Substrate processing apparatus and film forming method

Abstract

To improve the uniformity of coating film thickness when forming a conformal coating film on a treated surface with uneven patterns.SOLUTION: There is provided a substrate processing device including: a holding part holding a substrate such that a treated surface, on which a pattern is formed, a coating liquid is supplied and a coating liquid film is formed, is parallel to a predetermined direction; and a rotating mechanism acting, on the coating liquid, a centrifugal force in a direction to press against the substrate, by rotating, around a rotation axis, the holding part in the state where the holding part holds the substrate such that the treated surface is oriented in the direction of the rotation axis extending in the predetermined direction and is parallel to the predetermined direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a substrate processing apparatus and a film forming method. [Background technology]

[0002] Patent Document 1 discloses a method for forming a coating film, which includes the steps of holding a substrate having a concave-convex pattern formed on its surface in a substrate holding section, a discharge step of discharging a mist of a coating liquid onto the surface of the substrate held in the substrate holding section, a coating step of rotating the substrate in an inclined state or changing the inclination angle of the substrate in order to cause the coating liquid to flow within recesses forming the concave-convex pattern and coat the side walls of the recesses with the coating liquid, and a coating film forming by drying the coating liquid. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-110444 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology according to the present disclosure improves the uniformity of the thickness of a coating film when the coating film is conformally formed on a treatment surface having a concave-convex pattern. [Means for solving the problem]

[0005] One aspect of the present disclosure is a substrate processing system including: a holder that holds a substrate such that a pattern is formed on the substrate and the processing surface is parallel to a predetermined direction; a coating liquid supply unit that supplies a coating liquid to the processing surface of the substrate; a first rotation mechanism that rotates the holder about a first rotation axis that penetrates the processing surface of the substrate; a cup that receives and recovers liquid from the substrate held by the holder that is rotated by the first rotation mechanism; and a housing that houses the holder, the coating liquid supply unit, and the cup. perpendicular to the first rotation axisThe substrate processing apparatus includes a second rotation mechanism that rotates the housing around a second rotation axis extending in the predetermined direction, and a control unit, wherein the control unit controls the processing to perform the following steps: supplying the coating liquid from the coating liquid supply unit to the processing surface of the substrate held in the holding unit and rotating the holding unit around the first rotation axis to form a coating liquid film on the processing surface of the substrate; and then, with the processing surface of the substrate facing the direction of the second rotation axis and parallel to the predetermined direction, rotating the housing around the second rotation axis to apply centrifugal force to the coating liquid in a direction pressing it against the substrate. [Effects of the Invention]

[0006] According to the present disclosure, when a coating film is conformally formed on a treatment surface having a concave-convex pattern, the uniformity of the thickness of the coating film can be improved. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view showing the configuration of a wafer processing apparatus as a substrate processing apparatus according to a first embodiment. [Figure 2] 1 is a vertical cross-sectional view showing the configuration of a wafer processing apparatus as a substrate processing apparatus according to a first embodiment. [Figure 3] 3 is a flowchart showing an example of the flow of a film forming method according to the first embodiment. [Figure 4] 2 is a partially enlarged cross-sectional view of a wafer W on which a coating liquid film is formed. [Figure 5] 3 is a partially enlarged cross-sectional view of a wafer W on which a coating liquid film is formed. FIG. [Figure 6] FIG. 10 is a partially enlarged cross-sectional view of a wafer W after conventional spin drying. [Figure 7] 10 is a diagram showing the state of the coating liquid applied to the processing surface W1 of the wafer W. FIG. [Figure 8] 10 is a diagram for explaining forces acting on a coating liquid film formed on a wafer W. FIG. [Figure 9]FIG. 10 is a cross-sectional view showing the configuration of a wafer processing apparatus as a substrate processing apparatus according to a second embodiment. [Figure 10] FIG. 10 is a vertical cross-sectional view showing the configuration of a wafer processing apparatus as a substrate processing apparatus according to a second embodiment. [Figure 11] FIG. 2 is a vertical cross-sectional view showing the outline of the configuration of a coating unit. [Figure 12] FIG. 2 is a cross-sectional view showing the outline of the configuration of the application unit. [Figure 13] 10 is a flowchart showing an example of the flow of a film forming method according to a second embodiment. [Figure 14] FIG. 10 is a cross-sectional view showing the configuration of a wafer processing apparatus as a substrate processing apparatus according to a third embodiment. [Figure 15] FIG. 10 is a vertical cross-sectional view showing the configuration of a wafer processing apparatus as a substrate processing apparatus according to a third embodiment. [Figure 16] 10 is a flowchart showing an example of the flow of a film forming method according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] In the manufacturing process of semiconductor devices and the like, there is a process of supplying a coating liquid such as a resist liquid onto a substrate such as a semiconductor wafer (hereinafter referred to as a "wafer") to form a coating film such as a resist film. This process widely uses so-called spin coating, in which the coating liquid is supplied to the substrate while the substrate is rotated about its center, and the coating liquid is applied to the entire substrate by centrifugal force to form a coating film. In addition, when a coating film is formed by spin coating, spin drying is used to dry the coating film by rotating the substrate about its center while the supply of the coating liquid is stopped.

[0009] When a concave-convex pattern is formed on the processing surface of a substrate on which a coating film is to be formed, it is sometimes desirable to form a coating film having undulations similar to those of the concave-convex pattern, i.e., a conformal coating film. However, when spin drying is performed after spin coating, it is difficult to form a conformal coating film. Techniques for forming conformal coating films have been proposed in the past (see Patent Document 1), but there is room for improvement in terms of film thickness uniformity, including at the corners on the opening sides of the recesses in the concave-convex pattern.

[0010] Therefore, the technology according to the present disclosure improves the uniformity of the thickness of a coating film when the coating film is conformally formed on a treatment surface having a concave-convex pattern.

[0011] Hereinafter, a substrate processing apparatus and a film forming method according to the present embodiment will be described with reference to the drawings. In this specification and the drawings, elements having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0012] (First embodiment) <Wafer processing equipment> 1 and 2 are a cross-sectional view and a longitudinal sectional view showing the configuration of a wafer processing apparatus as a substrate processing apparatus according to a first embodiment.

[0013] 1 and 2, the wafer processing apparatus 1 has a housing 10 whose interior can be sealed. The housing 10 is formed, for example, in a rectangular shape when viewed from above (the positive side in the Z direction in the drawings). The housing 10 rotates by a rotation mechanism 31, which will be described later. The peripheral wall of the housing 10 is provided with loading / unloading openings 11 for wafers W. The number of loading / unloading openings 11 provided is, for example, the same as the number of chucks 20, which will be described later. Each loading / unloading opening 11 is provided with an opening / closing shutter (not shown).

[0014] A chuck 20 is provided within the housing 10 as a holding unit. The chuck 20 holds the wafer W so that the processing surface (i.e., front surface) W1 of the wafer W is parallel to a predetermined direction, i.e., the vertical direction (Z direction in the figure). Specifically, the chuck 20 is configured to hold the wafer W so that the processing surface W1 of the wafer W faces the direction of a rotation axis J extending in the vertical direction (Z direction in the figure) and is parallel to the rotation axis J (i.e., parallel to the vertical direction). The center of the holding surface of the chuck 20 is on a circle of radius R centered on the rotation axis J extending in the vertical direction, and the holding surface is disposed in a direction perpendicular to the circle. In other words, a normal line from the center of the holding surface of the chuck 20 perpendicularly intersects with the rotation axis J, and the distance from the center of the holding surface to the rotation axis J is R. The four chucks 20 are disposed at the same height and are evenly spaced. In this embodiment, a concave-convex pattern is formed in advance on the processing surface W1 of the wafer W held by the chuck 20, and a coating liquid is supplied to form a coating liquid film on the processing surface W1. The holding surface of the chuck 20 is provided with suction holes (not shown) for suctioning the back surface of the wafer W. The chuck 20 suction-holds the wafer W by suction through these suction holes. Note that the method of holding the wafer W by the chuck 20 is not limited to suction-holding.

[0015] For example, a plurality of (four in this example) chucks 20 are provided in the housing 10. The number of chucks 20 can be selected arbitrarily. In the following description, the four chucks 20 may be referred to as chucks 20A, 20B, 20C, and 20D, respectively.

[0016] Each chuck 20 is connected to the inner wall surface of the housing 10 via legs 21. The distances R from each chuck 20 (specifically, the processing surface W1 of the wafer W held by each chuck 20) to a rotation axis J, which will be described later, are equal to each other.

[0017] A rotation mechanism 31 is connected to the wall of the housing 10 on the lower vertical side (negative side in the Z direction in the drawing), i.e., the bottom wall, via a shaft 30. The rotation mechanism 31 allows the housing 10 to rotate at a desired speed around a rotation axis J (specifically, the central axis of the shaft 30). This makes it possible to rotate the chuck 20 at a desired speed around the rotation axis J. The rotation mechanism 31 has a rotation drive source (not shown) such as a motor that generates a drive force for rotating the housing 10. The rotation mechanism 31 is controlled by a control unit U, which will be described later.

[0018] Furthermore, a filter fan unit (FFU) 40 is provided in the upper part of the housing 10. The FFU 40 is an example of a heating mechanism that heats the coating liquid film formed on the wafer W held by the chuck 20, and supplies clean air heated to a temperature higher than that of the wafer W into the housing 10. The FFU 40 has, for example, a heater (not shown) upstream of the filter, which enables it to supply clean air heated to a temperature higher than room temperature.

[0019] In the illustrated example, one common FFU 40 is provided for a plurality of chucks 20, but an FFU 40 may be provided for each chuck 20, and high-temperature clean air may be supplied from each FFU 40 toward the processing surface W1 of the wafer W held on the corresponding chuck 20.

[0020] The wafer processing apparatus 1 further includes a control unit U. The control unit U is, for example, a computer equipped with a CPU, memory, etc., and has a program storage unit (not shown). The program storage unit stores a program that controls the operation of the drive system, such as the rotation mechanism, to control the wafer processing described below. The program may be recorded on a computer-readable non-transitory storage medium M and installed from the storage medium M into the control unit U. The storage medium M may be either temporary or non-transitory. Part or all of the program may be realized by dedicated hardware (circuit board).

[0021] <Film formation process> The film forming method according to this embodiment will be described with reference to FIGS. 3 to 8. FIG. 3 is a flowchart showing an example of the flow of the film forming method according to this embodiment. FIG. 4 is a partially enlarged cross-sectional view of a wafer W on which a coating liquid film is formed. FIG. 5 is a partially enlarged cross-sectional view of a wafer W on which a coating liquid film has been formed. FIG. 6 is a partially enlarged cross-sectional view of a wafer W after conventional spin drying. FIG. 7 is a diagram showing the state of the coating liquid applied to the processing surface W1 of the wafer W. FIG. 8 is a diagram for explaining forces acting on the coating liquid film formed on the wafer W.

[0022] (Step S1) 3, a coating liquid is supplied to a processing surface W1 of a wafer W to be processed in the wafer processing apparatus 1 by an apparatus external to the wafer processing apparatus 1, forming a coating liquid film. Specifically, the coating liquid is supplied to the processing surface of each wafer W to be processed in the wafer processing apparatus 1 by spin coating in an apparatus external to the wafer processing apparatus 1, forming a coating liquid film so as to cover the entire processing surface W1, and adjusting the thickness of the entire coating liquid film, i.e., the entire surface. 4, each wafer W on which a coating liquid film is to be formed has a concave-convex pattern P formed on its processing surface W1, the concave-convex pattern P being recessed (or protruding) in the thickness direction of the wafer W. The concave-convex pattern P is, for example, a line pattern or a hole pattern. The recesses P1 of the concave-convex pattern P have a depth of, for example, 50 to 500 μm and a width of, for example, 50 to 500 μm in a cross-sectional view. The viscosity of the coating liquid supplied to the processing surface W1 of the wafer W is, for example, 30 cp to 1000 cp. The type of coating liquid is, for example, a resist liquid or a coating liquid for forming a protective film.

[0023] 5, a conformal coating liquid film F1 is formed having undulations similar to those of the concave-convex pattern P. The thickness A of the coating liquid film F1 (specifically, the thickness of the coating liquid film F1 at the top surface W11 of the concave-convex pattern P) is, for example, 5 μm or more. The reason for setting the thickness A of the coating liquid film F1 to 5 μm or more will be described later.

[0024] Furthermore, at the end of step S1, the coating liquid film F1 is not completely dried, and the coating liquid constituting the coating liquid film F1 has high fluidity. However, the fluidity of the coating liquid constituting the coating liquid film F1 is reduced compared to immediately after it is supplied to the processing surface W1. Specifically, drying has progressed, the viscosity has increased, and the fluidity has reduced to the extent that the wafer W does not drip even when the wafer W is in a vertical position, i.e., the processing surface W1 is parallel to the vertical direction, and the coating defects described below do not occur.

[0025] (Step S2) Next, the wafer W is carried into the housing 10 of the wafer processing apparatus 1 and held by the chuck 20 in a predetermined orientation. For example, first, the loading / unloading port 11 corresponding to the chuck 20A is opened, and a transfer device (not shown) holding the wafer W in a vertical orientation is inserted through the loading / unloading port 11, so that the wafer W faces the chuck 20A. Next, suction is started through the suction holes (not shown) of the chuck 20A, and the transfer device moves the wafer W to the chuck 20A, so that the wafer W is transferred from the transfer device to the chuck 20A and held by suction. At this time, the processing surface W1 of the wafer W is parallel to the vertical direction and faces the direction of the rotation axis J (see FIG. 1). After suction and holding, the transfer device is removed from the housing 10, and the loading / unloading port 11 corresponding to the chuck 20A is closed. Next, the housing 10 is rotated around the rotation axis J, and the positions of the loading / unloading port 11 corresponding to the chuck 20B and the transport device are adjusted, and then the wafer W is adsorbed and held by the chuck 20B in the same manner as the chuck 20A. Similarly, the wafer W is held by suction on the chucks 20C and 20D.

[0026] (Step S3) Thereafter, the wafer W is rotated about the rotation axis J, and centrifugal force is applied to the coating liquid in a direction C (see FIGS. 7 and 8) in which the coating liquid is pressed against the wafer W. Specifically, the rotation mechanism 31 rotates the housing 10, in which the internal chucks 20 suction-hold the wafer W, about the rotation axis J. As a result, the wafer W, whose processing surface W1 is parallel to the vertical direction, i.e., parallel to the rotation axis J and facing the direction of the rotation axis J, is rotated about the rotation axis J, and centrifugal force acts on the coating liquid film F1 in the direction C pressing the coating liquid film F1 against the wafer W. With the centrifugal force acting in this manner, the fluidity of the coating liquid constituting the coating liquid film F1 is reduced, that is, the coating liquid film F1 is dried.

[0027] A method for drying the coating liquid film on the processing surface W1 of the wafer W, which is different from the method of this embodiment, is the conventional, or ordinary, spin drying method in which the wafer W is rotated around its center. However, with this conventional spin drying, as shown in FIG. 6, the opening-side corners of the recesses P1 of the concave-convex pattern P may not be covered by the coating liquid film F1 after spin drying, i.e., the opening-side corners may be exposed. This is thought to be due to the fact that, as shown in FIG. 5, the surface tension T applied to the coating liquid film F1 covering the opening-side corners of the recesses P1 of the concave-convex pattern P includes a force component in a direction along the top surface W11 of the wafer W away from the opening-side corners. If this force component acts in a direction away from the opening-side corners, as the coating liquid film F1 dries and thins, the coating liquid film F1 breaks near the opening-side corners of the recesses P1 of the concave-convex pattern P, exposing the corners. With conventional spin drying, the force resisting this surface tension T is absent or small during the drying process, which is thought to be why the opening-side corners of the recesses P1 of the concave-convex pattern P are exposed, as described above.

[0028] In contrast, in this embodiment, in the process of drying the coating liquid film F1, a centrifugal force acts on the coating liquid film F1 in a direction pressing the coating liquid film F1 against the wafer W. As shown in Fig. 7, when a centrifugal force acts on the coating liquid film F1 in a direction C pressing the coating liquid film F1 against the wafer W, the coating liquid film F1 changes from, for example, a droplet state D1 to a crushed state D2. Similarly, as shown in Fig. 8, when a centrifugal force acts on the coating liquid film F1 in the direction C pressing the coating liquid film F1 against the wafer W, the coating liquid film F1 on the top surface W11 of the wafer W is crushed, and as a result, a force C1 acts on the coating liquid film F1 along the top surface W11 in a direction toward the opening-side corner of the pattern P. During step S3, a force C1 acting in a direction toward the opening side corner of the pattern P constantly acts on the coating liquid film F1, and serves as a resistance force against the force acting in a direction away from the opening side corner of the pattern P due to surface tension T. Therefore, in step S3, the corners on the opening side of the recesses P1 of the concave / convex pattern P can be prevented from being exposed.

[0029] It should be noted that centrifugal force is proportional to the mass of a substance. In the case of the coating liquid film F1, the centrifugal force acting is also proportional to the mass of the coating liquid film F1, i.e., the film thickness. Therefore, in order to sufficiently crush the coating liquid film F1 by centrifugal force against the surface tension acting on the coating liquid film F1 (not limited to the surface tension acting on the portions near the corners on the opening side of the recesses P1 of the uneven pattern P), it is preferable that the coating liquid film F1 has a certain amount of mass, i.e., film thickness. Specifically, it is preferable that the thickness A of the coating liquid film F1 (specifically, the thickness of the coating liquid film F1 at the top surface W11 of the uneven pattern P) be 5 μm or more.

[0030] The rotation speed of the chuck 20 by the rotation mechanism 31 in step S3 is a rotation speed at which the movement of the coating liquid parallel to the wafer W due to surface tension T is suppressed by the centrifugal force in the direction C. Specifically, the rotation speed of the chuck 20 by the rotation mechanism 31 in step S3 is a rotation speed at which the force C1 acting toward the opening-side corner of the pattern P due to the centrifugal force in the direction C is greater than the force acting in the direction away from the opening-side corner of the pattern P due to surface tension T. More specifically, the rotation speed of the chuck 20 by the rotation mechanism 31 in step S3 is a rotation speed at which a centrifugal force of 50 G or more, more preferably 100 G or more, acts.

[0031] In order to suppress the difference in the centrifugal force acting on the coating liquid film F1 across the wafer W, it is preferable that the distance R from the processing surface W1 of the wafer W held by the chuck 20 to the rotation axis J be 170 mm or more.

[0032] In step S3, the rotation of the wafer W held by the chuck 20 by the rotation mechanism 31 is continued until the fluidity of the coating liquid decreases, for example, as follows: That is, the rotation of the wafer W in step S3 is continued until the fluidity of the coating liquid decreases to such an extent that the coating liquid film F1 does not deform due to the surface tension T even when the rotation is stopped and no centrifugal force is applied.

[0033] Furthermore, in step S3, while the wafer W held by the chuck 20 is being rotated by the rotation mechanism 31, clean air heated to a high temperature, i.e., hot air, may be supplied from the FFU 40 into the housing 10. In this case, for example, the temperature of the hot air is set to 50°C, and the flow rate of the hot air is set to 1 m 3 By supplying the hot air in this manner, the fluidity of the coating liquid constituting the coating liquid film F1 can be quickly reduced to a desired range.

[0034] (Step S4) After step S3, each wafer W is carried out from the housing 10 of the wafer processing apparatus 1 by reversing the procedure of step S2.

[0035] (Step S5) Then, the wafers W processed in the wafer processing apparatus 1 are heated and further dried in an apparatus external to the wafer processing apparatus 1. Specifically, each wafer W processed in the wafer processing apparatus 1 is heated in an apparatus external to the wafer processing apparatus 1, and the solvent of the coating liquid film F1 is further removed, forming a coating film that has no fluidity. This completes a series of film formation processes.

[0036] As described above, in this embodiment, when drying the coating liquid film F1 formed on the processing surface W1 of the wafer W having the pattern P thereon, i.e., when reducing its fluidity, the wafer W, with the processing surface W1 parallel to and facing the rotation axis J, is rotated about the rotation axis J. This applies centrifugal force to the coating liquid film in the direction C, pressing the coating liquid film against the wafer W, reducing the fluidity of the coating liquid constituting the coating liquid film F1. When the centrifugal force is applied, as described above, a force C1 acts on the coating liquid film F1 along the top surface W11 of the wafer W toward the opening-side corners of the pattern P. This force C1 prevents the opening-side corners of the recesses P1 of the concave-convex pattern P from being exposed. Therefore, when the coating liquid film F1 is conformally formed on the processing surface W1 having the concave-convex pattern, the thickness uniformity of the coating liquid film F1 can be improved. Similarly, when the coating liquid film F1 is further dried, the thickness uniformity can be improved when the coating liquid film F1 is conformally formed.

[0037] (Second embodiment) <Wafer processing equipment> 9 and 10 are a horizontal cross-sectional view and a vertical cross-sectional view showing the configuration of a wafer processing apparatus as a substrate processing apparatus according to the second embodiment.

[0038] As shown in Figures 9 and 10, the wafer processing apparatus 1a has a housing 10a whose interior can be sealed. The housing 10a is formed, for example, in a rectangular shape when viewed from the front side (the positive side in the Y direction in the figure). The housing 10a is rotated by a rotation mechanism 31a, which will be described later. A loading / unloading opening 11 for the wafer W is provided in the wall on the front side (the positive side in the Y direction in the figure) of the housing 10a. The loading / unloading openings 11a are provided in the same number as the chucks 20a, which will be described later, for example. Each loading / unloading opening 11a is provided with an opening / closing shutter (not shown).

[0039] A coating unit Q including a chuck 20a as a holder and a discharge nozzle 122 as a coating liquid supply unit is provided within the housing 10a. The chuck 20a holds the wafer W so that the processing surface (i.e., front surface) W1 of the wafer W is parallel to a predetermined direction (Y direction in the figure) perpendicular to the vertical direction (Z direction in the figure). Specifically, the chuck 20a is configured to hold the wafer W so that the processing surface W1 of the wafer W faces the direction of a rotation axis Ja extending in a predetermined direction (Y direction in the figure) perpendicular to the vertical direction (Z direction in the figure) and is parallel to the rotation axis Ja. The chuck 20a has, for example, a holding surface parallel to the predetermined direction (Y direction in the figure), and the holding surface is provided with suction holes (not shown) for suctioning the back surface of the wafer W. The chuck 20a suction-holds the wafer W by suction through the suction holes. Note that the method of holding the wafer W by the chuck 20a is not limited to suction-holding.

[0040] A plurality of coating units Q (four in this example) including the above-described chuck 20a are provided in the housing 10a, for example. The number of coating units Q can be selected arbitrarily. In the following description, the four coating units Q may be referred to as coating units QA, QB, QC, and QD, respectively.

[0041] A rotation mechanism 31a is connected to the wall of the housing 10a on the far side (negative side in the Y direction in the drawing) via a shaft 30a. The housing 10a can be rotated at a desired speed around a rotation axis (specifically, the central axis of the shaft 30a) Ja by the rotation mechanism 31a. This makes it possible to rotate the chuck 20 at a desired speed around the rotation axis Ja. The rotation mechanism 31a has a rotation drive source (not shown) such as a motor that generates a drive force for rotating the housing 10a. The rotation mechanism 31a is controlled by the control unit U.

[0042] <Coating Unit Q> Next, we will explain the configuration of each coating unit Q. Figures 11 and 12 are a vertical cross-sectional view and a horizontal cross-sectional view, respectively, showing the outline of the configuration of each coating unit Q.

[0043] 11, each coating unit Q has the above-described chuck 20a. In this embodiment, the chuck 20a holds the wafer W and rotates the wafer W around the center of the wafer W. The chuck 20a is provided therein with a heater 100 as a heating mechanism. The heater 100 is, for example, a resistance heater.

[0044] The chuck 20a is connected to a driving mechanism 111 via a shaft 110, and can be rotated at a desired speed around a rotation axis (specifically, the central axis of the shaft 110) by the driving mechanism 111. The driving mechanism 111 has a rotation driving source (not shown) such as a motor that generates a driving force for rotating the chuck 20a. The driving mechanism 111 is controlled by a control unit U.

[0045] The chuck 20a is connected to the inner wall surface of the housing 10a via a shaft 110 and a drive mechanism 111. Although not shown, lifter pins are provided around the chuck 20a for transferring the wafer W to and from an external transfer device. These lifter pins can be raised and lowered in the vertical direction by a lifting mechanism (not shown) having an actuator such as a motor, thereby supporting and lifting the wafer W. This allows the wafer W to be transferred between the chuck 20a and the transfer mechanism (not shown).

[0046] Furthermore, a cup 112 is provided around the chuck 20a to receive and collect liquid that splashes or drops from the wafer W.

[0047] 12, a rail 120 extending in the Y direction is formed on the outside of the cup 112. The rail 120 is formed, for example, from the outside on the negative Y direction side of the cup 112 to the outside on the positive Y direction side. An arm 121 is attached to the rail 120.

[0048] 11 and 12, a discharge nozzle 122 that supplies a coating liquid onto the processing surface W1 of the wafer W is supported on the arm 121. The arm 121 is movable on a rail 120 by a nozzle driving mechanism 123 shown in FIG. 12. This allows the discharge nozzle 122 to move from a waiting section 124 installed outside the cup 112 on the negative Y-direction side to above the center of the wafer W in the cup 112, and further move over the wafer W in the radial direction of the wafer W. The arm 121 is also movable up and down by the nozzle driving mechanism 123, allowing the height of the discharge nozzle 122 to be adjusted. A supply section (not shown) that supplies the resist liquid to the discharge nozzle 122 is connected to the discharge nozzle 122.

[0049] <Film formation process> The film forming method according to this embodiment will be described with reference to Fig. 13. Fig. 13 is a flowchart showing an example of the flow of the film forming method according to this embodiment.

[0050] (Step S11) First, as shown in FIG. 13, the wafer W is carried into the housing 10a of the wafer processing apparatus 1a and held by the chuck 20a in a predetermined orientation. For example, first, with the coating unit QA positioned at the lowest position, the loading / unloading port 11a corresponding to the coating unit QA is opened. A transfer device (not shown) holding a wafer W facing upward (i.e., with the processing surface W1 facing the positive side of the Z direction) is inserted through the loading / unloading port 11a, so that the wafer W faces the chuck 20a of the coating unit QA. Next, the lift pins are raised and lowered and the transfer device is removed from the housing 10a, and the wafer W is transferred from the transfer device to the chuck 20a of the coating unit QA. Furthermore, suction is applied through the suction holes (not shown) of the chuck 20a of the coating unit QA, and the wafer W is suction-held by the chuck 20a. At this time, the processing surface W1 of the wafer W is parallel to and faces the rotation axis J. Thereafter, the loading / unloading port 11a corresponding to the coating unit QA is closed. Next, the housing 10a is rotated around the rotation axis Ja, and the positions of the loading / unloading opening 11a corresponding to the coating unit QB and the transport device are adjusted, and then the wafer W is adsorbed and held by the chuck 20a of the coating unit QB in the same manner as the chuck 20a of the coating unit QA. Similarly, the wafer W is held by suction on the chucks 20a of the coating units QC and QD.

[0051] (Step S12) Next, the coating liquid is supplied to form a coating liquid film on the processing surface W1 of the wafer W. Specifically, the coating liquid is supplied to the processing surface of each wafer W by spin coating, and a coating liquid film is formed so as to cover the entire processing surface W1, and the film thickness of the entire coating liquid film, i.e., the entire surface, is adjusted. do.

[0052] Specifically, the discharge nozzle 122 of each coating unit Q is moved to a processing position where discharge is performed (for example, a position above the center of the wafer W). Subsequently, the chuck 20a is rotated about the central axis of the shaft portion 110, thereby rotating the wafer W about the central axis, and during this rotation, the coating liquid is continuously discharged from the discharge nozzle 122 onto the wafer W. The discharged coating liquid is spread over the entire surface of the wafer W due to the rotation of the wafer W, thereby forming a coating liquid film F1.

[0053] Thereafter, the discharge of the coating liquid is stopped, and the discharge nozzle 122 is retracted to the standby section 124. After the discharge of the coating liquid is stopped, the rotation of the chuck 20a may be continued, and the rotation of the wafer W may also be continued. However, the rotation of the wafer W after the discharge of the coating liquid is stopped is performed to an extent that does not cause the above-mentioned coating defects.

[0054] (Step S13) Next, the wafer W, whose processing surface W1 is parallel to the vertical direction, i.e., parallel to the rotation axis Ja and facing in the direction of the rotation axis Ja, is rotated around the rotation axis Ja, and centrifugal force is applied in a direction pressing the wafer W against the coating liquid. Specifically, the rotation mechanism 31a rotates the housing 10a, in which the internal chucks 20a suction-hold the wafer W, about the rotation axis Ja. As a result, the wafer W, whose processing surface W1 is parallel to a predetermined direction (the Y direction in FIG. 9), i.e., parallel to the rotation axis J and facing the direction of the rotation axis J, is rotated about the rotation axis J, and a centrifugal force acts on the coating liquid film F1 in a direction pressing the coating liquid film F1 against the wafer W. With the centrifugal force acting in this manner, the fluidity of the coating liquid constituting the coating liquid film F1 is reduced, that is, the coating liquid film F1 is dried.

[0055] Furthermore, in step S13, the heater 100 may heat the coating liquid film F1 while the rotation mechanism 31a is rotating the wafer W held by the chuck 20. By heating in this manner, the fluidity of the coating liquid constituting the coating liquid film F1 can be quickly reduced to a desired range.

[0056] In step S13, the wafer W held by the chuck 20 is rotated by the rotation mechanism 31a until the fluidity of the coating liquid decreases to such an extent that deformation of the coating liquid film F1 does not occur due to the surface tension T even when the rotation is stopped and centrifugal force is not applied.

[0057] (Step S14) After step S13, each wafer W is carried out from the housing 10a of the wafer processing apparatus 1a in the reverse order of step S12.

[0058] (Step S15) Then, the wafers W processed in the wafer processing apparatus 1a are heated and further dried in an apparatus external to the wafer processing apparatus 1a. Specifically, each wafer W processed in the wafer processing apparatus 1a is heated in an apparatus external to the wafer processing apparatus 1a, and the solvent in the coating liquid film F1 is further removed. This completes a series of film formation processes.

[0059] According to this embodiment as well, when the coating liquid film F1 is conformally formed on the processing surface W1 having an uneven pattern, the uniformity of the thickness of the coating liquid film F1 can be improved.

[0060] (Third embodiment) <Wafer processing equipment> 14 and 15 are a horizontal cross-sectional view and a vertical cross-sectional view showing the configuration of a wafer processing apparatus as a substrate processing apparatus according to the third embodiment.

[0061] As shown in Figures 14 and 15, the wafer processing apparatus 1b has a housing 10b whose interior can be sealed. The housing 10b is formed, for example, in a rectangular shape when viewed from above (the positive side in the Z direction in the figure). The housing 10b is rotated by a rotation mechanism 31. Loading / unloading openings 11b for the wafer W are provided on the peripheral wall of the housing 10b. The number of loading / unloading openings 11b provided is, for example, the same as the number of chucks 20a. Each loading / unloading opening 11b is provided with an opening / closing shutter (not shown).

[0062] A unit Qa similar to the coating unit Q of the wafer processing apparatus 1b of the second embodiment is provided inside the housing 10b. The unit Qa of this embodiment differs from the coating unit Q in at least the following respects: That is, the unit Qa is different at least in that the angle of the chuck 20a is configured to be changeable.

[0063] 15, an angle changing mechanism 200 that changes the angle of the chuck 20a is connected to the chuck 20a of the coating unit Qa. The angle changing mechanism 200 can change the angle of the chuck 20a between an angle where the holding surface of the chuck 20a is horizontal and perpendicular to the rotation axis J, and an angle where the holding surface of the chuck 20a is parallel to the rotation axis J and faces the direction of the rotation axis J. The angle changing mechanism 200 can also change the angle of the cup 112. In the following description, it is assumed that the coating unit Qa and the coating unit Q have the same configuration except for the above.

[0064] A plurality of (four in this example) coating units Qa, each including the angle changing mechanism 200, are provided in the housing 10b, for example. The number of coating units Qa can be selected arbitrarily. In the following description, the four coating units Q may be referred to as coating units QAa, QBa, QCa, and QDa, respectively.

[0065] A rotation mechanism 31 is connected to the wall of the housing 10b on the lower vertical side (negative side in the Z direction in the drawing), i.e., the bottom wall, via a shaft 30. The rotation mechanism 31 allows the housing 10b to rotate at a desired speed around a rotation axis J (specifically, the central axis of the shaft 30). This makes it possible to rotate the chuck 20 at a desired speed around the rotation axis J.

[0066] <Film formation process> The film forming method according to this embodiment will be described with reference to Fig. 16. Fig. 16 is a flowchart showing an example of the flow of the film forming method according to this embodiment.

[0067] (Step S21) First, as shown in FIG. 16, the wafer W is carried into the housing 10b of the wafer processing apparatus 1b and held by the chuck 20a with the holding surface perpendicular to the rotation axis J and horizontal. For example, first, the loading / unloading port 11b corresponding to the coating unit QAa is opened, and a transfer device (not shown) holding a wafer W facing upward (i.e., with the processing surface W1 facing the positive side in the Z direction) is inserted through the loading / unloading port 11b, so that the horizontal holding surface of the chuck 20a of the coating unit QAa faces the wafer W. Next, the lift pins are raised and lowered and the transfer device is removed from the housing 10b, and the wafer W is transferred from the transfer device to the chuck 20a of the coating unit QAa. Furthermore, suction is applied through the suction holes (not shown) of the chuck 20a of the coating unit QAa, and the wafer W is suction-held by the chuck 20a. Thereafter, the loading / unloading port 11a corresponding to the coating unit QA is closed. Next, the housing 10a is rotated around the rotation axis J, and the positions of the loading / unloading port 11b corresponding to the coating unit QBa and the transport device are adjusted, and then the wafer W is adsorbed and held by the chuck 20a of the coating unit QBa in the same manner as the chuck 20a of the coating unit QAa. Similarly, the wafer W is held by suction on the chucks 20a of the coating units QCa and QDa.

[0068] (Step S22) Next, the coating liquid is supplied to form a coating liquid film on the processing surface W1 of the wafer W. Specifically, the coating liquid is supplied to the processing surface of each wafer W by spin coating, and a coating liquid film is formed so as to cover the entire processing surface W1, and the film thickness of the entire coating liquid film, i.e., the entire surface, is adjusted. do.

[0069] Specifically, similarly to step S12, a coating liquid film F1 is formed on the processing surface W1 of the wafer W by each coating unit Qa.

[0070] (Step S23) Next, the angle of the chuck 20a is changed so that the processing surface W1 of the wafer W is parallel to the vertical direction, i.e., parallel to the rotation axis J and faces the direction of the rotation axis J, and then the wafer W is rotated around the rotation axis J, and centrifugal force is applied in a direction pressing the wafer W against the coating liquid. Specifically, the angle changing mechanism 200 changes the angle of the chuck 20a so that the holding surface of the chuck 20a, which was horizontal while holding the wafer W, becomes parallel to the vertical direction and faces the direction of the rotation axis J. Thereafter, the rotation mechanism 31 rotates the housing 10b, in which each chuck 20a suction-holds the wafer W, about the rotation axis J. As a result, the wafer W, whose processing surface W1 is parallel to the vertical direction, i.e., parallel to the rotation axis J and facing the direction of the rotation axis J, is rotated about the rotation axis J, and a centrifugal force acts on the coating liquid film F1 in a direction pressing it against the wafer W. With this centrifugal force acting, the fluidity of the coating liquid constituting the coating liquid film F1 is reduced, that is, the coating liquid film F1 is dried.

[0071] Furthermore, in step S23, hot air may be supplied by the FFU 40 while the wafer W held by the chuck 20a is being rotated by the rotation mechanism 31. In addition to or instead of the supply of hot air by the FFU 40, the heater 100 may heat the coating liquid film F1.

[0072] In step S23, the wafer W held by the chuck 20a is rotated by the rotation mechanism 31 until the fluidity of the coating liquid decreases to such an extent that deformation of the coating liquid film F1 does not occur due to the surface tension T even when the rotation is stopped and centrifugal force is not applied.

[0073] (Step S24) Next, the angle of the chuck 20a is changed so that the holding surface of the chuck 20a is horizontal and perpendicular to the rotation axis J, and then normal spin drying is performed. Conventional spin drying provides greater in-plane drying uniformity than hot air supply, so after the fluidity of the coating liquid has decreased to a certain extent, as in this example, conventional spin drying can be performed to improve film thickness uniformity when the fluidity of the coating liquid is reduced to a desired range.

[0074] (Step S25) Thereafter, the wafer W is unloaded from the housing 10b of the wafer processing apparatus 1b by reversing the procedure of step S22.

[0075] (Step S26) Then, the wafers W processed in the wafer processing apparatus 1b are heated and further dried in an apparatus external to the wafer processing apparatus 1b. Specifically, each wafer W processed in the wafer processing apparatus 1b is heated in an apparatus external to the wafer processing apparatus 1b, and the solvent in the coating liquid film F1 is further removed. This completes a series of film formation processes.

[0076] According to this embodiment as well, when the coating liquid film F1 is conformally formed on the processing surface W1 having an uneven pattern, the uniformity of the thickness of the coating liquid film F1 can be improved.

[0077] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0078] 1, 1a, 1b Wafer processing equipment 20, 20a, 20A, 20B, 20C, 20D chuck 31, 31a, 31b Rotation mechanism F1 coating liquid film J, Ja rotation axis P uneven pattern W wafer W1 treated surface

Claims

1. a holder that holds the substrate so that the processing surface on which the pattern is formed is parallel to a predetermined direction; a coating liquid supply unit that supplies a coating liquid to the processing surface of the substrate; a first rotation mechanism that rotates the holder around a first rotation axis that penetrates the processing surface of the substrate; a cup that receives and recovers liquid from the substrate held by the holder rotated by the first rotation mechanism; a housing in which the holding unit, the coating liquid supply unit, and the cup are provided; a second rotation mechanism that rotates the housing about a second rotation axis that extends in the predetermined direction perpendicular to the first rotation axis; a control unit; The control unit supplying the coating liquid from the coating liquid supply unit to the processing surface of the substrate held by the holding unit and rotating the holding unit around the first rotation axis to form a coating liquid film on the processing surface of the substrate; Then, with the processing surface of the substrate facing the direction of the second rotation axis and parallel to the predetermined direction, the housing is rotated around the second rotation axis, thereby applying centrifugal force to the coating liquid in a direction pressing it against the substrate.

2. 2. The substrate processing apparatus according to claim 1, wherein the rotation speed of the housing in the step of applying the centrifugal force is a rotation speed at which the centrifugal force prevents the coating liquid from moving parallel to the substrate due to surface tension of the coating liquid.

3. 3. The substrate processing apparatus according to claim 2, wherein the viscosity of the coating liquid is 30 cP to 1000 cP.

4. 4. The substrate processing apparatus according to claim 1, wherein a radius of rotation of said holder caused by rotation of said housing about said second rotation axis is 170 mm or more.

5. 5. The substrate processing apparatus according to claim 1, further comprising a heating mechanism that heats the coating liquid film on the substrate held by the holding portion while the housing rotates around the second rotation axis.

6. 6. The substrate processing apparatus according to claim 1, wherein the coating liquid film has a thickness of 5 μm or more before the centrifugal force is applied.

7. A film forming method using a substrate processing apparatus, comprising: The substrate processing apparatus includes: a holder that holds the substrate so that the processing surface on which the pattern is formed is parallel to a predetermined direction; a coating liquid supply unit that supplies a coating liquid to the processing surface of the substrate; a first rotation mechanism that rotates the holder around a first rotation axis that passes through the processing surface of the substrate held by the holder; a cup that receives and recovers liquid from the substrate held by the holder rotated by the first rotation mechanism; a housing in which the holding unit, the coating liquid supply unit, and the cup are provided; a second rotation mechanism that rotates the housing about a second rotation axis that extends in the predetermined direction perpendicular to the first rotation axis, The film forming method includes: supplying the coating liquid from the coating liquid supply unit to the processing surface of the substrate held by the holding unit and rotating the holding unit around the first rotation axis to form a coating liquid film on the processing surface of the substrate; Then, with the processing surface of the substrate parallel to the predetermined direction and facing the direction of the second rotation axis, the housing is rotated around the second rotation axis, thereby applying centrifugal force to the coating liquid in a direction pressing it against the substrate.

8. The film forming method according to claim 7 , wherein the coating liquid film has a thickness of 5 μm or more before the step of applying the centrifugal force.

9. 9. The film forming method according to claim 7, wherein the centrifugal force is 50 G or more in the step of applying the centrifugal force.

10. 10. The film forming method according to claim 7, wherein the coating liquid film is heated in the step of applying centrifugal force.

11. The film forming method according to any one of claims 7 to 10, further comprising a step of drying the coating liquid film after the step of applying centrifugal force.

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