JP2007194508A - Substrate transport device, substrate transport method, and computer program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas-floatation substrate transport device capable of stably transporting a substrate. <P>SOLUTION: The substrate transport device is configured so as to provide a transport path formation member that is extended in the transport direction of the substrate, and has a transport surface becoming lower as it becomes closer to the central section, and the heights of both ends are the same as that of the floated substrate or are higher than that of the substrate as viewed in cross-section; and a group of gas delivering holes that are provided along the transport direction of the substrate on the transport surface of the substrate, and deliver the gas upwardly to float the substrate. The gas delivered onto the transport surface to float the substrate is stored on the transport surface, forms a gas layer so as to enclose the transported substrate, and the substrate is transported at the central section of the transport path while the substrate is receiving the pressure of the stored gas from the right/left hands, thereby suppressing the right/left off-positioning of the substrate, thus enabling the system to stably transport the substrate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a substrate transfer apparatus, a substrate transfer method, and a computer program for carrying out the method, which transfer a substrate while floating with a gas such as air.

  As a substrate transport mechanism in a semiconductor manufacturing process, a transport arm is the mainstream, but a mechanism for moving the transport arm back and forth, a mechanism for transporting along a transport path, and the like are necessary. As the substrate size increases, these mechanisms also increase. For example, when the size of a semiconductor wafer becomes 12 inches or 16 inches, the drive section in those mechanisms becomes considerably large, and particles generated by wear of the drive section are generated. In order to suppress adhesion to the substrate, it is necessary to devise measures for dust generation such as forming a dedicated exhaust flow. On the other hand, since the size of the semiconductor manufacturing apparatus is increased with the increase in size of the substrate, there is an increasing demand for simplifying the structure as much as possible.

  From this point of view, the method of floating and transporting with air as the substrate transport mechanism is advantageous because the apparatus can be made thin. This technique is widely known. For example, Patent Document 1 discloses a flat structure that forms a conveyance path and a conveyance mechanism that is provided with a cover so as to cover the entire lower surface of the flat structure, and the flat structure that forms a conveyance surface of a substrate. A large number of pores obliquely upward are formed along the transport path on the upper surface of the. In this transport mechanism, air is supplied to the vent chamber surrounded by the cover and the flat structure, and the substrate placed on the transport surface is discharged by the air supplied to the vent chamber being discharged from the pores. As it ascends, it moves along the transport path under the thrust of this air. Patent Document 2 also shows a transport mechanism having a configuration similar to this.

  However, the substrate that has been levitated by air in this way is in an unstable state because no frictional force is acting on it, and it is likely to be displaced in the horizontal direction during movement due to the action of a slight force, and in a stable and positioned state. Difficult to carry. A substrate that has been misaligned will be ejected from the transport path, and if guides are provided on the left and right sides of the transport path to prevent the projecting, it will be impacted by colliding with the guide, and the substrate will be processed. The surface may be affected.

Further, since the air supplied to the ventilation chamber presses the conveyance surface from below, a portion receiving high pressure on the conveyance surface gradually rises, and there is a possibility that the air discharge direction around the raised portion changes. The change in the ejection direction may cause the substrate to be displaced more easily during the movement as described above.
For example, in a coating / developing apparatus that performs resist coating and development on a substrate, the number of processing units is large. For example, processing blocks are stacked and conveyed directly through the block where processing units are arranged for operational convenience. However, when transporting such a long distance, the gas floating type transport mechanism is considered to be advantageous because it is thin. ing.

JP-A-57-128940: page 2, lower left column, lines 12-17 JP 2001-358206 (paragraphs 0008 and 0010)

  The present invention has been made under such circumstances, and an object of the present invention is to provide a gas floating substrate transport apparatus, a substrate transport method, and a computer that implements the method, which can transport the substrate stably. To provide a program.

  The substrate transfer device of the present invention is a substrate transfer device that discharges gas and transfers the substrate while floating from the transfer surface of the transfer path. The substrate transfer device extends along the transfer direction of the substrate and is centered when viewed in a cross section. A transport path forming member having a transport surface that is lower or higher as the height of the substrate rises toward the part, and is equal to or higher than the height of the substrate, and is provided along the transport direction of the substrate on the transport surface of the substrate, And a gas discharge hole group for discharging gas upward and floating the substrate.

  The transport surface of the substrate is curved downward when viewed in a cross section, for example. The gas discharge hole group may include a gas discharge hole that is provided as a pair on both the left and right sides across the center line of the transport path and discharges gas obliquely upward toward the center side of the transport path. Further, in some cases, the substrate may further include a gas discharge hole for discharging gas obliquely upward toward the other end side of the transfer path so as to transfer the floated substrate from one end of the transfer path toward the other end. Furthermore, a plurality of air passages partitioned from each other for supplying gas to the gas ejection hole group along the substrate transport direction may be provided below the transport path member.

  Opening / closing means for independently discharging and stopping gas from the gas discharge holes in each divided area formed by dividing the substrate conveyance path into a plurality of divisions in the conveyance direction, and the position in the conveyance direction on the substrate conveyance path And a control unit for controlling the discharge and stop of the gas in each divided area via the opening / closing means based on the detection result by the position detection means. The position detection means is, for example, a substrate detection sensor that is provided in each of the divided regions and detects the presence or absence of the substrate. Further, the substrate transfer device determines whether or not the substrate is located at a preset height based on the height detection means for detecting the height of the substrate from the transfer path and the detection result of the height detection means. And a means for performing.

  The substrate transfer method of the present invention extends along the substrate transfer direction, and when viewed in a cross section, it becomes lower toward the center and the height of both ends is equal to or higher than the height of the substrate that has floated. A step of positioning the substrate on a conveyance path forming member having a conveyance surface, and conveying the substrate by discharging gas upward from a group of gas ejection holes provided along the conveyance direction of the substrate on the conveyance surface of the substrate And a process of floating and conveying from the surface.

  For example, the step of transporting the substrate by floating from the transport surface is, for example, obliquely upward from a group of gas discharge holes provided in pairs on the left and right sides across the center line of the transport path toward the center of the transport path. It may include a step of discharging gas, and it is transported from one end of the transport path to the other end from a group of gas discharge holes provided in pairs on the left and right sides across the center line of the transport path In some cases, the method may include a step of discharging gas obliquely upward toward the other end side of the conveyance path.

  Further, the transport method includes a step of supplying gas to a plurality of mutually separated ventilation paths for supplying gas to the gas discharge hole group provided below the transport path member along the transport direction of the substrate. A step of detecting the position in the transport direction on the transport path of the substrate, and control of gas discharge and stop in each divided area formed by dividing the transport path of the substrate into a plurality of transport directions, A step of performing based on the detection result of the step.

  The computer program of the present invention is a computer program used for a substrate transport apparatus that transports a gas while discharging a substrate from a transport surface of a transport path, and includes a group of steps for carrying out the above-described substrate transport method It is characterized by being assembled.

  According to the present invention, when the transport path forming member of the substrate is viewed in a cross section, the transport surface becomes lower as it goes toward the center and the height of both ends is equal to or higher than the height of the surfacing substrate. The gas discharge hole group which discharges gas toward the upper direction along the conveyance direction of a board | substrate is formed in the conveyance surface. The gas discharged on the transfer surface to float the substrate is stored on the transfer surface, and a layer is formed so as to surround the periphery of the transferred substrate. It is transported through the center of the transport path while receiving pressure. Even if the substrate moves to the left and right due to the force acting toward the left and right of the transport path on this substrate, the distance between the substrate and the transport surface becomes closer, so the pressure between them increases, and the substrate In response to the force toward the central portion of the paper, it again moves to the central portion of the transport path. Accordingly, it is possible to suppress the substrate from jumping out of the transport path, and it is possible to transport the substrate stably.

  FIG. 1 is a view showing a substrate transfer apparatus according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a long transfer path plate that is a transfer path member that forms a transfer path of a substrate. The transport path plate 1 is provided horizontally, and its upper surface forms a transport surface 10 of the substrate. The conveyance path plate 1 is curved so as to have a bilaterally symmetric shape, and the conveyance surface 10 is directed downward from the left and right sides (upper and lower sides in FIG. 1) toward the center, and sandwiches the center of the conveyance path. It is formed as a symmetrical curved surface. In this transport path plate 1, one end side (left end side in FIG. 1) and the other end side form a delivery table 2 for carry-in and a delivery table 3 for carry-out, respectively. The transfer table 2 for loading is a part into which a semiconductor wafer W (hereinafter referred to as a wafer), which is a substrate, is loaded from an external horseshoe-shaped transfer arm 20, and the transfer of the wafer is performed between the transfer arm 20 and the transfer table 2. The three raising / lowering pins 21 are provided so as to protrude and be able to be immersed. Similarly, the transfer table 3 for unloading is also provided with three lifting pins 31 protruding and retractable so that the wafer W can be transferred between a transfer arm (not shown) and the transfer table 3. ing.

  Further, the transport path plate 1 is divided into a plurality of parts in the transport direction, and is divided into eight parts including the delivery tables 2 and 3 in FIG. If this divided area is referred to as a divided area, eight divided areas S1 to S8 are arranged from one end side of the conveyance path plate 1 (the divided areas S1 and S8 are respectively the delivery tables 2, 3). Equivalent to

  In the divided areas S1 to S7 of the transport path plate 1, a plurality of gas discharge holes 4 penetrating the front and back surfaces of the transport path plate 1 are arranged in the width direction (in FIG. 1, for convenience, four are provided). A large number of arrangement groups of the holes 4 are arranged along the length direction, that is, the conveyance direction. Gas discharge holes 4a and 4a that are paired with each other across the center line of the transport path are provided on the center side of the transport surface 10, and gas discharge holes 4b that are paired with each other so as to sandwich these gas discharge holes 4a and 4a. 4b is provided. As shown in FIG. 2, these gas discharge holes 4 (4a, 4b) discharge gas obliquely upward from one end side (transfer table 2) to the other end side (transfer table 3) of the transfer path, The wafer W is lifted and a thrust is applied to the wafer W that has floated and the frictional force is zero, and the wafer W transferred to the center of the transfer path by the transfer arm 20 is moved along the center of the transfer path. It is perforated so as to be inclined with respect to the thickness direction of the plate so that it can be conveyed toward the delivery table 3.

  The conveyance surface 10 and the gas discharge holes 4 will be described with reference to FIG. FIG. 3 shows a transverse plane of the conveyance path plate 1 in the width direction. For example, as shown in this figure, each gas discharge hole 4 is perforated so that the cross section thereof is orthogonal to the transport surface 10, and each gas discharge hole 4 is formed on the other end side (the delivery table 3 side) of the transport path. It is perforated to discharge gas toward the center and to discharge gas obliquely upward toward the center side of the conveyance path as indicated by an arrow in the figure. The gas discharge holes 4a and 4a on the inner side of the transfer path and the outer sides 4b and 4b are formed symmetrically with respect to the center of the transfer path, and the floated wafer W passes through the gas discharge holes 4a and 4b. It is conveyed toward the delivery table 3 along the central portion of the conveyance path while receiving a force toward the center of the conveyance path by the discharged gas. Further, in the divided areas S2 to S7, guide members 11 and 12 are provided on both side edges of the transfer path so as not to fall when the track of the wafer W deviates from side to side as shown in FIGS. In FIG. 1, one guide member 12 is omitted), and the inner surfaces of the guide members 11, 12 are, for example, continuous with the transport surface 10 of the transport path plate 1 and extend the transport surface 10 substantially upward. It is provided to do.

  Then, when the gas is discharged upward from the gas discharge hole 4 during the transfer of the wafer W, the discharged gas is stored on the transfer surface 10 as indicated by a dotted line in FIG. A layer is formed so as to surround the lower surface and the side surface. During this transfer, for example, the wafer W is displaced to the left, and when it is about to collide with the guide 11 on the left side of the transfer path as shown in FIG. 4B, the gas between the guide 11 and the wafer W is pressed, The pressure between the guide 11 and the wafer W increases. Due to the pressure of the pressed gas, the wafer W receives a force toward the right side, that is, the center side of the transfer path, and does not come into contact with the guide 11 as shown in FIG. It returns to the central part and is conveyed downstream along the central part.

In this example, the gas discharged from the gas discharge holes 4a, 4b is directed toward the center of the transfer path by applying the force toward the center of the transfer path to the wafer W, so that the wafer W is more reliably placed at the center of the transfer path. However, in order to form a gas layer as described above on the transfer surface 10, the gas discharge direction of each gas discharge hole 4 is the center of the transfer path as described above. For example, in FIG. 3, the cross section of the gas discharge hole 4 may be perforated so as to be directed right above. Alternatively, only one of the gas discharge holes 4a and 4b may discharge gas toward the transfer table 3 and give a thrust toward the transfer table 3 to the wafer W.
In this example, the height position of the wafer W that has floated is set to a position between the guides 11 and 12, but the height position of the wafer W that has floated from the gas discharge hole 4 as shown in FIG. You may set so that it may become the same as the upper end of the conveyance surface 10 of the conveyance path plate 1, or lower than it.

  In addition, the height between the center of the conveyance surface 10 in this conveyance path plate 1 shown in FIG. 6 and the right and left ends of the conveyance surface 10 is, for example, 0.3 mm to 0.5 mm, and the width of the conveyance surface 10 is The size h2 (the distance between the left end and the right end of the transport surface 10) is, for example, 300 mm to 350 mm. Further, an angle θ formed by a line segment connecting the center of the transport path and the left and right ends of the transport surface 10 with respect to the horizontal axis is, for example, 0.1 to 0.3 degrees.

  Next, the transfer table 3 for carrying out the wafer, which is the terminal portion of the transfer path, will be described with reference to FIG. The transfer table 3 includes a plurality of, for example, six alignment gas discharge holes in a circumferential direction along a circle centered on the center at a position closer to the center of the wafer W than a position corresponding to the outer edge of the wafer W. 51 are arranged. Further, an annular groove 52 is formed along a concentric circle smaller than the circle, and the wafer W is aligned on the delivery table 3 radially from the annular groove 52 toward the alignment gas discharge holes 51. An alignment airflow forming groove 53 for alignment is formed. Further, a suction hole 54 is provided on the bottom surface of the annular groove 52, for example, on the extension of each positioning airflow forming groove 53 in the center direction, and this suction hole is formed on the back surface of the transport path plate 1 as shown in FIG. One end of an exhaust pipe 55 is connected to 54. The other end of the exhaust pipe 55 extends to the outside of a later-described venting chamber 49 and is connected to a suction means 56 such as a vacuum pump through a valve V9.

  Then, the wafer W is transferred toward the downstream side of the transfer path, and when the wafer W is transferred from the divided section S7 onto the delivery table 4, air is discharged from the gas discharge hole 51 through the vent chamber 49. . Further, for example, air is exhausted from the suction hole 54 substantially simultaneously with the discharge of the air, and the air flow from each gas discharge hole 51 through the air flow forming groove 53 to the corresponding suction hole 54 as shown by an arrow in FIG. Is formed. The wafer W transferred to the transfer table 3 is positioned at a predetermined position and rests in a state where it is floated on the transfer table 3 by riding on this air flow.

  The gas discharge holes 4 and 51 are configured to discharge and control gas independently for each of the divided areas S1 to S8. That is, as shown in FIGS. 2 and 3, a plurality of ventilation path forming members 40 are provided for each divided area on the lower surface side of the divided areas S1 to S7 of the conveying path plate 1, and A ventilation chamber forming member 48 is provided on the lower surface side. FIG. 7 is a perspective view of the air passage forming member 40. As shown in FIG. 7, the air passage forming member 40 is formed as a container having an open upper surface. Inside the air passage forming member 40, block-shaped air flow restricting members 41, 41 are arranged in parallel with each other along the length direction of the air passage forming member 40, and with the side wall of the air passage forming member 40. By being provided at an interval, an air passage 42 is formed so as to surround the air flow restriction members 41, 41. Then, as shown in FIG. 3, the air passage forming members 40 are attached to the divided regions S <b> 1 to S <b> 7 so that the inlet side of the group 4 of gas discharge holes opens into the air passage 42. Note that the upper surface of the air flow path forming member 40 and the upper surface of the air flow regulating member 41 are curved along the lower surface of the transport path plate 1, and the gas flowing into the air flow path 42 does not leak to the outside of the air flow path forming member 40 in FIG. As indicated by an arrow, the gas flows through the air passage 42 and is discharged from the gas discharge hole 4.

  The vent chamber forming member 48 forms, for example, a vent chamber 49 which is a hollow region at the lower portion of the divided section S8 by covering the lower surface of the divided section S8, and the inlet side of each positioning gas discharge hole 51 is the vent chamber 49. Is open.

  A gas supply pipe 45 is connected to each of the ventilation path forming member 40 and the ventilation chamber forming member 48 so as to communicate with the ventilation path 42 and the ventilation chamber 49, respectively. Valves V1 to V8, which are opening / closing means for supplying and stopping, are interposed. F is a filter for particle removal. Each gas supply pipe 45 is connected to a common pipe 46 on the base end side, and is connected to a gas supply source 47 that is an air supply source via a mass flow controller MFC that is a flow rate adjusting unit and a valve V10.

  For the divided region S1 (S8), as shown in FIG. 9, the sleeve 22a (32a) is disposed at a position corresponding to the installation position of the elevating pin 21 (31) in the ventilation path 42 and the ventilation chamber 49. 42, The raising / lowering pin 21 (31) can be raised / lowered from the lower part of the ventilation chamber 49 through the hole formed in the sleeve 22a (32a) and the delivery stand 2 (3). In FIG. 7, reference numeral 23 (33) denotes an elevating mechanism that elevates and lowers the elevating pin 21 (31) via the support member 24 (34). In addition, although the conveyance path plate 1 may be comprised with an integral plate, the structure which connected the plate which comprises each division | segmentation area S1-S8 may be sufficient.

  In the divided areas S2 to S8, a wafer detection sensor 5 including a reflection sensor or a capacitance sensor, which is an optical sensor serving as a position detection unit for detecting the position of the wafer W in the transfer direction, is provided. Then, it arrange | positions in the width direction center part and upstream end in division area S2-S8. Each wafer detection sensor 5 is connected to the control unit 100 as shown in FIG. 2, and the control unit 100 determines the position of the wafer W based on the detection signals from these wafer detection sensors 5, and the determination result. For example, a software program for controlling the valves V1 to V9 based on the (detection result) is provided.

  For example, in this program, when the wafer detection sensor 5 in one divided area detects the wafer W in the divided areas S2 to S7, a valve corresponding to the divided area is opened and gas is discharged, and one of the divided areas is discharged. A step group is set so that when the wafer detection sensor 5 in the downstream divided section stops detecting the wafer W, the valve corresponding to the one divided section is closed and gas discharge is stopped. Accordingly, for example, focusing on the divided area S2, when the wafer detection sensor 5 provided at the entrance of the divided area S2 is turned on, the valve V2 is opened, and the wafer detection sensor 5 at the entrance of the one divided area S3 on the downstream side. When V is turned from on to off, the valve V2 is closed.

  The control unit 100 has a program storage unit made up of, for example, a computer. By storing the program in the program storage unit, the program is read out by the control unit 100, and the control unit 100 is described above. Execute each step. The program is stored in the program storage unit while being stored in a recording medium such as a hard disk, a compact disk, a magnetic optical disk, or a memory card.

  In the divided area S1 (transfer table 2 for loading), for example, the lift pins 21 are in the raised position, that is, the wafer W is placed, and the wafer W is not present on the transfer table 3 for unloading. Sometimes, for example, when the raising / lowering pin 31 of the delivery table 3 is in the lowered position, the valve V1 is opened to discharge gas from the gas discharge hole 4, and the wafer detection sensor 5 at the entrance of the divided region S2 is turned off from on. When this happens, the valve V1 is closed and gas discharge stops. Further, for the divided region S8 (the delivery table 3 for unloading), when the wafer detection sensor 5 at the entrance of the divided region S8 is turned on, the valve V8 is opened and gas is discharged from the gas discharge hole 4, The valve V8 is closed when the elevating pin 31 is in the raised position. The program is configured so that such a sequence is assembled.

  The guide members 11 and 12 are provided with height detection means for detecting the flying height of the wafer W, for example, for each of the divided areas S2 to S8. In this example, as shown in FIG. 10, the height h3 (height from the center of the transfer surface 10) when the wafer W is normally lifted, for example, a level H1 lower than 0.5 mm and a level H2 higher than 0.5 mm. Transmission type optical sensors 13 and 14 which are height detection sensors each having an optical axis are arranged. In addition, the light emission part 13a (14a) and the light-receiving part 13b (14b) in the optical sensor 13 (14) are provided in the guide members 11 and 12, respectively.

  Actually, a plurality of these optical sensors 13 or 14 are arranged in the vertical direction at intervals smaller than the thickness of the wafer W, and can be detected when the wafer W is located in a certain height zone. .

  The output of the light receiving unit 13b (14b) is sent to the control unit 100, and the control unit 100 has a function of outputting an alarm when any received light signal is detected. Further, the control unit 100 performs a display corresponding to the received light signal, for example, a signal or display corresponding to a decrease in levitation force when the light receiving unit 13b detects the wafer W, and a levitation force when the light receiving unit 14b detects the wafer W. It is good also as a structure provided with the function which performs the signal or display to the effect of being too large.

  The control unit 100 has a function of measuring, for example, the time elapsed from when the wafer detection sensor 5 in the divided area S2 detects the wafer W until the wafer detection sensor 5 in the divided area S8 detects the wafer W. For example, if the wafer detection sensor 5 in the divisional section S8 does not detect the wafer W even after a preset time has elapsed, a function is provided to output an alarm that the transfer of the wafer W is stopped on the transfer path. Have.

  Next, the operation of the above embodiment will be described. As shown in FIG. 1, if the wafer W is held from the outside by the transfer arm 20 and is positioned above the transfer table 2 on one end side of the transfer path plate 1, the lift pins 21 protrude and transfer. The wafer W on the arm 20 is pushed up and held, and then the transfer arm 20 is retracted, the elevating pins 21 are lowered, and the wafer W is placed on the delivery table 2. Subsequently, the valve V1 (see FIG. 2) is opened on the condition that the wafer W is not placed on the unloading delivery table 3 on the other end side of the transfer path plate 1, and from the gas discharge hole 4 of the delivery table 2. Air is discharged and the wafer W rises. As shown in FIGS. 2 and 3, the gas discharge hole 4 is directed toward the center of the transfer path and discharges air obliquely upward toward the transfer table 3, so that the wafer W is transferred by receiving the pressure of the air. It starts to move toward the delivery table 3 so as to slide on the transport surface 10 of the transport path plate 1 while being aligned with the center of the path.

  When the wafer W is positioned on the transfer table 2 for loading, the valves V2 to V8 in the other divided sections S2 to S8 are closed and no air is discharged, but the wafer W is divided into the divided sections S2. , The passage of the wafer W is detected by the wafer detection sensor 5 located there, and as a result, the valve V2 in the divided area S2 is opened and air is discharged from the gas discharge hole 4. The discharged air is stored in a space surrounded by the transfer surface 10 and the guide members 11 and 12, and an air layer is formed so as to surround the lower side and the side of the wafer.

  The wafer W surrounded by air in this way proceeds further toward the delivery table 3 while approaching the divided area S2 toward the center. FIG. 11 is a diagram showing the correspondence between the position of the wafer W and the discharge of air. If the wafer W is now accommodated in the divided area S3, air is discharged only in the divided area S3. When the wafer W advances and part of the wafer W reaches the division area S4, the wafer detection sensor 5 at the entrance is turned on from off, and in the division area S4, the valve V4 is opened and air is discharged to discharge the wafer. W is in a state of being levitated by the air discharged from the divided sections S3 and S4. When the wafer W further advances and passes through the divided area S3 and the wafer detection sensor 5 at the entrance of the divided area S changes from on to off, the valve V3 in the divided area S3 is closed and the discharge of air is stopped.

  As described above, in the divided areas S1 to S8, air is discharged only in a necessary area as the wafer W moves, and the wafer W is transferred to the delivery table 3 for unloading. Further, for example, a force in the left-right direction is applied to the wafer W in the divided areas S2 to S7, so that the wafer W and the guide member 11 (12) are likely to collide with the guide member 11 (12) due to positional displacement. The air layer sandwiched between the wafers is pressed, and the air pushes the wafer W back to the center side of the transfer path, whereby the wafer W is aligned again to the center side of the transfer path. When the wafer W reaches the entrance of the transfer table 3 and the wafer detection sensor 5 of the transfer table 3 is turned on from off, the valve V8 is opened and air is discharged from the alignment gas discharge hole 51 and the valve V9. Is opened, and suction and exhaust are performed from the suction hole 54, and an airflow is formed in each alignment airflow formation groove 53 toward the center of the delivery table 3.

  Further, when the wafer W moves to the center of the delivery table 3 and the wafer detection sensor 5 is turned from on to off, the valve V7 is closed, and gas discharge from the gas discharge holes 4 in the divided section S7 is stopped. Even after the gas from the gas discharge holes 4 stops, the wafer W moves downstream due to inertia and rides on the airflow formed in the alignment airflow formation groove 53 at a predetermined position on the transfer table 3. Stand still in the state of floating with air.

  Subsequently, the lift pins 31 push up the wafer W, close the valves V8 and V9 to stop the discharge and suction of air, and then the lift pins 31 are lowered to place the wafer W on the delivery table 3. Become. Thereafter, the wafer W is received and carried out by the transfer arm (not shown) in cooperation with the lift pins 31.

  Further, if a defect occurs in the gas discharge system during a series of such transfers of the wafer W, the buoyancy of the wafer W becomes insufficient, and the height level of the wafer W becomes H1, the wafer W is detected by the height detection sensor 13. As a result, the control unit 100 determines that the buoyancy of the wafer W is insufficient and issues an alarm. If the buoyancy of the wafer W is too large and the height level of the wafer W becomes H2, the height detection sensor 13 detects the wafer W. As a result, the control unit 100 determines that the buoyancy of the wafer W is too large. Determine and issue an alarm. The height levels H1 and H2 are set so that the wafer W in a certain height zone can be detected instead of the height of one point as described above.

  Further, when the buoyancy of the wafer W is lost and the wafer W falls between the height detection sensor 13 of one division area and the height detection sensor 13 on the downstream side thereof, the conveyance is stopped. When a predetermined time elapses after the wafer detection sensor 5 detects the wafer W, the control unit 100 determines that the transfer of the wafer W is stopped on the transfer path and issues an alarm.

  According to the above-described embodiment, the transfer surface 10 of the transfer path plate 1 has a width that is larger than the width of the wafer W to be transferred, and is curved so that the center side is directed downward. Guide members 11 and 12 that are formed and are directed upward so as to be continuous with the conveyance surface 10 are provided. Air that is discharged to float the wafer W and transport it to the delivery table 3 is stored on the transport surface 10 so as to surround the periphery of the wafer W that has floated so as to be sandwiched between the guide members 11 and 12. As a result, even if the wafer W receives a force toward the left and right during the transfer and is displaced, the pressure between the guide members 11 and 12 and the wafer W decreases as the distance between the guide members 11 and 12 decreases. The wafer W is pushed back to the center of the transfer path, so that the wafer W can be transferred stably and the collision with the guide members 11 and 12 can be suppressed.

  In addition, since a plurality of partitioned air passages 42 for supplying gas to the gas discharge holes 4 are formed immediately below the gas discharge holes 4 provided along the conveyance path in each of the divided regions S1 to S7. The pressure applied to the lower surface of the transport path plate 1 where the discharge holes 4 are not formed is suppressed. Therefore, it is possible to suppress the transfer path plate 1 from being deformed and the transfer of the wafer W being affected.

  Further, the transfer path plate 1 is divided into a plurality in the transfer direction, the position of the wafer W in the transfer direction on the transfer path is detected by the wafer detection sensor 5, and the wafer W of the divided areas S1 to S8 is detected based on the detection result. Since air is discharged only in the area that contributes to the transfer, that is, air is sequentially discharged in the area through which the wafer W passes, and after passing, the air discharge in that area is stopped. Can be reduced.

  The present inventor has actually manufactured the substrate transfer apparatus according to the above-described embodiment and conducted an experiment, and confirmed that the wafer can be transferred stably. In the apparatus used for the experiment, the length of the conveyance path is 2000 mm, and the width of the conveyance surface 10 indicated by h2 in FIG. 6 is 320 mm. In this apparatus, the height between the center of the conveying surface 10 indicated by h in FIG. 6 and the left and right ends of the conveying surface 10 is 0.5 mm, and the center of the conveying path and the conveying surface with respect to the horizontal axis indicated by θ in FIG. The angle formed by the line connecting the left and right ends of 10 is 0.2 degrees. Further, the gas discharge holes are formed in the transfer surface 10 so that the gap between the gas discharge holes 4 and 4 in the length direction of the transfer path is 65 mm and the interval between the gas discharge holes 4 and 4 in the width direction of the transfer path is 50 mm. Four groups were formed, and a 12-inch wafer was used as a wafer to be transferred.

Further, in the above-described embodiment, instead of forming the gas discharge hole 4 so as to discharge air obliquely, the gas discharge hole 4 is formed so as to discharge air directly above and the transfer stage 3 side (wafer on the transfer path) The conveyance path plate 1 is tilted so that the W traveling side) is positioned below the delivery stage 2 side, and a pressing member that moves from the delivery stage 2 toward the stage 3 is provided on the conveyance surface 10 by air. The wafer W that has floated may be transferred toward the delivery stage 3 by sliding down on the transfer path according to the movement of the pressing member by its own weight while the front end portion is held by the pressing member.
In the embodiment described above, the transfer path plate 1 is not limited to be configured such that the transfer surface 10 of the wafer W is a curved surface, and the transfer surface 10 has a central portion as shown in a transverse plane in FIG. The conveyance path plate 1 may be configured to have a smooth surface facing downward.

  Next, an example in which the substrate transfer apparatus of the present invention is applied to a semiconductor manufacturing apparatus will be described with reference to FIGS. This semiconductor manufacturing apparatus is a coating and developing apparatus for applying a resist to a wafer and developing the exposed wafer with a developer. FIG. 13 shows a plan view of an embodiment of this system, FIG. 14 is a schematic perspective view thereof, and FIG. 15 is a schematic side view thereof. This coating / developing apparatus is installed in a clean room in an air atmosphere, and a carrier block P1 for carrying in / out a carrier 120 in which 13 wafers W, which are substrates, for example, wafers are hermetically stored, and a plurality of, for example, 4 A processing block P2 configured by vertically arranging the blocks B1 to B4 and the transport block M1, an interface block P3, and an exposure apparatus P4 are provided.

  In the carrier block P 1, a mounting table 121 on which a plurality of carriers 120 can be mounted, an opening / closing part 122 provided on a wall surface in front of the mounting table 121, and a wafer from the carrier 120 via the opening / closing part 122. A transfer arm C for taking out W is provided. The transfer arm C can be moved forward and backward, can be raised and lowered, can be rotated about a vertical axis, and can be rotated about a vertical axis so as to transfer the wafer W to and from transfer stages TRS 1 and 2 of blocks B 1 and B 2 described later. It is configured to be movable.

  A processing block P2 surrounded by a casing 124 is connected to the back side of the carrier block P1. In this example, the processing block P2 is a first block (DEV layer) B1 for carrying out development processing, a transport block M1, and an antireflection film (hereinafter referred to as “upper antireflection coating) formed on the upper layer side of the resist film from the lower side in this example. A second block (BCT layer) B2 for forming a film), a third block (COT layer) B3 for applying a resist solution, and a reflection formed on the lower layer side of the resist film It is assigned as a fourth block (TCT layer) B4 for performing an anti-reflection film (hereinafter referred to as “lower anti-reflection film”) forming process. These blocks B1 to B4 and the transport block M1 extend from the carrier block P1 toward the interface block P3. Here, the DEV layer B1 corresponds to a developing block, and the BCT layer B2, the COT layer B3, and the TCT layer B4 correspond to a coating film forming block for forming a coating film made of a photosensitive material such as a resist. Each block is partitioned by a partition plate (base body).

  Subsequently, the configuration of the first to fourth blocks B (B1 to B4) will be described. In the present embodiment, these blocks B1 to B4 include many common portions, and each block B has a substantially similar layout. It consists of Therefore, the DEV layer B1 will be described as an example with reference to FIG. In the central portion of the DEV layer B1, a transfer path R1 for transferring the wafer W for connecting the carrier block P1 and the interface block P3 in the lateral direction, specifically in the length direction of the DEV layer B1 (Y direction in the figure). Is formed.

  As viewed from the carrier block P1 side of the transport path R1, a plurality of coating units for performing a developer coating process as a liquid processing unit are provided on the right side from the front side (carrier block P1 side) to the back side. Is provided along the transport path R1. In addition, on the left side from the front side to the back side of the DEV layer B1, four shelf units U1, U2, U3, U4 in which heating / cooling heat treatment units are sequentially arranged, and an exhaust unit 500 are for conveyance. It is provided along the passage R1. That is, the developing unit 3 and the shelf units U1 to U4 are arranged to face each other via the conveyance path R1. In the shelf units U1 to U4, thermal processing units for performing pre-processing and post-processing of processing performed in the developing unit 300 are stacked in two stages.

  Among the thermal processing units described above, for example, a heating unit that heat-treats the wafer W after exposure or heat-treats the wafer W after development processing to dry, and after the processing in this heating unit A cooling unit or the like for adjusting the wafer W to a predetermined temperature is included. In the present embodiment, the heating units are stacked in two stages as the shelf units U1, U2, U3 in the DEV layer B1, and the cooling units are stacked in two stages as the shelf unit U4.

  Here, the transfer block M1 is provided with the substrate transfer apparatus 1A of the present invention which is a direct transfer means for transferring the wafer W directly from the carrier block P1 to the interface block P3. The substrate transfer apparatus 1A is configured by the above-described air floating type substrate transfer apparatus, and is configured, for example, in the same manner as shown in FIG. 1, and corresponds to the transfer table 2 for transfer described above. The wafer W is transferred from the transfer stage TRSB1 to the transfer stage TRSB5 corresponding to the transfer table 3 for unloading.

  An area adjacent to the carrier block P1 in the transfer path R1 and the transfer area M2 of the transfer block M1 is a first wafer transfer area R2, and this area R2 has a main area as shown in FIGS. A shelf unit U5 is provided at a position where the arm A1, the substrate transfer apparatus 1A, and the transfer arm C can access, and a transfer arm that is a lifting and lowering transfer means for transferring the wafer W to the shelf unit U5. D1 is provided.

  In the shelf unit U5, a delivery stage TRS1B and a delivery stage TRS1 are provided in this order from the upper stage in the block B1, and the transfer arm C and the delivery arm D1 are configured to be accessible to the delivery stage TRS1B. The delivery stage TRS1 is configured so that the main arm A1, the transfer arm C, and the delivery arm D1 can be accessed. As the structures of the delivery stage TRS1 and the delivery stage TRS1B, for example, a square housing is provided, and a stage having a mechanism for adjusting the temperature of the wafer W to a predetermined temperature by placing the wafer W in the housing. Also provided is a pin that can project and retract on the stage. For example, each arm can enter the housing through a transfer port provided on a side surface facing each arm of the housing, and each arm can hold the back surface of the wafer W floating from the stage through the pins. Alternatively, a structure in which the wafer W transferred by each arm is placed on the plate via the pins is provided.

  In this example, as shown in FIG. 15, each of the blocks B2 to B4 is provided with two delivery stages TRS2 to TRS4, but each TRS has the structure as described above. The TRS2 to TRS4 are configured so that the wafer W can be transferred to and from the main arms A2 to A4 and the transfer arm D1 provided in each layer. In addition to these arms, the TRS 2 is configured so that the wafer can be transferred with the transfer arm C. By the way, the number of each TRS is not limited, and two or more units may be provided corresponding to each block.

  The transfer arm D1 moves between the layers B1 to B4, and can move forward and backward and move up and down so that the wafer W can be transferred to the transfer stages TRS1 to TRS4 and the transfer stage TRS1B provided in each layer. It is configured. Further, the transfer stages TRS1, TRS2 and the transfer stage TRS1B are configured such that the wafer W is transferred to and from the transfer arm C in this example.

  Furthermore, the area adjacent to the interface block P3 in the transfer path R1 of the DEV layer B1 and the transfer area M2 of the transfer block M1 is a second wafer transfer area R3. This area R3 includes the area shown in FIG. Is provided with a shelf unit U6. As shown in FIG. 13, the shelf unit U6 is provided with the transfer stages TRS5B and TRS5 in this order from the top, and the transfer stage TRS5B can transfer the wafer W between the substrate transfer apparatus 1A and the interface arm B. It is configured as follows. The transfer stage TRS5 is configured to transfer the wafer W between the main arm A1 and the interface arm B. The transfer stages TRS5B and TRS5 have, for example, the same structure as the transfer stage TRS1B described above, and have a cooling function for the wafer W so that the temperature of the transferred wafer W can be controlled.

An exposure device P4 is connected to the back side of the shelf unit U6 in the processing block P2 via an interface block P3. The interface block P3 is provided with an interface arm B for delivering the wafer W to the shelf unit U6 of the processing block P2 and the exposure apparatus P4. In this interface arm B, for example, one arm 201 for supporting the central region on the back surface side of the wafer W is provided along the base 202 so as to be able to advance and retract. The base 202 is attached to a lift 203 so as to be rotatable about a vertical axis by a rotation mechanism 204, and is provided so as to be movable up and down along a lift rail 205. In this way, the arm 201 is configured to be able to move forward and backward, move up and down, and rotate about a vertical axis.
The above-described delivery arm D1 is also configured in the same manner as the interface arm B except that it does not rotate around the vertical axis.

  The interface arm B serves as a transfer means for the wafer W interposed between the processing block P2 and the exposure apparatus P4. In this embodiment, the interface arm B receives the wafer W from the transfer stage TRS5 of the block B1 and supplies it to the exposure apparatus P4. On the other hand, the wafer W is received from the exposure apparatus P4 and transferred to the stage TRS5B.

  Here, an example of the flow of the wafer W when the antireflection film is formed on the upper and lower sides of the resist film will be described with respect to the action in the coating and developing apparatus. The carrier 120 is carried into the carrier block P1 from the outside, and the wafer W is taken out from the carrier 120 by the transfer arm C. The wafer W is transferred from the transfer arm C to the main arm A2 of the BCT layer B2 via the transfer stage TRS2 of the shelf unit U5. In the BCT layer B2, by the main arm A2, the cooling unit → the antireflection film forming unit (not shown, but a unit corresponding to the developing unit 300) → the heating unit → the delivery unit TRS2 in the order of the shelf unit U5. The lower antireflection film is formed by being conveyed.

  Subsequently, the wafer W of the transfer stage TRS2 is transferred by the transfer arm D1 to the transfer stage TRS3 of the COT layer B3, and then transferred to the main arm A3 of the COT layer B3. In the COT layer B3, the main arm A3 transports the wafer W in the order of cooling unit → resist coating unit → heating unit, forms a resist film on the upper layer of the lower antireflection film, and then transports it to the edge exposure unit. Then, the peripheral edge is exposed and further conveyed to the delivery stage TRS3 of the shelf unit U5.

  Next, the wafer W of the transfer stage TRS3 is transferred to the transfer stage TRS4 of the TCT layer B4 by the transfer arm D1, and transferred to the main arm A4 of the TCT layer B4. In the TCT layer B4, the main arm A4 transports the resist film in the order of cooling unit → second antireflection film forming unit (not shown, but corresponding to the developing unit 300) → heating unit. After the upper antireflection film is formed on the upper layer, the film is transported to the delivery stage TRS4 of the shelf unit U5.

  The wafer W on the transfer stage TRS4 is transferred to the transfer stage TRS1B by the transfer arm D1. Next, the wafer W floats as described above by the substrate transfer apparatus of the present invention, moves to the interface block P3 side, and is transferred to the delivery stage TRS5B. The stage TRS5B may be configured as a cooling plate that is a temperature adjustment plate for adjusting the wafer W to a temperature at the time of exposure in the exposure apparatus. The wafer W placed on the stage TRS5B is transferred to the exposure apparatus P4 by the interface arm B, where a predetermined exposure process is performed.

  The wafer W after the exposure processing is transferred to the transfer stage TRS5 of the shelf unit U6 by the interface arm B, and the wafer W on the stage TRS5 is received by the main arm A1 of the DEV layer B1, and in the DEV layer B1, the shelf W The units U1 to U4 are conveyed in the order of heating unit → cooling unit → developing unit 300 → heating unit → cooling unit, and a predetermined developing process is performed. The wafer W thus developed is transferred to the delivery stage TRS1 of the shelf unit U5 and returned to the original carrier 120 mounted on the carrier block P1 by the transfer arm C.

It is a perspective view which shows embodiment of the board | substrate conveyance apparatus of this invention. It is a longitudinal cross-sectional view which shows the said embodiment. It is a cross-sectional view which shows the said embodiment. It is explanatory drawing which shows the mode of the board | substrate which floats on the conveyance surface of a board | substrate. It is explanatory drawing which shows the mode of another board | substrate which floats on a conveyance surface. It is a cross-sectional view of the conveyance path member in the said board | substrate conveyance apparatus. It is explanatory drawing which shows the structure of the termination | terminus of a conveyance path. It is a perspective view of the ventilation path formation member provided in the lower part of a conveyance path. It is a longitudinal cross-sectional view which shows the both ends of the said conveyance path member. It is explanatory drawing which shows a mode that the height of a board | substrate is detected. It is explanatory drawing which shows a mode that the discharge position of gas changes according to the conveyance position of a board | substrate. It is a longitudinal cross-sectional view of the conveyance path member different from the said conveyance path member. It is a top view which shows embodiment which applied the board | substrate conveyance apparatus which concerns on this invention to the coating and developing apparatus. It is a perspective view which shows the said coating and developing apparatus. It is side part sectional drawing which shows the said application | coating and developing apparatus. FIG. 4 is a perspective view showing a DEV layer coating unit, a shelf unit, a main arm, and an exhaust unit in the coating and developing apparatus.

Explanation of symbols

W Semiconductor wafer 1 Transport path plate 10 Transport surface 13, 14 Wafer height detection sensor
2 Delivery stage 3 for delivery 3 Delivery stages 21 and 31 for delivery Elevating pins S1 to S8 Division area 4 Gas discharge hole 40 Ventilation passage forming member 42 Ventilation passage 44 Ventilation chamber 45 Gas supply pipes V1 to V9 Valve 5 Wafer detection sensor

Claims (14)

In a substrate transfer device that discharges gas and transfers the substrate while floating from the transfer surface of the transfer path,
Forming a transport path with a transport surface that extends along the transport direction of the substrate and becomes lower toward the center when viewed in cross section, and the height of both ends is equal to or higher than the height of the substrate that has floated A member,
A substrate transfer apparatus, comprising: a gas discharge hole group provided on a transfer surface of the substrate along the transfer direction, for discharging gas upward and levitation of the substrate.   2. The substrate transfer apparatus according to claim 1, wherein the transfer surface of the substrate is curved downward when viewed in cross section.   The gas discharge hole group includes a gas discharge hole that is provided to be paired on both the left and right sides with respect to the center line of the transport path and discharges gas obliquely upward toward the center side of the transport path. The substrate transfer apparatus according to claim 1 or 2.   The gas discharge hole group includes a gas discharge hole that discharges gas obliquely upward toward the other end side of the transfer path so as to transfer the floated substrate from one end of the transfer path toward the other end. 4. The substrate transfer apparatus according to any one of items 3 to 3.   5. A plurality of mutually-divided air passages for supplying gas to the gas discharge hole group along the substrate conveyance direction are provided below the conveyance path member. The board | substrate conveyance apparatus as described in one. Opening / closing means for independently performing discharge and stop of gas from the gas discharge holes for each divided area formed by dividing the transport path of the substrate into a plurality of transport directions,
Position detecting means for detecting the position in the transport direction on the transport path of the substrate;
6. A control unit that controls the discharge and stop of gas in each divided area via the opening / closing means based on the detection result by the position detecting means. The board | substrate conveyance apparatus of description.   7. The substrate transfer apparatus according to claim 6, wherein the position detection means is a substrate detection sensor that is provided in each of the divided regions and detects the presence or absence of a substrate. Height detection means for detecting the height of the substrate from the transport path;
A means for determining whether or not the substrate is positioned at a preset height based on a detection result of the height detection means is provided. The board | substrate conveyance apparatus of description. Forming a transport path with a transport surface that extends along the transport direction of the substrate and becomes lower toward the center when viewed in cross section, and the height of both ends is equal to or higher than the height of the substrate that has floated Positioning the substrate on the member;
A step of discharging gas upwardly from a group of gas discharge holes provided along the substrate transfer direction on the transfer surface of the substrate to float the substrate from the transfer surface and transferring the substrate;
The board | substrate conveyance method characterized by including.   In the process of floating the substrate from the transfer surface and transferring the gas obliquely upward toward the center of the transfer path from a group of gas discharge holes provided in pairs on the left and right sides across the center line of the transfer path. 10. The substrate transfer method according to claim 9, further comprising a discharging step.   In the step of transporting the substrate by floating from the transport surface, the substrate is transported from one end of the transport path to the other end from a group of gas discharge holes provided in pairs on the left and right sides across the center line of the transport path. The substrate transport method according to claim 9, further comprising a step of discharging gas obliquely upward toward the other end side of the transport path.   Including a step of supplying gas to a plurality of air passages partitioned from each other for supplying gas to the gas discharge hole group provided below the transfer path member along the transfer direction of the substrate. The substrate carrying method according to claim 9. Detecting the position in the transport direction on the transport path of the substrate;
And a step of controlling the discharge and stop of the gas in each divided area formed by dividing the substrate transport path into a plurality of directions in the transport direction, based on the detection result of the step. The substrate carrying method according to any one of 9 to 12. A computer program used in a substrate transfer device that discharges gas and transfers the substrate while floating from the transfer surface of the transfer path,
A computer program comprising a set of steps for carrying out any one of claims 9 to 13.

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