be described. The coating film forming apparatus 1 is an apparatus that forms a coating film R (see FIG. 6 and the like) on the surface of the workpiece W (see FIG. 6 and the like).

Here, the workpiece W has a substrate (wafer) W1 and at least one convex portion W2, as shown in FIG. The substrate W1 may have a disk shape, a part of a circle may be cut out, or may have a shape other than a circle, such as a polygon. The substrate W1 may be, for example, a semiconductor substrate, a glass substrate, a mask substrate, an FPD (Flat Panel Display) substrate, or other various substrates. The convex portion W2 is provided on the surface W1a of the substrate W1. The convex part W2 should just protrude outward from the surface W1a of the board | substrate W1. The shape of the convex portion W2 may be a rectangular parallelepiped shape or other various shapes, and is not limited at all. The material of the convex portion W2 may be an organic material or an inorganic material as long as the coating film R can be formed on the surface W2a (the upper surface and the outer peripheral surface exposed to the outside) of the convex portion W2. It is not limited. In the present specification, the “surface of the object to be processed W” refers to a surface obtained by combining the surface W1a of the substrate W1 and the surface W2a of the convex portion W2.

The coating film R is formed on the surface of the workpiece W by the coating film forming apparatus 1. The material constituting the coating film R may be a resist material, a color resist material, a polyimide material, an SOC (Spin On Carbon) material, a metal hard mask material, or other materials, and is not limited at all. The resist material may be a resin material or other materials, and is not limited at all. The resist material may be, for example, a photosensitive material that is sensitive to light having a predetermined wavelength. The photosensitive material may be a negative type or a positive type.

The coating film forming apparatus 1 includes a carrier block 2, a processing block 3, and a controller (control unit) CU as shown in FIG. 1 to FIG.

The carrier block 2 has a carrier station 21 and a carry-in / carry-out unit 22. The carrier station 21 supports a plurality of carriers 10. The carrier 10 accommodates at least one workpiece W in a sealed state. On the side surface 10a of the carrier 10, an opening / closing door (not shown) for taking in and out the workpiece W is provided.

The loading / unloading section 22 is located between the carrier station 21 and the processing block 3. As shown in FIG. 2, the carry-in / carry-out unit 22 includes a plurality of opening / closing doors 22 a. When the carrier 10 is placed on the carrier station 21, the opening / closing door of the carrier 10 faces the opening / closing door 22a. By opening the opening / closing door 22a and the opening / closing door on the side surface 10a at the same time, the inside of the carrier 10 and the inside of the carry-in / out unit 22 are communicated. The carry-in / carry-out unit 22 incorporates a delivery arm A1. The delivery arm A 1 takes out the workpiece W from the carrier 10 and delivers it to the processing block 3, receives the workpiece W from the processing block 3, and returns it to the carrier 10.

As shown in FIGS. 2 and 3, the processing block 3 includes a plurality of

processing modules

31, 32, a shelf 33, and a transfer arm A2. For example, as illustrated in FIG. 2, the

processing modules

31 and 32 are arranged so as to be aligned along the moving direction of the transfer arm A2.

As illustrated in FIG. 3, the processing module 31 includes a plurality of liquid processing units U1 arranged in the vertical direction, a coating liquid source B1, and a nitrogen gas source B2. The liquid processing unit U1 is configured to apply a liquid for forming the coating film R onto the surface of the object to be processed W. The coating liquid source B1 and the nitrogen gas source B2 are disposed below the liquid processing unit U1. Each of the coating liquid source B1 and the nitrogen gas source B2 contains a coating liquid and nitrogen gas (N ₂ gas) to be supplied to the liquid processing unit U1. The coating solution stored in the coating solution source B1 is obtained by diluting the material particles (solute) of the coating solution with a solvent (solvent). The solvent is not particularly limited as long as it is a known solvent suitable for dilution of coating solution material particles. For example, isopropyl alcohol (hereinafter also referred to as IPA), propylene glycol monomethyl ether acetate (hereinafter PGMEA). And γ-butyrolactone (hereinafter sometimes referred to as GBL) may also be used. The boiling point of IPA is 82.4 ° C. The boiling point of PGMEA is 146 ° C. The boiling point of GBL is 204 ° C.

The processing module 32 includes a plurality of heat treatment units U2 (second heating units) arranged in the vertical direction, as shown in FIG. The heat treatment unit U 2 is configured to perform heat treatment on the workpiece W when forming the coating film R. Specific examples of the heat treatment include heat treatment for volatilizing the solvent of the coating solution and curing the coating solution material.

As shown in FIG. 2, the shelf 33 is disposed on the carrier block 2 side in the processing block 3. The shelf 33 temporarily accommodates the workpiece W and is used for delivery of the workpiece W between the delivery arm A1 and the processing block 3. The transport arm A 2 transports the workpiece W between the shelf 33 and the

processing modules

31 and 32 and between the

processing modules

31 and 32.

The controller CU controls the coating film forming apparatus 1 partially or entirely. As shown in FIG. 4, the controller CU includes a reading unit M1, a storage unit M2, a processing unit M3, and an instruction unit M4 as functional modules. These functional modules are merely the functions of the controller CU divided into a plurality of modules for convenience, and do not necessarily mean that the hardware configuring the controller CU is divided into such modules. Each functional module is not limited to that realized by execution of a program, and is realized by a dedicated electric circuit (for example, a logic circuit) or an integrated circuit (ASIC: Application Specific Integrated Circuit) in which these are integrated. May be.

The reading unit M1 reads a program from the computer-readable recording medium 200. The recording medium 200 records a program for causing the coating film forming apparatus 1 to execute various operations. The recording medium 200 may be, for example, a semiconductor memory, an optical recording disk, a magnetic recording disk, or a magneto-optical recording disk.

The storage unit M2 stores various data. The storage unit M2 stores, for example, setting data input from an operator via an external input device (not shown), for example, in addition to the program read by the reading unit M1.

The processing unit M3 processes various data. For example, the processing unit M3 generates a signal for operating the liquid processing unit U1 and the heat treatment unit U2 based on various data stored in the storage unit M2.

The instruction unit M4 transmits the signal generated in the processing unit M3 to the liquid processing unit U1 or the heat treatment unit U2.

The hardware of the controller CU is composed of, for example, one or a plurality of control computers. The controller CU includes, for example, a circuit CU1 illustrated in FIG. 5 as a hardware configuration. The circuit CU1 may be composed of electric circuit elements (circuitry). Specifically, the circuit CU1 includes a processor CU2, a memory CU3, a storage CU4, a driver CU5, and an input / output port CU6. The processor CU2 configures each functional module described above by executing a program in cooperation with at least one of the memory CU3 and the storage CU4 and executing input / output of signals via the input / output port CU6. The driver CU5 is a circuit that drives various devices of the coating film forming apparatus 1. The input / output port CU6 inputs and outputs signals between the driver CU5 and the various apparatuses of the coating film forming apparatus 1.

In the present embodiment, the coating film forming apparatus 1 includes one controller CU, but may include a controller group (control unit) including a plurality of controllers CU. When the coating film forming apparatus 1 includes a controller group, each of the above functional modules may be realized by one controller CU, or may be realized by a combination of two or more controllers CU. Good. When the controller CU is composed of a plurality of computers (circuit CU1), each of the above functional modules may be realized by one computer (circuit CU1), or two or more computers (circuit CU1). ) May be realized. The controller CU may have a plurality of processors CU2. In this case, each of the functional modules may be realized by one processor CU2, or may be realized by a combination of two or more processors CU2.

[Configuration of liquid processing unit]
Subsequently, the liquid processing unit U1 will be described in more detail with reference to FIGS. As shown in FIG. 6, the liquid processing unit U1 includes a rotation holding unit 40, a driving unit 50, a pump P, a valve V, a heater 71, and a heat insulating material 72.

The rotation holding unit 40 includes a rotation unit 41 and a holding unit 42. The rotating part 41 has a shaft 43 protruding upward. The rotating unit 41 rotates the shaft 43 using, for example, an electric motor as a power source. The holding portion 42 is provided at the tip portion of the shaft 43. A workpiece W is arranged on the holding unit 42. The holding unit 42 holds the workpiece W substantially horizontally, for example, by suction or the like. That is, the rotation holding unit 40 has a posture of the workpiece W substantially horizontal, and the workpiece W around an axis (rotation axis) perpendicular to the surface of the workpiece W (surface W1a of the substrate W1). Rotate. In the present embodiment, the rotation axis passes through the center of the object to be processed W (substrate W1) having a circular shape, and is also the center axis. In the present embodiment, as shown in FIG. 6, the rotation holding unit 20 rotates the workpiece W clockwise as viewed from above.

The driving unit 50 is configured to drive the nozzle N. The drive unit 50 includes a guide rail 51, a slide block 52, and an arm 53. The guide rail 51 extends along the horizontal direction above the rotation holding unit 40 (object W). The slide block 52 is connected to the guide rail 51 so as to be movable in the horizontal direction along the guide rail 51. The arm 53 is connected to the slide block 52 so as to be movable in the vertical direction. A nozzle N is connected to the lower end of the arm 53. In the arm 53, a channel through which the coating liquid can flow is formed. The flow path is connected to the coating liquid source B1 via the pump P.

The driving unit 50 moves the slide block 52 and the arm 53 by a power source (not shown) such as an electric motor, and moves the nozzle N accordingly. In plan view, the nozzle N moves along the radial direction of the object to be processed W on a straight line perpendicular to the rotation axis of the object to be processed W when discharging the coating liquid.

The nozzle N opens downward toward the surface of the workpiece W. The nozzle N may be, for example, an internal mixing type two-fluid nozzle, an external mixing type two-fluid nozzle, or a one-fluid nozzle. In the present specification, the structure of the nozzle N will be described with reference to FIG. 7, taking an internal mixing type two-fluid nozzle as an example. The nozzle N has a main body N1 having a substantially cylindrical shape and a pipe N2 connected to a side surface of the main body N1. The pipe N2 is connected to the nitrogen gas source B2 via the valve V and the heater 71.

Flow paths N3 and N4 are formed inside the main body N1. The flow path N3 communicates with the flow path of the coating liquid formed inside the arm 53. The flow path N3 extends in the vertical direction in the main body N1, and the lower end communicates with the discharge port N5 of the nozzle N. The flow path N4 communicates with the pipe N2. The flow path N4 extends from the outer peripheral surface of the main body N1 to the vicinity of the lower end of the flow path N3 in the main body N1. In the merging portion N6 where the flow path N4 joins the flow path N3, the coating liquid flowing through the flow path N3 and the nitrogen gas flowing through the flow path N4 collide and are mixed to form minute droplets (coating liquid) of the coating liquid. Droplet) is generated. From the discharge port N5, the droplet is blown out (sprayed) toward the surface of the workpiece W. The height position of the discharge port N5 from the surface of the target object W (the linear distance between the discharge port N5 and the surface of the target object W in the vertical direction) is the size of the target object W, the flow rate of the coating liquid, and the coating Although it can be appropriately set depending on the flow rate of the liquid, the heating temperature of the coating liquid (details will be described later), etc., for example, it may be about 50 mm to 100 mm, may be about 65 mm to 80 mm, or may be 70 mm to 75 mm. It may be a degree.

As shown in FIG. 6, the pump P receives a control signal from the controller CU and sends the coating liquid from the coating liquid source B1 to the nozzle N. The pump P, the arm 53, the nozzle N (flow path N3), and the coating liquid source B1 constitute a supply unit 60 for supplying the coating liquid to the workpiece W as shown in FIG.

As shown in FIG. 6, the valve V receives a control signal from the controller CU and sends nitrogen gas from the nitrogen gas source B2 to the nozzle N.

The heater 71 receives the control signal from the controller CU and heats the nitrogen gas sent out from the nitrogen gas source B2 to a predetermined temperature (a temperature higher than room temperature). Therefore, when the nitrogen gas heated by the heater 71 merges with the coating liquid at the merging portion N6, the coating liquid is heated to become a heated liquid. That is, the heating liquid is blown out in the form of droplets from the discharge port N5 of the nozzle N.

Here, the heating amount of the nitrogen gas by the heater 71 is set so that the temperature of the heating liquid (liquid droplets of the coating liquid) at the discharge port N5 of the nozzle N is equal to or less than ½ of the boiling point of the solvent (solvent) of the coating liquid. It may be set (first temperature range). Specifically, the temperature of the heated liquid at the discharge port N5 may be 41.2 ° C. or lower when the solvent is IPA, may be 73 ° C. or lower when the solvent is PGMEA, When is GBL, it may be 102 ° C. or lower. In this case, since the coating liquid after mixing with the heated nitrogen gas is unlikely to become high temperature, it is suppressed that the volatilization amount of the solvent (solvent) is excessive, and the droplets blown out from the nozzle N are to be processed W It becomes difficult to solidify before reaching the surface.

Alternatively, the heating amount of the nitrogen gas by the heater 71 may be set so that the temperature of the heating liquid (liquid droplets of the coating liquid) at the discharge port N5 of the nozzle N is 35 ° C. to 60 ° C. (second temperature) range). Also in this case, the liquid droplets blown out from the nozzle are difficult to solidify before reaching the surface of the object to be processed. Alternatively, the heating amount of the nitrogen gas by the heater 71 is set so that the temperature of the heating liquid (coating liquid droplet) at the discharge port N5 of the nozzle N satisfies both the first and second temperature ranges. It is also possible (third temperature range).

The heat insulating material 72 is arrange | positioned around the piping N2, and suppresses the movement of heat inside and outside the piping N2. Therefore, the heat insulating material 72 suppresses a decrease in the temperature of the heated liquid until the coating liquid (heated liquid) heated by the heater 71 is discharged from the discharge port N5.

The valve V, the pipe N2, the nozzle N (flow path N4), the nitrogen gas source B2, and the heater 71 supply the heated nitrogen gas to the nozzle N and heat supply for heating the coating liquid with the heated nitrogen gas. Part 70 (first heating unit) is configured.

[Configuration of heat treatment unit]
Then, with reference to FIG.8 and FIG.9, the structure of the heat processing unit U2 is demonstrated. The heat treatment unit U 2 includes a heating chamber 110 that heats the workpiece W and a transport mechanism 120 that transports the workpiece W in the housing 100. A loading / unloading port 101 for carrying the workpiece W into the casing 100 and carrying the workpiece W out of the casing 100 on both side walls of the portion corresponding to the transport mechanism 120 in the casing 100. Is formed.

The heating chamber 110 includes a lid portion 111 and a hot plate housing portion 112. The lid portion 111 is located above the hot plate housing portion 112 and can be moved up and down between an upper position separated from the hot plate housing portion 112 and a lower position placed on the hot plate housing portion 112. It is. The lid part 111 constitutes the processing chamber PR together with the hot plate accommodating part 112 when in the lower position. An exhaust part 111 a is provided at the center of the lid part 111. The exhaust part 111a is used for exhausting gas from the processing chamber PR.

The hot plate accommodating portion 112 has a cylindrical shape, and accommodates the hot plate 113 therein. The outer peripheral portion of the hot plate 113 is supported by a support member 114. The outer periphery of the support member 114 is supported by a cylindrical support ring 115. A gas supply port 115 a that opens upward is formed on the upper surface of the support ring 115. The gas supply port 115a ejects an inert gas into the processing chamber PR.

The hot plate 113 is a flat plate having a circular shape as shown in FIG. The outer shape of the hot plate 113 is larger than the outer shape of the workpiece W. The hot plate 113 is formed with three through holes HL extending in the thickness direction (see FIG. 9). On the upper surface of the hot plate 113, six support pins 113a for supporting the workpiece W are erected (see FIG. 8). The height of the support pin 113a may be about 100 μm, for example.

Returning to FIG. 8, a heater 116 is disposed on the lower surface of the hot plate 113. The heater 116 is connected to the controller CU and is controlled based on an instruction signal from the controller CU.

An elevating mechanism 119 is disposed below the hot plate 113. The elevating mechanism 119 includes a motor 119a disposed outside the housing 100, and three elevating pins 119b that move up and down by the motor 119a. The elevating pins 119b are configured to be able to pass through the corresponding through holes HL. When the controller CU transmits an ascending signal or a descending signal to the motor 119a, the elevating pins 119b move up and down while moving in the corresponding through holes HL. When the tip of the lift pin 119b protrudes above the hot plate 113, the workpiece W can be placed on the tip of the lift pin 119b. The workpiece W placed on the tip of the lifting pin 119b moves up and down as the lifting pin 119b moves up and down.

The transport mechanism 120 is located adjacent to the heating chamber 110. The transport mechanism 120 includes a transport plate 121 on which the workpiece W is placed. The conveyance plate 121 is a flat plate having a rectangular shape as shown in FIG. An end of the transport plate 121 on the heating chamber 110 side has an arc shape protruding toward the heating chamber 110.

The conveyance plate 121 is attached to a rail 122 extending toward the heating chamber 110 side. The transport plate 121 is driven by the drive unit 123 and can move horizontally on the rail 122. The transport plate 121 moved to the heating chamber 110 side is located above the hot plate 113.

The transport plate 121 is formed with two slits 124 extending along the extending direction of the rail 122. The slit 124 is formed so as to extend from the end of the transport plate 121 on the heating chamber 110 side to the vicinity of the center of the transport plate 121. The slit 124 prevents interference between the transport plate 121 moved to the heating chamber 110 side and the lift pins 119b protruding on the heat plate 113.

As shown in FIG. 8, an elevating mechanism 125 is disposed below the transport plate 121. The elevating mechanism 125 includes a motor 125a disposed outside the housing 100 and three elevating pins 125b that move up and down by the motor 125a. The elevating pins 125b are configured to be able to pass through the slits 124, respectively. When the controller CU transmits an ascending signal or a descending signal to the motor 125a, the elevating pin 125b moves up and down while moving in the slit 124. When the tip of the lift pin 125b protrudes above the transport plate 121, the workpiece W can be placed on the tip of the lift pin 125b. The workpiece W placed on the tip of the elevating pin 125b moves up and down as the elevating pin 125b moves up and down.

[Method of forming coating film]
Subsequently, a method of forming the coating film R on the surface of the workpiece W (coating film forming method) will be described with reference to FIGS. 10 and 11. First, the controller CU controls the delivery arm A1, and the workpiece W in the carrier 10 is conveyed to the shelf 33 by the delivery arm A1. Next, the controller CU controls the transport arm A2, takes out the workpiece W from the shelf 33 by the transport arm A2, and transports it to the heat treatment unit U2. In the heat treatment unit U2, the controller CU controls the transport mechanism 120 (transport plate 121), and the workpiece W is transported into the heating chamber 110 (Step S1). When the workpiece W is placed on the hot plate 113, the controller CU controls the lifting mechanism 119 to lower the lid 111 to the lower position by the lifting mechanism 119. As a result, the object to be processed W is accommodated in the processing chamber PR constituted by the lid portion 111 and the hot plate accommodating portion 112.

Next, the controller CU controls the heating chamber 110 and heats the workpiece W to a predetermined temperature by the heating chamber 110 (step S2; first step; first processing). The heating temperature of the target object W in the heating chamber 110 may be set to a temperature that is 0 ° C. to 30 ° C. lower than the boiling point of the solvent contained in the droplets. When the heating temperature of the object W to be processed in the heating chamber 110 is equal to or higher than the temperature 30 ° C. lower than the boiling point of the solvent contained in the droplets, volatilization of the solvent of the droplets sprayed in step S5 described later is facilitated. . Therefore, it is possible to prevent the droplets from collecting in the concave portions (between the convex portions W2) of the workpiece W and increasing the film thickness of the coating film R particularly on the base end side of the convex portions W2. If the heating temperature of the object W to be processed by the heating chamber 110 is equal to or lower than the temperature 0 ° C. lower than the boiling point of the solvent contained in the droplets (that is, a temperature equal to the boiling point), the droplets sprayed in step S5 described later It is difficult for a situation in which most of the solvent of the droplets volatilizes before reaching the surface of the workpiece W. Therefore, it is suppressed that the coating liquid material particles contained in the coating liquid droplets are successively deposited on the surface of the workpiece W while maintaining the shape.

When the solvent of the coating solution is IPA, since the boiling point of IPA is 82.4 ° C., the heating temperature of the workpiece W in the heating chamber 110 may be set to about 55 ° C. to 85 ° C. When the solvent of the coating solution is PGMEA, since the boiling point of PGMEA is 146 ° C., the heating temperature of the workpiece W in the heating chamber 110 may be set to about 110 ° C. to 150 ° C. When the solvent of the coating solution is GBL, since the boiling point of GBL is 204 ° C., the heating temperature of the workpiece W in the heating chamber 110 may be set to about 150 ° C. to 205 ° C.

Next, the controller CU controls the elevating mechanism 119 and the transport mechanism 120 to carry out the heated workpiece W from the heating chamber 110. Next, the controller CU controls the transport arm A2, takes out the workpiece W from the heat treatment unit U2 by the transport arm A2, and transports it to the liquid processing unit U1 (step S3). The time required for the workpiece W to be transported to the liquid processing unit U1 after being heated by the heating chamber 110 is, for example, about several seconds to 10 seconds. During this conveyance, the temperature of the heated object W can be lowered by about 20 ° C. to 30 ° C., for example.

When the object to be processed W is conveyed to the liquid processing unit U1 and is held by the holding part 42 of the rotation holding part 40, the controller CU controls the rotating part 41 to rotate the object to be processed W (step S4). . In this state, the controller CU controls the drive unit 50, the pump P, the valve V, and the heater 71, and the nozzle N is on a straight line perpendicular to the rotation axis of the workpiece W along the radial direction of the workpiece W. While moving, the heated coating liquid droplets (heated liquid droplets) are sprayed from the discharge port N5 of the nozzle N to the surface of the rotating workpiece W (step S5; FIG. 11A). Reference; third step: second treatment).

At this time, nitrogen gas heated by the heater 71 is supplied to the nozzle N and mixed with the coating liquid to form a heating liquid (first heating liquid) (second process; second process). For this reason, as shown in FIG. 11A, the solvent of the droplets volatilizes immediately after the droplets are blown from the nozzle N, and the fluidity of the droplets (coating liquid) decreases. At this time, the object to be processed W is heated in step S2, and the surface of the object to be processed W is at a predetermined temperature. Therefore, the liquid droplet immediately before adhering to the object to be processed W or the solvent of the liquid droplet adhering to the object to be processed W is volatilized by receiving heat from the object to be processed W. Thereby, the material particles (coating liquid material) of the droplets adhere to the surface of the object to be processed W (see FIG. 11B). As the nozzle N reciprocates once or a plurality of times on the surface of the workpiece W, a coating film having a predetermined thickness is formed on the surface of the workpiece W (see FIG. 11C).

Next, the controller CU controls the transport arm A2, takes out the workpiece W from the liquid processing unit U1 by the transport arm A2, cools the workpiece W to a predetermined temperature, and transports it to the shelf 33. At this time, the workpiece W may be forcibly cooled using a cooling mechanism such as a cooling plate or may be natural cooling. Thereafter, the controller CU controls the delivery arm A1, and returns the workpiece W from the shelf 33 into the carrier 10 by the delivery arm A1 (step S6). Thereby, the formation process of the coating film R is completed.

[Action]
In the present embodiment as described above, when the coating liquid is sprayed onto the surface of the workpiece W, the coating liquid is heated to form a heated liquid. Therefore, when the heated liquid is blown out from the nozzle N, the solvent (solvent) is volatilized immediately after that, and the concentration of the material particles (solute) in the coating liquid increases, so that the fluidity of the coating liquid (heating liquid) decreases. It will be in the state. Therefore, the droplets are prevented from aggregating and flowing on the surface (uneven surface) of the workpiece W. As a result, the material particles of the coating liquid easily adhere uniformly to the surface of the workpiece W. As described above, the coating film R can be more uniformly formed along the surface of the workpiece W including the convex portion W2.

In addition, since the volatilization of the solvent (solvent) is promoted immediately after the heated liquid is blown from the nozzle N, the solvent (solvent) in the droplets reaching the surface of the workpiece W is completely volatilized. There is no need to transport the treatment body W to the heat treatment unit U2. Therefore, in order to form the coating film R having a desired thickness on the surface of the object to be processed W, it is not necessary to reciprocate the object to be processed W between the liquid processing unit U1 and the heat treatment unit U2. Therefore, the time for forming the coating film R on the workpiece W can be extremely shortened.

In this embodiment, before spraying droplets on the surface of the object to be processed W, the object to be processed W is heated in the heat treatment unit U2 in step S2. Therefore, the solvent (solvent) of the coating liquid sprayed in step S 5 receives the heat from the object to be processed and volatilizes on the entire surface of the object to be processed. Therefore, it is further suppressed that droplets aggregate and flow on the surface (uneven surface) of the workpiece W. Therefore, the coating film R can be formed more uniformly along the surface of the workpiece W including the convex portion W2.

In the present embodiment, the heating liquid is obtained by heating the coating liquid by mixing the coating liquid and the heated nitrogen gas in the nozzle N. Therefore, the fluidity of the coating liquid remains high until immediately before the coating liquid is discharged from the nozzle N. Therefore, it becomes easy to blow the coating liquid from the nozzle N in the form of droplets. As a result, before discharging from the nozzle N, it is desired to increase the fluidity of the coating liquid to generate droplets, but after discharging from the nozzle N, the fluidity of the coating liquid is reduced to reduce the surface of the workpiece W. It is possible to meet the conflicting demands for uniformly adhering the material particles of the coating liquid with a simple method.

In the present embodiment, in step S5, droplets are sprayed from the nozzle N onto the surface of the object to be processed W while the object to be processed W is rotated. Therefore, compared with the case where droplets are sprayed from the nozzle N onto the surface of the workpiece W while the nozzle N is meandering on the surface of the stationary workpiece W, the droplets from the nozzle N are removed from the workpiece W. It is difficult to be sprayed on the surface. Therefore, the coating film R can be formed more uniformly along the surface of the workpiece W including the convex portion W2.

[Other Embodiments]
As mentioned above, although embodiment concerning this indication was described in detail, you may add various deformation | transformation to said embodiment within the range of the summary of this invention. For example, in the present embodiment, the heat treatment unit U2 performs the process of heating the object to be processed W in the heating chamber 110 (step S2), and the process of spraying the coating liquid droplets onto the surface of the object to be processed W from the nozzle N (step S5). ) Is performed in the liquid processing unit U1, but both processes may be performed in the processing chamber using a processing chamber having both the liquid processing unit U1 and the heat treatment unit U2. In this case, when heating the workpiece W, it is preferable to stop the rotation of the workpiece W.

In the case where there are a plurality of convex portions W2 in the radial direction of the substrate W1, the centrifugal force becomes smaller as it is closer to the rotation axis of the substrate W1, so that when the droplets aggregate on the surface of the workpiece W, the convexity closer to the rotation axis. The coating liquid aggregated as part W2 tends to stay. Therefore, when the nozzle N is positioned in the vicinity of the rotation axis, the moving speed of the nozzle N may be increased. In this case, since the amount of droplets sprayed near the rotation axis on the surface of the workpiece W is small, the coating liquid droplets are difficult to aggregate.

The controller CU may control the rotating unit 41 so that the rotation speed of the workpiece W increases as the position of the nozzle N is closer to the rotation axis of the substrate W1. At this time, the controller CU may control the rotating unit 41 so that the moving speed (linear velocity) of the workpiece W immediately below the nozzle N is constant regardless of the position of the nozzle N. The controller CU increases the rotational speed of the workpiece W as the position of the nozzle N is closer to the rotation axis of the substrate W1, and increases the moving speed of the nozzle N as the nozzle N is positioned closer to the rotation axis. You may perform in combination with control. The controller CU may control the rotating unit 41 such that the number of rotations of the workpiece W is constant regardless of the position of the nozzle N with respect to the substrate W1.

When the area where the droplets from the nozzle N are sprayed is larger than the size of the surface of the object to be processed W, the nozzle N does not have to be moved, and the object to be processed W need not be rotated. .

In addition to step S2, the object to be processed W may also be heated in the process of spraying droplets from the nozzle N onto the surface of the object to be processed W (step S5). Or the process of step S2 which heats the to-be-processed object W previously does not need to be performed.

For example, as shown in FIG. 12, the liquid processing unit U1 further includes a gas nozzle GN configured to blow heated nitrogen gas (high-temperature nitrogen gas) onto the surface of the object to be processed W. From the controller CU Based on the instruction, the operation of the gas nozzle GN may be controlled by the gas supply unit. Specifically, in step S5, the controller CU controls the gas supply unit to cause the gas nozzle GN to follow the nozzle N, while supplying high-temperature nitrogen gas to the sprayed portion of the droplet on the surface of the workpiece W. You may spray from gas nozzle GN. In this case, since the solvent is dried by the high-temperature nitrogen gas from the gas nozzle GN during the spraying of the droplets, the time required to form the coating film R on the surface of the workpiece W can be shortened. The temperature of the high-temperature nitrogen gas may be about 50 ° C. to 150 ° C.

In the above embodiment, the nitrogen gas is heated by the heater 71, and the coating liquid is further heated by the heated nitrogen gas. However, as shown in FIG. A heater 81 may be provided on the upstream side of the arm 53 to directly heat the coating solution. Also in this case, the fluidity of the coating liquid can be maintained until immediately before the coating liquid is discharged from the nozzle N. Therefore, it becomes easy to blow out the coating liquid from the nozzle N in a droplet state. Therefore, before discharging from the nozzle N, it is desired to increase the fluidity of the coating liquid to generate droplets, but after discharging from the nozzle N, the fluidity of the coating liquid is reduced to form the surface of the workpiece W. It is possible to meet the conflicting demands for the material particles of the coating solution to adhere uniformly by a simple method.

As shown in FIG. 14, a bypass channel that connects the upstream side of the valve V and the downstream side of the heater 71 may be further provided, and the valve 73 may be provided in the bypass channel. In this case, the controller CU controls the valves V and 73 so that the nitrogen gas heated by the heater 71 and the nitrogen gas not heated by the heater 71 (normal temperature nitrogen gas) are selectively supplied to the nozzle N. Can be supplied. Specifically, when the process of ejecting droplets to the surface of the object to be processed W is the first time, the controller CU closes the valve V and opens the valve 73 so that the heating liquid (first heating liquid ) May be relatively low. On the other hand, when the process of ejecting droplets to the surface of the workpiece W is performed for the second time or later, the controller CU opens the valve V and closes the valve 73, so that the heating liquid (second heating liquid) is discharged. The temperature may be relatively high (fourth step; third treatment). In this case, the first droplet sprayed on the surface of the object to be processed W (third step; second process) tends to have high fluidity. It becomes easy to enter (between the convex portions W2). On the other hand, since the liquid droplets (fifth step; third treatment) sprayed on the surface of the workpiece W for the second time or later tend to have low fluidity, the droplets are formed on the side surface of the convex portion W2 of the workpiece W. It becomes easy to adhere. Therefore, the coating film R can be formed more uniformly along the surface of the workpiece W including the convex portion W2. In addition, in order to prevent the material particles of the coating liquid from solidifying in the nozzle N and blocking the nozzle N, the controller CU closes the valve V after the droplet spraying process from the nozzle N is performed and the valve N By opening 73, normal temperature nitrogen gas may be supplied to the nozzle N to cool the nozzle N.

As shown in FIG. 15, in order to prevent the material particles of the coating liquid from solidifying in the nozzle N and clogging the nozzle N, the liquid processing unit U1 may further include a cleaning unit 82 for the nozzle N. Good. The washing | cleaning part 82 is a container which stores a solvent, for example. The nozzle N that has been subjected to the droplet spraying process is immersed in the solvent in the cleaning unit 82, whereby the nozzle N is cooled and cleaned.

As the gas mixed in the coating solution, various gases other than nitrogen gas (for example, inert gas, air, etc.) may be used.

When the coating film R is formed on the surface of the workpiece W using the coating film forming apparatus 1 according to this embodiment, the coating film R is uniformly formed along the surface of the workpiece W including the convex portion W2. In order to confirm that it was possible, the following test was conducted.

A workpiece W having a plurality of convex portions W2 provided on a disk-shaped substrate W1 having a diameter of 150 mm was prepared. Further, a resist solution in which a positive photoresist was diluted with PGMEA was prepared.

Next, the workpiece W was heated at 120 ° C. for 60 seconds by the heat treatment unit U2. Next, the heated object W was transported to the liquid processing unit U1, and the prepared resist solution was sprayed from the nozzle N of the two-fluid nozzle onto the surface of the object W. At this time, the rotational speed of the workpiece W by the rotation holding unit 40 was varied within the range of 60 rpm to 600 rpm so that the moving speed (linear velocity) of the workpiece W just below the nozzle N was constant. The moving speed of the nozzle N was 10 mm / second to 150 mm / second. Further, the nozzle N was reciprocated 14 times on the surface of the workpiece W. Thus, a resist film (coating film R) was formed on the surface of the object to be processed W.

Next, the state of the cross section of any two convex portions W2 was observed with an electron microscope. In FIG. 16 (a), (b), the electron micrograph of the said 2 convex part W2 was shown typically. It was confirmed that the resist film (coating film R) was formed extremely uniformly along the surface of the workpiece W including the convex portion W2 in any of the trial convex portions W2.

DESCRIPTION OF SYMBOLS 1 ... Coating film formation apparatus, 60 ... Supply part, 70 ... Heat supply part (1st heating part), 71, 81 ... Heater, 72 ... Heat insulating material, CU ... Controller (control part), N ... Nozzle, N5 ... Discharge port, R ... coating film, U1 ... liquid processing unit, U2 ... heat treatment unit (second heating unit), W ... target object, W1 ... substrate, W1a ... surface, W2 ... convex, W2a ... surface.

Claims

A first step of heating an object to be processed including a substrate and a convex portion provided on the surface of the substrate;
A second step of heating the coating liquid to obtain a first heated liquid;
And a third step of spraying the first heated liquid in a droplet state from the nozzle onto the surface of the object to be processed after being heated in the first step.
The said 2nd process WHEREIN: The said coating liquid is heated so that the temperature of the said 1st heating liquid in the exit of the said nozzle may become 1/2 or less of the boiling point of the solvent contained in the said coating liquid. The coating film formation method of description.
The coating film forming method according to claim 1, wherein, in the second step, the coating liquid is heated so that a temperature of the first heating liquid at an outlet of the nozzle becomes 35 ° C to 60 ° C.
2. The coating film formation according to claim 1, wherein, in the second step, the coating liquid is heated to obtain the first heated liquid by mixing the coating liquid and a heated gas in the nozzle. Method.
The coating film forming method according to claim 1, wherein, in the second step, the first heating liquid is obtained by heating the coating liquid with a heater on the upstream side of the nozzle.
After the third step, a fourth step of heating the coating liquid to obtain a second heated liquid;
After the fourth step, the method further includes a fifth step of spraying the second heating liquid from the nozzle in the form of droplets on the surface of the object to be processed on which the coating film is formed,
2. The coating film forming method according to claim 1, wherein the temperature of the second heating liquid in the fourth step is set higher than the temperature of the first heating liquid in the second step.
In the third step, the droplets are sprayed from the nozzle onto the surface of the object to be processed, and a gas nozzle different from the nozzle is made to follow the nozzle while the surface of the object to be processed is The coating film forming method according to claim 1, wherein a heated nitrogen gas is sprayed from the gas nozzle to a location where the droplets are sprayed.
A first heating unit configured to heat the coating solution;
A second heating unit configured to heat an object to be processed including a substrate and a convex portion provided on the surface of the substrate;
A supply unit having a nozzle;
A control unit,
The controller is
A first process for controlling the second heating unit to heat the object to be processed;
By controlling the first heating unit and the supply unit, the coating liquid heated by the first heating unit is applied to the surface of the object to be processed after being heated by the first processing. A coating film forming apparatus that executes a second process in which a certain first heated liquid is ejected from the nozzle in a droplet state.
The said 1st heating part heats the said coating liquid so that the temperature of the said 1st heating liquid in the exit of the said nozzle may become 1/2 or less of the boiling point of the solvent contained in the said coating liquid. The coating film forming apparatus as described in 2. above.
The coating film forming apparatus according to claim 8, wherein the first heating unit heats the coating liquid so that a temperature of the first heating liquid at an outlet of the nozzle becomes 35 ° C to 60 ° C.
The said 1st heating part is comprised so that the said coating liquid may be heated by supplying the heated gas to the said nozzle and mixing the said gas and the said coating liquid in the said nozzle. 8. The coating film forming apparatus according to 8.
The coating film forming apparatus according to claim 8, wherein the first heating unit is a heater that heats the coating liquid upstream of the nozzle.
The control unit controls the first heating unit and the supply unit after the second processing, and the surface of the object to be processed is heated by the first heating unit. Further executing a third process of blowing the second heating liquid, which is a coating liquid, from the nozzle in the form of droplets;
The coating film forming apparatus according to claim 8, wherein a temperature of the second heating liquid in the third process is set higher than a temperature of the first heating liquid in the second process.
A gas supply unit configured to discharge the heated nitrogen gas from the gas nozzle;
In the second process, the control unit controls the first heating unit and the supply unit to spray the droplets from the nozzles, and also controls the gas supply unit to control the gas nozzles. The coating film forming apparatus according to claim 8, wherein nitrogen gas heated from the gas nozzle is blown from a portion of the surface of the object to be blown while the nozzle is followed.
A computer-readable recording medium storing a program for causing a coating film forming apparatus to execute the coating film forming method according to claim 1.