TWI693109B - Coating method - Google Patents

Abstract

The first chemical solution C1 is placed in a spiral shape on the solvent film SL of the substrate W without a gap. The rotation of the circular substrate W expands the first chemical solution C1 and the second chemical solution C2, respectively. Since the first medical solution C1 draws the second medical solution C2 having a higher viscosity than the first medical solution C1, it assists in expanding the second medical solution C2. Moreover, the second chemical solution C2 is placed on the first chemical solution C1 having a lower viscosity than the second chemical solution C2, and the solvent SL enters the recess H formed on the front surface of the circular substrate W. Therefore, by rotating the circular substrate W, the first chemical solution C1 can enter the recess H more easily than the second chemical solution C2.

Description

Coating method

The present invention relates to a coating method, which is applied to substrates for FPD (Flat Panel Display) and glass substrates for photomasks such as semiconductor substrates, liquid crystal displays and organic EL (Electroluminescence) display devices , Substrates for optical discs, substrates for magnetic discs, ceramic substrates, substrates for solar cells and other substrates, thick films are coated with chemical solutions of high viscosity.

The coating device includes: a holding rotating portion that holds a circular substrate and rotates the circular substrate; and a nozzle that is disposed above the circular substrate held by the holding rotating portion and supplies the chemical solution onto the circular substrate ( For example, refer to Patent Documents 1 and 2). The coating device rotates the circular substrate at a low speed while supplying the chemical solution onto the circular substrate from the nozzle. Thereafter, the coating device rotates the circular substrate at high speed. By this, a chemical liquid film (thin film) is formed on the circular substrate with a specific thickness.

In addition, Patent Document 3 discloses the following liquid treatment method. The substrate is rotated at the first revolution. Then, the supply of the processing liquid is started at a position on the front surface of the substrate, which is a distance from the center of rotation of the substrate that exceeds 0% to 40% of the radius of the substrate. Then, the supply position of the processing liquid is moved. After the supply position of the processing liquid reaches the center of rotation, while supplying the processing liquid, the substrate is rotated at a second number of revolutions greater than the first number of revolutions. By this, the processing liquid is spread and applied to the outer peripheral side of the substrate. That is, by eccentricity of the supply start position, the possibility of uneven coating state of the processing liquid due to the mixing of bubbles is eliminated. Furthermore, the viscosity of the treatment liquid is 20 ~ 220 cP (centipoise, centipoise). [Prior Technical Literature] [Patent Literature]

[Patent Literature 1] Japanese Patent Laid-Open No. 60-217627 [Patent Literature 2] Japanese Patent No. 3970695 [Patent Literature 3] Japanese Patent No. 5931230

[Problems to be solved by the invention]

It is desirable to form a thick chemical liquid film on a circular substrate with unevenness formed on the front surface (upper surface), and to fill the concave portion formed on the front surface of the circular substrate with the chemical liquid. However, in the case of using a high-viscosity chemical solution of more than 1000 cP (centipoise), even if the coating solution can be spread over the whole (the entire surface) of the circular substrate, there is a problem that the high-viscosity chemical solution is difficult to enter the recess.

For example, there is a method in which a circular substrate is filled with a solvent and the chemical liquid is replaced. In this method, if a large amount of solvent and a large amount of high-viscosity chemical solution are used, it may be possible to form a high-viscosity chemical solution film thickly while allowing the high-viscosity chemical solution to enter the concave portion. However, this method is not good because it wastes a large amount of solvent and a large amount of high-viscosity chemical solution. Therefore, there is a need for a method capable of thickly forming a chemical liquid film on a round substrate with a relatively small amount of solvent and high viscosity, and simultaneously filling the concave portion formed on the circular substrate with the chemical liquid film.

The present invention has been completed in view of this situation, and its object is to provide a coating method that can form a thick chemical film on a round substrate with a relatively small amount of solvent and a high-viscosity chemical solution. The chemical liquid film fills the recesses formed on the front surface of the circular substrate. [Technical means to solve the problem]

In order to achieve such an object, the present invention adopts the following configuration. That is, the coating method of the present invention is characterized by including the steps of: while rotating a circular substrate having a plurality of concave portions on the front side, while spraying the solvent from the solvent nozzle onto the circular substrate, whereby the solvent enters the concave portion At the same time, a solvent film is formed on the circular substrate; after the solvent film is formed, the first chemical liquid nozzle is moved from the first chemical liquid nozzle to the first chemical liquid while the first chemical liquid nozzle is moved in the radial direction of the circular substrate The first chemical solution is ejected from the solvent film of the circular substrate rotating relative to the nozzle, whereby the first chemical solution is placed spirally on the solvent film of the circular substrate without a gap; the first chemical solution After being placed in a spiral shape without a gap, a second chemical solution having a higher viscosity than the first chemical solution is ejected from the second chemical solution nozzle toward the center of the circular substrate on the first chemical solution; and by making the circle The shaped substrate rotates to expand the first chemical solution and the second chemical solution toward the peripheral edge side of the circular substrate, respectively.

With the coating method of the present invention, the first chemical solution is placed on the solvent film of the circular substrate in a spiral shape without gaps. The rotation of the circular substrate expands the first chemical solution and the second chemical solution, respectively. Because the first medical fluid draws the second medical fluid with a higher viscosity than the first medical fluid, it assists in expanding the second medical fluid. In addition, the second chemical solution is placed on the first chemical solution having a lower viscosity than the second chemical solution. In addition, the solvent enters the concave portion on the front surface forming the circular substrate. Therefore, by rotating the circular substrate, the first chemical solution can enter the concave portion more easily than the second chemical solution. As a result, a relatively small amount of solvent and a high-viscosity chemical liquid can form the chemical liquid film on the circular substrate thickly, and at the same time fill the concave part formed on the front surface of the circular substrate with the chemical liquid film.

Furthermore, in the above coating method, an example of the steps of expanding the first chemical solution and the second chemical solution respectively is that the second chemical solution ejected from the second chemical solution nozzle reaches the first chemical solution After that, the second chemical solution is ejected while rotating the circular substrate. Because the first medical fluid draws the second medical fluid with a higher viscosity than the first medical fluid, it assists in expanding the second medical fluid. At this time, since the second chemical liquid ejected from the second chemical liquid nozzle is sequentially expanded, the second chemical liquid can be smoothly expanded.

In addition, in the above coating method, an example of the step of expanding the first chemical solution and the second chemical solution separately is to discharge only the preset amount of the second chemical solution and stop the ejection of the second chemical solution To rotate the circular substrate. With this, the first chemical solution and the second chemical solution can be expanded by the rotation of the circular substrate in a state where a predetermined amount of the second chemical solution is ejected onto the first chemical solution.

Furthermore, in the above coating method, it is preferable that the second chemical solution nozzle has a circular or regular polygonal discharge port. Since it is difficult to deform the second chemical solution ejected onto the first chemical solution, the second chemical solution can be easily spread uniformly in a concentric shape.

Furthermore, in the above coating method, it is preferable that the second chemical solution is the same kind of chemical solution as the first chemical solution. The first chemical solution and the second chemical solution can be made into a film that is not easily distinguishable after drying.

Furthermore, in the coating method, it is preferable that the step of forming the solvent film is to spray the solvent from the solvent nozzle onto the rotating circular substrate while moving the solvent nozzle in the radial direction of the circular substrate . Thereby, since the ejection port of the solvent nozzle can face each of the recesses, the solvent easily enters the recesses. [Effect of invention]

According to the coating method of the present invention, a relatively small amount of solvent and a high-viscosity chemical solution can be used to form a thick chemical film on a round substrate while filling the chemical film on the front surface of the circular substrate Recess.

[Example]

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of a coating apparatus of an embodiment. 2 is a plan view showing a solvent nozzle moving mechanism and two chemical liquid nozzle moving mechanisms.

<Configuration of coating device 1> Refer to Figure 1. The coating device 1 includes a holding rotary unit 2, a solvent nozzle 3, and two chemical liquid nozzles 4, 5. In addition, the chemical liquid nozzle 4 corresponds to the first chemical liquid nozzle of the present invention, and the chemical liquid nozzle 5 corresponds to the second chemical liquid nozzle of the present invention.

The holding rotation section 2 holds a circular substrate (hereinafter referred to as a "substrate" as appropriate) W in a substantially horizontal state, and rotates the held substrate W. The holding rotary unit 2 includes a rotary chuck 7 and a rotary drive unit 8. The rotary chuck 7 is provided so as to be rotatable about a rotation axis AX1 and hold the substrate W. The rotary chuck 7 is configured to hold the substrate W by vacuum suction of the back surface (lower surface) of the substrate W, for example. The rotation drive unit 8 drives the rotation chuck 7 to rotate about the rotation axis AX1. The rotation drive unit 8 includes, for example, an electric motor. In addition, the rotation axis AX1 substantially coincides with the center CT of the substrate W.

The shield 9 is provided so as to surround the substrate W and hold the side of the rotating portion 2. The shroud 9 is configured to move in the vertical direction by a drive unit (not shown).

The solvent nozzle 3 ejects the solvent SL. As the solvent SL, for example, a diluent, PGMEA (Propylene Glycol Methyl Ether Acetate), ethyl lactate, and IPA (Isopropyl Alcohol) can be used. Pre-wetting is performed by spraying the solvent SL onto the substrate W, for example, the first chemical solution C1 ejected from the chemical solution nozzle 4 is easily attached to the substrate W, and the first chemical solution C1 is easily attached to the substrate W Expand. In addition, the solvent SL allows the first chemical solution C1 to easily enter the recess H.

The chemical solution nozzle 4 ejects the first chemical solution C1. The chemical liquid nozzle 4 has a rectangular or slit-shaped ejection port 4a. By making the discharge port 4a rectangular, compared to the case where the discharge port 4a is circular or square, the coating area per rotation can be increased. The chemical liquid nozzle 5 ejects the second chemical liquid C2. The chemical liquid nozzle 5 has a regular polygonal ejection port 5a such as a circle, regular quadrangle, regular hexagon, or the like. As a result, the second chemical solution C2 ejected onto the first chemical solution film SF is not easily deformed, that is, because it is close to a circle, the second chemical solution C2 can be easily spread on the substrate W into a concentric shape uniformly.

The first chemical liquid C1 ejected from the chemical liquid nozzle 4 and the second chemical liquid C2 ejected from the chemical liquid nozzle 5 use a relatively high-viscosity chemical liquid. The viscosity of the first liquid C1 is 300 cP (centipoise) or more and less than 1000 cP. In addition, the viscosity of the first chemical solution C1 is preferably 300 cP or more and less than 700 cP. In addition, the viscosity of the first chemical solution C1 is more preferably 500 cP or more and less than 700 cP. The viscosity of the second chemical solution C2 is 1000 cP or more and 10000 cP or less.

For the first chemical solution C1 and the second chemical solution C2, for example, a resist (for example, solder resist, photoresist), polyimide, or the like is used. In addition, as the first chemical solution C1 and the second chemical solution C2, chemical solutions for forming a protective film, an interlayer insulating film, a SOD (Spin On Dielectric) film, or the like are used. Although the second chemical solution C2 is the same chemical solution (for example, solder resist) as the first chemical solution C1, the viscosity is different. The second chemical solution C2 has the same main component as the first chemical solution C1. For example, the second chemical solution C2 has a higher viscosity by changing the content of the solvent SL than the first chemical solution C1. The first chemical solution C1 and the second chemical solution C2 are chemical solutions that cannot distinguish objects after drying or calcination.

The coating device 1 includes a solvent supply source 13, a solvent piping 15, a pump P1, and an on-off valve V1. The solvent supply source 13 includes, for example, a container such as a bottle. The solvent SL from the solvent supply source 13 is supplied to the solvent nozzle 3 through the solvent piping 15. The solvent piping 15 is provided with a pump P1, an on-off valve V1, and the like. The pump P1 sends the solvent SL to the solvent nozzle 3, and the switching valve V1 supplies and stops the solvent SL.

In addition, the coating device 1 includes a first chemical solution supply source 17, a chemical solution piping 19, a pump P2, and an on-off valve V2. The first chemical solution supply source 17 includes, for example, a container such as a bottle. The first chemical solution C1 from the first chemical solution supply source 17 is supplied to the chemical solution nozzle 4 through the chemical solution piping 19. The chemical liquid piping 19 is provided with a pump P2 and an on-off valve V2. The pump P2 sends the first chemical solution C1 to the nozzle 4, and the on-off valve V2 supplies the first chemical solution C1 and stops it.

In addition, the coating device 1 includes a second chemical solution supply source 21, a chemical solution piping 23, a pump P3, and an on-off valve V3. The second chemical solution supply source 21 includes, for example, a container such as a bottle. The second chemical liquid C2 from the second chemical liquid supply source 21 is supplied to the chemical liquid nozzle 5 through the chemical liquid pipe 23. The chemical liquid piping 23 is provided with a pump P3, an on-off valve V3, and the like. The pump P3 sends the second chemical solution C2 to the nozzle 5, and the on-off valve V3 supplies the second chemical solution C2 and stops it.

The coating device 1 includes a solvent nozzle moving mechanism 25, a first chemical liquid nozzle moving mechanism 27, and a second chemical liquid nozzle moving mechanism 29. Refer to Figure 2.

The solvent nozzle moving mechanism 25 rotates (moves) the solvent nozzle 3 around the rotation axis AX2. The solvent nozzle moving mechanism 25 includes an arm 31, a shaft 33, and a rotation driving section 35. The arm 31 supports the solvent nozzle 3 and the shaft 33 supports the arm 31. That is, the solvent nozzle 3 is connected to one end of the rod-shaped arm 31, and the shaft 33 is connected to the other end of the arm 31. The rotation drive unit 35 rotates the shaft 33 about the rotation axis AX2 to rotate the solvent nozzle 3 and the arm 31 about the rotation axis AX2. The rotation drive unit 35 includes an electric motor. Furthermore, the movement of the solvent nozzle 3 by the solvent nozzle moving mechanism 25 is included in the movement in the radial direction.

The first chemical liquid nozzle moving mechanism 27 moves the chemical liquid nozzle 4 in the vertical direction (Z direction) and in a specific first direction (for example, X direction) along the front surface of the substrate W. The first chemical liquid nozzle moving mechanism 27 includes an arm 37, a vertical moving part 39, and a plane moving part 41. The arm 37 supports the chemical liquid nozzle 4. The vertical movement part 39 moves the chemical liquid nozzle 4 and the arm 37 in the vertical direction. The plane moving part 41 moves the chemical liquid nozzle 4, the arm 37, and the vertical moving part 39 in the first direction. In addition, the chemical liquid nozzle 4 is arranged so that the longitudinal direction of the ejection port 4a is parallel to the first direction (X direction).

The second chemical liquid nozzle moving mechanism 29 moves the chemical liquid nozzle 5 in the vertical direction (Z direction) and in a specific first direction (for example, X direction) along the front surface of the substrate W. The second chemical liquid nozzle moving mechanism 29 includes an arm 43, a vertical moving part 45, and a plane moving part 47. The arm 43 supports the chemical liquid nozzle 5. The vertical movement part 45 moves the chemical liquid nozzle 5 and the arm 43 in the vertical direction. The plane moving part 47 moves the chemical liquid nozzle 5, the arm 43, and the vertical moving part 45 in the first direction.

The up and down moving parts 39 and 45 and the plane moving parts 41 and 47 are provided with, for example, electric motors, screw shafts, and guide rails. In addition, the plane moving parts 41 and 47 may be configured to move the chemical liquid nozzles 4, 5 and the like not only in the first direction but also in the second direction (Y direction) orthogonal to the first direction. The solvent nozzle 3 and the two chemical liquid nozzles 4 and 5 are configured such that their centers pass above the center CT of the substrate W.

Further, the solvent nozzle moving mechanism 25 may move the solvent nozzle 3 in the vertical direction (Z direction) like the first chemical liquid nozzle moving mechanism 27, or may move the solvent nozzle 3 in at least one of the first direction and the second direction One moves. On the other hand, the two chemical liquid nozzle moving mechanisms 27 and 29 may rotate the chemical liquid nozzle 4 or the chemical liquid nozzle 5 about the rotation axis arranged on the side of the shield 9 like the solvent nozzle moving mechanism 25. In addition, the solvent nozzle moving mechanism 25 and the two chemical liquid nozzle moving mechanisms 27 and 29 may include a multi-joint arm.

The coating device 1 shown in FIG. 1 includes one or a plurality of control sections 51 and operation sections 53. The control unit 51 includes, for example, a central processing unit (CPU). The control unit 51 controls each configuration of the coating device 1. The operation unit 53 includes a display unit (for example, a liquid crystal display), a memory unit, and an input unit. The memory section includes, for example, at least one of ROM (Read-Only Memory), RAM (Random-Access Memory), and hard disk. The input unit includes at least one of a keyboard, a mouse, and various buttons. In the memory section, various conditions of the coating process and operation programs required for the control of the coating device 1 are stored.

<Operation of coating device 1> Next, the operation of the coating device 1, that is, the coating method will be described with reference to the flowchart shown in FIG. 3. First, a transport mechanism (not shown) transports the substrate W to the holding and rotating unit 2. The rotating chuck 7 holding the rotating part 2 vacuum-absorbs the back surface of the substrate W to hold the substrate W.

[Step S01] Prewetting The control unit 51 rotates the substrate W having the plurality of recesses H by holding the rotation unit 2, and ejects the solvent SL onto the substrate W from the solvent nozzle 3. With this, the solvent film SL is formed on the substrate W while the solvent SL enters the concave portion H of the substrate W. Furthermore, as shown in FIG. 4( a ), a plurality of concave portions H are formed on the front surface of the substrate W. The recess H is, for example, at least any one of a space, a hole, and a groove. The hole is, for example, at least any one of a via, a via, and a contact hole.

The pre-wetting treatment will be specifically described. The steps of the pre-wetting treatment include a moving ejection step, an overflow step, a reverse moving step, and a thin film forming step. The solvent nozzle moving mechanism 25 shown in FIG. 2 moves the solvent nozzle 3 from the standby position outside the substrate W to above the center CT of the substrate W (see FIG. 4(a)). In addition, the holding rotation unit 2 rotates the held substrate W.

[Mobile ejection step] The moving and ejecting step is performed after moving the solvent nozzle 3 above the center CT of the substrate W. First, the on-off valve V1 is opened, and the solvent SL is ejected from the solvent nozzle 3 onto the substrate W rotating at the ejection speed. After the solvent SL reaches the substrate W, the solvent SL is ejected from the solvent nozzle 3 onto the rotating substrate W, and the solvent nozzle 3 is moved by the solvent nozzle moving mechanism 25 from above the center CT of the substrate W to the periphery of the substrate W Above part E (end or edge). Furthermore, the ejection speed is greater than 0 rpm and less than 500 rpm, preferably greater than 0 rpm and 300 rpm or less. In addition, the ejection speed is more preferably 100 rpm or more and 200 rpm or less.

The solvent nozzle 3 ejects the solvent SL directly downward. In addition, by setting the columnar or rod-shaped solvent SL ejected from the solvent nozzle 3 to reach the area A (refer to the enlarged view of FIG. 4(b)) over the entire area of the front surface (upper surface) of the substrate W, set The moving speed of the solvent nozzle 3 by the solvent nozzle moving mechanism 25. That is, as shown in FIG. 4(c), the moving speed of the solvent nozzle 3 is set such that, at the nth week and the n+1th week, the gap 61 of the columnar solvent SL such as a two-dot chain line is not vacated, and becomes real. The solvent SL in the shape of a line is 61 without gaps. Thereby, since the discharge port of the solvent nozzle 3 can face each of the recessed parts H, the solvent SL can easily enter (refer to the arrow in the enlarged view of FIG. 4(b)). As a result, the solvent SL can enter substantially all of the plurality of recesses H formed over the entire front surface of the substrate W. Furthermore, there is a case where it is difficult to allow the solvent to enter the recess H using only the flow along the front surface of the substrate W generated by the rotation of the substrate W.

[Overflow step] Fig. 5(a) is a diagram for explaining the overflow step. The flooding step is performed after the solvent nozzle 3 is moved above the peripheral edge portion E of the substrate W, that is, after the moving and ejecting step. First, the holding rotation section 2 reduces the rotation speed of the substrate W to a speed for overflow that is smaller than the discharge speed, and suppresses the amount of the solvent SL that is scattered (discharged) out of the substrate W. With this, the holding rotary unit 2 holds the solvent SL on the substrate W. At this time, at a specific time, the on-off valve V1 is closed to stop the discharge of the solvent SL from the solvent nozzle 3. After that, the solvent SL is held on the substrate W until the substrate W is rotated at a speed for overflow for a predetermined time. This allows the solvent SL to enter each recess H more easily. Furthermore, the speed for overflow is preferably 0 rpm or higher (including static) and 10 rpm or lower.

[Reverse moving ejection step] Fig. 5(b) is a diagram for explaining the reverse movement ejection procedure. The reverse moving ejection step is performed after the overflow step. The reverse moving ejection step is a step of moving the solvent nozzle 3 in a direction opposite to the moving direction of the moving ejection step. The holding rotation section 2 restores the rotation speed of the substrate W from the overflow speed to the ejection speed. The on-off valve V1 is opened again, and the solvent SL is ejected from the solvent nozzle 3 onto the substrate W rotating at the ejection speed. After the solvent SL reaches the substrate W, the solvent SL is ejected from the solvent nozzle 3 onto the rotating substrate W, and the solvent nozzle 3 is moved by the solvent nozzle moving mechanism 25 from above the peripheral portion E of the substrate W to the center of the substrate W Above CT. With this, the concave portion H that is not filled with the solvent SL can be reduced.

[Thin film step] Fig. 5(c) is a diagram for explaining the step of thinning. The thin film forming step is performed after the reverse moving ejection step. The holding rotating portion 2 rotates the substrate W at a thinning speed higher than the discharging speed. At this time, at a specific time, the on-off valve V1 is closed to stop the discharge of the solvent SL from the solvent nozzle 3. By rotating the substrate W at a thinning speed, the excess solvent SL is scattered outside the substrate W. Thereafter, the rotation of the substrate W is stopped, and the solvent nozzle 3 is returned to the standby position. The speed for thin film formation is hundreds to thousands of rpm, and the rotation time is, for example, 1 second.

By the pre-wetting treatment as described above, the solvent SL is formed on the substrate W while introducing the solvent SL into the concave portion H of the substrate W (refer to FIG. 6 ). Furthermore, the moving ejection step and the reverse moving ejection step can also be exchanged as needed. In addition, the overflow step can also be omitted. Moreover, the moving discharge step or the reverse moving discharge step may be omitted. In addition, for example, a plurality of moving ejection steps may be performed, or the order of these steps may be reversed. Furthermore, as long as the solvent SL can be formed on the substrate W while introducing the solvent SL into the concave portion H of the substrate W, the above method may not be used. For example, the solvent SL is ejected from the solvent nozzle 3 to the center CT of the substrate W rotating at tens of rpm, and the solvent SL is introduced into substantially all of the concave portions H. After that, the substrate W can be rotated at several hundred rpm, so that the excess solvent SL is scattered outside the substrate W.

According to this step S01, while the solvent nozzle 3 is moved in the radial direction of the substrate W, the solvent SL is ejected from the solvent nozzle 3 onto the rotating substrate W. Thereby, since the discharge port of the solvent nozzle 3 can face each of the recessed parts H, the solvent SL easily enters the recessed parts H.

[Step S02] Step of placing the first chemical solution in a ring shape (week 1) After forming the solvent film SL, the control unit 51 does not move the chemical liquid nozzle 4 in the radial direction of the substrate W, but ejects the first chemical liquid C1 from the chemical liquid nozzle 4 onto the solvent film SL of the rotating substrate W. Thereby, the first chemical solution C1 is placed in a ring shape so as to be in contact with the peripheral edge portion E of the substrate W.

Be specific. The first chemical liquid nozzle moving mechanism 27 moves the chemical liquid nozzle 4 from the standby position outside the substrate W to above the peripheral portion E of the substrate W (see FIG. 6 ). In addition, the first chemical liquid nozzle moving mechanism 27 moves the chemical liquid nozzle 4 in the vertical direction. As a result, the chemical liquid nozzle 4 is positioned above the peripheral edge portion E of the substrate W. In addition, the gap CL between the front end surface 4c of the chemical liquid nozzle 4 and the front surface of the substrate W is set to 1.0 mm or less (for example, 0.5 mm). Furthermore, when the gap CL becomes higher, when the substrate W is rotated, the first chemical solution C1 is ejected from the chemical solution nozzle 4 to form the liquid column of the first chemical solution C1 between the chemical solution nozzle 4 and the front surface of the substrate W It becomes unstable, and there is a risk of "liquid break" due to the breakage of the liquid column.

In the first week, as shown in FIG. 7( a ), the first chemical solution C1 is placed in a ring shape so as to be in contact with the peripheral edge portion E of the substrate W. First, the substrate W is rotated at a first rotation speed of several tens of rpm for one revolution without stopping the chemical liquid nozzle 4 in the radial direction of the substrate W. In this state, the on-off valve V2 is opened, and the first chemical solution C1 is ejected from the chemical solution nozzle 4 located above the peripheral portion E of the substrate W. As a result, the outermost first chemical solution C1 is placed along the peripheral edge portion E of the substrate W.

As shown by arrow G in FIG. 7(b), when the first chemical solution C1 is placed in a spiral shape near the peripheral edge portion E of the substrate W, a region where the first chemical solution C1 is not placed occurs. As a result, in the area where the first chemical solution C1 is not placed (see arrow G in FIG. 7(b)), the first chemical solution C1 and the second chemical solution C2 cannot be expanded well. However, by placing the first chemical solution C1 in a ring shape so as to be in contact with the peripheral edge portion E of the substrate W, it is possible to prevent the area where the first chemical solution C1 is not placed (see arrow G in FIG. 7(b)) .

In addition, as a method of not generating the area where the first chemical solution C1 is not placed in the arrow G shown in FIG. 7(b), there are the following methods. In this method, the first chemical liquid C1 is ejected from the chemical liquid nozzle 4 to the outside of the substrate W, and the chemical liquid nozzle 4 is moved above the substrate W. However, in this method, for example, when passing through the boundary (peripheral portion E) between the inside and the outside of the substrate W, the liquid column of the first chemical liquid C1 ejected from the chemical liquid nozzle 4 is unstable, and the following steps cannot be placed well. S03 spiral first chemical solution C1. In addition, if the first chemical solution C1 adheres to the side surface of the substrate W, it may cause contamination, for example. Furthermore, when the first chemical solution C1 is ejected out of the substrate W, the usage amount of the first chemical solution C1 increases. Since the first chemical solution C1 is placed in a ring shape along the peripheral edge portion E, such problems can be prevented.

The first rotation speed of the substrate W in steps S02 to S04 is set to such an extent that the chemical solution does not overflow from the peripheral edge portion E of the substrate W. In addition, the first rotation speed is variable (for example, 13 rpm or more and 40 rpm or less).

[Step S03] Step of placing the first chemical solution in a spiral shape (after the second week) After forming the solvent film SL and placing the first chemical solution C1 in a ring shape, the control unit 51 discharges the first chemical solution C1 from the chemical solution nozzle 4 while moving the chemical solution nozzle 4 in the radial direction of the substrate W On the solvent film SL of the rotating substrate W. Thereby, the first chemical solution C1 is placed on the solvent film SL of the substrate W in a spiral shape without a gap (see FIG. 8 ). That is, a spiral first chemical solution film C1 is formed inside the annular first chemical solution film C1 in step S02. Furthermore, the solid line of the spiral shown in FIG. 8 indicates the trajectory of the chemical liquid nozzle 4 in this step. The one-dot chain line shown in FIG. 8 represents the trajectory of the chemical liquid nozzle 4 in step S02. Furthermore, after the chemical solution nozzle 4 moves above the center CT of the substrate W, the on-off valve V2 is closed, and the supply of the first chemical solution C1 is stopped.

The steps of placing the first chemical solution C1 in steps S02 and S03 can also be performed by dividing the coating area under the following conditions. That is, when moving the chemical liquid nozzle 4 from the peripheral edge portion E of the substrate W to the center CT, for example, the clearance CL between the front end surface 4c of the chemical liquid nozzle 4 and the front surface of the substrate W, the moving speed of the chemical liquid nozzle 4, When the rotation speed of the substrate W changes, the first chemical solution C1 is ejected. With this, for example, the first chemical solution C1 can be spread well.

FIG. 9 shows an example of a plurality of regions of the coating range on the substrate W. The front surface of the substrate W is divided into a plurality of areas. Each area is determined based on the position based on the center CT of the substrate W. As shown in FIG. 9, for example, the first area Z1 to the fifth area Z5 and the sixth area (core) Z6 are set on the front surface of the substrate W. In addition, for the convenience of illustration, the 1st zone Z1-the 6th zone Z6 of FIG. 9 have shown the approximate range. FIG. 10 is a diagram showing an example of the application conditions of the respective zones Z1 to Z6. The “nozzle movement distance” item in FIG. 10 represents the distance (mm) from the center CT of the substrate W. The diameter of the substrate W is 300 mm. In FIG. 10, for example, the distance between the first zone Z1 and the center CT of the substrate W is 143 mm, and the chemical liquid nozzle 4 stops and does not move. The first zone Z1 represents the step of placing the first chemical solution C1 in the ring shape of step S02.

First, the gap CL between the front end surface 4c of the chemical liquid nozzle 4 and the front surface of the substrate W will be described with reference to FIG. In FIG. 11, there are two positions PS1 and PS2. The position PS2 is located closer to the center CT than the position PS1. In this case, the gap CL at the position PS2 is set larger than the gap CL at the position PS1. That is, the chemical liquid nozzle 4 sets the gap CL larger from the peripheral edge portion E of the substrate W toward the center CT side.

For example, in the first zone Z1 and the second zone Z2, the gap CL is set to 0.5 mm. As the chemical liquid nozzle 4 moves toward the center CT side, the gap CL is gradually increased. Then, in the sixth zone Z6, the gap CL is set to 3.0 mm.

The effect of changing the gap CL will be described. The faster the relative rotation speed between the chemical liquid nozzle 4 and the substrate W from the center CT of the substrate W toward the peripheral edge portion E side of the substrate W. Therefore, when the first chemical solution C1 reaches the solvent film SL of the substrate W, the force applied to the first chemical solution C1 in the direction of rotation becomes large, and liquid breakage is likely to occur. In addition, the liquid breakage means that the ejected first chemical liquid C1 is disconnected and cut off. Therefore, when the chemical liquid nozzle 4 is located on the peripheral edge portion E side, the gap CL becomes smaller. This can prevent liquid breakage. In addition, when the chemical liquid nozzle 4 is positioned on the center CT side, the gap CL becomes larger. This can prevent the first chemical solution C1 from adhering to the chemical solution nozzle 4.

Next, the rotation speed (first rotation speed) of the substrate W will be described. In FIG. 11, the rotation speed of the position PS2 is set to be faster than the rotation speed of the position PS1. That is, the rotation speed is set so that the closer to the center CT side from the peripheral edge portion E of the substrate W the chemical liquid nozzle 4 is.

For example, in the first zone Z1 and the second zone Z2, the rotation speed of the substrate W is set to 13 rpm. As the chemical liquid nozzle 4 moves toward the center CT side, the rotation speed of the substrate W is increased stepwise. Then, in the sixth zone Z6, the rotation speed of the substrate W is set to 40 rpm.

The effect of changing the rotation speed will be described. As the center CT of the substrate W approaches the peripheral edge E side of the substrate W, the relative rotation speed between the chemical liquid nozzle 4 and the substrate W increases. Therefore, when the first chemical solution C1 reaches the solvent film SL of the substrate W, the force applied to the first chemical solution C1 in the direction of rotation becomes large, and liquid breakage is likely to occur. Therefore, when the chemical liquid nozzle 4 is located on the peripheral edge portion E side, the rotation speed of the substrate W is slowed. This can prevent liquid breakage. In addition, when the chemical liquid nozzle 4 is positioned on the center CT side, the rotation speed of the substrate W is increased. With this, it is possible to prevent excessive discharge of the chemical liquid.

In addition, the discharge speed of the chemical solution (discharge rate, unit: ml/s) is the lowest speed that does not cause liquid breakage (which can suppress liquid breakage) with respect to the rotation speed of the substrate W. By using this ejection speed, the liquid medicine can be saved.

Next, the moving speed of the chemical liquid nozzle 4 will be described. As shown in FIG. 9, since the coating range increases from the center CT of the substrate W toward the peripheral edge portion E, the discharge time of the first chemical solution C1 becomes long. Therefore, in FIG. 11, the moving speed of the chemical liquid nozzle 4 at the position PS2 is faster than the moving speed of the chemical liquid nozzle 4 at the position PS1. That is, the closer the chemical liquid nozzle 4 is from the peripheral edge portion E of the substrate W to the center CT, the faster the moving speed of the chemical liquid nozzle 4 is set. With this, the spiral first chemical solution film C1 can be formed well.

In addition, it is preferable that the first chemical liquid film C1 (including the first chemical liquid film C1 in the ring shape of the first week) of each cycle in the spiral first chemical liquid film C1 is adjacent to the radial direction of the substrate W The first chemical liquid film C1 of Zhou Zhi overlaps each other without a gap. That is, it is preferable that the spiral first chemical solution C1 is placed on the solvent film SL without a gap.

Figure 12(a) is a preferred example. For example, the first chemical liquid film C1 of the n-1th week and the first chemical liquid film C1 of the nth week overlap each other. On the other hand, Fig. 12(b) is an example of poor. For example, the first chemical liquid film C1 of the n-1th week is separated from the first chemical liquid film C1 of the nth week, and a gap occurs. If a gap is formed between the first chemical liquid film C1 of each week and the first chemical liquid film C1 of an adjacent week, it may exist when the substrate W is rotated at high speed to expand the first chemical liquid C1 and the second chemical liquid C2 described later , The liquid medicine avoids the gap or the recess H existing in the gap flows. Therefore, by not generating the gap, the first chemical solution C1 and the second chemical solution C2 can be expanded well. Furthermore, if they overlap each other, the first chemical solution C1 and the second chemical solution C2 can be expanded more reliably and well.

Through the processes of steps S02 and S03, the first chemical solution C1 is placed on the solvent film SL of the substrate W in a ring shape and a spiral shape. Furthermore, the first chemical liquid film C1 is formed on the substrate W via the solvent film SL due to the affinity between the solvent film SL and the first chemical liquid film C1, or directly on the substrate W.

[Step S04] ejection of the second chemical solution The chemical solution nozzle 4 that ejects the first chemical solution C1 is moved from above the substrate W to the standby position. Instead of the chemical liquid nozzle 4, the chemical liquid nozzle 5 moves above the substrate W. The second chemical liquid nozzle moving mechanism 29 moves the chemical liquid nozzle 5 from a standby position outside the substrate W to a position above the center CT of the substrate W. Thereafter, after forming the first chemical solution C1 in a spiral shape without a gap, the control unit 51 ejects the second chemical solution C2 from the chemical solution nozzle 5 to the first chemical solution film toward the center CT of the substrate W rotating at the first speed On C1, the second chemical solution C2 has a higher viscosity than the first chemical solution C1. That is, by opening the on-off valve V3 shown in FIG. 1, as shown in FIG. 13(a), aiming at the center CT of the substrate W from the chemical liquid nozzle 5, the second chemical liquid C2 starts to be ejected onto the first chemical liquid C1 .

[Step S05] Steps of expanding the first chemical solution and the second chemical solution respectively The case where the second chemical solution C2 expands will be described with reference to FIGS. 13(a) to 13(d). As shown in FIG. 13(a), after the second chemical liquid C2 ejected from the chemical liquid nozzle 5 reaches the first chemical liquid film C1, the control unit 51 ejects the second chemical liquid C2 while making the substrate W lower than the first The second speed with the highest speed rotates. More specifically, after the second chemical solution C2 that has reached the first chemical solution C1 is covered with the first chemical solution C1 at the center CT of the substrate W, the substrate W is rotated at the second speed. Thereby, the first chemical solution C1 is expanded to the peripheral edge portion E side of the substrate and the excess first chemical solution C1 is scattered outside the substrate W, and the second chemical solution film C2 is expanded to the peripheral edge portion E side. In addition, the second speed is, for example, 1000 rpm.

Since the first medical solution C1 has a lower viscosity than the second medical solution C2, the first medical solution C1 is easier to move than the second medical solution. In addition, the first chemical solution film C1 has been formed to the peripheral edge portion E of the substrate W having a large influence of centrifugal force. Therefore, when the substrate W is rotated at the second speed, the first chemical solution C1 moves concentrically from the center CT side of the substrate W to the peripheral edge portion E side of the substrate W, so that the excess first chemical solution C1 is directed toward the substrate W Scattered outside. By the movement of the first chemical solution C1, the second chemical solution C2 following the first chemical solution C1 is drawn by the first chemical solution C1 and expands into a concentric shape. At this time, the second chemical liquid C2 discharged from the chemical liquid nozzle 5 and reaching the second chemical liquid C2 expands relatively smoothly in the order of arrival. In addition, the first chemical solution C1 and the second chemical solution C2 are expanded in the order of FIG. 13(b), FIG. 13(c), and FIG. 13(d). In addition, the second chemical solution C2 is also expanded by the rotation of the substrate W.

Further, by rotating the substrate W at the second speed, the first chemical solution C1 flows on the substrate W. Therefore, the solvent SL entering the concave portion H is replaced with the first chemical solution C1, and then the first chemical solution C1 is filled in the concave portion H (refer to an enlarged view of FIG. 13(d)). Furthermore, since the solvent SL has entered the concave portion H, it is easy to fill the concave portion H with the solvent SL. Further, by rotating the substrate W at the second speed, the first chemical solution C1 is gradually replaced with the second chemical solution from the center CT side of the substrate W to the peripheral edge portion E side of the substrate W mainly on the substrate W other than the recess H C2.

When the substrate W is rotated at the second speed to extend the extension of the second chemical solution C2 to the peripheral edge portion E, the switching valve V3 shown in FIG. 1 is closed, and the ejection of the second chemical solution C2 from the chemical solution nozzle 5 is stopped. In addition, the timing of stopping the ejection of the second chemical solution C2 is arbitrary. For example, the expansion of the second chemical solution C2 by rotation may be stopped immediately before extending to the peripheral edge E, or it may be stopped after the expansion of the second chemical solution C2 by rotation is sufficiently extended to the peripheral edge E. After stopping the discharge of the second chemical solution C2, the chemical solution nozzle 5 is returned from above the substrate W to the standby position.

By stopping the ejection of the second chemical solution C2, the substrate W is also rotated at the second speed, so that the excess first chemical solution C1 and the second chemical solution C2 are scattered outside the substrate W. Further, the rotation speed is adjusted up and down so that the film thickness from the center CT of the substrate W to the peripheral edge portion E of the substrate W is flat. For example, when the film thickness on the E side of the peripheral portion is larger than the film thickness on the center CT side, the rotation speed is reduced; when the film thickness on the E side of the peripheral portion is smaller than the film thickness on the center CT side, the rotation speed is increased. In addition, in the area other than the recess H on the substrate W, only the second chemical liquid film C2 may be formed, or the first chemical liquid film C1 and the second chemical liquid film C2 may be formed (see FIG. 14(c) described later) .

[Step S06] Film thickness adjustment (main rotation) After the second chemical liquid film C2 (or the first chemical liquid film C1 and the second chemical liquid film C2) is flattened, the control unit 51 rotates the substrate W at the third speed. With this, the thickness of the second chemical liquid film C2 (or the first chemical liquid film C1 and the second chemical liquid film C2) is adjusted. The third speed is hundreds of rpm (for example, 400 to 500 rpm). The third speed is changed according to the desired film thickness. After rotating the substrate W at a specific time and at the third speed, the holding rotation unit 2 stops rotating.

14(a) is a cross-sectional view showing the state of the second chemical liquid film C2 and the like after the film thickness is adjusted. The concave portion H is filled with the first chemical solution C1. In addition, on the front surface of the substrate W, a second chemical liquid film C2 of a specific thickness is formed. Furthermore, as shown in FIG. 14(b), at least a part of the recess H may be filled with the second chemical solution C2. Moreover, as shown in FIG. 14(c), the second chemical liquid film C2 may be formed on the substrate W via the first chemical liquid film C1.

After the second chemical liquid film C2 is formed by the above steps, the solvent SL is ejected from a nozzle (not shown), and EBR (Edge Bead Removal) processing (also called edge cleaning processing) is performed, or Back cleaning process. The EBR process is a process of removing the first chemical liquid film C1 and the second chemical liquid film C2 formed near the peripheral portion E of the substrate W. The back surface cleaning process is a process of spraying a cleaning liquid to wash the back surface (lower surface) of the substrate W. Thereafter, in a state where the rotation of the substrate W is stopped, the holding rotation unit 2 releases the holding of the substrate W. The substrate transfer mechanism (not shown) transfers the substrate W from the holding rotary unit 2. The first chemical solution C1 filled with the recess H and the second chemical solution film C2 on the substrate W are dried (or calcined (baked)). After drying, since the first chemical solution C1 and the second chemical solution C2 are of the same type, as shown in FIG. 15, the first chemical solution C1 and the second chemical solution C2 become one body that is difficult to distinguish after drying (or calcination) membrane. The chemical film after drying (or calcination) is represented by symbol C3.

＜Viscosity of the first chemical liquid film＞ In the present invention, the first chemical solution film C1 is formed on the entire front surface (upper surface) of the substrate W. This makes it easy to spread the second chemical solution C2 on the substrate W and fill the recess H with the first chemical solution C1. In the case where the viscosity of the first chemical solution C1 and the viscosity of the second chemical solution C2 are the same or more than 1000 cP, even if the solvent film SL as shown in FIG. 6 is formed, it is difficult to embed the first chemical solution C1 into the concave portion H. Therefore, when the viscosity of the first chemical solution C1 is lower than that of the second chemical solution C2, when the viscosity of the first chemical solution C1 is 700 cP or less, the first chemical solution C1 is more likely to enter the recess H.

On the other hand, when the viscosity of the first chemical solution C1 is less than 300 cP, the first chemical solution film C1 formed first has the property of being easily dried. That is, when the first chemical solution C1 is ejected from the chemical solution nozzle 4 while moving the chemical solution nozzle 4 from above the vicinity of the peripheral edge portion E of the substrate W to above the center CT of the substrate W, it is first formed on the peripheral edge portion E The first chemical liquid film C1 is easy to dry.

For example, in the case of a viscosity of about 10 cP, as shown in FIG. 16(a), the first chemical solution C1 placed in steps S02 and S03 falls into the recess H, and is dried in a state where it enters the recess H. In this case, not only is it difficult for the first chemical solution C1 and the second chemical solution C2 to expand, but also when the first chemical solution C1 entering the recess H has been dried, it is difficult for the first chemical solution C1 and the The second chemical solution C2 fills the recess H. Further, as shown in FIG. 16(b), when the viscosity of the first chemical solution C1 becomes higher than that in the case of FIG. 16(a), the first chemical solution C1 does not enter the concave portion H. However, the first chemical solution C1 formed first in the peripheral edge portion E is dried. Therefore, as shown by a dotted line LN1 in FIG. 16(b), the thickness of the chemical liquid film formed thereafter becomes larger at the dry portion.

Therefore, the viscosity requirement of the first chemical solution C1 is easy to enter by the rotation of the substrate W and is not easy to dry. Therefore, it is preferable that when the first chemical solution C1 and the second chemical solution C2 are expanded by the rotation of the substrate W at the second speed, the first chemical solution C1 covers the concave portion H in which the solvent SL has been filled, and the peripheral edge formed first The first chemical solution C1 near the part E is not dried but has fluidity. Therefore, as shown by the two-dot chain line LN2 shown in FIG. 16(c), the chemical liquid film can be formed uniformly.

According to this embodiment, the first chemical solution C1 is placed on the solvent film SL of the substrate W in a spiral shape without a gap. The rotation at the second speed of the substrate W expands the first chemical solution C1 and the second chemical solution C2, respectively. Since the first medical solution C1 draws the second medical solution having a higher viscosity than the first medical solution C1, it assists in expanding the second medical solution C2. In addition, the second chemical solution C2 is placed on the first chemical solution C1 having a lower viscosity than the second chemical solution C2. In addition, the solvent SL is contained in the recess H formed on the front surface of the substrate W. Therefore, by the rotation of the substrate W, the first chemical solution C1 can enter the recess H more easily than the second chemical solution C2. As a result, it is possible to fill the concave portion H formed on the front surface of the substrate W with a relatively small amount of the solvent SL and the high-viscosity chemical liquid while forming the chemical liquid film thickly on the substrate W.

After the second chemical solution C2 ejected from the chemical solution nozzle 5 reaches the first chemical solution film C1, the second chemical solution C2 is ejected while rotating the substrate W at a second speed faster than the first speed. The expansion of the first medical solution C1 assists the expansion of the second medical solution C2 having a higher viscosity than the first medical solution C1. At this time, since the second chemical liquid C2 ejected from the chemical liquid nozzle 5 is sequentially expanded, the second chemical liquid C2 can be smoothly expanded.

The present invention is not limited to the above-mentioned embodiment, and can be implemented with variations as described below.

(1) In the above embodiment, step S05 is that after the second chemical solution C2 ejected from the chemical solution nozzle 5 reaches the first chemical solution C1, the second chemical solution C2 is ejected while the substrate W is lower than the first Rotate at the second speed with the highest speed. This expands the first chemical solution C1 and the second chemical solution C2, respectively. It can also be changed as follows.

That is, in the step of expanding the second chemical solution C2 in step S05, only the predetermined amount of the second chemical solution C2 may be ejected and the ejection of the second chemical solution C2 may be stopped to rotate the substrate W at the second speed. That is, as shown in FIG. 17, the step of expanding the second chemical solution C2 first ejects a predetermined amount of the second chemical solution C2 to the first chemical solution film C1 to form the second chemical solution on the first chemical solution film C1 Liquid accumulation (covering) PD of C2. Then, after closing the on-off valve V3 and stopping the ejection of the second chemical solution C2, the substrate W is rotated at the second speed. With this, it is possible to expand the first chemical solution C1 and the second chemical solution C2 by the rotation of the substrate W in a state where the predetermined amount of the second chemical solution C2 is covered on the first chemical solution C1. As a result, as in the embodiment, it is possible to fill the recess H formed on the front surface of the substrate W with a relatively small amount of solvent and a high-viscosity chemical while thickly forming the chemical film on the substrate W .

(2) In the above embodiment and modified example (1), when the first chemical liquid C1 is ejected from the chemical liquid nozzle 4, the chemical liquid nozzle 4 is moved from the peripheral portion of the substrate W by the first chemical liquid nozzle moving mechanism 27 E (end or edge) moves above the center CT of the substrate W. For this, the chemical liquid nozzle 4 may also be moved in the reverse direction. That is, when the first chemical liquid C1 is ejected from the chemical liquid nozzle 4, the chemical liquid nozzle 4 can also be moved from above the center CT of the substrate W to above the peripheral edge portion E of the substrate W by the first chemical liquid nozzle moving mechanism 27. . After the chemical liquid nozzle 4 moves from above the center CT, the chemical liquid nozzle 5 is arranged instead of the chemical liquid nozzle 4. Therefore, the timing of starting the ejection of the second chemical solution C2 can be made earlier.

(3) In the above embodiments and various modifications, the conditions such as the gap CL between the front end surface 4c of the chemical liquid nozzle 4 and the front surface of the substrate W, the rotation speed of the substrate W, and the moving speed of the chemical liquid nozzle 4 are changed. The first chemical solution C1 is placed in a spiral shape and a ring shape. However, a certain condition may not be changed as necessary. That is, the first chemical liquid C1 may be placed in a spiral shape or a ring shape by changing any of the clearance CL, the rotation speed of the substrate W, and the moving speed of the chemical liquid nozzle 4 as the chemical liquid nozzle 4 moves.

(4) In the above-mentioned embodiment and each modification, the solvent nozzle moving mechanism 25 moves the solvent nozzle 3. In addition, the first chemical liquid nozzle moving mechanism 27 moves the chemical liquid nozzle 4, and the second chemical liquid nozzle moving mechanism 29 moves the chemical liquid nozzle 5. For this, for example, the first chemical liquid nozzle moving mechanism 27 may move at least two of the solvent nozzle 3 and the two chemical liquid nozzles 4 and 5. In addition, for example, the first chemical liquid nozzle moving mechanism 27 may be configured to hold the nozzles 3, 4, and 5 interchangeably.

(5) In the above-mentioned embodiment and each modified example, the holding rotary unit 2 rotates the substrate W when the first chemical liquid C1 is ejected from the chemical liquid nozzle 4. In this regard, the first chemical liquid nozzle moving mechanism 27 may rotate the chemical liquid nozzle 4 with respect to the substrate W about the rotation axis AX1 while moving the chemical liquid nozzle 4 in the radial direction. That is, when the first chemical solution C1 is ejected from the chemical solution nozzle 4, the holding rotary unit 2 stops the rotation of the substrate W, and the first chemical solution nozzle moving mechanism 27 causes the chemical solution nozzle 4 to move in a ring shape and spirally. .

(6) In the above-mentioned embodiment and each modified example, when the second chemical liquid C2 starts to be discharged from the chemical liquid nozzle 5, the substrate W rotates at several tens of rpm. For this, the ejection of the second chemical liquid C2 may also be started on the substrate W in a state where it is not rotating. In this case, after the second chemical solution C2 ejected from the chemical solution nozzle 5 reaches the first chemical solution C1 of the stationary substrate W, or the overflow is performed on the stationary substrate W and the second chemical solution is stopped After the ejection of C2, the substrate W is rotated at the second speed.

1‧‧‧Coating device 2‧‧‧ keep the rotating part 3‧‧‧Solvent nozzle 4‧‧‧drug nozzle 4a‧‧‧Spray outlet 4c‧‧‧Front face 5‧‧‧Medicinal liquid nozzle 5a‧‧‧Spray outlet 7‧‧‧ Rotating chuck 8‧‧‧rotation drive 9‧‧‧Shield 13‧‧‧Solvent supply source 15‧‧‧Piping 17‧‧‧The first chemical liquid supply source 19‧‧‧ liquid medicine piping 21‧‧‧Second chemical liquid supply source 23‧‧‧ liquid medicine piping 25‧‧‧ Solvent nozzle moving mechanism 27‧‧‧ First chemical liquid nozzle moving mechanism 29‧‧‧Second chemical liquid nozzle moving mechanism 31‧‧‧arm 33‧‧‧axis 35‧‧‧rotation drive 37‧‧‧arm 39‧‧‧Move up and down 41‧‧‧Plane Mobile Department 43‧‧‧arm 45‧‧‧Move up and down 47‧‧‧Plane Mobile Department 51‧‧‧Control Department 53‧‧‧Operation Department 61‧‧‧Gap AX1‧‧‧rotation axis AX2‧‧‧rotation axis C1‧‧‧1st medicinal solution (or 1st medicinal solution film) C2‧‧‧ 2nd medicinal solution (or 2nd medicinal solution film) CT‧‧‧Substrate W Center E‧‧‧Circumferential part of substrate W G‧‧‧arrow H‧‧‧recess P1‧‧‧Pump P2‧‧‧Pump P3‧‧‧Pump PD‧‧‧Liquid accumulation PS1‧‧‧Location PS2‧‧‧Location SL‧‧‧Solvent (or solvent film) V1‧‧‧ On-off valve V2‧‧‧ On-off valve V3‧‧‧ On-off valve W‧‧‧Substrate X‧‧‧ direction Y‧‧‧ direction Z‧‧‧ direction Z1‧‧‧ Zone 1 Z2‧‧‧ Zone 2 Z3‧‧‧ Zone 3 Z4‧‧‧ Zone 4 Z5‧‧‧ Zone 5 Z6‧‧‧ Region 6

FIG. 1 is a schematic configuration diagram of a coating apparatus of an embodiment. 2 is a plan view showing a solvent nozzle moving mechanism and two chemical liquid nozzle moving mechanisms. 3 is a flowchart showing the operation of the coating device. FIG. 4(a) is a longitudinal cross-sectional view for explaining the pre-wetting treatment, and FIGS. 4(b) and 4(c) are longitudinal cross-sectional views for explaining the moving ejection step. 5(a) is a longitudinal cross-sectional view for explaining the solvent overflow step, FIG. 5(b) is a longitudinal cross-sectional view for explaining the reverse moving ejection step, and FIG. 5(c) is a longitudinal cross-sectional view for explaining the thin film forming step . 6 is a longitudinal cross-sectional view showing the arrangement of the first chemical liquid nozzle and the solvent film. 7(a) and 7(b) are plan views for explaining the step of placing the first chemical solution in a ring shape. 8 is a plan view for explaining the step of placing the first chemical solution in a spiral shape. FIG. 9 is a plan view showing an example of a plurality of regions of a coating range on a circular substrate. FIG. 10 is a diagram showing an example of coating conditions in each area. 11 is a longitudinal cross-sectional view for explaining the gap between the front end surface of the first chemical liquid nozzle and the front surface of the circular substrate. 12(a) and 12(b) are longitudinal cross-sectional views for explaining the steps of placing the ring-shaped and spiral-shaped first chemical solution. 13(a) to 13(d) are longitudinal cross-sectional views for explaining the steps of ejecting the second chemical solution and the steps of expanding the first and second chemical solutions, respectively. 14(a) is a longitudinal cross-sectional view showing the state of the second chemical liquid film after the film thickness is adjusted, and FIGS. 14(b) and 14(c) are longitudinal cross-sectional views showing a modification of (a). Fig. 15 is a diagram showing a chemical liquid film after drying (calcination). 16(a) to 16(c) are longitudinal cross-sectional views for explaining the viscosity of the first chemical solution. FIG. 17 is a longitudinal cross-sectional view showing the overflow of the second chemical liquid formed on the first chemical liquid.

2‧‧‧ keep the rotating part

5‧‧‧Medicinal liquid nozzle

7‧‧‧ Rotating chuck

AX1‧‧‧rotation axis

C1‧‧‧1st medicinal solution (or 1st medicinal solution film)

C2‧‧‧ 2nd medicinal solution (or 2nd medicinal solution film)

E‧‧‧Circumferential part of substrate W

H‧‧‧recess

SL‧‧‧Solvent (or solvent film)

W‧‧‧Substrate

Claims (6)

A coating method, comprising the steps of: rotating a circular substrate having a plurality of recesses on the front side, while spraying solvent from the solvent nozzle onto the circular substrate, thereby allowing the solvent to enter the recesses while A solvent film is formed on the circular substrate; after the solvent film is formed, the first chemical liquid nozzle is rotated relative to the first chemical liquid nozzle from the first chemical liquid nozzle pair while moving the first chemical liquid nozzle in the radial direction of the circular substrate The first chemical solution is ejected on the solvent film of the circular substrate, thereby placing the first chemical solution in a spiral shape on the solvent film of the circular substrate without a gap; After being placed in a spiral shape with a gap, and before expanding the first chemical solution by the rotation of the circular substrate and scattering the excess first chemical solution out of the circular substrate, the direction from the second chemical solution nozzle begins The center of the circular substrate ejects a second chemical solution having a higher viscosity than the first chemical solution onto the first chemical solution; and by rotating the circular substrate, the above is simultaneously expanded toward the peripheral edge side of the circular substrate The first chemical solution and the second chemical solution described above. The coating method according to claim 1, wherein the step of simultaneously expanding the first chemical solution and the second chemical solution is after the second chemical solution ejected from the second chemical solution nozzle reaches the first chemical solution, While ejecting the second chemical solution, the circular substrate is rotated. The coating method according to claim 1, wherein The step of simultaneously expanding the first chemical solution and the second chemical solution is to eject only a predetermined amount of the second chemical solution and stop the ejection of the second chemical solution, and then rotate the circular substrate. The coating method according to any one of claims 1 to 3, wherein the second chemical liquid nozzle has a circular or regular polygonal discharge port. The coating method according to any one of claims 1 to 3, wherein the second chemical solution is the same kind of chemical solution as the first chemical solution. The coating method according to any one of claims 1 to 3, wherein the step of forming the solvent film is to spray the solvent from the solvent nozzle to the rotating surface while moving the solvent nozzle in the radial direction of the circular substrate On a round substrate.

Images