SUBSTRATE PROCESSING APPARATUS, SUBSTRATE PROCESSING METHOD, AND STORAGE MEDIUM

Abstract

To provide a resist film forming apparatus capable of preventing, without increasing the exhaust pressure, a mist-like processing liquid from leaking out of a liquid receiving portion.SOLUTION: A liquid receiving portion 14 includes, in an upper part, a hole through which a substrate W held by a holding and rotating portion passes and which serves as an opening to the upper space so that an inside is exhausted. Substrate processing includes: supply processing of supplying a film-forming treatment liquid to the substrate and rotating the substrate; and drying processing of rotating the substrate after the supply processing, and drying the film-forming treatment liquid on the substrate. A resist film forming apparatus includes an annular ring member 60 configured to be movable to approach toward or to retract from an upper surface of the liquid receiving portion. A control unit is installed on the upper surface of the liquid receiving portion such that the ring member closes a periphery of the hole of the liquid receiving portion during the supply processing, and performs control such that the ring member is retracted from the upper surface of the liquid receiving portion during the drying processing.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a substrate processing apparatus, a substrate processing method, and a storage medium. [Background technology]

[0002] Patent Document 1 discloses a coating device for forming a coating film on a substrate. In this device, while exhausting the processing atmosphere in which the substrate is placed, resist liquid diluted with a solvent is discharged onto the surface of the substrate rotating about a vertical axis to form a coating film made of the resist liquid. Next, exhaust of the processing atmosphere is stopped, and in a state in which a solvent atmosphere generated in the resist liquid shaken off from the outer edge of the substrate is formed on the outer periphery of the substrate, the substrate is rotated about the vertical axis and the resist liquid on the surface of the substrate is dried. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6206316 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology disclosed herein prevents film forming processing liquid that has been spun off from a rotating substrate and hits the liquid receiving portion, turning into a mist, from leaking outside the liquid receiving portion, without increasing the exhaust pressure used to evacuate the inside of the liquid receiving portion. [Means for solving the problem]

[0005] One aspect of the present disclosure is a substrate processing apparatus for processing a substrate, the substrate processing apparatus comprising: a holding and rotating unit for holding and rotating a substrate; a supply unit for supplying a film formation processing liquid to the substrate held by the holding and rotating unit; a liquid receiving unit for receiving the film formation processing liquid spun off from the substrate by the rotation by the holding and rotating unit; and a control unit for controlling substrate processing, the liquid receiving unit having a hole at an upper portion through which the substrate held by the holding and rotating unit passes and which serves as an opening to an upper space, and the inside is evacuated, the substrate processing includes a supply process for supplying the film formation processing liquid to the substrate and rotating the substrate, and a drying process for rotating the substrate after the supply process to dry the film formation processing liquid on the substrate, the substrate processing apparatus further comprising an annular ring member configured to be freely advanced and retreated relative to an upper surface of the liquid receiving unit, the control unit controls the annular member to be placed on the upper surface of the liquid receiving unit so as to close the periphery of the hole in the liquid receiving unit during the supply process, and to retract the annular member from the upper surface of the liquid receiving unit during the drying process. The surface of the annular member facing the substrate held by the holding and rotating part is an inclined surface that is gradually lowered from the outer periphery toward the inner periphery. . Effect of the Invention

[0006] According to the present disclosure, it is possible to prevent film forming processing liquid that has been spun off from a rotating substrate and collided with a liquid receiving portion and turned into a mist from leaking outside the liquid receiving portion without increasing the exhaust pressure used to evacuate the inside of the liquid receiving portion. [Brief description of the drawings]

[0007] [Figure 1] 1 is a vertical sectional view showing a schematic outline of the configuration of a resist film forming apparatus as a substrate processing apparatus according to an embodiment of the present invention; [Diagram 2] 1 is a plan view showing a schematic outline of a configuration of a resist film forming apparatus as a substrate processing apparatus according to an embodiment of the present invention; [Diagram 3] 1 is a partially enlarged cross-sectional view showing a schematic configuration of a resist film forming apparatus as a substrate processing apparatus according to an embodiment of the present invention; [Figure 4] 11 is an explanatory diagram showing the movement of mist particles of a film forming processing liquid in a conventional substrate processing apparatus. [Diagram 5]5 is an explanatory diagram showing the movement of mist particles of a film forming processing liquid in the substrate processing apparatus according to the present embodiment. FIG. [Figure 6] 11 is a graph showing a relationship between the exhaust pressure by the exhaust mechanism and the number of particles of the mist-like film forming liquid detected outside the cup. [Figure 7] 13A and 13B are diagrams illustrating other examples of the circular ring member. [Figure 8] 13A and 13B are diagrams illustrating other examples of the circular ring member. [Figure 9] 13A and 13B are diagrams illustrating other examples of the circular ring member. [Figure 10] 13A and 13B are diagrams illustrating another example of the circular ring member. [Figure 11] FIG. 13 is a diagram showing another example of the cup. [Figure 12] FIG. 13 is a diagram showing another example of the cup. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] In the manufacturing process of semiconductor devices and the like, there is a process of supplying a film-forming liquid such as a coating liquid onto a substrate such as a semiconductor wafer (hereinafter referred to as a "wafer") to form a desired film such as a resist film. For this process, a method known as spin coating is widely used in which the coating liquid is supplied to the substrate while the substrate is rotating, and the coating liquid is applied to the entire substrate by centrifugal force (see Patent Document 1). In addition to the coating liquid, a pre-wet liquid may also be used as the film-forming liquid, which is supplied to the substrate before the coating liquid is applied.

[0009] A substrate processing apparatus used for spin coating includes a holding and rotating unit that holds and rotates a substrate, a supply unit that supplies a film-forming processing liquid to the substrate held by the holding and rotating unit, and a liquid receiving unit that receives the film-forming processing liquid that has been shaken off from the substrate by the rotation by the holding and rotating unit. An opening that serves as an opening to the space above is provided at the top of the liquid receiving unit, and the substrate is placed on and held by the holding and rotating unit through this opening. The inside of the liquid receiving unit is evacuated for the purpose of generating a desired airflow on the surface of the substrate held by the holding and rotating unit.

[0010] However, the film forming processing liquid that is shaken off from the substrate by the rotation collides with the liquid receiving portion and turns into a mist, and the mist of the film forming processing liquid may leak to the outside of the liquid receiving portion through the opening hole. If the leaked mist of the film forming processing liquid adheres to the substrate outside the liquid receiving portion, it may cause defects, and therefore it is necessary to prevent such leakage. The above-mentioned leakage can be prevented by increasing the exhaust pressure for exhausting the inside of the liquid receiving portion, but increasing the exhaust pressure increases the running costs.

[0011] Therefore, the technology disclosed herein prevents the film forming processing liquid that has been spun off from the rotating substrate and hits the liquid receiving portion, turning into a mist, from leaking outside the liquid receiving portion, without increasing the exhaust pressure used to evacuate the inside of the liquid receiving portion.

[0012] Hereinafter, a substrate processing apparatus and a substrate processing 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 denoted by the same reference numerals, and duplicated description will be omitted.

[0013] 1 to 3 are a longitudinal sectional view, a plan view, and a partially enlarged sectional view, respectively, which are schematic diagrams illustrating an outline of the configuration of a resist film forming apparatus 1 as a substrate processing apparatus according to this embodiment.

[0014] The resist film forming apparatus 1 includes a spin chuck 11 as a holding and rotating unit. The spin chuck 11 holds a wafer W, specifically, by vacuum-adsorbing the center of the back surface of a circular wafer W having a diameter of, for example, 300 mm, the wafer W horizontally. The spin chuck 11 is connected to a rotation mechanism 12 having an actuator such as a motor. When the rotation mechanism 12 rotates the spin chuck 11 around a vertical axis, the wafer W held by the spin chuck 11 also rotates in the same manner.

[0015] A cup 14 serving as a liquid receiving section is provided to surround the wafer W held by the spin chuck 11. The cup 14 can receive and recover film forming liquid, such as a coating liquid or a pre-wet liquid, that is shaken off from the wafer W by the rotation of the spin chuck 11.

[0016] A drain port 15 is provided at the bottom of the cup 14. An exhaust pipe 16 is also provided at the bottom of the cup 14, and an exhaust mechanism 30 having an exhaust pump and the like is connected to the exhaust pipe 16. The inside of the cup 14 is evacuated by the exhaust mechanism 30 via the exhaust pipe 16 during processing of the wafer W. By exhausting the inside of the cup 14, the periphery of the wafer W and the surface of the wafer W are evacuated.

[0017] Furthermore, the cup 14 has a hole 17 at its upper portion, which is circular in plan view and concentric with the spin chuck 11. This hole 17 serves as an opening to the space above in the cup 14. The wafer W passes through this opening, that is, the hole 17, to be placed on and held by the spin chuck 11.

[0018] The cup 14 also has a side wall 18 against which the processing liquid spun out laterally from the wafer W due to the rotation of the spin chuck 11 collides. The side wall 18 includes a cylindrical peripheral wall 18a extending in the vertical direction and an inclined wall 18b extending inwardly and upwardly all around the circumference from the upper end of the peripheral wall 18a. The inclined wall 18b is located to the side of the wafer W held by the spin chuck 11, and the processing liquid spun out laterally from the wafer W collides against the inclined wall 18b.

[0019] Furthermore, the cup 14 has a top wall 19 that is annular in plan view and extends horizontally inward from the side wall 18 all the way around to form the hole 17. In the example shown in the figure, the top wall 19 is connected to the upper end of the inclined wall 18b. The top wall 19 may be shaped to extend inward and upward from the side wall 18 all the way around at an angle closer to horizontal than the side wall 18.

[0020] A protrusion 20 is provided on the inner circumferential edge of the top wall 19, which is annular in plan view, so as to extend vertically upward along the entire circumference of the inner circumferential edge.

[0021] An annular guide member 21 having inner and outer slopes 21a, 21b is disposed around the spin chuck 11 inside the cup 14. A bevel cleaning nozzle 24 is provided at the top of the guide member 21. The bevel cleaning nozzle 24 ejects a solvent for the resist liquid onto the peripheral portion of the rear surface of the wafer W to clean the bevel portion of the wafer W. The bevel cleaning nozzle 24 is connected to a solvent supply mechanism (not shown). This solvent supply mechanism includes a pump, a valve, etc., and supplies the solvent for the resist liquid to the bevel cleaning nozzle 24.

[0022] Lift pins 31 are arranged around the spin chuck 11. These lift pins 31 can be raised and lowered in the vertical direction by a lift mechanism 32 having an actuator such as a cylinder, and can support and raise and lower the wafer W. This allows the wafer W to be transferred between the spin chuck 11 and a wafer transfer mechanism (not shown).

[0023] A fan filter unit (FFU) 31 serving as an airflow forming unit is provided above the hole 17 of the cup 14, and forms a downward airflow of clean air as clean gas, and supplies the air into the cup 14 through the hole 17. The clean air supplied to the wafer W in the cup 14 is exhausted to the outside of the cup 14 by the exhaust mechanism 30.

[0024] Furthermore, the resist film forming apparatus 1 includes a resist liquid supply nozzle 41 and a solvent supply nozzle 51 as supply units for supplying a film forming liquid to the wafer W held by the spin chuck 11, as shown in FIGS.

[0025] The resist liquid supply nozzle 41 discharges the resist liquid as a coating liquid, for example, vertically downward. The resist liquid supply nozzle 41 is connected to a resist supply mechanism 42. The resist supply mechanism 42 includes a pump, a valve, and the like, and supplies the resist liquid to the resist liquid supply nozzle 41.

[0026] 2, the resist liquid supply nozzle 41 is supported at the tip of an arm 43, and the base end side of the arm 43 is connected to a moving mechanism 44. The moving mechanism 44 is movable in the direction of the reciprocating arrow in the figure along a guide rail 45 by an actuator such as a motor. The resist liquid supply nozzle 41 supported by the arm 43 is also movable in the vertical direction. The resist liquid supply nozzle 41 can wait in a waiting section 46 arranged outside the cup 14.

[0027] The solvent supply nozzle 51 discharges an organic solvent as a pre-wet liquid, for example, vertically downward. The solvent supply nozzle 51 is connected to a solvent supply mechanism 52. The solvent supply mechanism 52 includes a pump, a valve, and the like, and supplies the organic solvent to the solvent supply nozzle 51.

[0028] The solvent supply nozzle 51 is supported at the tip of an arm 53, and the base end side of the arm 53 is connected to a moving mechanism 54. The moving mechanism 54 is movable in the direction of the reciprocating arrow in the figure along a guide rail 55 by an actuator such as a motor. The solvent supply nozzle 51 supported by the arm 53 is also movable in the vertical direction. The solvent supply nozzle 51 can wait in a waiting section 56 arranged outside the cup 14.

[0029] 1 and 2, the resist film forming apparatus 1 is provided with a circular member 60 having a circular shape in a plan view.

[0030] In a conventional resist film forming apparatus not having an annular member 60, unless the exhaust pressure for exhausting the inside of the cup 14 is high, the film forming processing liquid that is thrown off from the wafer W by rotation and collides with the inner surface of the inclined wall 18b of the cup 14, turning into a mist, may leak out of the cup 14 through the hole 17. As a result of extensive simulations conducted by the present inventors regarding this leakage, the following points were found. That is, it was found that, even in the above-mentioned conventional resist film forming apparatus, if the diameter of the hole 17 in the cup 14 is made smaller than that of the wafer W, for example, 240 mm, it is possible to prevent the mist-like film forming liquid from leaking out of the cup 14 without increasing the exhaust pressure. However, in reality, the diameter of the hole 17 in the cup 14 cannot be made smaller than that of the wafer W. This is because the wafer W cannot be placed on the spin chuck 11 from outside the cup 14 through the hole 17.

[0031] Therefore, in this embodiment, the annular member 60 is provided as described above. The circular member 60 has a hole 60a in its center, the hole 60a being smaller in diameter than the hole 17 of the cup 14. The circular member 60 is connected to a lifting mechanism 62, which serves as a retracting mechanism and has an actuator such as a cylinder, via a support member 61. The lifting mechanism 62 allows the circular member 60 to be raised and lowered relative to the upper surface of the cup 14, specifically, between a first position shown by a dashed line in FIG. 1 and a second position shown by a solid line in FIG. 1. The first position is a position where the circular member 60 is installed on the upper surface of the cup 14 so as to cover the entire periphery of the hole 17 of the cup 14. The second position is a position above the first position, and is a position where the circular member 60 does not interfere with the wafer W when the wafer W is transferred between a wafer transfer mechanism (not shown) and the spin chuck 11 via the lifting pins 31. In this example, the annular member 60 is concentric with the hole 17 of the cup 14 and the spin chuck 11 (and the wafer W held by it) whether in the first position or the second position.

[0032] When the mist-like film forming liquid is generated, the annular member 60 is placed on the upper surface 14a of the cup 14 (specifically, on the upper surface of the top wall 19) as shown in FIG. 3, that is, placed in the first position (lower position) described above. When placed in the first position, the annular member 60 closes the periphery of the hole 17 of the cup 14 and is extended from the inner peripheral end of the top wall 19 that forms the hole 17 to the inner peripheral side. In other words, by placing the annular member 60 in the first position (lower position), the opening to the upper space of the cup 14 is reduced in diameter from the hole 17 of the cup 14 to the hole 60a of the annular member 60, which has a smaller diameter than the hole 17. Therefore, a cup 14 with a smaller diameter of the hole 17 can be realized in a pseudo manner.

[0033] On the other hand, the circular member 60 is disposed at the second position (upper position) described above when the wafer W is transferred between a wafer transfer mechanism (not shown) and the spin chuck 11 via the lift pins 31. Therefore, there is no interference between the circular member 60 and the wafer W when the wafer W is transferred. The circular member 60 is also disposed at the second position (upper position) when no mist-like film forming liquid is generated other than when the wafer is transferred.

[0034] Further, the annular member 60 has a peripheral cover portion 100 and a connecting portion 110, as shown in FIG.

[0035] The peripheral cover part 100 is formed in a circular plate shape and is arranged so as to be horizontal. The outer diameter of the peripheral cover part 100 is slightly smaller than the diameter of the hole 17 of the cup 14, and the inner diameter of the peripheral cover part 100 is smaller than the diameter of the wafer W, for example, 140 mm to 260 mm. The peripheral cover part 100 is arranged so as to be concentric with the spin chuck 11 (the wafer W held by the spin chuck 11) and the hole 17 of the cup 14 in a plan view. When the circular member 60 is in the first position described above, the peripheral cover part 100 covers the entire periphery of the hole 17 of the cup 14, and is extended from the inner peripheral end of the top wall 19 that forms the hole 17 toward the inner peripheral side. The lower surface of the peripheral cover part 100 in this example is horizontal.

[0036] The connecting portion 110 connects the peripheral cover portion 100 and the support member 61. The connecting portion 110 is formed so as to extend from the outer peripheral end of the peripheral cover portion 100 to the outside in a plan view over the entire circumference. The connecting portion 110 has a shape that follows the inner peripheral portion of the upper portion of the cup 14 when the annular member 60 is in the first position described above (specifically, a shape that follows the inner peripheral upper surface of the top wall 19 and the outer peripheral surface, upper surface, and inner peripheral surface of the protruding portion 20). Specifically, for example, the connecting portion 110 has a curved surface 110a that is curved in accordance with the shape of the inner peripheral portion of the upper portion of the cup 14, and the protruding portion 20 of the cup 14 can be received in the recess formed by the curved surface 110a. Since the connecting portion 110 is configured as described above, the gap between the annular member 60 and the cup 14 is made small when the annular member 60 is in the first position described above.

[0037] Furthermore, the resist film forming apparatus 1 is provided with a control unit U. The control unit U is, for example, a computer equipped with a CPU, a memory, and the like, and has a program storage unit (not shown). A program for controlling the processing of the wafer W in the resist film forming apparatus 1 is stored in the program storage unit. The stored program incorporates commands (each step) for transmitting control signals to each unit of the resist film forming apparatus 1 to control its operation. For example, the control unit U controls the change in the number of rotations of the spin chuck 11 by the rotation mechanism 12, i.e., the number of rotations (rotation speed) of the wafer W, and the movement of the resist liquid supply nozzle 41 and the solvent supply nozzle 51. The control unit U also controls the supply and stop of the resist liquid from the resist supply mechanism 42 to the resist liquid supply nozzle 41, the supply and stop of the solvent from the solvent supply mechanism 52 to the solvent supply nozzle 51, and the supply and stop of the solvent of the resist liquid from the solvent supply mechanism (not shown) to the bevel cleaning nozzle 24. Furthermore, the control unit U also controls the lifting and lowering of the annular member 60, the amount of exhaust by the exhaust mechanism 30, and the like. The above-mentioned program may be recorded in a non-transitory computer-readable storage medium and installed from the storage medium to the control unit U. A part or all of the program may be realized by dedicated hardware (circuit board).

[0038] Next, an example of a resist film forming method using the resist film forming apparatus 1 will be described.

[0039] (Placement of wafer W and suction holding) First, the wafer W is placed on the spin chuck 11 and held by suction. Specifically, a wafer transfer device (not shown) holding the wafer W is inserted into the resist film forming apparatus 1, and the wafer W is transferred between the wafer transfer device and the spin chuck 11 via the lift pins 31, thereby being placed on the spin chuck 11. Thereafter, the wafer W is held by suction on the spin chuck 11. In this step, the circular member 60 is located at the second position (raised position) described above. The second position (raised position) is a position where the wafer W and the wafer transfer device do not interfere with the circular member 60 when transferring the wafer W described above, and where the circular member 60 does not interfere with the FFU 31. The second position (raised position) is, for example, a position 40 to 70 mm from the wafer W held by the spin chuck 11.

[0040] (Pre-wet) Next, a pre-wet process is performed on the wafer W. Specifically, the solvent supply nozzle 51 is moved above the center of the wafer W held by the spin chuck 11, and an organic solvent is supplied onto the wafer W from the solvent supply nozzle 51. At the same time, the wafer W is rotated at a high rotation speed, for example, 2000 rpm or more. In this example, the rotation speed of the wafer W is 2000 rpm. In addition, in this process, the exhaust pressure for exhausting the inside of the cup 14 is, for example, 21 Pa.

[0041] During the pre-wet process, the rotation speed of the wafer W is high as described above, so that the pre-wet liquid shaken off from the wafer W collides with the cup 14, generating a mist of pre-wet liquid. Therefore, in this process, the annular member 60 is positioned at the first position (lower position) described above. This reduces the opening to the space above the cup 14, preventing the mist of pre-wet liquid from leaking through the opening.

[0042] (resist liquid film formation) Next, a resist liquid film forming process is performed to form a liquid film of resist liquid on the wafer W. Specifically, after the solvent supply nozzle 51 is retracted, the resist liquid supply nozzle 41 is moved above the center of the wafer W held by the spin chuck 11, and the resist liquid is supplied onto the wafer W from the resist liquid supply nozzle 41. At the same time, the wafer W is rotated at a high rotation speed, for example, 2000 rpm or more. As a result, a liquid film of resist liquid covering the entire upper surface of the wafer W is formed. Note that the rotation speed of the wafer W is 2500 rpm in this example. Also, in this process, the exhaust pressure for exhausting the inside of the cup 14 is, for example, 21 Pa.

[0043] During the resist liquid film forming process, the rotation speed of the wafer W is high as described above, so the resist liquid shaken off from the wafer W collides with the cup 14, generating mist-like resist liquid. Therefore, in this process, following the process of performing the pre-wet process, the annular member 60 is placed in the first position (lower position). This reduces the diameter of the opening relative to the space above the cup 14, making it difficult for the mist-like resist liquid to leak through the opening.

[0044] (Dry) Next, a process is performed on the wafer W to dry the liquid film of the resist liquid and form a resist film on the wafer W. Specifically, the resist liquid supply nozzle 41 is retracted, and the wafer W is rotated at a low rotation speed, for example, 1500 rpm or less. As a result, the liquid film of the resist liquid on the wafer is dried while shaking off excess resist liquid, and a resist film is formed. In this example, the rotation speed of the wafer W is 1500 rpm. Also, in this process, the exhaust pressure for exhausting the inside of the cup 14 is, for example, 21 Pa. In other words, the exhaust pressure is the same in the pre-wet process and the resist liquid film forming process and the drying process.

[0045] During the drying process, since the rotation speed of the wafer W is low as described above, the resist liquid shaken off from the wafer W does not collide with the cup 14, and therefore no mist of the resist liquid is generated. Also, during the drying process, the airflow formed on the surface of the wafer W by exhausting air from the FFU 31 affects the shape of the resist film. Therefore, if the annular member 60 is placed in the first position (lower position) described above during the drying process, it will adversely affect the film thickness distribution of the resist film, such as making only the peripheral side of the resist film thicker. Therefore, in this step, the position of the annular member 60 is placed in the second position (upper position) described above.

[0046] (Bevel cleaning) Thereafter, a cleaning process is performed on the bevel portion of the wafer W. Specifically, the bevel cleaning nozzle 24 supplies a solvent of the resist liquid to the peripheral portion of the rear surface of the wafer W. At the same time, the wafer W is rotated. This removes unnecessary resist film from the peripheral side of the rear surface of the wafer W and the bevel portion.

[0047] (Export) Then, the wafer W is unloaded from the resist film forming apparatus 1 by performing the steps of placing and suction-holding the wafer W in reverse order.

[0048] As described above, in this embodiment, the resist film forming apparatus 1 includes the annular member 60 that is configured to be able to rise and fall relative to the upper surface of the cup 14.

[0049] In the supply process (i.e., the above-mentioned pre-wet process and resist liquid film forming process) in which the resist film forming apparatus 1 supplies the film forming process liquid to the wafer W and rotates the wafer W, the rotation speed of the wafer W is high because the film forming process liquid needs to be spread over the entire upper surface of the wafer W. Therefore, in the above-mentioned supply process, the film forming process liquid shaken off from the wafer W may collide with the cup 14 and become mist-like.

[0050] Unlike the present embodiment, when the annular member 60 is not provided, as shown in FIG. 4, the distance from the position where the film forming processing liquid collides in the cup 14, that is, the position where the mist-like film forming processing liquid is generated, to the edge of the hole 17, which is the opening to the space above the cup 14 in this case, is short. In addition, since the gap between the lower surface of the ceiling wall 19 and the surface of the wafer W is large, the flow rate of the clean air from the FFU 31 passing through the gap tends to be slow. Therefore, if the exhaust pressure by the exhaust mechanism 30 is not increased during the supply process, the mist particles M of the film forming processing liquid may reach the edge of the opening (i.e., the edge of the hole 17) without being exhausted together with the gas exhausted from the inside of the cup 14. Therefore, the mist-like film forming processing liquid may leak out to the outside of the cup 14 through the opening, that is, the hole 17.

[0051] In contrast, in this embodiment, the annular member 60 is provided, and during the supply process, the annular member 60 is set to the first position (lower position). That is, during the supply process, the annular member 60 is placed on the upper surface 14a of the cup 14 so as to close the periphery of the hole 17 of the cup 14. Therefore, during the supply process, the opening to the space above the cup 14 becomes the hole 60a formed by the annular member 60, which is smaller than the hole 17. As a result, as shown in FIG. 5, the distance from the position where the mist of the film forming processing liquid is generated to the edge of the opening to the space above the cup 14 (i.e., the edge of the hole 60a) becomes longer. In addition, since the gap between the lower surface of the annular member 60 (specifically, the lower surface of the peripheral cover part 100) and the surface of the wafer W is small, the flow rate of the clean air from the FFU 31 passing through the gap tends to be fast. Therefore, even if the exhaust pressure by the exhaust mechanism 30 is not increased during the supply process, the mist particles M of the film-forming processing liquid are discharged together with the gas discharged from the inside of the cup 14 without reaching the edge of the opening (i.e., the edge of the hole 60a). Therefore, according to this embodiment, even if the exhaust pressure by the exhaust mechanism 30 (i.e., the exhaust pressure for exhausting the inside of the cup 14) is not increased, the mist-like film-forming processing liquid does not leak out of the cup 14 during the supply process. In addition, if the exhaust pressure by the exhaust mechanism 30 during the supply process is increased, it is possible to more reliably prevent the mist-like film-forming processing liquid from leaking out of the cup 14 during the supply process. In other words, according to this embodiment, it is possible to efficiently prevent the mist-like film-forming processing liquid from leaking out of the cup 14 during the supply process.

[0052] Furthermore, in this embodiment, during the drying process, the circular member 60 is in the second position (upper position) and is separated from the upper surface 14a of the cup 14. Therefore, the circular member 60 does not adversely affect the film thickness distribution of the resist film on the wafer W.

[0053] If a disk member that is circular in plan view and has a diameter equal to the outer diameter of the ring member 60 is used instead of the ring member 60, clean air from the FFU 31 is not introduced into the cup 14 during the resist liquid film forming process and the like. As a result, the thickness of the resist film becomes non-uniform within the surface. For this reason, the ring member 60 is used instead of the disk member described above.

[0054] The results of an actual test conducted by the inventors on the annular member 60 are shown in the graph of Fig. 6. In the test conducted by the inventors, both the pre-wet process and the resist liquid film forming process were performed. The rotation speed of the wafer W during the pre-wet process and the resist liquid film forming process was set to 4000 rpm. In the graph of Fig. 6, the horizontal axis indicates the exhaust pressure by the exhaust mechanism 30, and the vertical axis indicates the number of particles of the mist-like film forming process liquid (both the organic solvent and the resist liquid) detected outside the cup 14.

[0055] 6, when the circular member 60 was not present, mist particles of the film forming processing liquid were detected outside the cup 14 even when the exhaust pressure was set high at 60 Pa. According to tests conducted by the present inventors, in order to prevent mist particles of the film forming processing liquid from being detected outside the cup 14 when the circular member 60 was not present, an extremely high exhaust pressure of 65 Pa or more was required.

[0056] In contrast, when a circular ring member 60 having an inner diameter of 240 mm is provided and the circular ring member 60 is placed in the first position (lower position) during the pre-wet process and the resist liquid film formation process, no mist particles of the film forming liquid are detected outside the cup 14 even when the exhaust pressure is as low as 15 Pa or 10 Pa.

[0057] When the annular member 60 having an inner diameter of 260 mm was provided, mist particles of the film forming processing liquid were not detected outside the cup 14 even when the exhaust pressure was low at 25 Pa to 30 Pa. When the annular member 60 having an inner diameter of 280 mm was provided, a relatively high exhaust pressure of 35 Pa or more was required to prevent mist particles of the film forming processing liquid from being detected outside the cup 14. Therefore, the inner diameter of the circular member 60 is preferably 260 mm or less.

[0058] Furthermore, according to tests conducted by the present inventors, even when the inner diameter of the annular member 60 is smaller than 240 mm, mist-like film forming liquid was not detected outside the cup 14, similar to when the inner diameter is 240 mm, even at low exhaust pressure. However, when the annular member 60 having an inner diameter smaller than 140 mm is provided, the thickness distribution of the resist film formed on the wafer W after the drying process may deteriorate. This is considered to be because clean air from the FFU 31 cannot be sufficiently taken into the cup 14 during the drying process, and a desired airflow cannot be formed on the upper surface of the wafer W. Therefore, the inner diameter of the circular member 60 is preferably 140 mm or more.

[0059] The material of the circular member 60 may be, for example, a resin material. By using a resin material for the circular member 60, a temperature drop in the circular member 60 caused by evaporation of the mist-like film forming solution during repeated processing can be suppressed, and condensation on the circular member 60 can be prevented, compared to when the circular member 60 is made of a metal material.

[0060] In this embodiment, the connecting portion 110 of the ring member 60 has a shape that fits along the inner circumferential portion of the upper portion of the cup 14 when the ring member 60 is in the first position (lower position) described above (specifically, a shape that fits along the inner circumferential upper surface of the top wall 19 and the outer circumferential surface, upper surface, and inner circumferential surface of the protrusion 20). This makes the gap between the ring member 60 and the cup 14 small when the ring member 60 is in the first position (lower position) described above. If the gap is small in this way, it is possible to prevent the mist-like film forming processing liquid from leaking out of the cup 14 through the gap. In order to more reliably prevent leakage through the gap, it is preferable that the ring member 60 and the cup 14 are in close contact with each other when the ring member 60 is in the first position (lower position) described above. However, if they are in close contact with each other in this way, there is a risk that the ring member 60 will rub against the cup 14 when it is raised and lowered, causing dust.

[0061] In the above example, the circular member 60 is advanced and retreated by raising and lowering it relative to the first position (lower position) described above (i.e., relative to the upper surface of the cup 14). That is, in the above example, the direction in which the circular member 60 advances and retreats relative to the first position described above is the vertical direction. The above-mentioned direction of advance and retreat may be approximately horizontal. If the direction of advance and retreat is not vertical and the position to which the circular member 60 is retreated from the first position described above is a position that does not prevent clean gas from the FFU 31 from being prevented from moving toward the cup 14 by the circular member 60, the inner diameter of the circular member 60 may be less than 140 mm.

[0062] 7 to 9 are diagrams showing other examples of the circular ring member. In the above example, the lower surface of the annular member 60 (specifically, the lower surface 100a of the peripheral cover portion 100), i.e., the surface facing the wafer W held by the spin chuck 11, is horizontal. The shape of the lower surface of the annular member 60 is not limited to this. For example, like the lower surface 201a of the peripheral cover portion 201 of the annular member 200 in FIG. 7, it may be an inclined surface that is gradually lower from the outer periphery side (the outer periphery end in the example of FIG. 7) toward the inner periphery end. This reduces the gap between the annular member 200 and the wafer W when the annular member 200 is in the first position (lower position) described above. As a result, the flow rate of the clean air supplied from the FFU 31 when it flows through the gap is increased. This makes it possible to more reliably prevent the mist-like film forming processing liquid from reaching the hole 60a formed by the annular member 200 and leaking out of the cup 14 through the hole 60a.

[0063] 8, the annular member 210 may have a convex portion 212 formed in a concentric annular shape with the annular member 210 on the inner circumferential side of the lower surface 211a of the peripheral cover portion 211 and protruding toward the wafer W held by the spin chuck 11. This reduces the gap between the annular member 210 and the wafer W when the annular member 210 is in the first position (lower position) described above. As a result, the flow rate of the clean air supplied from the FFU 31 flowing through the gap increases. This makes it possible to more reliably prevent the mist-like film forming processing solution from reaching the hole 60a formed by the annular member 210 and leaking out of the cup 14 through the hole 60a.

[0064] 9, the inner end of the peripheral cover portion 221 of the circular member 220 may be formed to be thicker in the vertical direction than the protrusion 20, and the entire upper surface 222 may be a horizontal flat surface. The inner peripheral end of the upper surface 222 of the circular member 220 may be located inside the outer peripheral end of the wafer W held by the spin chuck 11, and the outer peripheral end of the upper surface 222 may be located outside the outer peripheral end of the hole 17 of the cup 14. This strengthens the downward rectification action at the inner end of the peripheral cover portion 221, making it easier to draw in the surrounding air, so that the clean air supplied from the FFU 31 is easily introduced into the cup 14 without stagnation on the upper surface 222 of the circular member 220 or moving in the outer circumferential direction. As a result, the amount of clean air introduced into the cup 14 is increased among the clean air supplied from the FFU 31. Therefore, it is possible to more reliably prevent the mist-like film forming liquid from reaching the holes 60a formed in the circular member 220 and leaking out of the cup 14 through the holes 60a.

[0065] FIG. 10 is a diagram showing another example of the annular member. Even if the annular member 60 is in the first position (lower position) and the periphery of the hole 17 of the cup 14 is covered with the periphery cover part 100, the mist-like film forming processing liquid may leak out of the cup 14 through a gap between the annular member 60 and the cup 14. In order to suppress this leakage, as shown in Fig. 10, a labyrinth structure R may be formed between a surface 230a of the annular member 230 facing the upper surface 14a of the cup 14 in the first position (lower position) and the upper surface 14a of the cup 14. In other words, a labyrinth structure R may be formed between a surface 230a of the annular member 230 placed on the upper surface 14a of the cup 14 facing the upper surface 14a of the cup 14 (hereinafter referred to as "facing surface") and the upper surface 14a of the cup 14. The labyrinth structure R in the example shown in the figure is composed of a plurality of (specifically, two) upwardly recessed recesses formed by the opposing surface 230a of the circular ring member 230, and a plurality of (specifically, two) protrusions 300 protruding upward from the upper surface 14a so as to be received in each of the above recesses of the cup 14.

[0066] FIG. 11 is a diagram showing another example of the cup. The cup 400 in FIG. 11 has a seal portion 401. The seal portion 401 seals between the outer periphery of the annular member 240 and the upper surface 14a of the cup 400 (specifically, the upper surface of the top wall 19), and is formed on the upper surface 14a. The seal portion 401 has a groove 402 into which the lower end of the outer periphery of the annular member 240 in the first position (lower position) is fitted, and the groove 402 is filled with water 403. The groove 402 is formed so as to be concentric with the hole 17 of the cup 14 in a plan view. By providing such a seal portion 401, it is possible to prevent the mist-like film forming solution from leaking out of the cup 400 through the gap between the annular member 240 and the cup 400.

[0067] FIG. 12 is a diagram showing another example of the cup. 12 has a suction path 501 as a suction section. The suction path 501 is for sucking gas in the gap between the circular member 240 and the cup 500. The suction path 501 is formed in the wall forming the cup 500, specifically, formed in the top wall 19 and the inclined wall 18b so as to straddle these walls. One end of the suction path 501 opens to the space between the circular member 240 and the cup 500, and the other end of the suction path 501 is connected to a suction mechanism (not shown) having a suction pump.

[0068] Furthermore, cup 500 has groove 502 into which the outer circumferential lower end of annular member 240 in the above-mentioned first position (lower position) is fitted. Groove 502 is formed so as to be concentric with hole 17 of cup 14 in plan view. The one end of suction path 501 communicates with groove 502, for example.

[0069] By providing the suction path 501 as described above, it is possible to prevent the mist of the film forming liquid from leaking out of the cup 500 through the gap between the annular member 240 and the cup 500 .

[0070] The annular member may be provided with a suction section for sucking gas from the gap between the annular member and the cup.

[0071] The embodiments disclosed herein should be considered as illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0072] 1. Resist film forming equipment 11 Spin chuck 14 cups 14a Top side 17 holes 41 Resist liquid supply nozzle 51 Solvent supply nozzle 60, 200, 210, 220, 230 Circular members U Control Unit W wafer

Claims

1. A substrate processing apparatus for processing a substrate, a holding and rotating unit that holds and rotates the substrate; a supply unit that supplies a film forming solution to the substrate held by the holding and rotating unit; a liquid receiving portion for receiving the film forming liquid that is shaken off from the substrate by the rotation of the holding and rotating portion; A control unit that performs control related to the substrate processing, the liquid receiving section has a hole at an upper portion through which the substrate held by the holding and rotating section passes and which serves as an opening to an upper space, and the inside of the liquid receiving section is evacuated; the substrate processing includes a supplying process of supplying a film forming processing liquid to a substrate and rotating the substrate, and a drying process of rotating the substrate after the supplying process to dry the film forming processing liquid on the substrate, A circular ring member configured to be movable forward and backward relative to the upper surface of the liquid receiving portion, the control unit performs control so that the circular member is placed on the upper surface of the liquid receiving portion so as to close the periphery of the hole of the liquid receiving portion during the supplying process, and so that the circular member is retracted from the upper surface of the liquid receiving portion during the drying process; The substrate processing apparatus, wherein the surface of the annular member facing the substrate held by the holding and rotating part is an inclined surface that is gradually lower from the outer periphery side toward the inner periphery end.

2. the liquid receiving portion has a top wall that forms the hole, The substrate processing apparatus according to claim 1 , wherein the annular member extends from an inner peripheral end of the top wall toward the inner peripheral side when the annular member is placed on the upper surface of the liquid receiving portion.

3. 3. The substrate processing apparatus according to claim 2, wherein the liquid receiving portion has a side wall against which the processing liquid spun out laterally from the substrate impinges, and the top wall extends from the side wall at an angle closer to horizontal than the side wall.

4. A substrate processing apparatus as described in any one of claims 1 to 3, wherein the circular member has a flat upper surface, the inner circumferential end of the upper surface is located inside the outer circumferential end of the substrate held in the holding rotation section, and the outer circumferential end of the upper surface is located outside the outer circumferential end of the hole in the liquid receiving section.

5. 5. The substrate processing apparatus according to claim 1, further comprising an airflow forming unit for forming a downward airflow of clean gas.

6. The substrate processing apparatus according to claim 5 , wherein the inner diameter of the annular member is not less than 140 mm and not more than 260 mm.

7. 7. The substrate processing apparatus according to claim 1, wherein a labyrinth structure is formed by an upper surface of the liquid receiving portion and a surface of the annular member placed on the upper surface, the surface facing the upper surface of the liquid receiving portion.

8. 8. The substrate processing apparatus according to claim 1, wherein the liquid receiving portion has a seal portion that seals a gap between an outer periphery of the annular member and the liquid receiving portion.

9. 9. The substrate processing apparatus according to claim 1, further comprising a suction section that sucks gas from a gap between the annular member and the liquid receiving section.

10. 10. The substrate processing apparatus according to claim 1, wherein a rotation speed of the substrate during the drying process is lower than a rotation speed of the substrate during the supply process.

11. A substrate processing method for processing a substrate using a substrate processing apparatus. The substrate processing apparatus includes: a holding and rotating unit that holds and rotates the substrate; a supply unit that supplies a film forming solution to the substrate held by the holding and rotating unit; a liquid receiving portion for receiving the film forming liquid that is shaken off from the substrate by the rotation of the holding and rotating portion, the liquid receiving section has a hole at an upper portion through which the substrate held by the holding and rotating section passes and which serves as an opening to an upper space; A circular ring member configured to be movable forward and backward relative to the upper surface of the liquid receiving portion, a surface of the annular member facing the substrate held by the holding rotation unit is an inclined surface that is gradually lowered from an outer circumferential side toward an inner circumferential end, a step of supplying a film forming liquid to a substrate and rotating the substrate while evacuating the inside of the liquid receiving section in a state in which the annular member is placed on an upper surface of the liquid receiving section so as to close a periphery of the hole; Thereafter, with the annular member retracted from the upper surface of the liquid receiving portion, the inside of the liquid receiving portion is evacuated while rotating the substrate to dry the film forming processing liquid on the substrate.

12. 12. A readable computer storage medium storing a program that runs on a computer of a control unit that controls the substrate processing apparatus so as to cause the substrate processing apparatus to perform the substrate processing method according to claim 11.

Images