Substrate processing method and substrate processing apparatus

Abstract

A substrate processing method according to the present disclosure comprises: a step in which a substrate is held with use of a holding unit that horizontally holds the substrate in a rotatable manner; a step in which the thus-held substrate is subsequently heated; a step in which the in-plane temperature distribution of the substrate is brought close to the in-plane temperature distribution thereof during the time when a first processing liquid is ejected from a first nozzle, which is arranged in a predetermined processing position, to the peripheral part of the rotating substrate by adjusting the temperature of the peripheral part before ejecting the first processing liquid to the peripheral part of the rotating substrate from the first nozzle arranged in the processing position; and a step in which the first processing liquid is subsequently ejected to the peripheral part of the rotating substrate from the first nozzle arranged in the processing position.

Description

[Technical Field]

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

[0002] BACKGROUND ART Conventionally, there is known a technique for etching away a film formed on the peripheral edge of a substrate such as a silicon wafer or a compound semiconductor wafer by supplying a processing liquid to the peripheral edge of the substrate (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6815799 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that can suppress variations in the width of film removal from the peripheral edge of a substrate between substrates due to warping of the substrate that occurs temporarily during substrate processing. [Means for solving the problem]

[0005] A substrate processing method according to one embodiment of the present disclosure includes holding a substrate using a holding unit that holds the substrate horizontally and rotatably, then heating the held substrate, then adjusting the temperature of the peripheral portion before a first processing liquid is ejected from a first nozzle positioned at a predetermined processing position onto the peripheral portion of the rotating substrate to approximate the in-plane temperature distribution of the substrate to the in-plane temperature distribution while the first processing liquid is being ejected from the first nozzle positioned at the processing position onto the peripheral portion of the rotating substrate, and then ejecting the first processing liquid from the first nozzle positioned at the processing position onto the peripheral portion of the rotating substrate. [Effects of the Invention]

[0006] According to the present disclosure, it is possible to suppress variations in the width of film removal from the peripheral edge of a substrate between substrates due to temporary warpage of the substrate during substrate processing. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a substrate processing system according to an embodiment. [Figure 2] FIG. 2 is a schematic plan view showing the configuration of a processing unit according to the embodiment. [Figure 3] FIG. 3 is a schematic cross-sectional view showing the configuration of a processing unit according to the embodiment. [Figure 4] FIG. 4 is a flowchart showing a series of processing steps executed by the processing unit according to the embodiment. [Figure 5] FIG. 5 is a timing chart showing an example of the operation of each unit in the temperature adjustment process according to the embodiment. [Figure 6] FIG. 6 is a diagram showing an example of the operation of the chemical liquid nozzle and the back surface nozzle in the temperature adjustment process according to the embodiment. [Figure 7] FIG. 7 is a diagram illustrating an example of the operation of the chemical liquid nozzle and the back surface nozzle in the temperature adjustment process according to the embodiment. [Figure 8] FIG. 8 is a timing chart showing another example of the operation of each unit in the temperature adjustment process according to the embodiment. [Figure 9] FIG. 9 is a timing chart showing another example of the operation of each unit in the temperature adjustment process according to the embodiment. [Figure 10] FIG. 10 is a schematic diagram showing the configuration of a processing unit according to another embodiment. [Figure 11] FIG. 11 is a flowchart showing the procedure of a recipe selection process executed by a processing unit according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, modes for carrying out a substrate processing method and a substrate processing apparatus according to the present disclosure (hereinafter referred to as "embodiments") will be described in detail with reference to the drawings. Note that the substrate processing method and substrate processing apparatus according to the present disclosure are not limited to these embodiments. Furthermore, the respective embodiments can be appropriately combined within the scope of not causing any contradiction in the processing content. Furthermore, the same components in the following embodiments will be given the same reference numerals, and redundant explanations will be omitted.

[0009] In addition, for ease of understanding, the drawings referred to below may show an orthogonal coordinate system in which the X-axis, Y-axis, and Z-axis directions are defined as being orthogonal to each other, with the positive Z-axis direction being the vertically upward direction. Also, the direction of rotation around the vertical axis may be referred to as the θ direction.

[0010] An edge cut process is known in which a film formed on the peripheral edge of a substrate is etched away using a processing liquid. The edge cut process is sometimes performed while heating the substrate in order to increase the etching rate.

[0011] When a processing liquid that is lower in temperature than the substrate (for example, room temperature) is supplied to the peripheral edge of the heated substrate, the temperature of the peripheral edge of the substrate drops. This causes a temperature difference between the peripheral edge and other areas of the substrate (for example, the center of the substrate). This temperature difference causes warping of the substrate. Hereinafter, warping of the substrate caused by the temperature difference between the peripheral edge and other areas of the substrate will be referred to as "thermal warping."

[0012] Thermal warping is a temporary warping that occurs in a substrate, and will disappear once the edge cutting process is complete, that is, once the temperature difference between the peripheral edge and other areas of the substrate is eliminated. Note that thermal warping is caused by the temperature difference between the peripheral edge and other areas of the substrate that occurs during the edge cutting process. Therefore, it goes without saying that a substrate before the edge cutting process will not have thermal warping, even if it has some inherent warping.

[0013] Thermal warping begins to develop gradually immediately after the processing liquid is supplied to the peripheral edge of the substrate. The development of thermal warping then stops after a certain amount of time has passed since the supply of the processing liquid began (thermal warping is complete). Note that the time it takes for thermal warping to complete varies depending on the processing conditions of the edge cut process (heating temperature, flow rate of processing liquid, discharge position of processing liquid, type of processing liquid, substrate type, film type, etc.), but is generally constant if these conditions are the same.

[0014] In edge cutting, a processing solution is ejected from a nozzle, which moves from the outside of the substrate to above the substrate, causing the processing solution to land at a predetermined target landing point on the substrate's peripheral edge. The target landing point is defined as a distance from the substrate's edge, such as "1 mm from the substrate's edge." The width of the film to be removed on the substrate's peripheral edge (hereinafter referred to as "cut width") is defined by the target landing point.

[0015] The position on the substrate that is set as the target liquid landing point fluctuates as the thermal warping progresses. Therefore, if an attempt is made to land the processing liquid on the target liquid landing point while the thermal warping is progressing, i.e., while the position on the substrate that is set as the target liquid landing point is fluctuating, there is a risk of variation in the cut width between substrates.

[0016] Therefore, there is a need for a technology that can precisely etch the peripheral edge of a substrate, specifically, a technology that can suppress variations in the cut width of the peripheral edge of a substrate between substrates due to thermal warping that temporarily occurs during substrate processing.

[0017] Fig. 1 is a diagram showing a schematic configuration of a substrate processing system according to an embodiment. As shown in Fig. 1, the substrate processing system 1 includes a loading / unloading station 2 and a processing station 3. The loading / unloading station 2 and the processing station 3 are provided adjacent to each other.

[0018] The carry-in / out station 2 includes a carrier placement section 11 and a transport section 12. On the carrier placement section 11, a plurality of carriers C are placed, each of which accommodates a plurality of substrates, in this embodiment, semiconductor wafers (hereinafter referred to as wafers W), in a horizontal state.

[0019] The transfer section 12 is provided adjacent to the carrier placement section 11 and includes a substrate transfer device 13 and a transfer section 14. The substrate transfer device 13 includes a wafer holding mechanism that holds the wafer W. The substrate transfer device 13 is capable of moving horizontally and vertically and rotating about a vertical axis, and transfers the wafer W between the carrier C and the transfer section 14 using the wafer holding mechanism.

[0020] The processing station 3 is provided adjacent to the transfer section 12. The processing station 3 includes a transfer section 15 and a plurality of processing units 16 (an example of a substrate processing apparatus). The plurality of processing units 16 are provided side by side on both sides of the transfer section 15. Note that the number of processing units 16 provided in the substrate processing system 1 is not limited to the example shown in the figure.

[0021] The transfer section 15 includes a substrate transfer device 17 therein. The substrate transfer device 17 includes a wafer holding mechanism that holds the wafer W. The substrate transfer device 17 is capable of moving in the horizontal and vertical directions and rotating about a vertical axis, and transfers the wafer W between the delivery section 14 and the processing unit 16 using the wafer holding mechanism.

[0022] The processing unit 16 performs predetermined substrate processing on the wafer W transferred by the substrate transfer device 17 .

[0023] The substrate processing system 1 also includes a control device 4. The control device 4 is, for example, a computer, and includes a control unit 18 and a storage unit 19. The storage unit 19 is realized by, for example, a semiconductor memory element such as a RAM or a flash memory, or a storage device such as a hard disk or an optical disk, and stores programs that control various processes executed in the processing unit 16. The control unit 18 includes a microcomputer having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), input / output ports, etc., and various circuits, and controls the operation of the processing unit 16 by reading and executing the programs stored in the storage unit 19.

[0024] Such a program may be recorded on a computer-readable storage medium and installed from that storage medium into the storage unit 19 of the control device 4. Examples of computer-readable storage media include hard disks (HDs), flexible disks (FDs), compact disks (CDs), magnetic optical disks (MOs), and memory cards.

[0025] In the substrate processing system 1 configured as described above, first, the substrate transfer device 13 in the loading / unloading station 2 removes the wafer W from the carrier C placed on the carrier placement unit 11 and places the removed wafer W on the delivery unit 14. The wafer W placed on the delivery unit 14 is then removed from the delivery unit 14 by the substrate transfer device 17 in the processing station 3 and loaded into the processing unit 16.

[0026] The wafer W carried into the processing unit 16 is processed by the processing unit 16, and then carried out of the processing unit 16 by the substrate transfer device 17 and placed on the transfer section 14. Then, the processed wafer W placed on the transfer section 14 is returned to the carrier C on the carrier placement section 11 by the substrate transfer device 13.

[0027] Next, the configuration of the processing unit 16 according to the embodiment will be described with reference to Fig. 2 and Fig. 3. Fig. 2 is a schematic plan view showing the configuration of the processing unit 16 according to the embodiment. Fig. 3 is a schematic cross-sectional view showing the configuration of the processing unit 16 according to the embodiment. Fig. 3 also shows a schematic cross-section taken along the line III-III in Fig. 2.

[0028] As shown in Figures 2 and 3, the processing unit 16 according to the embodiment includes a processing vessel 10, a holding section 20, a heating mechanism 30, a first supply section 40, a second supply section 50, a lower cup 60, and an outer cup 70.

[0029] The processing vessel 10 accommodates a holder 20, a heating mechanism 30, a first supply unit 40, a second supply unit 50, a lower cup 60, and an outer cup 70.

[0030] The holder 20 rotatably holds the wafer W. Specifically, the holder 20 includes a vacuum chuck 21, a shaft 22, and a drive unit 23. The vacuum chuck 21 suction-holds the wafer W by vacuuming. The vacuum chuck 21 has a smaller diameter than the wafer W and suction-holds the central portion of the back surface of the wafer W. The shaft 22 horizontally supports the vacuum chuck 21 at its tip. The drive unit 23 is connected to the base end of the shaft 22 and rotates the shaft 22 around a vertical axis. The wafer W is held horizontally with its front surface facing upward relative to the holder 20.

[0031] The heating mechanism 30 is disposed below the wafer W and outside the holder 20. Specifically, the heating mechanism 30 is disposed between the holder 20 and the lower cup 60.

[0032] The heating mechanism 30 heats the wafer W by supplying a heated fluid to the backside of the wafer W held by the holder 20. Specifically, the heating mechanism 30 has a plurality of discharge ports arranged in a line in the circumferential direction of the wafer W, and supplies the heated fluid from these plurality of discharge ports to the backside of the wafer W. The heated fluid may be, for example, heated N2 gas.

[0033] When the processing unit 16 is viewed from above, the multiple discharge ports of the heating mechanism 30 are located radially inward of the peripheral edge of the wafer W. As an example, the peripheral edge of the wafer W is an annular region having a width of approximately 1 mm to 3 mm, with the edge face of the wafer W as its outermost periphery. The multiple discharge ports supply heated fluid to the rear surface of the wafer W radially inward of the peripheral edge of the wafer W.

[0034] The first supply unit 40 supplies a processing liquid to the peripheral portion on the front surface side of the wafer W. The first supply unit 40 includes a chemical liquid nozzle 41 (an example of a first nozzle), a rinse nozzle 42, an arm 43, and a movement mechanism 44. The chemical liquid nozzle 41 and the rinse nozzle 42 are disposed above the wafer W with their discharge ports facing downward.

[0035] The chemical liquid nozzle 41 discharges a first processing liquid onto the peripheral edge portion on the front surface side of the wafer W. The first processing liquid is, for example, a chemical liquid that etches and removes a film formed on the front surface of the wafer W. For example, the first processing liquid may be hydrofluoric acid (HF), dilute hydrofluoric acid (DHF), hydrofluoric nitric acid, etc. Hydrofluoric nitric acid is a mixed liquid of hydrofluoric acid (HF) and nitric acid (HNO3).

[0036] The rinse nozzle 42 discharges a rinse liquid onto the peripheral edge of the front surface of the wafer W. The rinse liquid is, for example, DIW (deionized water).

[0037] The temperatures of the first processing liquid and the rinse liquid are lower than the temperature of the wafer W heated by the heating mechanism 30. For example, the temperature of the wafer W heated by the heating mechanism 30 is about 100°C. On the other hand, the temperatures of the first processing liquid and the rinse liquid are room temperature (about 20°C to 25°C).

[0038] Arm 43 extends in the horizontal direction (here, the Y-axis direction) and supports chemical nozzle 41 and rinse nozzle 42 at its tip. Movement mechanism 44 is connected to the base end of arm 43 and moves arm 43, for example, along the horizontal direction (here, the X-axis direction). This allows chemical nozzle 41 and rinse nozzle 42 to move between a processing position above wafer W and a retracted position outside wafer W.

[0039] The second supply unit 50 supplies the second processing liquid to the peripheral edge of the back surface of the wafer W. The second processing liquid may be, for example, a liquid that does not affect the film formed on the back surface of the wafer W. "Does not affect" means, for example, that it does not dissolve the film formed on the back surface of the wafer W (does not contribute to etching). Examples of such a liquid include DIW or an organic solvent. The second processing liquid may also be a chemical liquid that etches and removes the film formed on the back surface of the wafer W. In this case, the second processing liquid may be the same chemical liquid as the first processing liquid.

[0040] The temperature of the second processing liquid is lower than the temperature of the wafer W heated by the heating mechanism 30. For example, the temperature of the second processing liquid is room temperature.

[0041] 3, the second supply unit 50 includes a back surface nozzle 51 (an example of a second nozzle), a pipe 52, a valve 53, a flow rate regulator 54, and a second processing liquid supply source 55. The back surface nozzle 51 is disposed below the wafer W and ejects the second processing liquid toward the peripheral edge of the back surface of the wafer W.

[0042] The target landing point of the second processing liquid on the back surface of the wafer W may be radially inward from the target landing point of the first processing liquid on the front surface of the wafer W. As an example, the target landing point of the first processing liquid may be 1 mm radially inward from the edge of the wafer W. Furthermore, the target landing point of the second processing liquid may be 3 mm radially inward from the edge of the wafer W.

[0043] Although not shown here, the second supply unit 50 may include a movement mechanism that moves the back surface nozzle 51 in the horizontal direction. In this case, the second supply unit 50 can move the back surface nozzle 51 between a processing position below the wafer W and a retracted position outside the wafer W.

[0044] The pipe 52 connects the back surface nozzle 51 and a second processing liquid supply source 55. The valve 53 is provided in the middle of the pipe 52 and opens and closes the pipe 52. The flow rate regulator 54 is provided in the middle of the pipe 52 and adjusts the flow rate of the second processing liquid flowing through the pipe 52. The second processing liquid supply source 55 is, for example, a tank, and stores the second processing liquid.

[0045] When the second processing liquid is a "liquid that does not affect the film formed on the backside of the wafer W," the second processing liquid may be, for example, DIW or an organic solvent. The organic solvent may be, for example, IPA (isopropyl alcohol). When the second processing liquid is a chemical liquid, the second processing liquid may be, for example, hydrofluoric acid (HF), dilute hydrofluoric acid (DHF), hydrofluoric nitric acid, or the like.

[0046] The lower cup 60 is an annular member disposed below the wafer W and outside the heating mechanism 30. The lower cup 60 is formed of a highly chemical-resistant member such as a fluororesin such as PTFE (polytetrafluoroethylene) or PFA (perfluoroalkoxyalkane).

[0047] The outer cup 70 is an annular member provided to surround the wafer W, and receives liquid splashed from the wafer W. A drainage port 71 is formed in the bottom of the outer cup 70. The chemical liquid and the like received by the outer cup 70 is stored in the space formed by the outer cup 70 and the lower cup 60, and then discharged from the drainage port 71 to the outside of the processing unit 16.

[0048] Next, a series of processing procedures executed by the processing unit 16 according to the embodiment will be described with reference to Fig. 4. Fig. 4 is a flowchart showing a series of processing procedures executed by the processing unit 16 according to the embodiment. Each processing procedure shown in Fig. 4 is executed under the control of the control unit 18.

[0049] 4, a loading process is first performed in the processing unit 16 (step S101). In the loading process, the substrate transfer device 17 (see FIG. 1) loads the wafer W into the processing container 10 of the processing unit 16. The loaded wafer W is held by the holder 20 of the processing unit 16.

[0050] Next, the processing unit 16 starts rotating and heating the wafer W (step S102). The rotation of the wafer W is performed by rotating the vacuum chuck 21 using the driving unit 23 of the holder 20. The heating of the wafer W is performed using the heating mechanism 30. The rotation of the wafer W continues until the processing of step S106 is completed. The heating of the wafer W also continues until at least the processing of step S104 is completed.

[0051] Next, a temperature adjustment process is performed in the processing unit 16 (step S103). The temperature adjustment process is a process for adjusting the temperature of the peripheral portion of the wafer W to approximate the in-plane temperature distribution of the wafer W to the in-plane temperature distribution while the first processing liquid is being discharged from the chemical liquid nozzle 41 disposed at the processing position onto the peripheral portion of the rotating wafer W.

[0052] Hereinafter, the in-plane temperature distribution while the first processing liquid is being discharged from chemical liquid nozzle 41 disposed at the processing position onto the peripheral edge of the rotating wafer W will be referred to as the "distribution during processing." The processing position of chemical liquid nozzle 41 is determined, for example, by the horizontal distance from a reference position of chemical liquid nozzle 41 outside of wafer W (nozzle position "P1," described below, the so-called home position). The processing position of chemical liquid nozzle 41 is set in advance as a position of chemical liquid nozzle 41 at which the first processing liquid lands on a target landing point of the first processing liquid (for example, 1 mm from the edge of wafer W).

[0053] In processing unit 16, a process is performed in which chemical liquid nozzle 41 is caused to advance (scan in) from outside wafer W to above wafer W while discharging the first processing liquid from chemical liquid nozzle 41, and chemical liquid nozzle 41 reaches the processing position. In this case, the first processing liquid lands on wafer W before chemical liquid nozzle 41 reaches the processing position. When the first processing liquid, which has a lower temperature than wafer W, lands on the peripheral edge of wafer W, heat is absorbed from the peripheral edge of wafer W, creating a temperature difference between the peripheral edge and other areas of wafer W, resulting in thermal warping.

[0054] The target liquid landing point fluctuates due to thermal warping. If chemical liquid nozzle 41 starts to discharge the first processing liquid at the processing position while thermal warping is progressing, i.e., while the target liquid landing point is fluctuating, the position on wafer W where the first processing liquid actually lands is likely to vary among multiple wafers W. In other words, the cutting width is likely to vary among multiple wafers W.

[0055] Therefore, in the processing unit 16 according to the embodiment, a temperature adjustment process is performed to complete the thermal warping before the first processing liquid is ejected from the chemical nozzle 41 positioned at the processing position onto the peripheral portion of the rotating wafer W.

[0056] After completing the temperature adjustment process in step S103, i.e., after thermal warping is completed, the processing unit 16 of the embodiment starts to eject the first processing liquid from the chemical liquid nozzle 41 positioned at the processing position onto the peripheral portion of the rotating wafer W (step S104).

[0057] In this way, after thermal warping is completed, the first processing liquid is ejected onto the peripheral edge of the rotating wafer W from the chemical nozzle 41 positioned at the processing position, thereby preventing the cut width from varying among multiple wafers W due to thermal warping, even if thermal warping occurs.

[0058] The processing unit 16 continues to discharge the first processing liquid at the processing position for a predetermined time, and then the processing unit 16 finishes discharging the first processing liquid (step S105).

[0059] Subsequently, a rinsing process is performed in processing unit 16 (step S106). In the rinsing process, processing unit 16 discharges a rinsing liquid from chemical liquid nozzle 41 onto the peripheral portion of the front surface side of wafer W. As a result, the first processing liquid remaining on the peripheral portion of wafer W is washed away by the rinsing liquid.

[0060] Subsequently, a drying process is performed in the processing unit 16 (step S107). In the drying process, the processing unit 16 increases the rotation speed of the wafer W. As a result, the liquid remaining on the wafer W is shaken off by centrifugal force, and the wafer W is dried.

[0061] Subsequently, in the processing unit 16, an unloading process is performed (step S108). In the unloading process, the wafer W is unloaded from the processing vessel 10 by the substrate transfer device 17 (see FIG. 1). The wafer W unloaded from the processing vessel 10 is then accommodated in the carrier C by the substrate transfer device 13.

[0062] Next, a specific example of the temperature adjustment process will be described. First, an example of a case where a second processing liquid is discharged onto the back surface of the wafer W to complete thermal warping of the wafer W before discharging a first processing liquid onto the wafer W will be described with reference to FIGS. 5 to 7. FIG. 5 is a timing chart showing an example of the operation of each part in the temperature adjustment process according to the embodiment. FIGS. 6 and 7 are diagrams showing an example of the operation of the chemical liquid nozzle 41 and the back surface nozzle 51 in the temperature adjustment process according to the embodiment.

[0063] 5 shows a timing chart with time on the horizontal axis and nozzle position on the vertical axis, and a timing chart with time on the horizontal axis and processing liquid flow rate on the vertical axis. In Fig. 5, the nozzle position and processing liquid flow rate of chemical liquid nozzle 41 are indicated by solid lines, and the nozzle position and processing liquid flow rate of back surface nozzle 51 are indicated by dashed lines.

[0064] Here, the nozzle positions indicate the horizontal positions of the chemical liquid nozzle 41 and the back surface nozzle 51. Nozzle position "0" is a predetermined position where the processing liquid is ejected onto the edge of the wafer W held by the holder 20. Nozzle positions "P1" and "P2" are both positions outside the wafer W. Nozzle position "P1" is a position farther from the edge of the wafer W than nozzle position "P2". Nozzle position "P3" is the processing position of the chemical liquid nozzle 41, and nozzle position "P4" is the processing position of the back surface nozzle 51. Nozzle position "P4" is located radially inward of the wafer W than nozzle position "P3".

[0065] 5, processing unit 16 first moves chemical nozzle 41 from nozzle position P1 to P2 at time t1, and then moves back surface nozzle 51 from nozzle position P1 to nozzle position P4, which is the processing position, at time t2.

[0066] Next, after the rear surface nozzle 51 reaches the nozzle position P4, at time t3, the processing unit 16 starts discharging the second processing liquid from the rear surface nozzle 51 onto the peripheral portion of the rear surface of the wafer W. The processing unit 16 increases the discharge flow rate of the second processing liquid from 0 to F1 from time t3 to time t4.

[0067] In this way, the processing unit 16 discharges the second processing liquid from the back surface nozzle 51 onto the peripheral edge of the back surface of the wafer W before discharging the first processing liquid (see FIG. 6). This causes the temperature of the peripheral edge of the wafer W to drop, and thermal warping begins to occur. In other words, the temperature distribution of the wafer W begins to approach the in-plane temperature distribution while the first processing liquid is being discharged onto the peripheral edge of the rotating wafer W from the chemical liquid nozzle 41 disposed at the processing position.

[0068] Next, at time t5, processing unit 16 starts discharging the first processing liquid from chemical liquid nozzle 41. At this time, chemical liquid nozzle 41 is still located at nozzle position P2. Therefore, the first processing liquid is discharged outward from wafer W. Processing unit 16 increases the discharge flow rate of the first processing liquid from 0 to F1 from time t5 to time t6.

[0069] Next, at time t7, processing unit 16 starts moving chemical liquid nozzle 41 from nozzle position P2 to nozzle position P3, which is the processing position. Processing unit 16 moves chemical liquid nozzle 41 to nozzle position P3 from time t7 to time t8. In this manner, processing unit 16 causes chemical liquid nozzle 41 to advance (scan in) from outside wafer W to above wafer W while discharging the first processing liquid from chemical liquid nozzle 41, and causes chemical liquid nozzle 41 to reach nozzle position P3, which is the processing position.

[0070] In processing unit 16, the time from time t4 to time t8 (hereinafter referred to as "temperature control period T") is set in advance so that chemical liquid nozzle 41 reaches nozzle position P3 after thermal warping is completed. Time t4 is the time when back surface nozzle 51 starts to discharge the second processing liquid at the processing position at the target flow rate (here, flow rate F1). Also, time t8 is the time when chemical liquid nozzle 41 starts to discharge the first processing liquid at the processing position at the target flow rate (here, flow rate F1).

[0071] In this way, in processing unit 16, the scan-in operation of chemical liquid nozzle 41 is controlled so that chemical liquid nozzle 41 reaches nozzle position P3, which is the processing position, after thermal warping has been completed, that is, after the fluctuation of the target liquid landing point due to thermal warping has settled. This makes it possible to suppress variations in the cutting width among multiple wafers W compared to when chemical liquid nozzle 41 reaches the processing position while the target liquid landing point is fluctuating.

[0072] In this example, the process of starting to eject the second processing liquid from the back surface nozzle 51 onto the peripheral portion of the back surface of the wafer W from time t4, which is before the temperature control period T, at time t8 when the chemical liquid nozzle 41 starts to eject the first processing liquid at the target flow rate at the processing position, is an example of a temperature adjustment process.

[0073] In this example, the second processing liquid may be DIW, an organic solvent, or the like. By performing the temperature adjustment process using such a second processing liquid, the in-plane temperature distribution of the wafer W can be made to approximate the distribution during processing without affecting the film formed on the backside of the wafer W. However, the second processing liquid is not limited to this, and may be a chemical liquid that etches and removes the film formed on the backside of the wafer W.

[0074] Furthermore, while the processing unit 16 is discharging the first processing liquid from the chemical liquid nozzle 41 disposed at the processing position onto the peripheral portion of the front surface side of the wafer W, it continues discharging the second processing liquid onto the peripheral portion of the back surface side of the wafer W. In other words, the second processing liquid is discharged onto the peripheral portion of the back surface side of the wafer W in parallel with the discharge of the first processing liquid at the processing position. This makes it possible to suppress changes in the state of thermal warping during the discharge of the first processing liquid at the processing position, compared to when the discharge of the second processing liquid is stopped midway. Therefore, it is possible to further suppress variations in the cutting width among multiple wafers W.

[0075] Next, a modified example of the temperature adjustment process shown in Figures 5 to 7 will be described with reference to Figure 8. Figure 8 is a timing chart showing another example of the operation of each unit in the temperature adjustment process according to the embodiment.

[0076] 8, processing unit 16 first moves chemical nozzle 41 from nozzle position P1 to P2 at time t11, and then moves back surface nozzle 51 from nozzle position P1 to nozzle position P4, which is the processing position, at time t12.

[0077] Next, after the rear surface nozzle 51 reaches the nozzle position P4, the processing unit 16 starts discharging the second processing liquid from the rear surface nozzle 51 and starts discharging the first processing liquid from the chemical liquid nozzle 41 at time t13.

[0078] The processing unit 16 increases the discharge flow rate of the first processing liquid from 0 to F1 from time t13 to time t14. On the other hand, the processing unit 16 increases the discharge flow rate of the second processing liquid from 0 to F2 (>F1) from time t13 to time t14.

[0079] The processing unit 16 continues to discharge the second processing liquid at the flow rate F2 from time t14 to time t15, and then reduces the discharge flow rate of the second processing liquid from F2 to F1. The processing unit 16 reduces the discharge flow rate of the second processing liquid from F2 to F1 from time t15 to time t16.

[0080] At time t16, processing unit 16 starts moving chemical nozzle 41 from nozzle position P2 to nozzle position P3, which is the processing position. Processing unit 16 moves chemical nozzle 41 to nozzle position P3 from time t16 to time t17.

[0081] In this way, the processing unit 16 discharges the second processing liquid at a first flow rate (flow rate F1) in parallel with the discharge of the first processing liquid at the processing position. Furthermore, before the discharge of the first processing liquid at the processing position is started, the processing unit 16 discharges the second processing liquid at a second flow rate (flow rate F2) that is higher than the first flow rate. By discharging the second processing liquid at a high flow rate before the discharge of the first processing liquid at the processing position is started, the time until thermal warping is completed (temperature control period T) can be shortened. In other words, the time required for a series of processes for one wafer W can be shortened.

[0082] Next, an example of gradually increasing the flow rate of the first processing liquid while the chemical liquid nozzle 41 is moving to approximate the in-plane temperature distribution of the wafer W to the distribution during processing before the chemical liquid nozzle 41 reaches the processing position will be described with reference to Fig. 9. Fig. 9 is a timing chart showing another example of the operation of each part in the temperature adjustment process according to the embodiment.

[0083] 9, processing unit 16 first moves chemical liquid nozzle 41 from nozzle position P1 to P2 at time t21, and then moves back surface nozzle 51 from nozzle position P1 to nozzle position P4, which is the processing position, at time t22.

[0084] Next, after the rear surface nozzle 51 reaches the nozzle position P4, at time t23, the processing unit 16 starts discharging the first processing liquid from the chemical liquid nozzle 41. The processing unit 16 increases the discharge flow rate of the first processing liquid from 0 to F1 from time t23 to time t26.

[0085] At time t24, which is after time t23 when the processing unit 16 starts discharging the first processing liquid and before the discharge flow rate of the first processing liquid reaches flow rate F1, the processing unit 16 starts moving the chemical liquid nozzle 41 from nozzle position P2 to nozzle position P3, which is the processing position. The processing unit 16 moves the chemical liquid nozzle 41 to nozzle position P3 from time t24 to time t25. Time t25 is before time t26 when the discharge flow rate of the first processing liquid reaches the target flow rate.

[0086] Thus, in this example, the discharge flow rate of the first processing liquid increases while chemical liquid nozzle 41 is moving. In other words, the discharge flow rate of the first processing liquid increases as chemical liquid nozzle 41 approaches the processing position. Furthermore, the discharge flow rate of the first processing liquid continues to increase even after chemical liquid nozzle 41 reaches the processing position, and then reaches the target flow rate.

[0087] Around the peripheral edge of the wafer W, an airflow is formed from the inside to the outside of the wafer W due to, for example, a swirling flow generated by the rotation of the wafer W. When the discharge flow rate of the first processing liquid is small, the first processing liquid discharged from the chemical liquid nozzle 41 is easily caused to flow outward of the wafer W by the airflow. Therefore, when the discharge flow rate of the first processing liquid is small, the landing point of the first processing liquid is shifted outward of the wafer W compared to when the discharge flow rate of the first processing liquid is large.

[0088] At the time (time t25) when chemical liquid nozzle 41 reaches the processing position, the discharge flow rate of the first processing liquid has not yet reached the target flow rate F1. Therefore, at this time, the first processing liquid lands radially outward of wafer W from the target landing point due to the influence of the airflow. Thereafter, as the flow rate of the first processing liquid gradually increases, the first processing liquid becomes less susceptible to the influence of the airflow. As a result, the landing point of the first processing liquid gradually approaches the target landing point.

[0089] In this example, the temperature adjustment period T from time t24 to time t26 is set in advance so that the discharge flow rate of the first processing liquid reaches the target flow rate F1 after thermal warping is complete. In this manner, the temperature adjustment process may be performed by increasing the discharge flow rate of the first processing liquid as chemical liquid nozzle 41 approaches the processing position. Alternatively, the temperature adjustment process may be performed by increasing the discharge flow rate of the first processing liquid so that the discharge flow rate of the first processing liquid reaches the target flow rate after chemical liquid nozzle 41 reaches the processing position. By allowing the discharge flow rate of the first processing liquid to reach the target flow rate after thermal warping is complete, i.e., after the fluctuation of the target liquid landing point due to thermal warping has subsided, it is possible to suppress variations in the cut width among multiple wafers W.

[0090] In this example, the processing unit 16 starts discharging the second processing liquid at time t27 after the discharge flow rate of the first processing liquid reaches the target flow rate F1. The processing unit 16 increases the discharge flow rate of the second processing liquid from 0 to F1 between time t27 and time t28.

[0091] Alternatively, the processing unit 16 may perform the temperature adjustment process by scanning in the chemical liquid nozzle 41 at a relatively slow speed to approximate the in-plane temperature distribution of the wafer W to the distribution during processing before the chemical liquid nozzle 41 reaches the processing position. The movement speed of the chemical liquid nozzle 41 may be determined based on the time from when the first processing liquid lands on the wafer W to when thermal warping is completed, which is determined in advance through experiments, for example. In this way, the first processing liquid can be made to reach the processing position after thermal warping is completed, i.e., after the fluctuation of the target liquid landing point due to thermal warping has subsided, thereby suppressing variations in the cut width among multiple wafers W.

[0092] (Other embodiments) 10 is a schematic diagram showing the configuration of a processing unit 16 according to another embodiment. As shown in FIG. 10, the processing unit 16 may include a warpage detection unit 80. The warpage detection unit 80 detects a change in the amount of warpage of the wafer W held by the holder 20.

[0093] The warpage detection unit 80 may be, for example, an imaging unit that captures an image of the peripheral portion of the wafer W. The imaging unit is, for example, a CCD (Charge Coupled Device) camera. An image (moving image) of the peripheral portion of the wafer W captured by the warpage detection unit 80 as an imaging unit is output to the control unit 18.

[0094] The control unit 18 can detect the progress of thermal warpage of the wafer W, i.e., the change in the amount of warpage of the wafer W, based on the image acquired from the warpage detection unit 80. Specifically, the control unit 18 can detect the amount of change in warpage of the wafer W and the time from when the warpage of the wafer W starts to change until the change in warpage settles, based on the image acquired from the warpage detection unit 80. The amount of change in warpage of the wafer W can be detected, for example, based on the amount of displacement of the edge face of the wafer W.

[0095] FIG. 11 is a flowchart showing the procedure of a recipe selection process executed by the processing unit 16 according to another embodiment.

[0096] 11, the control unit 18 determines whether or not the processing conditions for a series of processes performed on the wafer W have been changed (step S201). Here, the processing conditions include, for example, the heating temperature by the heating mechanism 30, the flow rate of the processing liquids (first processing liquid and second processing liquid), the discharge position of the processing liquid, the liquid type of the processing liquid, the substrate type, and the film type. These processing conditions are stored in the storage unit 19 as recipe information. The control unit 18 may determine that the processing conditions have been changed when the content of the recipe information stored in the storage unit 19 has been changed.

[0097] In step S201, if the processing conditions have not been changed (step S201, No), the control unit 18 repeats the processing of step S201. On the other hand, if it is determined that the processing conditions have been changed (step S201, Yes), the control unit 18 performs a thermal warpage detection process (step S202).

[0098] For example, the control unit 18 uses the warpage detection unit 80 to detect a change in the amount of warpage of, for example, the first wafer W among a plurality of wafers W (an example of a group of substrates to be processed) accommodated in the carrier C when a first processing liquid is discharged from the chemical liquid nozzle 41 onto the first wafer W. Specifically, the warpage detection unit 80 acquires an image showing how the peripheral edge of the wafer W gradually warps due to thermal warpage. Based on the image, the control unit 18 detects the amount of change in the warpage of the wafer W and the time from when the warpage of the wafer W starts to change until the change in the warpage settles down.

[0099] Here, the processing of the first wafer W may be performed based on the changed recipe, for example. However, the temperature adjustment processing is not performed. In addition, the "amount of change in warpage of the wafer W" means, in other words, the amount of warpage caused by thermal warpage, excluding the warpage of the wafer W before processing.

[0100] Next, the control unit 18 determines whether the detected amount of thermal warpage exceeds a threshold value (step S203). In this process, if it is determined that the amount of thermal warpage exceeds the threshold value (step S203, Yes), the control unit 18 selects a recipe including a temperature adjustment process (step S204). In other words, the control unit 18 determines to add a temperature adjustment process to a series of processes for the wafer W.

[0101] Next, the control unit 18 determines the time required for the thermal warping to be completed based on the detection result in step S202 (step S205).

[0102] Next, the control unit 18 determines the temperature adjustment period T based on the identified required time (step S206). For example, the control unit 18 may determine the identified required time as the length of the temperature adjustment period T, or may determine the identified required time plus a predetermined time as the length of the temperature adjustment period T. Then, the control unit 18 changes the recipe information of the process executed in step S202 so that the temperature adjustment process is performed during the determined temperature adjustment period T.

[0103] On the other hand, if the amount of thermal warpage does not exceed the threshold value in step S203 (step S203, No), the control unit 18 selects a recipe without temperature adjustment processing (step S207). That is, the control unit 18 does not add temperature adjustment processing to the series of processing for the wafer W. In other words, the control unit 18 does not change the recipe information of the processing executed in step S202.

[0104] When the process of step S206 or step S207 is completed, the control unit 18 ends the recipe selection process.

[0105] Thereafter, the control unit 18 performs a series of processes on the remaining wafers W accommodated in the carrier C in accordance with the recipe determined or selected in step S206 or step S207.

[0106] The warpage detection unit 80 may be something other than an imaging unit. For example, the warpage detection unit 80 may be a temperature detection unit that detects the in-plane temperature distribution of the wafer W. For example, an infrared camera or the like may be used as such a temperature detection unit.

[0107] If the warpage detection unit 80 is a temperature detection unit, the control unit 18 may, for example, in the determination process of step S203, determine whether the difference between the temperature of the peripheral portion of the wafer W and the temperature radially inward of the peripheral portion of the wafer W (for example, the center of the wafer W) exceeds a threshold value.

[0108] As described above, the substrate processing apparatus (for example, processing unit 16) according to the embodiment includes a holder (for example, holder 20), a heating mechanism (for example, heating mechanism 30), a first nozzle (for example, chemical liquid nozzle 41), a second nozzle (for example, back surface nozzle 51), a moving mechanism (for example, moving mechanism 44), and a controller (for example, controller 18). The holder holds a substrate (for example, wafer W) horizontally and rotatably. The heating mechanism heats the substrate held by the holder. The first nozzle supplies a first processing liquid to the peripheral portion of the front surface of the substrate. The second nozzle supplies a second processing liquid to the peripheral portion of the back surface of the substrate. The moving mechanism moves the first nozzle. The controller executes a heating process, a temperature adjustment process, and a first discharge process. In the heating process, the substrate held by the holder is heated using the heating mechanism. In the temperature adjustment process, after the heating process, before the first processing liquid is discharged from the first nozzle arranged at a predetermined processing position onto the peripheral portion of the front surface of the rotating substrate, the second processing liquid is discharged from the second nozzle onto the peripheral portion of the back side of the rotating substrate, thereby approximating the in-plane temperature distribution of the substrate to the in-plane temperature distribution (as an example, the distribution during processing) when the first processing liquid is discharged from the first nozzle arranged at the processing position onto the peripheral portion of the front surface of the rotating substrate. In the first discharge process, after the temperature adjustment process, the first processing liquid is discharged from the first nozzle arranged at the processing position using the movement mechanism onto the peripheral portion of the front surface of the rotating substrate.

[0109] Therefore, the substrate processing apparatus according to the embodiment can suppress variations in the width of film removal from the peripheral edge of a substrate between substrates, which may be caused by temporary warping of the substrate during substrate processing.

[0110] The disclosed embodiments should be considered in all respects as illustrative and not restrictive. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0111] 1. Substrate Processing System 4. Control device 16 Processing Unit 17 Substrate transport device 18 Control Unit 19 Memory section 20 Holding part 21 Vacuum chuck 22 Shaft 23 Drive unit 30 Heating mechanism 40 1st supply section 41 Chemical nozzle 42 Rinse nozzle 43 Arm 44 Moving mechanism 50 2nd supply section 51 Back nozzle 80 Warp detection unit W wafer

Claims

1. holding the substrate using a holder that holds the substrate horizontally and rotatably; Thereafter, heating the held substrate; thereafter, before a first processing liquid is discharged from a first nozzle disposed at a predetermined processing position onto a peripheral portion of the front surface of the rotating substrate, a second processing liquid is discharged from a second nozzle onto the peripheral portion of the back surface of the rotating substrate, thereby approximating an in-plane temperature distribution of the substrate to an in-plane temperature distribution while the first processing liquid is being discharged from the first nozzle disposed at the processing position onto the peripheral portion of the front surface of the rotating substrate; Thereafter, the first processing liquid is discharged from the first nozzle disposed at the processing position onto the peripheral portion of the front surface of the rotating substrate. Including, The approximation and the discharge of the first processing liquid are performed while continuing to heat the substrate.

2. In parallel with the discharging of the first processing liquid, the second processing liquid is discharged from the second nozzle toward the peripheral portion on the back surface side of the rotating substrate. The method of claim 1 , comprising:

3. Discharging the second treatment liquid includes: The second processing liquid is discharged at a first flow rate onto the peripheral edge portion on the back surface side of the substrate; The approximating step may include: The substrate processing method according to claim 2 , wherein the second processing liquid is discharged onto the peripheral portion on the back surface side of the substrate at a second flow rate that is greater than the first flow rate.

4. 2. The substrate processing method according to claim 1, wherein the second processing liquid is a liquid that does not affect a film formed on the rear surface of the substrate.

5. Discharging the first treatment liquid includes: moving the first nozzle from outside the substrate to the processing position while discharging the first processing liquid from the first nozzle; The approximating step may include:

2. The substrate processing method according to claim 1, wherein the discharge flow rate of the first processing liquid is increased as the first nozzle approaches the processing position.

6. When the processing conditions are changed, determining whether or not to perform the approximation on the substrate. The substrate processing method according to any one of claims 1 to 5, comprising:

7. detecting a change in warpage of one of the group of substrates to be processed when the first processing liquid is discharged from the first nozzle onto the one substrate; Including, The determining step comprises: The substrate processing method according to claim 6, further comprising determining whether or not to perform the approximation on substrates to be processed after the first substrate among the group of substrates to be processed, based on the detection results of the detection.

8. a holder that holds the substrate horizontally and rotatably; a heating mechanism for heating the substrate held by the holder; a first nozzle that supplies a first processing liquid to a peripheral portion of the front surface of the substrate; a second nozzle that supplies a second processing liquid to the peripheral portion of the back surface of the substrate; a moving mechanism that moves the first nozzle; Control unit and Equipped with The control unit a heating process for heating the substrate held by the holder using the heating mechanism; a temperature adjustment process in which, after the heating process, before the first processing liquid is discharged from the first nozzle disposed at a predetermined processing position onto the peripheral portion of the front surface of the rotating substrate, the second processing liquid is discharged from the second nozzle onto the peripheral portion of the back surface of the rotating substrate, thereby approximating an in-plane temperature distribution of the substrate to an in-plane temperature distribution obtained when the first processing liquid is discharged from the first nozzle disposed at the processing position onto the peripheral portion of the front surface of the rotating substrate; performing a first discharge process in which, after the temperature adjustment process, the first processing liquid is discharged onto the peripheral portion of the front surface of the rotating substrate from the first nozzle disposed at the processing position using the moving mechanism; The control unit The substrate processing apparatus performs the temperature adjustment process and the first discharge process while continuing the heating process.

9. The control unit The substrate processing apparatus according to claim 8 , further comprising: a second discharging process for discharging the second processing liquid from the second nozzle onto the peripheral portion on the rear surface side of the rotating substrate, in parallel with the first discharging process.

10. The control unit 10. The substrate processing apparatus of claim 9, wherein in the second ejection process, the second processing liquid is ejected from the second nozzle to the peripheral portion of the back surface side of the substrate at a first flow rate, and in the temperature adjustment process, the second processing liquid is ejected from the second nozzle to the peripheral portion of the back surface side of the substrate at a second flow rate that is greater than the first flow rate.

11. The control unit 9. The substrate processing apparatus of claim 8, wherein, in the first ejection process, the first nozzle is moved from outside the substrate to the processing position while ejecting the first processing liquid from the first nozzle, and, in the temperature adjustment process, the ejection flow rate of the first processing liquid is increased as the first nozzle approaches the processing position.

12. a warpage detection unit that detects a change in warpage of the substrate held by the holding unit; Equipped with The control unit a detection process of detecting, using the warp detection unit, a change in warp of one of the group of substrates to be processed when the first processing liquid is discharged from the first nozzle onto the one substrate; A substrate processing apparatus according to any one of claims 8 to 11, further comprising: a determination process for determining whether or not to perform the temperature adjustment process on substrates to be processed after the first substrate among the group of substrates to be processed, based on the detection results of the detection process.

13. The substrate processing apparatus according to claim 12 , wherein the warpage detection unit is an imaging unit that images the peripheral edge portion of the substrate.

14. The substrate processing apparatus according to claim 12 , wherein the warpage detection unit is a temperature detection unit that detects an in-plane temperature distribution of the substrate.

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