JP2019012806A - Coating film formation method, coating film formation device and storage medium - Google Patents

Abstract

To provide a technique for forming a coating film having a flattened surface on a board having a step pattern on the surface.SOLUTION: When forming a resist film 103 on a wafer W having a step pattern 100 formed on the surface, the wafer W is coated with resist liquid, and while the inside of the resist film 103 is having fluidity, the surface of the resist film 103 and the lower surface of a flat plate part 7 facing the surface of the resist film 103 are brought into contact. Furthermore, while bringing the lower surface of a flat plate part 7 into contact with the surface of the resist film 103, the wafer W is rotated and the resist film 103 is dried while being flattened. Furthermore, after the resist film 103 is dried, the surface of the resist film 103 and the lower surface of the flat plate part 7 are separated, thus flattening the surface of the resist film 103 formed on the wafer W.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a technique for forming a coating film on a substrate having a step pattern on the surface.

  With the recent high integration of semiconductor circuits, devices with more complicated three-dimensional structures are being studied. When manufacturing such a device, the step pattern formed on the substrate may include a step of locally etching, and a resist solution is applied to the surface of the wafer inside the step pattern. Also, in the etching process, the etching selectivity of the etching target with respect to the resist film may be small, and there is a demand for the resist film to be a thick film on the order of μm, for example. Thus, in order to make the resist film thick, a resist solution having a high viscosity of, for example, 200 cP or more may be used.

  For example, when applying a resist solution to a semiconductor wafer (hereinafter referred to as “wafer”), a spin coating method is generally used in which the resist solution is supplied to the substrate and the substrate is rotated to spread the resist solution on the surface of the substrate. However, when a highly viscous coating solution is applied to a substrate with a step pattern by spin coating, the surface of the coating film is recessed above the recess formed on the substrate, and the surface of the coating film does not become flat. In addition, when a coating film is applied to the substrate by spin coating, the outer peripheral side of the substrate has a strong centrifugal force, and there is a problem that the film thickness is difficult to stabilize and flattening.

In Patent Document 1, a flat lid is provided so as to face a horizontally held substrate through a gap, and a coating liquid is supplied from a coating liquid supply port opened on the lower surface of the lid. A technique for obtaining a flat coating film by filling the gap between the coating liquid and drying is described.
However, if the gap between the coating film and the lid is narrow, the coating liquid does not flow easily, and when the resist solution is applied to the substrate on which the step pattern is formed, the step pattern may not be filled without a gap.

Japanese Patent No. 6068377

  The present invention has been made under such circumstances, and an object thereof is to provide a technique for forming a coating film having a flat surface on a substrate having a step pattern on the surface.

The coating film forming method of the present invention is a coating film forming method for forming a coating film on the surface of a substrate on which a step pattern is formed.
Applying a coating solution to the surface of the substrate held horizontally;
A step of bringing the lower surface of the flattening member whose bottom surface is a flat surface into contact with the surface of the liquid film of the coating solution while the coating liquid applied to the substrate has fluidity;
Rotating at least one of the substrate and the lower surface of the planarizing member around the vertical axis to flatten the surface of the coating film and drying the coating film;
Thereafter, a step of separating the surface of the substrate and the lower surface of the planarizing member is included.

The storage medium of the present invention is a storage medium storing a computer program used in a coating film forming apparatus for forming a coating film on the surface of a substrate on which a step pattern is formed,
The computer program includes a program for executing a group of steps for executing the above-described coating film forming method.

The coating film forming apparatus of the present invention is a coating film forming apparatus that forms a coating film on the surface of a substrate on which a step pattern is formed.
A substrate holder for horizontally holding the substrate;
A coating solution supply unit that supplies a coating solution toward the substrate held by the substrate holding unit;
A planarizing member having a flat surface facing the surface of the substrate held by the substrate holding portion on the lower surface;
A rotation mechanism for rotating at least one of the substrate and the lower surface of the planarizing member around a vertical axis;
An elevating mechanism for elevating and lowering the planarizing member;
Applying the coating liquid to the surface of the substrate held horizontally; contacting the lower surface of the planarizing member to the surface of the liquid film of the coating liquid while the coating liquid applied to the substrate has fluidity; Rotating at least one of the substrate and the lower surface of the planarizing member around the vertical axis to planarize the surface of the coating film and drying the coating film, and then the surface of the substrate and the lower surface of the planarizing member. And a step of separating, and a control unit that performs control so as to execute.

  In the present invention, when forming a coating film on a substrate having a step pattern on the surface, the coating liquid is applied to the substrate, and while the coating film has fluidity, the lower surface is the coating film on the surface of the coating film. The lower surface of the flattening member that is in parallel with is contacted. Further, at least one of the substrate and the lower surface of the planarizing member is rotated around the vertical axis to dry the coating film while planarizing the coating film. After the coating film is dried, the surface of the coating film is separated from the lower surface of the planarizing member. I have to. Therefore, the surface of the coating film formed on the substrate can be planarized.

It is a longitudinal cross-sectional view of the resist coating apparatus which concerns on 1st Embodiment. It is a top view of the resist coating apparatus which concerns on 1st Embodiment. It is a perspective view which shows the structure of the flat plate part applied to a resist coating device. It is sectional drawing which shows the surface structure of a to-be-processed substrate. It is explanatory drawing which shows the effect | action of the resist coating device which concerns on 1st Embodiment. It is sectional drawing which shows the surface structure of the wafer after application | coating of a resist liquid. It is explanatory drawing which shows the effect | action of the resist coating device which concerns on 1st Embodiment. It is explanatory drawing which shows the effect | action of the resist coating device which concerns on 1st Embodiment. It is explanatory drawing which shows the effect | action of the resist coating device which concerns on 1st Embodiment. It is explanatory drawing which shows the effect | action of the resist coating device which concerns on 1st Embodiment. It is explanatory drawing which shows the effect | action of the resist coating device which concerns on 1st Embodiment. It is explanatory drawing which shows the effect | action of the resist coating device which concerns on 1st Embodiment. It is sectional drawing which shows the other example of a flat plate part. It is a perspective view which shows the other example of a flat plate part. It is a top view which shows the other example of the vent formed in a flat plate part. It is a longitudinal cross-sectional view of the resist coating apparatus which concerns on 2nd Embodiment. It is explanatory drawing which shows the effect | action of 2nd Embodiment.

[First Embodiment]
A first embodiment in which a coating film forming apparatus of the present invention is applied to a resist coating apparatus will be described. As shown in FIG. 1, the resist coating apparatus includes a spin chuck 11 that is a substrate holding unit that holds the wafer W horizontally by vacuum-sucking the central portion of the back surface of the wafer W having a diameter of 300 mm, for example. The spin chuck 11 is connected to a rotating mechanism 13 from below through a shaft portion 12, and can be rotated around the vertical axis by the rotating mechanism 13.

  A circular plate 14 is provided below the spin chuck 11 so as to surround the shaft portion 12 with a gap. The circular plate 14 is formed with three through holes 17 in the circumferential direction, and each through hole 17 is provided with a lift pin 15. A common lift plate 18 is provided below the lift pins 15, and the lift pins 15 are configured to be lifted and lowered by a lift mechanism 16 provided below the lift plate 18.

  A cup body 2 is provided so as to surround the periphery of the wafer W held by the spin chuck 11. The cup body 2 receives the drained liquid splashed or spilled from the rotating wafer W, and discharges the drained liquid to the outside of the resist coating apparatus. The cup body 2 includes a mountain-shaped guide portion 21 provided in a ring shape having a mountain-shaped cross section around the circular plate 14, and an annular vertical wall extending downward from the outer peripheral end of the mountain-shaped guide portion 21. 23 is provided. The chevron guide portion 21 guides the liquid spilled from the wafer W to the lower side outside the wafer W.

  Further, a vertical cylindrical portion 22 is provided so as to surround the outer side of the mountain-shaped guide portion 21, and an upper guide portion 24 that extends obliquely from the upper edge of the cylindrical portion 22 toward the inner upper side. The upper guide portion 24 is provided with a plurality of openings 25 in the circumferential direction. Further, a cylindrical portion 31 is provided so as to extend upward from the peripheral edge on the proximal end side of the upper guide portion 24, and from the upper edge of the cylindrical portion 31 toward the upper peripheral portion of the wafer W held by the spin chuck 11. The inclined wall 32 is provided so as to extend.

  On the lower side of the cylindrical portion 22, a ring-shaped liquid receiving portion 26 whose cross section is a concave shape is formed below the mountain-shaped guide portion 21 and the vertical wall 23. In the liquid receiving portion 26, a drainage passage 27 is connected to the outer peripheral side on the bottom surface, and an exhaust pipe 28 is provided on the inner peripheral side of the drainage passage 27 so as to protrude from below. . The liquid scattered by the rotation of the wafer W held by the spin chuck 11 is received by the inclined wall 32, the upper guide part 24, and the vertical walls 23, 31 and introduced into the liquid discharge path 27.

  The resist coating apparatus includes a nozzle unit 5 for supplying a solvent and a resist solution, which is a medium-viscosity and high-viscosity coating solution of about 50 to 5000 cP, to the wafer W. The nozzle unit 5 includes a resist solution nozzle 50 that is a coating solution nozzle and a solvent nozzle 51 that respectively discharge a resist solution and a solvent downward. The resist solution nozzle 50 and the solvent nozzle 51 are connected to a resist solution supply mechanism 53 and a solvent supply mechanism 55 via supply pipes 52 and 54, respectively.

  The resist solution supply mechanism 53 and the solvent supply mechanism 55 include devices such as a pump, a valve, and a filter, for example, and discharge a predetermined amount of solvent and resist solution from the tips of the solvent nozzle 51 and the resist solution nozzle 50, respectively. It is configured. As shown in FIG. 2, the nozzle unit 5 has a discharge mechanism above the center of the wafer W and a standby bus outside the cup body 2 by a moving mechanism including an arm 56, a moving body 57, a lifting mechanism (not shown) and a guide rail 58. 59 to move between.

  In addition, the resist coating apparatus includes a peripheral rinse nozzle 6 that supplies rinse toward the peripheral portion of the wafer W coated with the resist film. The peripheral rinse nozzle 6 is connected via a supply pipe 61 to a rinse liquid supply mechanism 62 including devices such as a pump, a valve, and a filter. As shown in FIG. 2, the peripheral rinse nozzle 6 is provided above the center of the wafer W and outside the wafer W by a moving mechanism including an arm 63, a moving body 64, a lifting mechanism (not shown) and a guide rail 65. It is configured to be movable between the peripheral side rinse nozzle 6 and the standby bus 60. The nozzle unit 5 and the peripheral-side rinse nozzle 6 are provided, for example, at different heights so as not to interfere with each other.

  As shown in FIGS. 1 to 3, the resist coating apparatus includes a flat plate portion 7 that is a flattening member for flattening the surface of the resist film. The flat plate portion 7 is formed in a disk shape that is smaller than the inner periphery of the tip portion of the inclined wall 32 and larger than the wafer W, and the lower surface of the flat plate portion 7 is the upper surface (surface) of the wafer W held by the spin chuck 11. ) It is provided to face the whole. The flat plate portion 7 is provided with a plurality of vent holes 75 having an inner diameter of 1 mm penetrating in the thickness direction on the entire surface thereof. Further, the lower surface (back surface) side of the flat plate portion 7 is a flat surface on which the entire surface has been subjected to water-repellent processing such as fractal structure processing or fluorine resin coating.

  Further, as shown in FIGS. 1 and 3, the flat plate portion 7 is supported in a horizontal posture by a support member 71 provided so as to avoid the inclined wall 32 of the cup body 2, and the support member 71 is interposed via an elevating mechanism 72. Are connected to the turning mechanism 73. By this lifting mechanism 72, the flat plate portion 7 moves up and down between a raised position indicated by a chain line in FIG. 1 and a lowered position where the lower surface of the flat plate portion 7 is pressed against the surface of the wafer W.

  The height position of the lowering position of the flat plate portion 7 is that the height position of the lower surface of the flat plate portion 7 in the lowering position is a step pattern described later on the surface of the wafer W before being applied with the resist solution held by the spin chuck 11. It is set to a height position above the target resist film thickness, for example, a height of 10 μm above, from the height position of the surface of the unetched region. Further, the flat plate portion 7 in the raised position is swung around the rotation center C shown in FIGS. 1 and 2 by the swivel mechanism 73, and swung between the upper position of the wafer W and the standby position outside the cup body 2. To do.

  Further, as shown in FIG. 1, the resist coating apparatus includes a control unit 10. For example, a program stored in a storage medium such as a flexible disk, a compact disk, a hard disk, an MO (magneto-optical disk), and a memory card is installed in the control unit 10. The installed program incorporates instructions (each step) to transmit a control signal to each part of the resist coating apparatus and control its operation in order to execute a resist film forming process described later.

  Next, the operation of the resist coating apparatus according to the above-described embodiment will be described. First, in a state where the flat plate portion 7, the nozzle unit 5, and the peripheral rinse nozzle 6 are positioned at the standby position and the standby buses 59 and 60, the wafer W as the substrate to be processed is transferred by an external transfer arm (not shown). . The wafer W is transferred to the spin chuck 11 by the cooperative action of the transfer arm and the lift pins 15. FIG. 4 shows an example of a wafer W that is a substrate to be processed. In this wafer W, for example, silicon oxide layers 101 and silicon nitride layers 102 are alternately stacked, and a groove-shaped step pattern 100 is formed on the surface. In FIG. 4, the grooves of the step pattern 100 are formed so as to extend from the front surface side to the back surface side in the drawing. The side walls of the groove-like step pattern 100 are etched stepwise so that the upper surface of the silicon oxide layer 101 is exposed among the alternately stacked layers.

  Next, the transfer arm is retracted, the nozzle unit 5 is moved, and the solvent nozzle 51 is positioned above the center of the wafer W. Further, the wafer W is rotated at 100 to 1000 rpm, and a prewetting solvent is discharged toward the wafer W. As a result, the solvent spreads the surface of the wafer W by centrifugal force, and the inside of the step pattern 100 and the surface of the wafer W become wet.

  Subsequently, the nozzle unit 5 is moved, the resist solution nozzle 50 is positioned above the center of the wafer W, and the wafer W is rotated at a rotational speed of 100 to 4000 rpm as shown in FIG. As a result, the resist pattern is filled in the step pattern 100, and the surface of the wafer W including the upper part of the step pattern 100 is covered with the resist solution liquid film.

  At this time, if a resist solution having a high viscosity is applied to the wafer W on which the step pattern 100 is formed, the upper portion of the step pattern 100 may be depressed on the surface of the resist film 103 as shown in FIG. Further, the film thickness of the resist film 103 may be nonuniform at the peripheral edge of the wafer W. At this time, the film thickness of the resist film 103 on the surface of the wafer W is such that the maximum film thickness of the resist film 103 in the region where the step pattern 100 on the surface of the wafer W is not formed is larger than the target film thickness, for example, The film thickness is about 20 μm with respect to a target film thickness of 10 μm with a 100 cp resist solution.

  Subsequently, as shown in FIG. 7, the supply of the resist solution is stopped, the nozzle unit 5 is retracted to the outside of the cup body 2, and the wafer W is rotated at a rotational speed of 100 to 2000 rpm for 5 to 10 seconds, for example, 5 seconds. . As a result, the fluidity of the surface of the resist film 103 is slightly lowered and the inside of the resist film 103 is kept in a state of high fluidity.

  Thereafter, as shown in FIG. 8, the flat plate portion 7 at the standby position is swung to be positioned above the wafer W, and after the rotational speed of the wafer W is reduced to 20 to 500 rpm or less, the flat plate portion as shown in FIG. 7 is lowered, and the lower surface of the flat plate portion 7 is pressed against the surface of the resist film 103. Next, as shown in FIG. 10, in a state where the flat plate portion 7 is pressed against the resist film 103, the rotation speed of the wafer W is increased to 1000 to 1500 rpm, for example, 1000 rpm, and is maintained for 30 to 100 seconds. The film thickness of the resist film 103 before contacting the flat plate portion 7 is 20 μm thicker than the target film thickness above the surface of the wafer W, and the flat plate portion 7 has a height lower than that at the lowered position. The position is set 10 μm above the upper surface of the wafer W. Therefore, by pressing the flat plate portion 7 against the resist film 103, the resist film 103 is pressed downward.

  As described above, since the inside of the resist film 103 is in a state of maintaining fluidity, by pressing the lower surface of the flat plate portion 7 against the surface of the resist film 103, as shown in FIG. The protruding portion is deformed so as to be pushed downward, the surface of the resist film 103 is leveled and flattened along the lower surface of the flat plate portion 7, and excess resist solution is pushed out of the wafer W. Further, at this time, the resist solution pushed out to the outside is supplied to the depressed portion of the resist film 103, so that the depression on the resist film 103 is filled and the surface of the resist film becomes flat. In addition, the resist film 103 near the center of the wafer W moves to the peripheral side, and the thickness of the region thinned by spin coating on the peripheral portion of the wafer W increases and the in-plane uniformity of the film thickness improves.

Since the flat plate portion 7 is provided with the vent hole 75, the resist film 103 is in contact with the atmosphere via the vent hole 75. Therefore, as shown in FIG. 10, by rotating the wafer W, the evaporation of the solvent in the resist film 103 is promoted, and the evaporated solvent is discharged from the vent hole 75. As a result, the planarized resist film 103 is dried and solidified. The vent hole 75 is formed with a diameter of 1 mm, and the resist solution has a high viscosity of 50 cP or more. Therefore, the resist solution does not enter the vent hole 75 due to the surface tension of the resist solution. Therefore, the surface of the resist film 103 is not roughened by the vent hole 75.
In addition, the resist film 103 tends to hardly dry on the center side of the wafer W, but the inside of the resist film 103 is agitated by rotating the wafer W. Therefore, the resist film 103 can be easily dried uniformly, and the drying time of the resist film 103 can be shortened.

  Thereafter, the rotation of the wafer W is stopped and the flat plate portion 7 is raised as shown in FIG. 11 to separate the lower surface of the flat plate portion 7 from the surface of the resist film 103. At this time, by stopping the rotation of the wafer W, it is possible to prevent the surface of the resist film 103 from being sheared by the edge of the vent hole 75 on the lower surface side of the flat plate portion 7. Further, the bottom surface of the flat plate portion 7 is subjected to water repellent treatment. For this reason, the resist solution is not easily applied to the lower surface of the flat plate portion 7, and the resist film 103 is not easily stuck. Therefore, when the lower surface of the flat plate portion 7 is separated from the resist film 103, the surface of the resist film 103 is not easily cut off.

  Subsequently, the flat plate portion 7 is raised to the raised position, and the flat plate portion 7 is further swung to be retracted outside the cup body 2. Next, as shown in FIG. 12, the peripheral rinse nozzle 6 is moved above the peripheral portion of the wafer W. Thereafter, the wafer W is rotated at 500 to 1500 rpm as necessary, and the rinse liquid is discharged toward the periphery of the wafer W. Thereby, the outer peripheral part of the resist film 103 is removed.

  According to the above-described embodiment, when the resist film 103 is formed on the wafer W having the step pattern 100 formed on the surface, the resist solution is applied to the wafer W, and the inside of the resist film 103 has fluidity. Meanwhile, the surface of the resist film 103 is brought into contact with the lower surface of the flat plate portion 7 facing the surface of the resist film 103. Further, with the lower surface of the flat plate portion 7 in contact with the surface of the resist film 103, the wafer W is rotated and dried while the resist film 103 is flattened. Further, after the resist film 103 is dried, the surface of the resist film 103 is separated from the lower surface of the flat plate portion 7. Therefore, the surface of the resist film 103 formed on the wafer W can be planarized.

  Further, after the resist solution is applied to the wafer W, the lower surface of the flat plate portion 7 is brought into contact with the surface of the resist film 103 without performing the step of rotating the wafer W to lower the fluidity of the surface of the resist film 103. In addition, since the lower surface of the flat plate portion 7 can be brought into contact with the surface of the resist film 103 while the resist film 103 has fluidity, the surface of the resist film 103 can be planarized. After the resist solution is applied to the wafer W, a process of rotating the wafer W to dry the surface of the resist film 103 causes the surface of the resist film 103 to maintain its fluidity and to reduce the adhesiveness of the surface. Therefore, sticking of the surface of the resist film 103 to the back surface of the flat plate portion 7 can be more reliably suppressed. In the step of reducing the fluidity of the surface of the resist film 103, for example, an inert gas such as nitrogen gas may be sprayed on the surface of the resist film, or the resist film 103 may be heated.

  Further, a chamber may be provided above the flat plate portion 7 so that the atmosphere on the upper surface of the flat plate portion 7 is set to a negative pressure. For example, as shown in FIG. 13, a flat cylindrical chamber 76 constituting a space is provided above the flat plate portion 7. Further, a suction port 77 for sucking the atmosphere in the chamber 76 is provided in the top plate portion of the chamber 76, and a suction pump 79 is connected to the suction port 77 via a suction pipe 78.

  In the resist coating apparatus described above, after the lower surface of the flat plate portion 7 is pressed against the surface of the resist film 103, the inside of the chamber 76 is set to a negative pressure. Further, the wafer W is rotated to flatten the surface of the resist film 103. In this way, by setting the atmosphere above the flat plate portion 7 to a negative pressure, the solvent in the resist film 103 is vaporized faster and the resist film 103 is easily dried. Therefore, the processing time of the wafer W can be shortened.

  Further, a heating part for heating the resist film 103 may be provided on the flat plate part 7. As an example of such a resist coating apparatus, a configuration in which a heater is embedded in the flat plate portion 7 can be given. In this resist coating apparatus, the resist film 103 is heated when the lower surface of the flat plate portion 7 is pressed against the surface of the resist film 103. As a result, the drying of the resist film 103 can be accelerated, so that the processing time of the wafer W can be shortened.

  Further, the height of the lowering position of the flat plate portion 7 may be adjusted by the lifting mechanism 72. With this configuration, the distance between the wafer W held on the spin chuck 11 and the lower surface of the flat plate portion 7 can be adjusted, and the film thickness of the resist film 103 to be formed can be adjusted. Further, the lifting mechanism 72 may be configured to adjust the pressure for pressing the flat plate portion 7 against the surface of the resist film 103. The film thickness of the resist film 103 can be similarly adjusted by adjusting the pressing pressure of the flat plate portion 7.

  Further, the substrate holding unit may be configured to hold the peripheral edge of the wafer W. For example, four beam portions extending horizontally at equal intervals in the circumferential direction of the spin chuck 11 are provided. With this configuration, it is possible to suppress the bending of the periphery of the wafer W held by the spin chuck 11. If the periphery of the wafer W is bent, when the flattened surface is brought into contact with the surface of the coating film and the coating film is flattened, the thickness of the coating film on the periphery of the wafer W is increased by the amount of bending. . Therefore, by configuring the substrate holding portion to hold the peripheral portion of the wafer W, the coating film can be flattened while suppressing the bending of the wafer W. Therefore, the coating film on the peripheral edge of the wafer W is more reliably flattened. Further, the deflection of the wafer W may be suppressed by increasing the diameter of the spin chuck 11 and supporting it to the region on the more peripheral side of the wafer W.

  Further, the flat plate portion 7 may be rotated around the vertical axis while the lower surface of the flat plate portion 7 is pressed against the surface of the resist film 103 and the wafer W is stationary. For example, as shown in FIG. 14, a rotation shaft 80 may be provided above the central portion of the flat plate portion 7, and the flat plate portion 7 may be configured to rotate around the vertical axis by a rotation mechanism 81 provided at the tip of the support member 71. With this configuration, the resist film 103 is flattened by pressing the flat plate portion 7. In addition, a rotating force can be applied to the inside of the resist film 103 by rotating the flat plate portion 7 in contact with the resist film 103. Therefore, since the inside of the resist film 103 can be stirred, drying of the resist film 103 is promoted.

  As shown in the above-described embodiment, drying of the wafer W is promoted by rotating the wafer W around the vertical axis while the lower surface of the flat plate portion 7 is in contact with the surface of the resist film 103. Therefore, the wafer W and the flat plate portion 7 may be rotated at the same speed in the same direction while the lower surface of the flat plate portion 7 is in contact with the surface of the resist film 103. Further, the vents formed in the flat plate portion 7 have, for example, as shown in FIG. 15, cuts 82 arranged in the vertical and horizontal directions of the flat plate portion 7 so as not to cut the four corner portions of the lattice and penetrating the flat plate portion 7 in the thickness direction. It may be formed.

Further, the wafer W may be rotated when the surface of the resist film 103 is separated from the lower surface of the flat plate portion 7. However, from the viewpoint of preventing the coating film from being sheared, the rotation speed of the wafer W and the flat plate portion 7 is 500 rpm or less, and preferably 50 to 500 rpm.
Further, in the step of bringing the lower surface of the flat plate portion 7 into contact with the surface of the resist film 103, the rotation of the wafer W may be stopped. When the spin chuck 11 is rattling, the wafer W is shaken when the wafer W is brought into contact with the bottom surface of the flat plate portion 7 while rotating at a high speed, and the lower surface of the flat plate portion 7 and the wafer W are inclined. In some cases, the resist film 103 may be slightly inclined. Therefore, the number of rotations of the wafer W in the step of bringing the surface of the resist film 103 into contact with the lower surface of the flat plate portion 7 is 500 rpm or less, and preferably 50 to 500 rpm.

[Second Embodiment]
A coating film forming apparatus according to the second embodiment will be described. FIG. 16 shows an example in which the coating film forming apparatus according to the second embodiment is applied to a resist coating apparatus. Instead of the flat plate portion of the resist coating apparatus shown in the first embodiment, flattening is performed. A pad 9 is provided, and the pad 9 is moved on the surface of the wafer W so that the surface of the resist film is flattened.

  The resist coating apparatus according to the second embodiment replaces the flat plate portion 7 of the resist coating apparatus shown in the first embodiment shown in FIGS. 9 is provided. As shown in FIG. 16, the pad 9 includes a pad member 90 that is a flat columnar planar member having a diameter of 30 to 50 mm whose lower surface is pressed against the surface of the resist film. The lower surface of the pad member 90 is a flat surface like the lower surface of the flat plate portion 7 and is water-repellent.

  In addition, a plate-like member 91 is provided on the upper surface of the pad member 90, and the plate-like member 91 extends from the outside of the cup body 2 toward the upper side of the center portion of the wafer W held by the spin chuck 11 and the tip of the support portion 93. Further, the lower surface of the pad member 90 is supported so as to be parallel to the wafer W held by the spin chuck 11. The support portion 93 is connected to the turning mechanism 73 via the lifting mechanism 72. By the lifting mechanism 72, the pad 9 moves up and down between an upper position and a lowered position where the lower surface of the pad 9 is brought into contact with the resist film 103 and the resist film 103 is flattened. Further, the pad 9 is swung by the swivel mechanism 73, and the pad 9 is swung at the lowered position, whereby the pad 9 is moved between the center portion of the wafer W and the peripheral portion of the wafer W, and the pad 9 is moved to the raised position. , The pad 9 moves between the upper center of the wafer W and the standby position outside the cup body 2.

  In the resist coating apparatus according to the second embodiment, in the step of flattening and drying the coating film, the lower surface of the pad 9 is brought into contact with the surface of the resist film 103, and then, as shown in FIG. The pad 9 is reciprocated several times in the radial direction of the wafer W at a speed of, for example, 10 to 20 mm / sec. With this configuration, the entire surface of the coating film formed on the wafer W can be leveled and flattened. Alternatively, the pad 9 may be moved on the surface of the wafer W while the wafer W is stopped to level the entire surface of the coating film.

2 Cup body 7 Flat plate part 9 Pad 10 Control part 11 Spin chuck 13 Rotating mechanism 50 Resist liquid nozzle 51 Solvent nozzle 75 Vent 100 Step pattern 103 Resist film W Wafer

Claims (11)

In the coating film forming method for forming the coating film on the surface of the substrate on which the step pattern is formed,
Applying a coating solution to the surface of the substrate held horizontally;
A step of bringing the lower surface of the flattening member whose bottom surface is a flat surface into contact with the surface of the liquid film of the coating solution while the coating liquid applied to the substrate has fluidity;
Rotating at least one of the substrate and the lower surface of the planarizing member around the vertical axis to flatten the surface of the coating film and drying the coating film;
And a step of separating the surface of the substrate and the lower surface of the planarizing member.   2. The method of forming a coating film according to claim 1, wherein the step of rotating at least one of the substrate and the lower surface of the planarizing member around the vertical axis rotates the substrate around the vertical axis.   The step of reducing the fluidity of the surface of the coating film is performed between the step of applying the coating liquid and the step of bringing the lower surface of the planarizing member into contact with the surface of the liquid film of the coating liquid. Item 3. The coating film forming method according to Item 1 or 2.   4. The method of forming a coating film according to claim 3, wherein the step of reducing the fluidity of the surface of the coating film comprises holding the substrate coated with the coating liquid on the surface horizontally and rotating the substrate around a vertical axis.   5. The flattening member is provided with a vent for discharging a solvent that volatilizes from the coating liquid on the lower surface, and the lower surface is configured to cover the entire surface of the substrate. The coating film forming method according to one item. The planarizing member has a lower surface area smaller than the surface area of the substrate,
The step of rotating at least one of the substrate and the lower surface of the flattening member around the vertical axis is performed by placing the lower surface of the flattening member on the substrate while the lower surface of the flattening member is in contact with the surface of the coating film. 5. The method of forming a coating film according to claim 1, wherein the substrate is rotated about a vertical axis while being moved in a radial direction.   7. The step of rotating at least one of the substrate and the lower surface of the planarizing member around the vertical axis heats the coating film to promote drying of the coating film. The coating film formation method of description.   7. The step of rotating at least one of the substrate and the lower surface of the planarizing member around the vertical axis promotes drying of the coating film by applying a negative pressure to the surface of the coating film. The method for forming a coating film according to claim 1.   The step of separating the surface of the substrate from the lower surface of the planarizing member is performed with the number of rotations of the lower surface of the planarizing member viewed from the substrate being 500 rpm or less, or in a state where the rotation of the lower surface of the substrate and the planarizing member is stopped. A coating film forming method according to any one of claims 1 to 8, A storage medium storing a computer program used in a coating film forming apparatus for forming a coating film on the surface of a substrate on which a step pattern is formed,
A storage medium comprising a program for executing a group of steps for executing the coating film forming method according to any one of claims 1 to 9. In a coating film forming apparatus for forming a coating film on the surface of a substrate on which a step pattern is formed,
A substrate holder for horizontally holding the substrate;
A coating solution supply unit that supplies a coating solution toward the substrate held by the substrate holding unit;
A planarizing member having a flat surface facing the surface of the substrate held by the substrate holding portion on the lower surface;
A rotation mechanism for rotating at least one of the substrate and the lower surface of the planarizing member around a vertical axis;
An elevating mechanism for elevating and lowering the planarizing member;
Applying the coating liquid to the surface of the substrate held horizontally; contacting the lower surface of the planarizing member to the surface of the liquid film of the coating liquid while the coating liquid applied to the substrate has fluidity; Rotating at least one of the substrate and the lower surface of the planarizing member around the vertical axis to planarize the surface of the coating film and drying the coating film, and then the surface of the substrate and the lower surface of the planarizing member. A coating film forming apparatus comprising: a control unit that performs control to execute the step of separating.

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