Substrate transport method, substrate processing apparatus, and recording medium

Abstract

To provide a substrate transfer method capable of preventing photocorrosion from occurring on the surface of a substrate.SOLUTION: In a substrate transport method, a substrate is transported into a receiving unit, and the presence of the substrate in the receiving unit is confirmed by detecting that the light emitted from an optical sensor 302 is blocked by the substrate transported to the receiving unit. Then, before the substrate is unloaded from the receiving unit, light irradiation from the optical sensor 302 is stopped.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a substrate transfer method, a substrate processing apparatus, and a non-transitory computer-readable recording medium on which a program for operating components of the substrate processing apparatus is recorded. [Background technology]

[0002] BACKGROUND ART Substrate processing apparatuses for processing substrates such as wafers are known (see, for example, Patent Document 1). In such substrate processing apparatuses, wafers are transported to various modules and processed in each module.

[0003] The substrate processing apparatus is equipped with an optical sensor that detects whether a wafer is present on the transfer stage of the substrate processing apparatus. When a wafer is transferred to each module, the wafer is transferred to the next module only after its presence is detected by the optical sensor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-050436 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, as semiconductor devices have become more highly integrated and denser, circuit wiring has become increasingly finer and the number of layers in multi-layer wiring has increased. Therefore, when light emitted from an optical sensor is irradiated onto a wafer, the metal formed on the wafer surface (more specifically, the device surface) is affected by the light and corrodes. In other words, photocorrosion occurs on the wafer surface.

[0006] Therefore, an object of the present invention is to provide a substrate transport method, a substrate processing apparatus, and a recording medium that can prevent photocorrosion from occurring on the surface of a substrate (for example, a wafer). [Means for solving the problem]

[0007] In one aspect, a substrate transport method in a substrate processing apparatus is provided, which involves transporting a substrate into a receiving unit for the substrate, detecting that light emitted from an optical sensor has been blocked by the substrate transported to the receiving unit, confirming that the substrate is present in the receiving unit, and stopping the emission of light from the optical sensor before transporting the substrate from the receiving unit.

[0008] In one aspect, the substrate is wet-processed in a wet processing module that is arranged upstream of the receiving unit in the transport direction of the substrate, and the optical sensor irradiates light onto the substrate that has been wet-processed in the wet processing module. In one aspect, after the light emitted from the optical sensor is blocked by the substrate brought into the receiving unit, it is confirmed that the substrate is present in the receiving unit within a predetermined time period after the substrate is placed on the mounting stage of the receiving unit, and after the predetermined time period has elapsed, the emission of light from the optical sensor is stopped. In one aspect, the light emitted from the optical sensor is stopped after a predetermined time has elapsed since the light emitted from the optical sensor was blocked by the substrate carried into the receiving unit.

[0009] In one aspect, when the substrate is placed on the mounting stage of the receiving unit, light irradiation from the optical sensor begins, and it is confirmed that the substrate is present in the receiving unit within a predetermined period of time after the substrate is placed on the mounting stage of the receiving unit, and after the predetermined period of time has elapsed, light irradiation from the optical sensor is stopped. In one aspect, the light sensor starts irradiating light before the substrate is transported to the receiving unit, and after confirming that the substrate is not present in the receiving unit, the light sensor stops irradiating light.

[0010] In one aspect, a substrate processing apparatus is provided, comprising: a receiving unit for a substrate; an optical sensor for detecting the presence or absence of the substrate transported to the receiving unit; and a control device for controlling the light projection operation of the optical sensor. The control device transports the substrate into the receiving unit, detects that the light emitted from the optical sensor is blocked by the substrate transported to the receiving unit, confirms that the substrate is present in the receiving unit, and stops the light projection from the optical sensor before transporting the substrate from the receiving unit.

[0011] In one aspect, the substrate processing apparatus includes a wet processing module that wet-processes the substrate and is arranged upstream of the receiving unit in the transport direction of the substrate, and the optical sensor irradiates light onto the substrate that has been wet-processed in the wet processing module. In one aspect, after the light irradiated from the optical sensor is blocked by the substrate brought into the receiving unit, the control device confirms that the substrate is present in the receiving unit within a predetermined period of time from when the substrate was placed on the loading stage of the receiving unit, and stops irradiating light from the optical sensor after the predetermined period of time has elapsed. In one aspect, the control device stops emitting light from the optical sensor after a predetermined time has elapsed since the light emitted from the optical sensor was blocked by the substrate carried into the receiving unit.

[0012] In one aspect, the control device starts irradiating light from the optical sensor when the substrate is placed on the mounting stage of the receiving unit, confirms that the substrate is present in the receiving unit within a predetermined time period after the substrate is placed on the mounting stage of the receiving unit, and stops irradiating light from the optical sensor after the predetermined time period has elapsed. In one aspect, the control device starts irradiating light from the optical sensor before the substrate is transported to the receiving unit, and stops irradiating light from the optical sensor after confirming that the substrate is not present in the receiving unit. In one aspect, the optical sensor comprises a light-emitting unit that emits light and a light-receiving unit that receives the light emitted from the light-emitting unit, the light-emitting unit being positioned on the back side of the substrate transported to the receiving unit, and the light-receiving unit being positioned on the front side of the substrate transported to the receiving unit.

[0013] In one aspect, the light projecting unit and the light receiving unit are disposed perpendicular to the transport direction of the substrate. In one aspect, the light projecting unit and the light receiving unit are disposed obliquely with respect to the transport direction of the substrate.

[0014] In one aspect, a non-transitory computer-readable recording medium is provided that stores a program for causing a computer to execute the steps of: transporting a substrate into a receiving unit for the substrate, detecting that light emitted from an optical sensor has been blocked by the substrate transported to the receiving unit, and confirming that the substrate is present in the receiving unit; and stopping the emission of light from the optical sensor before transporting the substrate out of the receiving unit.

[0015] In one aspect, a program is recorded to cause a computer to execute the steps of wet-processing the substrate in a wet-processing module that is positioned upstream of the receiving unit in the transport direction of the substrate, and wet-processing the substrate in a wet-processing module, and irradiating light onto the substrate that has been wet-processed in the wet-processing module using the optical sensor. In one aspect, a program is recorded to cause a computer to execute the following steps: after the light irradiated from the optical sensor is blocked by the substrate carried into the receiving unit, confirming that the substrate is present in the receiving unit within a predetermined time period from when the substrate is placed on the mounting stage of the receiving unit; and after the predetermined time period has elapsed, stopping the irradiation of light from the optical sensor. In one aspect, a program is recorded to cause a computer to execute a step of stopping the emission of light from the optical sensor after a predetermined time has elapsed since the light emitted from the optical sensor was blocked by the substrate carried into the receiving unit. In one aspect, a program is recorded to cause a computer to execute the following steps: starting to irradiate light from the optical sensor when the substrate is placed on the mounting stage of the receiving unit; confirming that the substrate is present in the receiving unit within a predetermined time period after the substrate is placed on the mounting stage of the receiving unit; and stopping to irradiate light from the optical sensor after the predetermined time period has elapsed. [Effects of the Invention]

[0016] In the substrate transfer method, the substrate is transferred into the transfer station, light from the optical sensor is irradiated, and the light irradiation is stopped before the substrate is transferred from the transfer station. Therefore, the problem of the light from the optical sensor continuing to irradiate the wafer W does not occur. As a result, the occurrence of photocorrosion on the surface of the substrate can be prevented. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a plan view showing an embodiment of a substrate processing apparatus; [Figure 2] FIG. 2(a) is a plan view showing the cleaning unit, and FIG. 2(b) is a side view showing the cleaning unit. [Figure 3] FIG. 10 is a diagram showing a transfer station arranged on a wafer transport path. [Figure 4] 10A and 10B are diagrams illustrating other embodiments of the light projecting unit and the light receiving unit. [Figure 5] 5(a) to 5(c) are diagrams showing a wafer being carried into the transfer station. [Figure 6] FIG. 10 is a diagram showing a control flow of the light projecting operation of the optical sensor by the control device when the wafer is carried into the transfer station. [Figure 7] 10A-10C illustrate one embodiment of the operation of the controller to transfer a wafer into and out of the transfer station. [Figure 8] 8(a) and 8(b) are diagrams showing the wafer being carried out from the transfer station. [Figure 9] FIG. 10 is a diagram showing a control flow of the light projecting operation of the optical sensor by the control device when the wafer is carried out from the transfer station. [Figure 10] FIG. 10 is a diagram showing how the presence of a wafer is confirmed before the wafer is carried out from the transfer station. [Figure 11] FIG. 10 is a diagram showing a control flow of the light projecting operation of the optical sensor by the control device before the wafer is carried out from the transfer station. [Figure 12] FIG. 10 is a diagram showing a control flow of the light projecting operation of the optical sensor by the control device when the wafer is carried into the transfer station. [Figure 13] 10A and 10B are diagrams illustrating another embodiment of the operation of the control device for loading a wafer into the transfer station and unloading the wafer from the transfer station. [Figure 14]FIG. 10 is a diagram showing a control flow of the light projecting operation of the optical sensor by the control device when the wafer is carried into the transfer station. [Figure 15] 10A and 10B are diagrams illustrating another embodiment of the operation of the control device for loading a wafer into the transfer station and unloading the wafer from the transfer station. DETAILED DESCRIPTION OF THE INVENTION

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a substrate processing apparatus according to the present invention will be described in detail with reference to the accompanying drawings. The same or corresponding components will be designated by the same reference numerals and redundant description will be omitted.

[0019] Fig. 1 is a plan view showing one embodiment of a substrate processing apparatus. As shown in Fig. 1, the substrate processing apparatus includes a substantially rectangular housing 1. The interior of the housing 1 is partitioned by partition walls 1a and 1b into a load / unload section 2, a polishing section 3, and a cleaning section 4.

[0020] The load / unload unit 2, polishing unit 3, and cleaning unit 4 are each assembled independently and evacuated independently. The substrate processing apparatus includes a control device 5 that controls the substrate processing operation. The load / unload unit 2 includes two or more (four in this embodiment) front load units 20 on which wafer cassettes that stock a large number of wafers (substrates) are placed.

[0021] The front loading unit 20 is disposed adjacent to the housing 1 and is arranged along the width direction (direction perpendicular to the longitudinal direction) of the substrate processing apparatus. An open cassette, a Standard Manufacturing Interface (SMIF) pod, or a Front Opening Unified Pod (FOUP) can be mounted on the front loading unit 20. The SMIF and FOUP are airtight containers that store wafer cassettes and are covered with a partition wall, thereby maintaining an environment independent from the external space.

[0022] In the load / unload section 2, a traveling mechanism 21 is installed along the arrangement direction of the front load section 20, and two transfer robots (loaders) 22 that can move along the arrangement direction of the wafer cassettes are installed on this traveling mechanism 21. The transfer robots 22 can access the wafer cassettes mounted on the front load section 20 by moving on the traveling mechanism 21.

[0023] The polishing section 3 is an area where wafer polishing (planarization) is performed, and includes a first polishing module 3A, a second polishing module 3B, a third polishing module 3C, and a fourth polishing module 3D. The first polishing module 3A, the second polishing module 3B, the third polishing module 3C, and the fourth polishing module 3D are arranged along the longitudinal direction of the substrate processing apparatus, as shown in FIG.

[0024] As shown in FIG. 1, the first polishing module 3A includes a polishing table 30A on which a polishing pad 10 having a polishing surface is attached, a top ring 31A for holding a wafer and polishing the wafer while pressing it against the polishing pad 10 on the polishing table 30A, a polishing liquid supply nozzle 32A for supplying a polishing liquid or a dressing liquid (e.g., pure water) to the polishing pad 10, a dresser 33A for dressing the polishing surface of the polishing pad 10, and an atomizer 34A for spraying a mixed fluid of a liquid (e.g., pure water) and a gas (e.g., nitrogen gas) or a liquid (e.g., pure water) onto the polishing surface in the form of a mist.

[0025] Similarly, the second polishing module 3B includes a polishing table 30B having a polishing pad 10 attached thereto, a top ring 31B, a polishing liquid supply nozzle 32B, a dresser 33B, and an atomizer 34B. The third polishing module 3C includes a polishing table 30C having a polishing pad 10 attached thereto, a top ring 31C, a polishing liquid supply nozzle 32C, a dresser 33C, and an atomizer 34C. The fourth polishing module 3D includes a polishing table 30D having a polishing pad 10 attached thereto, a top ring 31D, a polishing liquid supply nozzle 32D, a dresser 33D, and an atomizer 34D.

[0026] The transfer mechanism for transferring wafers will now be described. As shown in Fig. 1, the substrate processing apparatus includes a first linear transporter 6 disposed adjacent to a first polishing module 3A and a second polishing module 3B. The first linear transporter 6 is a mechanism for transferring wafers between four transfer positions (first transfer position TP1, second transfer position TP2, third transfer position TP3, and fourth transfer position TP4) along the arrangement direction of the polishing modules 3A and 3B.

[0027] The substrate processing apparatus includes a second linear transporter 7 disposed adjacent to the third polishing module 3C and the fourth polishing module 3D. The second linear transporter 7 is a mechanism for transporting wafers between three transfer positions (fifth transfer position TP5, sixth transfer position TP6, and seventh transfer position TP7) along the arrangement direction of the polishing modules 3C and 3D.

[0028] The wafer is transported to the polishing modules 3A and 3B by the first linear transporter 6. The top ring 31A of the first polishing module 3A moves between the polishing position and the second transfer position TP2 by its swing motion. Therefore, the wafer is transferred to and from the top ring 31A at the second transfer position TP2.

[0029] Similarly, the top ring 31B of the second polishing module 3B moves between the polishing position and the third transfer position TP3, and wafers are transferred to and from the top ring 31B at the third transfer position TP3. The top ring 31C of the third polishing module 3C moves between the polishing position and the sixth transfer position TP6, and wafers are transferred to and from the top ring 31C at the sixth transfer position TP6. The top ring 31D of the fourth polishing module 3D moves between the polishing position and the seventh transfer position TP7, and wafers are transferred to and from the top ring 31D at the seventh transfer position TP7.

[0030] At the first transfer position TP1, a lifter 11 is disposed for receiving a wafer from the transfer robot 22. The wafer is delivered from the transfer robot 22 to the first linear transporter 6 via the lifter 11.

[0031] The substrate processing apparatus includes a shutter (not shown) provided on the partition wall 1a. The shutter is disposed between the lifter 11 and the transfer robot 22. When transferring a wafer, the shutter is opened and the wafer is handed over from the transfer robot 22 to the lifter 11. A swing transporter 12 is disposed between the first linear transporter 6, the second linear transporter 7, and the cleaning unit 4.

[0032] The swing transporter 12 has a hand that can move between the fourth transfer position TP4 and the fifth transfer position TP5. The swing transporter 12 transfers wafers from the first linear transporter 6 to the second linear transporter 7. The wafers are transported by the second linear transporter 7 to the third polishing module 3C and / or the fourth polishing module 3D. The wafers polished in the polishing unit 3 are transported by the swing transporter 12 to the cleaning unit 4 via the temporary table 180. That is, the swing transporter 12 holds the wafer positioned at the fourth transfer position TP4 or the fifth transfer position TP5, turns the wafer over, and then transports it to the temporary table 180. As a result, the wafer is placed on the temporary table 180 with its device surface facing upward.

[0033] Fig. 2(a) is a plan view showing the cleaning unit, and Fig. 2(b) is a side view showing the cleaning unit. As shown in Fig. 2(a) and Fig. 2(b), the cleaning unit 4 is partitioned into a first cleaning chamber 190, a first transfer chamber 191, a second cleaning chamber 192, a second transfer chamber 193, and a drying chamber 194. An upper primary cleaning module 201A and a lower primary cleaning module 201B are arranged in the vertical direction within the first cleaning chamber 190.

[0034] The upper primary cleaning module 201A is disposed above the lower primary cleaning module 201B. Similarly, an upper secondary cleaning module 202A and a lower secondary cleaning module 202B are disposed in the second cleaning chamber 192, arranged in the vertical direction. The upper secondary cleaning module 202A is disposed above the lower secondary cleaning module 202B. The primary and secondary cleaning modules 201A, 201B, 202A, and 202B are cleaning machines that clean wafers using a cleaning liquid.

[0035] A wafer temporary placement table 203 is provided between the upper secondary cleaning module 202A and the lower secondary cleaning module 202B. An upper drying module 205A and a lower drying module 205B are arranged in the vertical direction in the drying chamber 194. The upper drying module 205A and the lower drying module 205B are isolated from each other.

[0036] Filter fan devices 207, 207 that supply clean air into the drying modules 205A, 205B are provided above the upper drying module 205A and the lower drying module 205B, respectively.

[0037] A first transfer robot 209 that is capable of moving up and down is disposed in the first transfer chamber 191, and a second transfer robot 210 that is also capable of moving up and down is disposed in the second transfer chamber 193. The first transfer robot 209 and the second transfer robot 210 are movably supported by support shafts 211 and 212 that extend vertically, respectively.

[0038] The first transfer robot 209 and the second transfer robot 210 are movable up and down along support shafts 211 and 212. As shown by the dotted line in FIG. 2(a), the first transfer robot 209 is disposed in a position where it can access the temporary placement table 180. When the first transfer robot 209 accesses the temporary placement table 180, a shutter (not shown) provided on the partition wall 1b opens.

[0039] The first transfer robot 209 operates to transfer the wafer W between the temporary placement table 180, the upper primary cleaning module 201A, the lower primary cleaning module 201B, the temporary placement table 203, the upper secondary cleaning module 202A, and the lower secondary cleaning module 202B.

[0040] The second transfer robot 210 operates to transfer the wafer W among the upper secondary cleaning module 202A, the lower secondary cleaning module 202B, the temporary placement table 203, the upper drying module 205A, and the lower drying module 205B.

[0041] 1 takes out a wafer from the upper drying module 205A or the lower drying module 205B and returns the wafer to the wafer cassette. When the transfer robot 22 accesses the drying module 205A or 205B, a shutter (not shown) provided on the partition wall 1a is opened.

[0042] As described above, a wafer is transported through the load / unload unit 2, polishing unit 3, and cleaning unit 4 in this order. When a wafer is transported to each module, its presence is detected by an optical sensor before it is transported to the next module. In this embodiment, when a wafer is transported to modules such as polishing modules 3A to 3D in the polishing unit 3 and cleaning modules 201A, 201B, 202A, and 202B in the cleaning unit 4, its presence is detected at the first transfer position TP1 to the seventh transfer position TP7.

[0043] The optical sensor can detect the presence of the wafer W without coming into contact with the wafer W. However, if the light emitted from the optical sensor is irradiated onto the wafer W for a long period of time, photocorrosion occurs on the surface of the wafer W (more specifically, the device surface). Therefore, the substrate processing apparatus has a configuration that prevents photocorrosion from occurring on the surface of the wafer W.

[0044] 3 is a diagram showing a transfer station arranged on a wafer transfer path. As shown in FIG. 3, the substrate processing apparatus includes a transfer station 301 arranged on a wafer W transfer path. The wafer W transfer path corresponds to the movement path of a single wafer W when it is transferred to the load / unload unit 2, the polishing unit 3, and the cleaning unit 4. The transfer station 301 corresponds to a transfer position when transferring the wafer W to each module (for example, a space where each transfer position TP2, TP3, TP6, TP7 and each temporary placement table 180, 203 are arranged).

[0045] 3, the substrate processing apparatus includes an optical sensor 302 that detects the presence or absence of a wafer W transferred to a transfer station 301, and a mounting stage 300 on which the wafer W is mounted. The mounting stage 300 corresponds to, for example, each of the temporary mounting tables 180 and 203.

[0046] The optical sensor 302 includes a light-projecting unit 302a that emits light and a light-receiving unit 302b that receives the light emitted from the light-projecting unit 302a. The light-projecting unit 302a is disposed below the upper end of the mounting stage 300 (i.e., the mounting surface of the wafer W) so as to be located on the backside of the wafer W mounted on the mounting stage 300. The light-receiving unit 302b is disposed above the upper end of the mounting stage 300 so as to be located on the front side of the wafer W mounted on the mounting stage 300. In the embodiment shown in FIG. 3, the light-projecting unit 302a and the light-receiving unit 302b are disposed perpendicular to the transport direction of the wafer W (i.e., the horizontal direction).

[0047] Fig. 4 is a diagram showing another embodiment of the light-projecting unit and the light-receiving unit. As shown in Fig. 4, the light-projecting unit 302a and the light-receiving unit 302b are disposed obliquely with respect to the transfer direction of the wafer W (i.e., the horizontal direction). In the embodiment shown in Fig. 4, the light-projecting unit 302a is also disposed below the wafer W placed on the mounting stage 300, and the light-receiving unit 302b is disposed above the wafer W placed on the mounting stage 300.

[0048] 3 and 4, the wafer W is placed on the mounting stage 300 with its top surface (i.e., the device surface) facing upward. Therefore, the light emitted from the light projecting unit 302a is irradiated onto the back surface of the wafer W. By projecting the light onto the back surface of the wafer W, the light is not directly irradiated onto the device surface of the wafer W, thereby reducing the effect of the light on the device surface of the wafer W. As a result, the occurrence of photocorrosion on the device surface of the wafer can be suppressed.

[0049] The amount (intensity) of light emitted from the light projector 302a attenuates depending on the distance. In the embodiment shown in Fig. 4, the obliquely irradiated light is irradiated onto the back surface of the wafer W with an attenuated amount (intensity). Therefore, the effect of light on the device surface of the wafer W can be further reduced, and as a result, the occurrence of photocorrosion on the device surface of the wafer can be further suppressed.

[0050] Furthermore, by irradiating the light obliquely, the area irradiated with the light onto the back surface of the wafer W can be increased, thereby preventing localized irradiation of the light onto the back surface of the wafer W. As a result, the occurrence of photocorrosion on the device surface of the wafer can be further suppressed.

[0051] 3 and 4, the optical sensor 302 is electrically connected to the control device 5. The control device 5 is configured to control the light projection operation (i.e., start and stop of light irradiation) of the optical sensor 302 (more specifically, the light projector 302a).

[0052] When the light-receiving unit 302b receives the light emitted from the light-projecting unit 302a, the light-receiving unit 302b is configured to send a detection signal to the control device 5. When the control device 5 receives the detection signal from the light-receiving unit 302b, the control device 5 determines that the wafer W is not present on the mounting stage 300. When the light emitted from the light-projecting unit 302a is blocked by the wafer W, the light-receiving unit 302b does not detect the light emitted from the light-projecting unit 302a, and transmission of the detection signal to the control device 5 is stopped. Based on the stop of transmission of the detection signal, the control device 5 determines that the wafer W has been placed on the mounting stage 300.

[0053] The control device 5 includes a storage device 5a that stores a program, and a processing device 5b that executes calculations in accordance with the program. The control device 5, which is configured as a computer, operates in accordance with the program electrically stored in the storage device 5a. The program causes the processing device 5b to execute the light-projecting operation of the optical sensor 302.

[0054] The program for causing the processing device 5b to execute the light projecting operation is stored in a computer-readable recording medium, which is a non-transitory tangible item, and is provided to the control device 5 via the recording medium. Alternatively, the program may be input to the control device 5 from a communication device (not shown) via a communication network such as the Internet or a local area network. The recording medium stores not only the program for causing the processing device 5b to execute the light projecting operation, but also a program (described later) for preventing the occurrence of photocorrosion on the surface of the wafer W.

[0055] Figures 5(a) to 5(c) are diagrams showing a wafer being carried into a transfer station. Figure 6 is a diagram showing a control flow of the light projection operation of the optical sensor by the control device when the wafer is carried into the transfer station. Figure 7 is a diagram showing one embodiment of the operation of the control device when the wafer is carried into the transfer station and when the wafer is carried out from the transfer station.

[0056] In the embodiment described below, an example will be described in which the wafer W polished in the polishing unit 3 is transported to the cleaning unit 4. Therefore, the mounting stage 300 arranged in the delivery station 301 corresponds to the temporary placement table 180 (see FIG. 1). The swing transporter 12 and the first transfer robot 209 (see FIG. 1) can access the temporary placement table 180 in the delivery station 301.

[0057] The control device 5 is configured to load the wafer W into the transfer station 301, operate the optical sensor 302 to irradiate light from the optical sensor 302, and stop the irradiation of light from the optical sensor 302 by operating the optical sensor 302 before the wafer W is removed from the transfer station 301.

[0058] 5(a) and step S101 in FIG. 6, the control device 5 starts irradiating light from the light projector 302a (light projection ON) and starts the operation of loading the wafer W. In one embodiment, the control device 5 may continue irradiating light from the light projector 302a from the time the previous wafer W is unloaded from the transfer station 301 until the time the next wafer W is loaded into the transfer station 301. With this configuration, it is not necessary to determine a trigger for starting irradiation of light from the light projector 302a before the next wafer W is loaded into the transfer station 301.

[0059] In one embodiment, the control device 5 may stop the emission of light from the light-projecting unit 302a (light projection OFF) after the previous wafer W is unloaded from the transfer station 301, and may start the emission of light from the light-projecting unit 302a (light projection ON) when the next wafer W is loaded into the transfer station 301. The control device 5 may start the emission of light, for example, at the timing when the swing transporter 12 starts the operation of loading the wafer W (more specifically, at the timing when the swing transporter 12 holding the wafer W changes direction to the transfer station 301). With this configuration, the light from the optical sensor 302 is intermittently emitted, thereby achieving a long life of the optical sensor 302.

[0060] As shown in FIG. 5(b), when the wafer W is carried into the transfer station 301 by the swing transporter 12, the light emitted from the light projector 302a is blocked by the wafer W. In the embodiment shown in FIG. 7, the control device 5 starts checking the presence of the wafer W when the wafer W is placed on the placement stage 300 after the light emitted from the optical sensor 302 is blocked by the wafer W carried into the transfer station 301. In other words, the control device 5 starts checking the presence of the wafer W when the carrying-in operation of the wafer W is completed. With this configuration, the control device 5 can determine that the wafer W has been reliably placed on the placement stage 300.

[0061] If the mounting stage 300 has a chuck for holding the wafer W, the controller 5 starts checking for the presence of the wafer W when the closure of the chuck of the mounting stage 300 is used as a trigger. If the mounting stage 300 does not have a chuck, the controller 5 starts checking for the presence of the wafer W when the swing transporter 12 issues a signal indicating the completion of the loading operation of the wafer W. For example, the signal is issued when the swing transporter 12 has descended to the lowest position.

[0062] After the controller 5 completes the loading operation of the wafer W (see step S102 in FIG. 6) and starts checking for the presence of the wafer W, the controller 5 determines whether the light reception by the light receiving unit 302b is blocked for a predetermined time (see step S103 in FIG. 6). If the light reception is blocked for a predetermined time (see "YES" in step S103 in FIG. 6), the controller 5 stops emitting light from the light projecting unit 302a (see FIG. 5(c) and step S104 in FIG. 6) and simultaneously ends checking for the presence of the wafer W (see FIG. 7).

[0063] In this embodiment, the predetermined time is 0.3 seconds or less, but the predetermined time may be set depending on the resolution of the optical sensor 302. If the optical sensor 302 has a relatively high resolution, the predetermined time may be 20 milliseconds or less.

[0064] Conventionally, light from the optical sensor 302 is constantly irradiated onto the wafer W from before the wafer W is transferred into the transfer station 301 until the wafer W is transferred out of the transfer station 301, so that the outer surface of the wafer W is continuously irradiated with light while the wafer W is staying in the transfer station 301. Therefore, there is a high possibility that photocorrosion will occur on the outer surface and inside of the wafer W.

[0065] According to this embodiment, the control device 5 is configured to load the wafer W into the transfer station 301, start irradiating the wafer W with light from the optical sensor 302, and stop irradiating the wafer W with light from the optical sensor 302 before the wafer W is unloaded from the transfer station 301. Therefore, there is no problem in that the wafer W is continuously irradiated with light from the optical sensor 302. As a result, the control device 5 can prevent photocorrosion from occurring on the outer surface and inside of the wafer W.

[0066] 6, if the received light is not interrupted until a predetermined time has elapsed (see "NO" in step S103 in FIG. 6), the control device 5 determines that an abnormality has occurred in the apparatus, such as the optical sensor 302 or the swing transporter 12, or the wafer W, and issues an abnormality alarm (see step S105 in FIG. 6). Thereafter, the control device 5 stops the emission of light from the light projecting unit 302a (see step S106 in FIG. 6).

[0067] 6, it may be determined whether the light reception continues to be blocked until a predetermined time has elapsed, thereby preventing erroneous detection when the light is blocked for a very short time due to an environmental disturbance such as water, and detecting that the wafer W is cracked on the hand of the swing transporter 12.

[0068] 8(a) and 8(b) are diagrams showing a wafer being transferred from the transfer station. Fig. 9 is a diagram showing a control flow of the light projection operation of the optical sensor by the control device when the wafer is transferred from the transfer station. As shown in Figs. 7 and 8(a), when the wafer W placed on the mounting stage 300 is to be transferred from the transfer station 301, the control device 5 opens the shutter 305 provided in the transfer station 301 and starts the operation of transferring the wafer W.

[0069] After opening the shutter 305, the control device 5 causes the first transfer robot 209 to access the wafer W on the mounting stage 300. The wafer W is carried out from the delivery station 301 while being held by the first transfer robot 209, and the control device 5 closes the shutter 305 and completes the operation of carrying out the wafer W (see FIG. 8(b) and step S201 in FIG. 9).

[0070] 7 and 8(b), the controller 5 starts emitting light from the light projecting unit 302a, triggered by the closing of the shutter 305, and starts checking for the presence of the wafer W (see step S202 in FIG. 9). As shown in step S203 in FIG. 9, the controller 5 determines whether or not light reception is interrupted during the period from the start of checking for the presence of the wafer W until a predetermined time has elapsed. In this case, too, the predetermined time is determined to be an extremely short time (for example, 0.3 seconds or less, 20 milliseconds or less) depending on the resolution of the optical sensor 302.

[0071] If the light reception is not interrupted for a predetermined time (see "NO" in step S203 in FIG. 9), the control device 5 determines that the wafer W is not present on the mounting stage 300, and ends the confirmation of the presence of the wafer W, and stops the irradiation of light from the light projecting unit 302a (see step S204 in FIG. 9). By this operation, the control device 5 can prevent the wafer W from being dropped off the mounting stage 300.

[0072] If the light reception is interrupted (see "YES" in step S203 in FIG. 9), for example, if the first transfer robot 209 fails to pick up the wafer W, the control device 5 determines that the wafer W is present on the mounting stage 300 and issues an abnormality alarm (see step S205 in FIG. 9). Thereafter, the light irradiation from the light projecting unit 302a is stopped (see step S206 in FIG. 9).

[0073] Fig. 10 is a diagram showing how the presence of a wafer is confirmed before the wafer is transferred from the transfer station. Fig. 11 is a diagram showing a control flow of the light projection operation of the optical sensor by the control device before the wafer is transferred from the transfer station. As shown in Figs. 10 and 11, the control device 5 may confirm the presence of the wafer W when the wafer W placed on the mounting stage 300 is transferred from the transfer station 301.

[0074] More specifically, the controller 5, triggered by the opening of the shutter 305, starts emitting light from the light-projecting unit 302a (see step S301 in FIGS. 10 and 11 ) and starts checking for the presence of the wafer W. The controller 5 determines whether light reception by the light-receiving unit 302b is interrupted during a predetermined time period from the start of checking for the presence of the wafer W (see step S302 in FIG. 11 ). If light reception is interrupted (see “YES” in step S302 in FIG. 11 ), the controller 5 determines that the wafer W is placed on the mounting stage 300 and ends checking for the presence of the wafer W. At this time, the controller 5 ends the emission of light from the light-projecting unit 302a (see step S303 in FIG. 11 ). Thereafter, the controller 5 performs the same operations as steps S201 to S203 in FIG. 9 .

[0075] If the received light is not blocked until a predetermined time has elapsed (see "NO" in step S302 in FIG. 11), the control device 5 determines that an abnormality has occurred in the device, such as the optical sensor 302, or the wafer W, and issues an abnormality alarm (see step S304 in FIG. 11). Thereafter, the control device 5 ends the emission of light from the light projecting unit 302a (see step S305 in FIG. 11).

[0076] 10 , the control device 5 checks whether the wafer W is present on the mounting stage 300 before unloading the wafer W from the transfer station 301. After the control device 5 determines the presence of the wafer W placed on the mounting stage 300, the wafer W is unloaded from the transfer station 301 by the first transfer robot 209. This configuration makes it possible to avoid a situation in which the wafer W is not present on the mounting stage 300 when the first transfer robot 209 unloads the wafer W.

[0077] Fig. 12 is a diagram showing a control flow of the light emitting operation of the optical sensor by the control device when the wafer is carried into the transfer station. Fig. 13 is a diagram showing another embodiment of the operation of the control device when the wafer is carried into the transfer station and when the wafer is carried out from the transfer station.

[0078] 12 and 13, the control device 5 starts irradiating light from the light projecting unit 302a and starts the operation of carrying in the wafer W. After that, the control device 5 detects that the light has been blocked by the wafer W, and then, using this as a trigger, stops irradiating light from the light projecting unit 302a after a predetermined time has elapsed (see FIG. 13).

[0079] The control device 5 starts checking for the presence of the wafer W while emitting light from the light projecting unit 302a (see step S401), and determines whether the light received by the light receiving unit 302b has been blocked (see step S402 in FIG. 12).

[0080] When the swing transporter 12 loads the wafer W into the transfer station 301, the edge of the wafer W blocks light, blocking light reception by the light receiving unit 302b (see "YES" in step S402). After detecting that light reception by the light receiving unit 302b has been blocked (i.e., after "YES" in step S402), the control device 5 determines whether a predetermined time has elapsed (see step S403). This determination is continued until the predetermined time has elapsed (see "NO" in step S403). If the predetermined time has elapsed (see "YES" in step S403), the control device 5 stops the light emission from the light projecting unit 302a (see step S404).

[0081] If the light received by the light receiving unit 302b is not blocked (see "NO" in step S402) even though the hand of the swing transporter 12 is extended toward the mounting stage 300, the control device 5 issues an abnormality alarm (see step S405) and stops the emission of light from the light projecting unit 302a (see step S406). Note that if the light receiving unit 302b receives light again before the predetermined time has elapsed, the control device 5 may issue an abnormality alarm or may return to step S402 again.

[0082] In FIG. 13, the timing at which confirmation of the presence of the wafer starts and the timing at which light reception is blocked start at the same time, but confirmation of the presence of the wafer may start slightly before light reception is actually blocked by the wafer.

[0083] This configuration further reduces the time that light from the optical sensor 302 is irradiated onto the wafer W, thereby enabling the control device 5 to more reliably prevent photocorrosion from occurring on the surface of the wafer W.

[0084] The embodiment shown in Fig. 10 can also be applied to the embodiment shown in Fig. 13. More specifically, in the embodiment shown in Fig. 13, the control device 5 may also check whether the wafer W is present on the mounting stage 300 before unloading the wafer W from the delivery station 301.

[0085] Fig. 14 is a diagram showing a control flow of the light projecting operation of the optical sensor by the control device when the wafer is carried into the transfer station. Fig. 15 is a diagram showing another embodiment of the operation of the control device when the wafer is carried into the transfer station and when the wafer is carried out from the transfer station.

[0086] As shown in steps S501 and S502 of FIG. 14 and FIG. 15, the controller 5 starts irradiating light and checking for the presence of the wafer W at the timing when the swing transporter 12 starts the operation of loading the wafer W.

[0087] After starting to check for the presence of the wafer W, the control device 5 determines whether the light reception by the light receiving unit 302b is interrupted until a predetermined time has elapsed (see step S503 in Figure 14). If the light reception is not interrupted until the predetermined time has elapsed (see "NO" in step S503 in Figure 14), the control device 5 stops emitting light from the light projecting unit 302a (see step S504 in Figure 14) and simultaneously confirms that the wafer W is not present on the mounting stage 300 (see Figure 15).

[0088] If the light reception is interrupted until a predetermined time has elapsed (see "YES" in step S503 in FIG. 14), the control device 5 determines that a previous wafer W is present on the mounting stage 300 and issues an abnormality alarm (see step S505 in FIG. 14). Thereafter, the control device 5 ends the irradiation of light from the light projecting unit 302a (see step S506 in FIG. 14).

[0089] 14, the control device 5 starts irradiating light from the optical sensor 302 when the wafer W loading operation is completed (see step S507 in FIG. 14), in other words, when the wafer W is placed on the mounting stage 300 (see step S508 in FIG. 14). The control device 5 starts checking for the presence of the wafer W when the light irradiated from the optical sensor 302 is blocked by the wafer W placed on the mounting stage 300 (see FIG. 15). With this configuration, the control device 5 can determine that the wafer W is securely placed on the mounting stage 300 and can further shorten the time during which the light from the optical sensor 302 is irradiated onto the wafer W.

[0090] After starting to check for the presence of the wafer W, the control device 5 determines whether the light reception by the light receiving unit 302b is interrupted until a predetermined time has elapsed (see step S509 in FIG. 14). If the light reception is interrupted until the predetermined time has elapsed (see "YES" in step S509 in FIG. 14), the control device 5 stops emitting light from the light projecting unit 302a (see step S510 in FIG. 14) and simultaneously ends the check for the presence of the wafer W (see FIG. 15).

[0091] If the received light is not blocked until a predetermined time has elapsed (see "NO" in step S509 in Figure 14), the control device 5 issues an abnormality alarm (see step S511 in Figure 14) and stops emitting light from the light-projecting unit 302a (see step S512 in Figure 14).

[0092] Thereafter, the controller 5 carries out the wafer W from the transfer station 301 by performing the same operation flow as the operation flow when the wafer W is carried out from the transfer station 301 (see FIG. 9).

[0093] 10 is also applicable to the embodiment shown in Fig. 15. More specifically, in the embodiment shown in Fig. 15, the control device 5 may also check whether the wafer W is present on the mounting stage 300 before the wafer W is carried out from the transfer station 301. In the case of the embodiments shown in Figs. 5 to 10, in checking the presence of the wafer W, the control device 5 determines that the wafer W is present if the light received by the light receiving unit 302b is blocked by the wafer W, and determines that the wafer W is not present if the light is not blocked.

[0094] In the above-described embodiment, the control of the light-projecting operation of the optical sensor 302 by the control device 5 when the wafer W is transported from the polishing unit 3 to the cleaning unit 4 via the transfer station 301 has been described, but the control of the light-projecting operation of the optical sensor 302 is not limited to the above-described embodiment.

[0095] In one embodiment, the control device 5 may control the light projecting operation of the optical sensor 302 when the wafer W is transferred from the load / unload unit 2 to the polishing unit 3. More specifically, the presence or absence of the wafer W is confirmed on the linear transporter at each of the transfer positions TP1 to TP7.

[0096] In one embodiment, the light projection operation of the optical sensor 302 may be controlled when the wafer W is transported to the first cleaning chamber 190 (cleaning modules 201A, 201B) or the second cleaning chamber 192 (cleaning modules 202A, 202B) or the drying chamber 194 (drying modules 205A, 205B).

[0097] In the above-described embodiment, the control of the light-projecting operation of the optical sensor 302 in the transfer station 301, which corresponds to the transfer position when transferring the wafer W to each module, has been described. However, the control of the light-projecting operation of the optical sensor 302 may also be performed on the lifter 11 and the first linear transporter 6 at the first transfer position TP1 to the fourth transfer position TP4.

[0098] The light-projecting operation of the optical sensor 302 may be controlled on the second linear transporter 7 at the fifth transfer position TP5 to the seventh transfer position TP7, or may be controlled in the temporary placement table 180, the temporary placement table 203, and each module (primary cleaning module 201, secondary cleaning module 202, drying module 205) of the cleaning unit 4. In this way, the light-projecting operation of the optical sensor 302 does not necessarily have to be controlled in the transfer station 300, but may be controlled in each module. The transfer station 300 and each module in which the light-projecting operation of the optical sensor 302 is controlled are collectively referred to as a receiving unit.

[0099] Photocorrosion is particularly likely to occur when the wafer W is wet. Therefore, the effect of controlling the light projection operation of the optical sensor 302 is particularly pronounced in processes after the wafer W has been wet-processed. Examples of wet-processing modules that wet-process the wafer W include polishing modules 3A to 3D and cleaning modules 201A, 201B, 202A, and 202B.

[0100] The wet processing module is disposed upstream of the transfer station 301 in the transport direction of the wafer W, and the optical sensor 302 is configured to irradiate light onto the wafer W that has been wet-processed in the wet processing module. With this configuration, the substrate processing apparatus can more effectively prevent photocorrosion from occurring on the surface of the wafer W.

[0101] The above-described embodiments have been described for the purpose of enabling a person of ordinary skill in the art to practice the present invention. Various modifications of the above-described embodiments would naturally be possible for a person skilled in the art, and the technical concept of the present invention may also be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, but should be accorded the broadest scope consistent with the technical concept defined by the claims. [Explanation of symbols]

[0102] 1. Housing 1a,1b bulkhead 2 Load / Unload Section 3 Polishing section 3A,3B,3C,3D polishing module 4 Cleaning section 5. Control device 6. First Linear Transporter 7. Second Linear Transporter 10 Polishing Pads 11 Lifter 12 Swing Transporter 20 Front Load Section 21 Running mechanism 22 Transport robot 30A, 30B, 30C, 30D Polishing Table 31A, 31B, 31C, 31D Top ring 32A, 32B, 32C, 32D Polishing liquid supply nozzle 33A, 33B, 33C, 33D Dresser 34A, 34B, 34C, 34D atomizer TP1, TP2, TP3, TP4, TP5, TP6, TP7 Transfer position 190 First Cleaning Room 191 Transport Room 1 192 Second Cleaning Room 193 Transport Room 2 194 Drying room 201A Upper Primary Cleaning Module 201B Lower Primary Cleaning Module 202A Upper Secondary Cleaning Module 202B Lower Secondary Cleaning Module 203 Temporary Stand 205A Upper Drying Module 205B Lower Drying Module 207 Filter fan device 209 First Transport Robot 210 Second Transport Robot 211,212 Support shaft 300 Mounting stage 301 Delivery Station 302 Optical Sensor 302a Light projector 302b Light receiving part 305 Shutter

Claims

1. carrying the substrate into a receiving unit for the substrate, and detecting that the light irradiated from the optical sensor is blocked by the substrate carried to the receiving unit, thereby confirming that the substrate is present in the receiving unit; before the substrate is transported out of the receiving unit, stopping the irradiation of light from the optical sensor; After the light irradiated from the optical sensor is blocked by the substrate carried into the receiving unit, it is confirmed that the substrate is present in the receiving unit within a predetermined time period after the substrate is placed on the placement stage of the receiving unit; the light irradiation from the optical sensor is stopped after the predetermined time has elapsed.

2. wet-processing the substrate in a wet-processing module that is arranged upstream of the receiving unit in a transport direction of the substrate; The substrate transport method according to claim 1 , wherein the optical sensor irradiates light onto the substrate that has been wet-processed in the wet processing module.

3. A substrate is carried into a receiving unit for the substrate, and light irradiated from an optical sensor is detected to be blocked by the substrate carried into the receiving unit, thereby confirming that the substrate is present in the receiving unit; before the substrate is carried out from the receiving unit, stopping the irradiation of light from the optical sensor; when the substrate is placed on the placement stage of the receiving unit, light irradiation from the optical sensor is started; confirming that the substrate is present in the receiving unit within a predetermined time period after the substrate is placed on the placement stage of the receiving unit; the light irradiation from the optical sensor is stopped after the predetermined time has elapsed.

4. A substrate transport method according to any one of claims 1 to 3, wherein light irradiation from the optical sensor is started before the substrate is transported to the receiving unit, and after confirming that the substrate is not present in the receiving unit, light irradiation from the optical sensor is stopped.

5. a receiving unit for the substrate; an optical sensor that detects the presence or absence of the substrate transported to the receiving unit; a control device for controlling the light projection operation of the optical sensor, The control device carrying the substrate into the receiving unit, and detecting that the light irradiated from the optical sensor is blocked by the substrate carried to the receiving unit, thereby confirming that the substrate is present in the receiving unit; before the substrate is transported out of the receiving unit, stopping the irradiation of light from the optical sensor; The control device After the light irradiated from the optical sensor is blocked by the substrate carried into the receiving unit, it is confirmed that the substrate is present in the receiving unit within a predetermined time period after the substrate is placed on the placement stage of the receiving unit; The substrate processing apparatus stops emitting light from the optical sensor after the predetermined time has elapsed.

6. the substrate processing apparatus includes a wet processing module that is arranged upstream of the receiving unit in a transport direction of the substrate and that wet processes the substrate; The substrate processing apparatus according to claim 5 , wherein the optical sensor irradiates light onto the substrate that has been wet-processed in the wet processing module.

7. A substrate receiving unit; an optical sensor that detects the presence or absence of the substrate transported to the receiving unit; a control device for controlling the light projection operation of the optical sensor, The control device carrying the substrate into the receiving unit, and detecting that the light irradiated from the optical sensor is blocked by the substrate carried to the receiving unit, thereby confirming that the substrate is present in the receiving unit; before the substrate is transported out of the receiving unit, stopping the irradiation of light from the optical sensor; The control device when the substrate is placed on the placement stage of the receiving unit, light irradiation from the optical sensor is started; confirming that the substrate is present in the receiving unit within a predetermined time period after the substrate is placed on the placement stage of the receiving unit; The substrate processing apparatus stops emitting light from the optical sensor after the predetermined time has elapsed.

8. A substrate processing apparatus according to any one of claims 5 to 7, wherein the control device starts irradiating light from the optical sensor before the substrate is transported to the receiving unit, and stops irradiating light from the optical sensor after confirming that the substrate is not present in the receiving unit.

9. The optical sensor a light-emitting unit that emits light; a light receiving unit that receives the light emitted from the light projecting unit, the light projecting unit is disposed on the back side of the substrate transported to the receiving unit, 9. The substrate processing apparatus according to claim 5, wherein the light receiving unit is disposed on the front surface side of the substrate transported to the receiving unit.

10. The substrate processing apparatus according to claim 9 , wherein the light projecting unit and the light receiving unit are disposed perpendicular to a transport direction of the substrate.

11. The substrate processing apparatus according to claim 9 , wherein the light projecting unit and the light receiving unit are disposed obliquely with respect to a transport direction of the substrate.

12. a step of transporting the substrate into a receiving unit for the substrate, and detecting that the light irradiated from the optical sensor is blocked by the substrate transported to the receiving unit, thereby confirming that the substrate is present in the receiving unit; before the substrate is transported out of the receiving unit, stopping the irradiation of light from the optical sensor; a step of confirming that the substrate is present in the receiving unit within a predetermined time period after the substrate is placed on the placement stage of the receiving unit, after the light irradiated from the optical sensor is blocked by the substrate carried into the receiving unit; and stopping the emission of light from the optical sensor after the predetermined time has elapsed.

13. wet-processing the substrate in a wet-processing module that wet-processes the substrate and that is arranged upstream of the receiving unit in a transport direction of the substrate; 13. The recording medium according to claim 12, wherein a program for causing a computer to execute the steps of: irradiating light onto the substrate that has been wet-processed in the wet processing module by the optical sensor is recorded.

14. A step of transporting a substrate into a receiving unit for the substrate, detecting that the light irradiated from an optical sensor is blocked by the substrate transported to the receiving unit, and confirming that the substrate is present in the receiving unit; before the substrate is transported out of the receiving unit, stopping the irradiation of light from the optical sensor; starting irradiation of light from the optical sensor when the substrate is placed on the placement stage of the receiving unit; confirming that the substrate is present in the receiving unit until a predetermined time has elapsed since the substrate was placed on the placement stage of the receiving unit; and stopping the emission of light from the optical sensor after the predetermined time has elapsed.

Images