JP6571253B2 - Substrate processing method and substrate processing apparatus - Google Patents

Description

  Embodiments disclosed herein relate to a substrate processing method and a substrate processing apparatus.

  Conventionally, in a drying process for removing a processing liquid remaining on a substrate such as a silicon wafer or a liquid crystal substrate, pattern collapse may occur due to the surface tension of the processing liquid acting on the pattern formed on the surface of the substrate. It was.

  Thus, in recent years, a technique has been proposed in which a water repellent is supplied to the surface of the substrate to make the surface of the substrate water repellent before the drying treatment (see, for example, Patent Document 1). According to such a technique, by making the substrate surface water-repellent, surface tension is less likely to act on the pattern on the substrate surface, so that pattern collapse can be suppressed.

JP 2012-222329 A

  However, in the above-described prior art, when water is present on the back surface of the substrate in the water repellent treatment, the atmosphere of the water repellent agent moves around the back surface of the substrate and acts on the water, thereby There is a risk of causing stains on the back.

  An object of one embodiment of the present invention is to provide a substrate processing method and a substrate processing apparatus that can provide a substrate without a stain on the back surface.

  A substrate processing method according to an aspect of an embodiment includes a cleaning step, a water repellency step, a drying step, and a removal liquid supply step. In the cleaning step, a cleaning liquid containing moisture is supplied to at least the first surface of the substrate. In the water repellent process, a water repellent is supplied to the first surface of the substrate after the cleaning process. In the drying step, the substrate is dried after the water repellent step. In the removing liquid supplying step, the water repellent and the moisture act on the second surface which is the surface opposite to the first surface in the substrate during or after the water repellent step. As a result, a removing liquid for removing a stain generated on the substrate is supplied.

  According to one aspect of the embodiment, a substrate without a stain on the back surface can be provided.

FIG. 1 is a diagram showing a schematic configuration of a substrate processing system according to the present embodiment. FIG. 2 is a schematic view of a stain generated on the back surface of the wafer. FIG. 3 is a diagram illustrating a configuration example of the processing unit according to the first embodiment. FIG. 4 is a flowchart showing a processing procedure of the substrate cleaning processing executed by the processing unit. FIG. 5A is an explanatory diagram of chemical treatment. FIG. 5B is an explanatory diagram of the rinsing process. FIG. 5C is an explanatory diagram of the first replacement process. FIG. 5D is an explanatory diagram of moisture removal processing. FIG. 5E is an explanatory diagram of the water repellent treatment. FIG. 5F is an explanatory diagram of the second replacement process. FIG. 6 is a diagram illustrating a configuration example of a processing unit according to the second embodiment. FIG. 7 is an explanatory diagram of moisture removal processing according to the second embodiment. FIG. 8 is a diagram illustrating a configuration of a fifth nozzle according to the first modification. FIG. 9 is a diagram illustrating a configuration of a fifth nozzle according to the second modification. FIG. 10A is an explanatory diagram of the rinsing process. FIG. 10B is an explanatory diagram of moisture removal processing. FIG. 10C is an explanatory diagram of the first replacement process. FIG. 11 is an explanatory diagram of moisture removal processing according to the fourth embodiment. FIG. 12 is a flowchart illustrating a processing procedure of the substrate cleaning process executed by the processing unit according to the fifth embodiment. FIG. 13A is an explanatory diagram of the water repellent treatment. FIG. 13B is an explanatory diagram of the water repellent treatment. FIG. 13C is an explanatory diagram of the removal liquid supply process. FIG. 14A is an explanatory diagram of the second replacement process. FIG. 14B is an explanatory diagram of a removal liquid supply process according to a modification. FIG. 15 is a diagram illustrating a configuration example of a processing unit according to the seventh embodiment.

  Hereinafter, embodiments of a substrate processing method and a substrate processing apparatus disclosed in the present application will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by embodiment shown below.

(First embodiment)
<Configuration of substrate processing system>
FIG. 1 is a diagram showing a schematic configuration of a substrate processing system according to the present embodiment. In the following, in order to clarify the positional relationship, the X axis, the Y axis, and the Z axis that are orthogonal to each other are defined, and the positive direction of the Z axis is the vertically upward direction.

  As shown in FIG. 1, the substrate processing system 1 includes a carry-in / out station 2 and a processing station 3. The carry-in / out station 2 and the processing station 3 are provided adjacent to each other.

  The carry-in / out station 2 includes a carrier placement unit 11 and a transport unit 12. A plurality of carriers C that accommodate a plurality of substrates, in this embodiment a semiconductor wafer (hereinafter referred to as a wafer W) in a horizontal state, are placed on the carrier placement unit 11.

  The transport unit 12 is provided adjacent to the carrier placement unit 11 and includes a substrate transport device 13 and a delivery unit 14 inside. The substrate transfer device 13 includes a wafer holding mechanism that holds the wafer W. Further, the substrate transfer device 13 can move in the horizontal direction and the vertical direction and can turn around the vertical axis, and transfers the wafer W between the carrier C and the delivery unit 14 using the wafer holding mechanism. Do.

  The processing station 3 is provided adjacent to the transfer unit 12. The processing station 3 includes a transport unit 15 and a plurality of processing units 16. The plurality of processing units 16 are provided side by side on the transport unit 15.

  The transport unit 15 includes a substrate transport device 17 inside. The substrate transfer device 17 includes a wafer holding mechanism that holds the wafer W. Further, the substrate transfer device 17 can move in the horizontal direction and the vertical direction and can turn around the vertical axis, and transfers the wafer W between the delivery unit 14 and the processing unit 16 using a wafer holding mechanism. I do.

  The processing unit 16 performs predetermined substrate processing on the wafer W transferred by the substrate transfer device 17.

  Further, the substrate processing system 1 includes a control device 4. The control device 4 is a computer, for example, and includes a control unit 18 and a storage unit 19. The storage unit 19 stores a program for controlling various processes executed in the substrate processing system 1. The control unit 18 controls the operation of the substrate processing system 1 by reading and executing the program stored in the storage unit 19.

  Such a program may be recorded on a computer-readable storage medium, and may be installed in the storage unit 19 of the control device 4 from the storage medium. Examples of the computer-readable storage medium include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnetic optical disk (MO), and a memory card.

  In the substrate processing system 1 configured as described above, first, the substrate transfer device 13 of the loading / unloading station 2 takes out the wafer W from the carrier C placed on the carrier placement unit 11 and receives the taken-out wafer W. Place on the transfer section 14. The wafer W placed on the delivery unit 14 is taken out from the delivery unit 14 by the substrate transfer device 17 of the processing station 3 and carried into the processing unit 16.

  The wafer W carried into the processing unit 16 is processed by the processing unit 16, then unloaded from the processing unit 16 by the substrate transfer device 17, and placed on the delivery unit 14. Then, the processed wafer W placed on the delivery unit 14 is returned to the carrier C of the carrier placement unit 11 by the substrate transfer device 13.

  The processing unit 16 according to the first embodiment treats the wafer W with various processing liquids, then supplies a water repellent to the wafer W to make the surface of the wafer W water repellent, and then the wafer W Dry. By making the surface of the wafer W water repellent, the processing liquid remaining on the wafer W is dried while maintaining the contact angle with the pattern close to 90 °, so that the surface tension acting on the pattern is reduced. The Therefore, the collapse of the pattern can be suppressed.

  Here, when the water repellent treatment is performed, if moisture exists on the back surface of the wafer W, the atmosphere of the water repellent agent moves around the back surface of the wafer W and acts on the water, thereby There is a risk of spotting on the back.

  FIG. 2 is a schematic diagram of a stain generated on the back surface of the wafer W. FIG. As shown in FIG. 2, it has been confirmed by the inventors of the present application that the stain D is generated on the outer peripheral portion of the back surface of the wafer W. Note that the stain D is an organic stain and exhibits a white color.

  Such a stain D may contaminate the apparatus or the like due to transfer or the like. Therefore, in the substrate processing system 1 according to the first embodiment, a process of removing moisture remaining on the back surface of the wafer W is performed before the water repellent process in order to suppress the generation of the stain D. Hereinafter, this point will be specifically described.

<Configuration of processing unit>
First, a configuration example of the processing unit 16 will be described with reference to FIG. FIG. 3 is a diagram illustrating a configuration example of the processing unit 16 according to the first embodiment.

  As shown in FIG. 3, the processing unit 16 includes a substrate holding unit 20 that holds the wafer W in a horizontal posture. The substrate holding part 20 has a disk-like base part 22 and a plurality of, for example, three chuck claws 24 attached to the base part 22, and a mechanical part for holding a plurality of positions on the peripheral edge of the wafer W by the chuck claws 24. It is formed as a spin chuck. The base unit 22 incorporates a plate (not shown) having lift pins 26 that support and lift the back surface of the wafer W when the wafer W is transferred to and from the substrate transfer device 17. The substrate holding unit 20 can be rotated by a rotation driving unit 28 having an electric motor, and thereby the wafer W held by the substrate holding unit 20 can be rotated around the vertical axis.

  The cup 40 includes an outermost stationary first cup 41, that is, an outer cup, an annular second cup 42 that can be moved up and down, and a second annular cup that can be moved up and down. 3 cups 43 and an immovable inner wall 44 located inside thereof. The second cup 42 and the third cup 43 are moved up and down by respective lifting mechanisms 42A and 43A schematically shown in FIG. The first to third cups 41 to 43 and the inner wall 44 do not rotate. A first flow path 411 is formed between the first cup 41 and the second cup 42, a second flow path 421 is formed between the second cup 42 and the third cup 43, and the third cup 43 A third channel 431 is formed between the inner wall 44 and the inner wall 44.

  A cup exhaust port 45 communicating with the first flow path 411, the second flow path 421, and the third flow path 431 is formed at the bottom of the cup 40. A cup exhaust passage 46 is connected to the cup exhaust port 45.

  A bent portion is provided in the middle of each of the first flow path 411, the second flow path 421, and the third flow path 431, and the gas-liquid mixed fluid that flows through each flow path when the direction is suddenly changed by the bent section. The liquid component is separated from The separated liquid component falls into the liquid receiver 412 corresponding to the first flow path 411, the liquid receiver 422 corresponding to the second flow path 421, and the liquid receiver 432 corresponding to the third flow path 431. Drain ports 413, 423, and 433 are formed at the bottoms of the liquid receivers 412, 422, and 432, respectively.

  The processing unit 16 further includes a plurality of processing liquid nozzles that supply the processing liquid toward the wafer W that is held by the substrate holding unit 20 and rotates. In this example, a first nozzle 61 that supplies a chemical solution (for example, DHF (dilute hydrofluoric acid)), a second nozzle 62 that supplies DIW (pure water) that is a rinsing liquid, and IPA (isopropyl) that is a volatile organic solvent. A third nozzle 63 for supplying alcohol) and a fourth nozzle 64 for supplying a water repellent agent are provided. Each of the nozzles 61 to 64 has a processing liquid supply mechanism (not shown) provided with a processing liquid supply path connected to a processing liquid supply source and provided with a flow rate regulator such as an on-off valve and a flow rate adjustment valve. Treatment liquid is supplied.

  Here, the water repellent agent is, for example, a water repellent agent for making the surface of the wafer W water-repellent diluted to a predetermined concentration with thinner. As the water repellent, a silylating agent (or silane coupling agent) can be used. Specifically, for example, TMSDMA (trimethylsilyldimethylamine), DMSDMA (dimethylsilyldimethylamine), TMSDEA (trimethylsilyldiethylamine), HMDS (hexamethylzinlazane), and TMDS (1,1,3,3-tetramethyldimethyl) Silazane) can be used as a water repellent.

  As the thinner, an ether solvent, an organic solvent belonging to a ketone, or the like can be used. Specifically, for example, PGMEA (propylene glycol monomethyl ether acetate), cyclohexanone, HFE (hydrofluoroether) or the like can be used as the thinner.

  Here, an example in which DIW is used as the rinsing liquid will be described. However, the rinsing liquid only needs to contain at least water, and is not necessarily DIW. Here, an example in which IPA is used as the organic solvent will be described. However, the organic solvent is not limited to IPA, and any organic solvent having affinity for both water and a water repellent agent may be used.

  Here, the processing unit 16 includes a first nozzle 61 for chemical liquid, a second nozzle 62 for DIW, a third nozzle 63 for IPA, and a fourth nozzle 64 for water repellent agent. However, the processing unit 16 may supply the chemical solution, DIW, IPA, and water repellent agent from one nozzle.

  The substrate holding unit 20 and the cup 40 are accommodated in the housing 70. A fan filter unit (FFU) 80 is provided on the ceiling of the housing 70.

  Below the ceiling of the housing 70, a rectifying plate 85 in which a large number of through holes 86 are formed is provided. The rectifying plate 85 rectifies the clean air (CA) blown downward from the FFU 80 so that it flows on the wafer W in a concentrated manner. A down flow of clean air that flows downward from the through hole 86 of the current plate 85 toward the wafer W is always formed in the housing 70.

  A housing exhaust port 72 for exhausting the atmosphere in the housing 70 is provided at the lower part of the housing 70 (specifically, at a position lower than at least the upper opening of the cup 40). ing. A housing exhaust path 74 is connected to the housing exhaust port 72.

  The cup exhaust passage 46 and the housing exhaust passage 74 are selected as the first exhaust line 91, the second exhaust line 92, and the third exhaust line 93 that form a part of the factory exhaust system, depending on the position of the valve body of the switching valve 50. Connected. Since the exhaust lines 91 to 93 are at negative pressure, the internal space of the cup 40 and the internal space of the housing 70 are sucked according to the position of the valve body of the switching valve 50.

  Further, the processing unit 16 includes a fifth nozzle 65. The fifth nozzle 65 is inserted into a hollow portion (not shown) formed in the central portion of the base portion 22 and supplies fluid to the back surface of the wafer W. A chemical liquid supply source 652 is connected to the fifth nozzle 65 via a valve 651, and a rinse liquid supply source 654 is connected via a valve 653. The fifth nozzle 65 supplies DHF and DIW supplied from the chemical solution supply source 652 and the rinse solution supply source 654 to the center of the back surface of the wafer W.

<Specific operation of processing unit>
Next, the contents of the substrate cleaning process performed by the processing unit 16 will be described with reference to FIGS. 4 and 5A to 5F. FIG. 4 is a flowchart showing a processing procedure of the substrate cleaning process executed by the processing unit 16. 5A is an explanatory view of the chemical treatment, FIG. 5B is an explanatory view of the rinsing process, FIG. 5C is an explanatory view of the first replacement process, and FIG. 5D is an explanatory view of the moisture removal process. 5E is an explanatory diagram of the water repellent process, and FIG. 5F is an explanatory diagram of the second replacement process.

  4 is performed by the control unit 18 reading out the program stored in the storage unit 19 of the control device 4 and controlling the processing unit 16 and the like based on the read command. Executed.

  As shown in FIG. 4, first, the substrate transfer device 17 (see FIG. 1) loads the wafer W into the housing 70 of the processing unit 16 (step S101). The wafer W is held by the chuck claws 24 (see FIG. 3) with the pattern formation surface facing upward. Thereafter, the control unit 18 rotates the substrate holding unit 20 at a predetermined rotation speed.

  Subsequently, the processing unit 16 performs a chemical solution process (step S102). Specifically, the processing unit 16 discharges DHF, which is a chemical solution, from the first nozzle 61 toward the surface of the rotating wafer W for a predetermined time, and at the same time, from the fifth nozzle 65 toward the back surface of the rotating wafer W. DHF, which is a chemical solution, is discharged for a predetermined time. The supply time of DHF is the same for the first nozzle 61 and the fifth nozzle 65. The DHF supplied to the front and back surfaces of the wafer W spreads over both surfaces of the wafer W due to the centrifugal force accompanying the rotation of the wafer W. As a result, the front and back surfaces of the wafer W are cleaned (see FIG. 5A).

  In the chemical treatment, the second cup 42 and the third cup 43 are located at the lowered position, and DHF, which is a chemical, passes through the first flow path 411 between the first cup 41 and the second cup 42. Flowing through. The clean air existing in the space above the wafer W flows through the first flow path 411, is discharged from the cup exhaust port 45, passes through the cup exhaust path 46 and the switching valve 50, and enters the first exhaust line 91. Flowing.

  Subsequently, the processing unit 16 performs a rinsing process (step S103). Specifically, the processing unit 16 discharges DIW, which is a rinsing liquid, from the second nozzle 62 toward the surface of the rotating wafer W for a predetermined time, and at the same time, directs it from the fifth nozzle 65 toward the back surface of the rotating wafer W. Then, DIW which is a rinsing liquid is discharged for a predetermined time. The DIW supply time is the same for the second nozzle 62 and the fifth nozzle 65. The DIW supplied to the front and back surfaces of the wafer W spreads over both surfaces of the wafer W due to centrifugal force accompanying the rotation of the wafer W. As a result, DHF remaining on the front and back surfaces of the wafer W is washed away by DIW (see FIG. 5B).

  In the rinsing process, the second cup 42 is located at the raised position and the third cup 43 is located at the lowered position, and DIW, which is the rinsing liquid, flows through the second flow path 421 and receives the liquid. The liquid drops to 422 and is discharged from the cup 40 through the drain port 423. Further, the gas (clean air) in the space above the wafer W flows into the cup 40 through the upper opening of the first cup 41, and then the second between the second cup 42 and the third cup 43. It flows through the flow path 421, is discharged from the cup exhaust port 45, and flows to the second exhaust line 92 through the cup exhaust path 46 and the switching valve 50. The gas existing in the space around the cup 40 in the internal space of the housing 70 is discharged from the housing exhaust port 72 and flows to the second exhaust line 92 through the housing exhaust path 74 and the switching valve 50.

  Thus, in the processing unit 16, DHF is supplied to both surfaces of the wafer W in the chemical processing. Accordingly, in the rinsing process, the processing unit 16 supplies DIW to both surfaces of the wafer W to wash away DHF remaining on both surfaces of the wafer W. In this way, in the processing unit 16, DIW is supplied to the back surface of the wafer W, so that moisture tends to remain on the back surface of the wafer W. The moisture supplied to the back surface of the wafer W is concentrated on the outer peripheral portion of the back surface of the wafer W due to the centrifugal force accompanying the rotation of the wafer W. For this reason, moisture tends to remain on the outer peripheral portion of the back surface of the wafer W.

  The rinsing process is performed on the first surface of the substrate, the first surface cleaning step for supplying the first cleaning liquid containing moisture, and the second surface which is the surface opposite to the first surface. This corresponds to an example of a second surface cleaning process for supplying the second cleaning liquid.

  Subsequently, the processing unit 16 performs a moisture removal process and a first replacement process on the surface of the wafer W (step S104). Specifically, as the moisture removal process, the processing unit 16 rotates the wafer W until the water repellent process (step S104) is started after the rinse process (step S103) is completed. The DIW remaining on the outer periphery of the back surface of the wafer W is removed by centrifugal force accompanying the rotation of the wafer W.

  Thus, moisture remaining on the outer peripheral portion of the back surface of the wafer W can be removed before the water repellent treatment is started. Therefore, even if the atmosphere of the water repellent agent wraps around the back surface of the wafer W in the water repellent treatment described later, the generation of the stain D can be suppressed.

  Further, as the first replacement process, the processing unit 16 waits for the wafer W rotating from the third nozzle 63 until the water repellent process (step S104) is started after the rinse process (step S103) is completed. IPA is discharged to the surface for a predetermined time. The IPA supplied to the surface of the wafer W spreads over the entire surface of the wafer W due to the centrifugal force accompanying the rotation of the wafer W. As a result, the DIW remaining on the surface of the wafer W is replaced with IPA having an affinity for the water repellent agent discharged to the wafer W in the subsequent water repellency treatment. Since IPA also has an affinity with DIW, replacement of DIW with IPA is easy.

  As described above, when performing the moisture removal process, the processing unit 16 supplies IPA, which is an organic solvent, to the surface of the wafer W and performs a replacement process to replace DIW on the surface of the wafer W with IPA. For this reason, according to the processing unit 16, it is possible to prevent the surface of the wafer W from being exposed during the moisture removing process (see FIGS. 5C and 5D).

  When the surface of the wafer W is exposed, in other words, when the processing liquid is not supplied to the surface of the wafer W, pattern collapse occurs due to the surface tension of the DIW acting on the pattern formed on the surface of the wafer W. There is a fear. Therefore, according to the processing unit 16, the collapse of the pattern during the moisture removal process can be suppressed by preventing the exposure of the surface of the wafer W during the moisture removal process.

  Subsequently, the processing unit 16 performs a water repellent process (step S105). Specifically, the processing unit 16 discharges a silylating agent, which is a water repellent agent, from the fourth nozzle 64 toward the surface of the rotating wafer W for a predetermined time. The water repellent agent supplied to the surface of the wafer W spreads over the entire surface of the wafer W due to the centrifugal force accompanying the rotation of the wafer W. Thereby, the silyl group is bonded to the OH group on the surface of the wafer W, and a water repellent film is formed on the surface of the wafer W.

  As shown in FIG. 5E, moisture remaining on the outer periphery of the back surface of the wafer W is removed before the start of the water repellent treatment. For this reason, even if the atmosphere of the water repellent agent wraps around the back surface of the wafer W in the water repellent treatment, the occurrence of the stain D can be suppressed.

  In the water repellent treatment, the second cup 42 and the third cup 43 are located at the ascending position, and the water repellent agent flows through the third flow path 431, falls on the liquid receiver 432, and is discharged. The liquid is discharged from the cup 40 through the liquid port 433. The gas (clean air) in the space above the wafer W flows into the cup 40 through the upper opening of the first cup 41, and then the third flow path 431 between the third cup 43 and the inner wall 44. Flows through the cup exhaust port 45, flows through the cup exhaust path 46 and the switching valve 50 to the third exhaust line 93. Gas existing in the space around the cup 40 in the inner space of the housing 70 is discharged from the housing exhaust port 72 and flows to the third exhaust line 93 through the housing exhaust path 74 and the switching valve 50.

  Subsequently, the processing unit 16 performs a second replacement process (step S106). The second replacement process is performed in the same procedure as the first replacement process described above. By the second replacement process, the water repellent agent remaining on the surface of the wafer W is replaced with IPA (see FIG. 5F).

  Subsequently, the processing unit 16 performs a drying process (step S107). Specifically, the processing unit 16 dries off the IPA remaining on the wafer W by increasing the rotational speed of the wafer W to dry the wafer W.

  Thereafter, the processing unit 16 performs a carry-out process (step S108). Specifically, after stopping the rotation of the wafer W, the processing unit 16 unloads the wafer W from the processing unit 16 by the substrate transfer device 17 (see FIG. 1). When such unloading processing is completed, a series of substrate processing for one wafer W is completed.

  As described above, the substrate processing method according to the first embodiment includes the rinsing process (corresponding to an example of the “first surface cleaning process” and the “second surface cleaning process”) and the moisture removal process (“moisture removal”). And a water repellent treatment (corresponding to an example of “water repellent step”) and a drying treatment (corresponding to an example of “drying step”). The rinsing process supplies DIW (corresponding to an example of “first cleaning liquid containing water”) to the front surface (corresponding to an example of “first surface”) of the wafer W, and at the same time the back surface ( DIW (corresponding to an example of “second cleaning liquid containing moisture”) is supplied to “corresponding to an example of“ second surface ”). In the moisture removing process, moisture remaining on the back surface of the wafer W is removed after the rinsing process. In the water repellent treatment, a water repellent is supplied to the surface of the wafer W after the water removal treatment. In the drying process, the wafer W is dried after the water repellent process.

  The substrate processing method according to the first embodiment supplies IPA (corresponding to an example of “organic solvent”) to the surface of the wafer W to perform DIW on the surface of the wafer W when performing moisture removal processing. A first replacement process (corresponding to an example of a “replacement process”) is performed in which IPA is replaced with IPA.

  Further, the processing unit 16 (corresponding to an example of “substrate processing apparatus”) according to the first embodiment includes a second nozzle 62 (corresponding to an example of “first surface cleaning unit”) and a fifth nozzle 65 (“ And a fourth nozzle 64 (corresponding to an example of a “water repellent agent supplying unit”), and a control unit 18. The second nozzle 62 supplies DIW to the surface of the wafer W. The fifth nozzle 65 supplies DIW to the back surface of the wafer W. The fourth nozzle 64 supplies a water repellent agent to the surface of the wafer W. The controller 18 supplies DIW to the front surface of the wafer W from the second nozzle 62 and rinses the DIW from the fifth nozzle 65 to the back surface of the wafer W (“first surface cleaning process”). ”And“ second surface cleaning process ”), a water removal process for removing water remaining on the back surface of the wafer W after the rinse process, and a surface of the wafer W from the fourth nozzle 64 after the water removal process. A water repellent process for supplying a water repellent to the substrate and a drying process for drying the wafer W after the water repellent process are performed.

  Thus, moisture remaining on the outer peripheral portion of the back surface of the wafer W can be removed before the water repellent treatment is started. Therefore, pattern collapse of the wafer W can be suppressed, and the wafer W having no stain D on the outer peripheral portion of the back surface can be provided.

  Here, an example in which the chemical liquid is supplied to both surfaces of the wafer W in the chemical liquid processing and the rinsing liquid is supplied to both surfaces of the wafer W in the rinsing processing is shown. However, the present invention is not limited thereto, and the processing unit 16 may supply the chemical liquid only to the surface of the wafer W in the chemical liquid processing and supply the rinsing liquid to both surfaces of the wafer W in the rinsing processing.

(Second Embodiment)
Next, a substrate processing system according to the second embodiment will be described. FIG. 6 is a diagram illustrating a configuration example of a processing unit according to the second embodiment. In the following description, parts that are the same as those already described are given the same reference numerals as those already described, and redundant descriptions are omitted.

  As shown in FIG. 6, the processing unit 16A according to the second embodiment includes a fifth nozzle 65A. In addition to the chemical liquid supply source 652 and the rinse liquid supply source 654, a gas supply source 656 is connected to the fifth nozzle 65A via a valve 655. The fifth nozzle 65 </ b> A supplies the gas supplied from the gas supply source 656 to the center of the back surface of the wafer W. Here, the gas supplied from the fifth nozzle 65A is N2, but the gas supplied from the fifth nozzle 65A may be a gas other than N2 (for example, argon gas). .

  Next, the content of the water removal process performed by the processing unit 16A will be described with reference to FIG. FIG. 7 is an explanatory diagram of moisture removal processing according to the second embodiment. The water removal process according to the second embodiment is performed after the rinsing process and before the water repellent process, similarly to the water removal process according to the first embodiment.

  As shown in FIG. 7, the processing unit 16A performs the moisture removal process from the fifth nozzle 65A while discharging the IPA from the third nozzle 63 toward the surface of the rotating wafer W for a predetermined time as the first replacement process. N2 is discharged toward the back surface of the rotating wafer W for a predetermined time.

  Thereby, compared with the moisture removal process according to the first embodiment, moisture remaining on the peripheral edge of the back surface of the wafer W can be removed in a shorter time. That is, since the time required for the moisture removal process can be shortened, the time required for a series of substrate processes can be shortened.

  The processing unit 16A may continue the process of supplying N2 to the back surface of the wafer W even after the moisture removal process. That is, by supplying N2 to the back surface of the wafer W even during the water repellency process performed after the moisture removal process, it becomes difficult for the atmosphere of the water repellent agent to flow from the front surface to the back surface of the wafer W. Even when the moisture on the outer peripheral portion of the back surface of the wafer W cannot be removed, it is possible to make it difficult for the stain D to occur.

  Next, a modified example of the fifth nozzle 65A will be described with reference to FIGS. FIG. 8 is a diagram illustrating the configuration of the fifth nozzle according to the first modification, and FIG. 9 is a diagram illustrating the configuration of the fifth nozzle according to the second modification.

  As illustrated in FIG. 8, the fifth nozzle 65 </ b> B according to the first modification supplies N2 obliquely toward the outer peripheral portion of the back surface of the wafer W. With this configuration, N2 can be directly supplied to the moisture remaining on the outer peripheral portion of the back surface of the wafer W. Therefore, it is possible to remove moisture remaining on the peripheral edge of the back surface of the wafer W in a shorter time compared to the fifth nozzle 65A.

  Although FIG. 8 shows an example in which the fifth nozzle 65B has two discharge ports, the fifth nozzle 65B only needs to have at least one discharge port.

  Further, as shown in FIG. 9, the fifth nozzle 65 </ b> C according to the second modification includes a discharge unit 657. The discharge unit 657 is a member extending in the horizontal direction and has a length substantially equal to the diameter of the wafer W. Then, the discharge unit 657 supplies N 2 from the discharge port 658 located below the back surface outer peripheral portion of the wafer W toward the back surface outer peripheral portion of the wafer W. With this configuration, N2 can be directly supplied from a position closer to the outer peripheral portion of the back surface of the wafer W as compared with the fifth nozzle 65B according to the first modification. Therefore, it is possible to remove the moisture remaining on the peripheral edge of the back surface of the wafer W in a shorter time compared to the fifth nozzle 65B.

  As described above, the processing unit 16A according to the second embodiment performs N2 on the back surface of the wafer W as a moisture removal process while the IPA is supplied to the front surface of the wafer W by the first replacement process. (Equivalent to an example of “gas”). As a result, evaporation of moisture remaining on the outer peripheral portion of the back surface of the wafer W is promoted, so that moisture can be removed in a shorter time than when moisture is removed only by centrifugal force.

(Third embodiment)
In the first and second embodiments described above, an example in which the water removal process and the first replacement process are performed in parallel after the rinse process and before the water repellent process has been described. You may perform after a process and before a 1st replacement process.

  Therefore, in the third embodiment, an example in which the water removal process is performed after the rinse process and before the first replacement process will be described with reference to FIGS. 10A to 10C. 10A is an explanatory diagram of the rinsing process, FIG. 10B is an explanatory diagram of the water removal process, and FIG. 10C is an explanatory diagram of the first replacement process.

  In the third embodiment, the processing unit 16 supplies a rinsing liquid (DIW) to both surfaces of the wafer W in the rinsing process (see FIG. 10A). Subsequently, after a sufficient time has elapsed for the DHF remaining on both surfaces of the wafer W to be washed away by the DIW, the processing unit 16 stops supplying the rinse liquid to the back surface of the wafer W, and The rinsing liquid is supplied only to (see FIG. 10B). Thereafter, as illustrated in FIG. 10C, the processing unit 16 performs a first replacement process for supplying IPA to the surface of the wafer W.

  Thus, in the processing unit 16 according to the third embodiment, moisture remaining on the outer peripheral portion of the back surface of the wafer W is sufficiently removed by the centrifugal force accompanying the rotation of the wafer W before the water repellent treatment is started. Can do. Further, since the rinsing liquid is supplied to the surface of the wafer W when the moisture removal process is performed, it is possible to prevent the surface of the wafer W from being exposed during the moisture removal process.

  If the time until the water remaining on the back surface of the wafer W is sufficiently removed by the centrifugal force accompanying the rotation of the wafer W is T1, and the IPA supply time in the first replacement process is T2, the wafer in the water removal process The supply time of DIW to the W surface can be, for example, T1-T2.

  Thus, here, the time required for shaking off the water remaining on the back surface of the wafer W by the centrifugal force accompanying the rotation of the wafer W is secured by extending the supply time of the rinse liquid to the surface of the wafer W by a predetermined time. To do.

(Fourth embodiment)
Next, a moisture removal process according to the fourth embodiment will be described with reference to FIG. FIG. 11 is an explanatory diagram of moisture removal processing according to the fourth embodiment. The water removal process according to the fourth embodiment is a processing unit including fifth nozzles 65A to 65C (see FIGS. 6, 8, and 9) that can supply a gas such as N 2 to the back surface of the wafer W. It is executed by. Here, as an example, it is assumed that the process is executed by the processing unit 16A (see FIG. 6) including the fifth nozzle 65A.

  As shown in FIG. 11, the processing unit 16A discharges DIW from the second nozzle 62 toward the surface of the rotating wafer W for a predetermined time, and at the same time, N2 toward the back surface of the rotating wafer W from the fifth nozzle 65A. Is discharged for a predetermined time.

  As described above, in the fourth embodiment, the processing unit 16 </ b> A supplies gas to the back surface of the wafer W while supplying the rinse liquid to the front surface of the wafer W. Thereby, compared with the moisture removal process according to the third embodiment, moisture remaining on the peripheral edge of the back surface of the wafer W can be removed in a shorter time. That is, since the time required for the moisture removal process can be shortened, the time required for a series of substrate processes can be shortened.

(Fifth embodiment)
In the first to fourth embodiments described above, an example in which the occurrence of a stain D is prevented by removing moisture remaining on the peripheral edge of the back surface of the wafer W before the water repellent treatment is described. did.

  On the other hand, the stain D has a property of being soluble in water or an organic solvent. Therefore, in the fifth embodiment, an example in which the stain D generated on the peripheral edge of the back surface of the wafer W is removed using water or an organic solvent will be described with reference to FIGS. 12 and 13A to 13C.

  FIG. 12 is a flowchart illustrating a processing procedure of the substrate cleaning process executed by the processing unit according to the fifth embodiment. 13A and 13B are explanatory diagrams of the water repellent process, and FIG. 13C is an explanatory diagram of the removal liquid supply process.

  Note that the processing in steps S201 to S203 shown in FIG. 12 is the same as the processing in steps S101 to S103 shown in FIG. Also, the first replacement process shown in step S204 of FIG. 12 is the same as the first replacement process in step S104 shown in FIG. Here, a series of substrate processing is performed by the processing unit 16 according to the first embodiment, but may be performed by the processing unit 16A according to the second embodiment.

  As shown in FIG. 12, in the fifth embodiment, since the water removal process described above is not performed, in the water repellent process shown in step S205, a state in which water remains on the outer peripheral portion of the back surface of the wafer W It has become. For this reason, when the atmosphere of the water repellent agent comes into contact with moisture (see FIG. 13A), a stain D is generated on the outer periphery of the back surface of the wafer W (see FIG. 13B).

  Subsequently, the processing unit 16 performs a removal liquid supply process and a second replacement process (step S206). Specifically, the processing unit 16 supplies DIW to the back surface of the wafer W rotating from the fifth nozzle 65 as the removal liquid supply process (see FIG. 13C). The DIW supplied to the back surface of the wafer W spreads over the entire back surface of the wafer W due to the centrifugal force accompanying the rotation of the wafer W. Thereby, DIW is supplied to the stain D generated on the outer peripheral portion of the back surface of the wafer W, and the stain D is removed. Further, as the second replacement process, the processing unit 16 discharges IPA to the surface of the wafer W rotating from the third nozzle 63 for a predetermined time (see FIG. 13C). Thereby, the water repellent agent remaining on the surface of the wafer W is replaced with IPA. Further, it is possible to prevent the surface of the wafer W from being exposed during the removal picture supply process.

  Thereafter, the processing unit 16 performs a drying process (step S207) and an unloading process (step S208), and ends a series of substrate processing.

  Here, an example in which DIW is supplied to the back surface of the wafer W in the removal liquid supply processing has been described. However, the processing unit 16 supplies, for example, IPA to the back surface of the wafer W instead of DIW. Also good. In such a case, the fifth nozzle 65 of the processing unit 16 only needs to be connected to the IPA supply source via a valve.

  Here, an example in which the removal liquid supply process is performed during the second replacement process has been described, but the removal liquid supply process does not necessarily have to be performed during the second replacement process. For example, the removal liquid supply process may be performed after the water repellent process and before the second replacement process, or may be performed after the second replacement process. In such a case, the removal liquid supply process may be performed by supplying DIW or IPA to the back surface of the wafer W and simultaneously supplying DIW or IPA to the front surface of the wafer W.

  Further, the removal liquid supply process may be performed during the water repellent process. That is, the processing unit 16 discharges the water repellent agent for a predetermined time onto the surface of the wafer W rotating from the fourth nozzle 64 and also applies DIW or IPA to the back surface of the wafer W rotating from the fifth nozzle 65. You may supply. The stain D occurs when a slight amount of moisture exists on the back surface of the wafer W. For this reason, during the water-repellent treatment, by continuing to supply a large amount of DIW or IPA to the back surface of the wafer W, it is possible to suppress the generation of a stain D, and even if a stain D occurs. It can be removed by DIW or IPA.

  As described above, the substrate processing method according to the fifth embodiment includes a rinsing process (corresponding to an example of “cleaning process”), a water repellent process (corresponding to an example of “water repellent process”), A drying process (corresponding to an example of “drying process”) and a removal liquid supply process (corresponding to an example of “removing liquid supply process”) are included. In the rinsing process, a rinsing liquid containing moisture is supplied to at least the surface of the wafer W. In the water repellent treatment, a water repellent is supplied to the surface of the wafer W (corresponding to an example of “first surface”) after the rinse treatment. In the drying process, the wafer W is dried after the water repellent process. The removal liquid supply process is performed by a water repellent and water acting on the back surface of the wafer W (corresponding to an example of “second surface”) during or after the water repellent process. DIW (corresponding to an example of “removed liquid”) for removing the stain D generated on the outer peripheral portion of the wafer W is supplied.

  Further, in the substrate processing method according to the fifth embodiment, when performing the removal liquid supply process, IPA (corresponding to an example of “organic solvent”) is supplied to the surface of the wafer W so as to be on the surface of the wafer W. A second replacement process (corresponding to an example of a “replacement step”) in which the water repellent is replaced with IPA is performed.

  Further, the processing unit 16 (corresponding to an example of “substrate processing apparatus”) according to the fifth embodiment includes a second nozzle 62 and a fifth nozzle 65 (corresponding to an example of “cleaning liquid supply unit”), and a fourth nozzle. 64 (corresponding to an example of “water repellent supplying part”), a fifth nozzle 65 (corresponding to an example of “removed liquid supplying part”), and a control part 18. The second nozzle 62 and the fifth nozzle 65 supply a rinsing liquid containing moisture to the wafer W. The fourth nozzle 64 supplies a water repellent agent to the wafer W. The fifth nozzle 65 supplies a removing liquid that removes the stain D generated on the outer peripheral portion of the wafer W by the action of the water repellent and moisture. The control unit 18 performs the rinsing process for supplying the rinsing liquid to the wafer W from the second nozzle 62 and the fifth nozzle 65, and after the rinsing process, makes the water repellent from the fourth nozzle 64 to the surface of the wafer W. The water repellent treatment for supplying the agent, the drying treatment for drying the wafer W after the water repellent treatment, and the fifth nozzle 65 against the back surface of the wafer W during or after the water repellent treatment. A removal liquid supply process for supplying the removal liquid is performed.

  Thereby, even if the stain D occurs on the outer peripheral portion of the back surface of the wafer W, the stain D can be removed. Therefore, the pattern collapse of the wafer W can be suppressed, and the wafer W having no stain D on the back surface can be provided.

  Here, an example in which the processing unit 16 performs the removal liquid supply process instead of the water removal process has been described, but the processing unit 16 performs both the water removal process and the removal liquid supply process. Also good. Thereby, generation | occurrence | production of the spot D can be prevented more reliably.

(Sixth embodiment)
In the fifth embodiment described above, an example in which the removal liquid is supplied from the fifth nozzle 65 to the back surface of the wafer W has been described as a method of supplying the removal liquid to the back surface of the wafer W in the removal liquid supply process. . However, the method of supplying the removal liquid to the back surface of the wafer W is not limited to the above example. Therefore, hereinafter, a modified example of the removal liquid supply process will be described with reference to FIGS. 14A and 14B. FIG. 14A is an explanatory diagram of a second replacement process, and FIG. 14B is an explanatory diagram of a removal liquid supply process according to a modification.

  As shown in FIG. 14A, in the second replacement process, the processing unit 16 discharges IPA to the surface of the rotating wafer W from the third nozzle 63 for a predetermined time while rotating the wafer W at the first rotation speed. Let Note that the rotation speed of the wafer W in the processing of steps S202 to S205 shown in FIG. 12 is also the first rotation speed.

  Subsequently, the processing unit 16 performs a removal liquid supply process. Specifically, the processing unit 16 changes the rotational speed of the wafer W to a second rotational speed lower than the first rotational speed during the second replacement process.

  As shown in FIG. 14B, the IPA supplied to the front surface of the wafer W goes from the front surface of the wafer W to the back surface as the number of rotations of the wafer W decreases. Thereby, IPA is supplied to the stain D (see FIG. 2) generated on the outer peripheral portion of the back surface of the wafer W, and the stain D is removed.

  As described above, the removal liquid supply process according to the sixth embodiment is performed by changing the rotation speed of the wafer W to the second rotation speed lower than the first rotation speed during the second replacement process. The IPA supplied to the front surface of W was supplied as a removal liquid by wrapping around the back surface of the wafer W. Thereby, the stain D generated on the outer periphery of the back surface of the wafer W can be efficiently removed.

(Seventh embodiment)
Next, the configuration of a processing unit according to the seventh embodiment will be described with reference to FIG. FIG. 15 is a diagram illustrating a configuration example of a processing unit according to the seventh embodiment.

  As shown in FIG. 15, the processing unit 16B according to the seventh embodiment includes an annular outer rotating cup 30 and an inner rotating cup 32 as rotating cups. For example, the outer rotating cup 30 and the inner rotating cup 32 are attached to the base portion 22 of the substrate holding portion 20 via a post (not shown) and rotate integrally with the base portion 22. A channel 34 is formed between the outer rotating cup 30 and the inner rotating cup 32, and the atmosphere above the wafer W is drawn into the outer rotating cup 30 through the channel 34. The inner peripheral surface of the outer rotating cup 30 receives the processing liquid that is supplied to the rotating wafer W and then shaken off from the wafer W and scatters, and guides it into the cup 40 (see, for example, FIG. 3). Further, the inner rotating cup 32 prevents the fluid containing the processing liquid flowing through the flow path 34 from entering the back surface of the wafer W. Further, the inner rotating cup 32 guides the airflow generated in the space between the base portion 22 and the back surface of the wafer W to the cup 40 as the substrate holding portion 20 rotates.

  A tapered surface 321 is formed on the upper end edge of the inner rotating cup 32 so as to gradually narrow toward the lower side. The processing unit 16 </ b> B holds the wafer W by locking the bevel portion of the wafer W to the tapered surface 321.

  The tapered surface 321 is formed over the entire circumference of the wafer W. That is, since the bevel surface of the wafer W is in contact with the tapered surface 321 over the entire circumference of the wafer W, the atmosphere of the water repellent agent generated on the surface side of the wafer W in the water repellent treatment. The wraparound to the back surface of the wafer W is suppressed. Therefore, even if moisture exists in the outer peripheral portion of the back surface of the wafer W, the atmosphere of the water repellent and the moisture do not easily come into contact with each other, so that the generation of a stain D can be suppressed.

  Here, an example has been described in which the atmosphere on the surface of the wafer W is separated from the space on the back surface side, thereby making it difficult for the atmosphere of the water repellent to enter the back surface of the wafer W. However, the present invention is not limited to this. For example, the atmosphere of the water repellent agent may be made difficult to flow around the back surface of the wafer W by increasing the exhaust amount from the cup exhaust port 45 or the housing exhaust port 72.

  In the embodiment described above, an example in which the first surface cleaning step and the second surface cleaning step are performed simultaneously has been described. However, the first surface cleaning step and the second surface cleaning step are not necessarily performed simultaneously. Is not required.

  In the above-described embodiment, the example has been described in the case where the first cleaning liquid and the second cleaning liquid are the same. However, the first cleaning liquid and the second cleaning liquid need not necessarily be the same. do not do.

  In the above-described embodiment, the example in which the first cleaning liquid and the second cleaning liquid are DIW has been described. However, the first cleaning liquid and the second cleaning liquid may be any cleaning liquid that contains moisture. Cleaning liquids other than DIW, such as DIW (HDIW) heated to a predetermined temperature, SC1 (ammonia / hydrogen peroxide / water mixture), SC2 (hydrochloric acid / hydrogen peroxide / water mixture), etc. Also good.

  Further effects and modifications can be easily derived by those skilled in the art. Thus, the broader aspects of the present invention are not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications can be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

D stain W wafer 1 substrate processing system 16 processing unit 18 control unit 61 first nozzle 62 second nozzle 63 third nozzle 64 fourth nozzle 65 fifth nozzle

Claims (6)

A cleaning step of supplying a cleaning liquid containing moisture to at least the first surface of the substrate while rotating the substrate ;
A water repellent step of supplying a water repellent to the first surface of the substrate in a state where the substrate is rotated after the cleaning step;
A drying step of drying the substrate after the water repellent step;
During the water repellent process or after the water repellent process, the water repellent agent and moisture act on the second surface of the substrate which is the surface opposite to the first surface. And a removal liquid supply step of removing a stain by supplying a removal liquid for removing a stain generated on the second surface of the substrate. When performing the removal liquid supply step, a replacement step is performed in which an organic solvent is supplied to the first surface of the substrate to replace the water repellent agent on the first surface with the organic solvent. The substrate processing method according to claim 1, wherein: The substrate processing method according to claim 1, wherein the removing liquid is pure water. The substrate processing method according to claim 1, wherein the removing liquid is an organic solvent. The replacement step includes
Supplying the organic solvent to the first surface of the substrate while rotating the substrate at a first rotational speed;
The removal liquid supply step includes
By changing the number of rotations of the substrate to a second number of rotations lower than the first number of rotations, the organic solvent supplied to the first surface wraps around the second surface as the removal liquid. The substrate processing method according to claim 2, wherein the substrate processing method is supplied. A holding unit for holding the substrate rotatably;
A cleaning liquid supply unit that supplies a cleaning liquid containing moisture to at least the first surface of the substrate held by the holding unit ;
A water repellent supplying part for supplying a water repellent to the first surface of the substrate held by the holding part ;
A removal liquid supply unit for supplying a removal liquid for removing a stain generated on a second surface of the substrate opposite to the first surface by the action of the water repellent agent and moisture; ,
While rotating the substrate using the holding unit, the cleaning liquid is supplied from the cleaning liquid supply unit to at least the first surface of the substrate, and the substrate is rotated after the cleaning process. A water repellent treatment for supplying a water repellent agent to the substrate from the water repellent agent supply unit, a drying treatment for drying the substrate after the water repellent treatment, and the water repellent agent. after treatment in or the water repellency processing, with respect to the second surface of the substrate, control unit for performing a removing solution supply process of removing the stain by supplying the removal liquid from the removing solution supply unit And a substrate processing apparatus.

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