JP2008177238A - Substrate conveyor and vertical heat treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress or prevent deflection at the central part due to the empty weight of a substrate having a large or super large diameter during substrate conveyance. <P>SOLUTION: In the substrate conveyor comprising a supporting portion 17 to be moved above or below a substrate w of large diameter and a mechanism 28 provided in the supporting portion 17 in order to support the substrate w by gripping the periphery thereof, the supporting portion 17 is provided with one or a plurality of noncontact suction holding portions 30 for suction holding the central portion of the upper or lower surface of the substrate through an air layer so that the substrate does not deflect at the center of the upper and lower surfaces. The noncontact suction holding portion 30 has a negative pressure forming protrusion 31 consisting of a column or a cone projecting toward the upper or lower surface of the substrate and a gas jet nozzle 32 for forming a negative pressure in the vicinity of the negative pressure forming protrusion 31 by jetting gas sideways for the negative pressure forming protrusion 31. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a substrate transfer apparatus and a vertical heat treatment apparatus, and more particularly to a technique for suppressing the bending of a substrate when a large-diameter substrate is transferred.

  In the manufacture of a semiconductor device, there are processes for subjecting a substrate, for example, a semiconductor wafer, to various heat treatments such as oxidation, diffusion, CVD, annealing, etc., and a number of wafers are used as one of the heat treatment apparatuses for performing these processes. A vertical heat treatment apparatus (semiconductor manufacturing apparatus) capable of performing heat treatment at a time is used.

  This vertical heat treatment apparatus includes a heat treatment furnace having a furnace port at the bottom, a lid for sealing the furnace port, and a plurality of wafers provided on the lid in a vertical direction via a ring-shaped support plate. A holder (also referred to as a boat) that holds at intervals, an elevating mechanism that moves the lid up and down to carry the holder into and out of the heat treatment furnace, and a storage container (also referred to as a hoop) that stores a plurality of wafers at predetermined intervals. And a substrate transfer device having a plurality of support portions (also referred to as forks) for transferring (transferring) the wafer between the holder and the holder. The ring-shaped support plate is used as a measure for suppressing or preventing slip (crystal defects) generated at the peripheral edge of the wafer during high-temperature heat treatment.

  A conventional substrate transfer apparatus includes a plurality of locking members that are locked to the lower side surface of the peripheral edge of the wafer and support the wafer in a suspended state, and each locking member supports the wafer in a suspended state. It is configured to be able to reciprocate between the support position and the wafer release position that moves to the outside of the outer peripheral edge of the wafer and releases the support state of the wafer, and each locking member is connected to the wafer support position and the wafer release position. There is known one that is configured to be reciprocally driven by an actuator within a range of positions (see Patent Document 1).

  However, the substrate transport apparatus has a problem that the structure is complicated because both of the locking members arranged on the front end side and the rear end side of the support portion are movable. As a substrate transfer apparatus or vertical heat treatment apparatus that solves this problem, an upper gripping mechanism for supporting a wafer by an upper grip is provided under the fork, and the upper gripping mechanism is provided at the front end portion of the fork. (Patent Document 2) has been proposed which comprises a fixed locking portion that locks the wafer and a movable locking portion that is provided on the rear end side of the fork and detachably locks the rear edge portion of the wafer.

JP 2003-338531 A Japanese Patent Laying-Open No. 2005-311306

  By the way, with the increase in the wafer diameter (diameter 300 mm) and the next-generation wafer ultra-large diameter (diameter 400 to 450 mm), in the current substrate transfer apparatus or vertical heat treatment apparatus, deflection of the wafer center due to its own weight occurs. It is expected that Further, it is expected that the above-described bending causes stress on the wafer and a decrease in conveyance accuracy (the dimension or space of the bent portion in the central portion of the wafer needs to be considered).

  The present invention has been made in view of the above circumstances, and can provide a substrate transfer apparatus capable of suppressing or preventing bending due to its own weight at the center of the substrate during substrate transfer accompanying an increase in the substrate diameter or an increase in the size of the substrate. An object is to provide a vertical heat treatment apparatus.

  In order to achieve the above object, the first invention has a support part that is moved above or below a large-diameter substrate and a gripping mechanism that is provided on the support part and grips and supports the peripheral edge of the substrate. In the substrate transport apparatus, the support portion is provided with one or more non-contact suction holding portions that hold non-contact suction through an air layer so as not to bend the central portion of the upper surface or the lower surface of the substrate. The suction holding part is formed by projecting a negative pressure forming protrusion made of a column or a cone projecting toward the upper surface or the lower surface of the substrate, and jetting gas from the side to the negative pressure forming protrusion. A gas jet nozzle for forming a negative pressure in the vicinity of the negative pressure forming projection is provided.

  The second invention is a heat treatment furnace having a furnace port at the bottom, a lid for sealing the furnace port, and a large number of large-diameter substrates provided on the lid through the ring-shaped support plate in the vertical direction. A holding tool that holds the plurality of substrates at a predetermined interval, and a lifting mechanism that lifts and lowers the lid and carries the holding tool into and out of the heat treatment furnace. A substrate transport device that supports and transports the substrate in a substantially horizontal state, and the transport device grips a peripheral portion of the substrate provided on the support portion and a support portion that is moved above or below the substrate. A non-contact suction holding unit that holds and holds the non-contact suction through the air layer so as not to bend the central portion of the upper surface or the lower surface of the substrate. One or a plurality of the non-contact suction holding portions are provided on the upper surface of the substrate or A negative pressure forming protrusion composed of a column or cone protruding toward the surface, and a negative pressure in the vicinity of the negative pressure forming protrusion by jetting gas from the side to the negative pressure forming protrusion And a gas ejection nozzle for forming the gas.

  The support unit includes: a rotation blowing nozzle that rotates the substrate by blowing gas in a tangential direction on the upper surface of the substrate; and an alignment unit that detects an alignment mark provided on the substrate and aligns the substrate. It is preferable to have.

  The support part preferably has a displacement sensor for optically detecting the tilt of the substrate and an attitude control mechanism for making the support part parallel to the substrate based on a detection signal from the displacement sensor. .

  A reference plate provided below the support, a displacement sensor provided on the reference plate for optically detecting the tilt of the substrate, and the support made parallel to the substrate based on a detection signal from the displacement sensor It is preferable to have an attitude control mechanism.

  According to the present invention, the central portion of the substrate can be sucked and held by the non-contact suction holding portion via the air layer in a non-contact manner, and the substrate center portion can be bent due to its own weight when the substrate is transported due to the super large diameter of the substrate. It can be suppressed or prevented. Thereby, generation | occurrence | production of the stress by the bending of a board | substrate and the fall of a conveyance precision can be suppressed thru | or prevented.

  The best mode for carrying out the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a longitudinal sectional view schematically showing a vertical heat treatment apparatus according to an embodiment of the present invention, FIG. 2 is a view schematically showing a substrate transfer apparatus, (a) is a front view, and (b) is a side view. It is. 3 is a longitudinal sectional view of the support portion, and FIG. 4 is a bottom view of the support portion.

  In these drawings, reference numeral 1 denotes a vertical heat treatment apparatus (semiconductor manufacturing apparatus). The vertical heat treatment apparatus 1 has a housing 2 that forms an outer shell, and a substrate such as a thin disk is formed above the housing 2. And a vertical heat treatment furnace 3 for accommodating a semiconductor wafer w having a large diameter (a diameter of 300 mm or a diameter of 400 to 450 mm) and performing a predetermined process such as a CVD process. This heat treatment furnace 3 includes a vertically long processing vessel having a lower portion opened as a furnace port 4, for example, a reaction tube 5 made of quartz, a lid 6 that can be moved up and down to open and close the furnace port 4 of the reaction tube 5, and the reaction tube. A heater (heating mechanism) 7 provided so as to cover the periphery of the reactor 5 and capable of controlling the inside of the reaction tube 5 to a predetermined temperature, for example, 300 to 1200 ° C. (may be 1000 ° C. or less for an ultra-large diameter wafer). It is configured.

  In the housing 2, for example, a base plate 8 made of SUS for installing the reaction tube 5 and the heater 7 constituting the heat treatment furnace 3 is provided horizontally. The base plate 8 is formed with an opening (not shown) for inserting the reaction tube 5 from below to above.

  An outward flange portion (not shown) is formed at the lower end portion of the reaction tube 5, and this flange portion is held on the base plate 8 by a flange holding member so that the reaction tube 5 moves the opening of the base plate 8 from below to above. It is installed in the inserted state. The reaction tube 5 can be removed downward from the base plate 8 for cleaning or the like. Connected to the reaction tube 5 are a plurality of gas introduction tubes for introducing a processing gas and an inert gas for purge into the reaction tube 5 and an exhaust pipe having a vacuum pump, a pressure control valve and the like capable of reducing the pressure in the reaction tube 5. (Not shown).

  Below the base plate 8 in the housing 2, a boat (holding tool) 9 provided on the lid body 6 is loaded into the heat treatment furnace 3 (that is, the reaction tube 5), or from the heat treatment furnace 3. A work area (loading area) 10 for carrying out (unloading) or transferring the wafer w to the boat 9 is provided. The work area 10 is provided with an elevating mechanism 11 for elevating and lowering the lid 6 so that the boat 9 can be carried in and out. The lid body 6 is configured to abut against the open end of the furnace port 4 and seal the furnace port 4. A rotating mechanism (not shown) for rotating the boat 9 is provided below the lid body 6.

  The boat 9 in the illustrated example is made of, for example, quartz, and supports a large number of wafers w of, for example, about 50 to 75 in a horizontal state via a ring-shaped support plate 13 at a predetermined interval (pitch) in the vertical direction. And a leg portion 9b that supports the main body portion 9a, and the leg portion 9b is connected to the rotation shaft of the rotation mechanism. A lower heating mechanism (not shown) is provided between the main body portion 9 a and the lid body 6 to prevent a temperature drop due to heat radiation from the furnace port 4. In addition, as the boat 9, it may have only the main-body part 9a, may not be provided with the leg part 9b, and may be mounted on the cover body 6 via a heat insulation cylinder.

  The boat 9 is engaged with a plurality of, for example, four struts 12, top plates 12 a and bottom plates 12 b provided at the upper and lower ends of the struts 12, and grooves provided at a predetermined pitch on the struts 12 in multiple stages. The ring-shaped support plate 13 is provided. The ring-shaped support plate 13 is made of, for example, quartz or ceramic, has a thickness of about 2 to 3 mm, and has an outer diameter slightly larger than the outer diameter of the wafer w.

  A FOUP 14 that is a storage container storing a plurality of, for example, about 25 wafers w at a predetermined interval is placed on the front portion of the housing 2 to carry in and out of the housing 2. A table (load port) 15 is installed. The hoop 14 is a hermetic storage container having a lid (not shown) detachably attached to the front surface. A door mechanism 16 for removing the lid of the hoop 14 and opening the hoop 14 to the work area 10 is provided before and after the work area 10. The work area 10 has a wafer w between the hoop 14 and the boat 9. A wafer transfer device (substrate transfer device) 18 having a fork (supporting portion) 17 that performs transfer (transfer) is provided.

  On the front upper side outside the work area 10, a storage shelf 19 for stocking the hoop 14 and a hoop conveyance (not shown) for conveying the hoop 14 from the load port 15 to the storage shelf 19 or vice versa. Device. In addition, the furnace port 4 is covered above the work area 10 in order to suppress or prevent the high-temperature furnace heat from being released from the furnace port 4 to the work area 10 below when the lid 6 is opened ( A shutter mechanism 20 is provided.

  The wafer transfer device 18 has a base 21 that can be raised and lowered and turned. Specifically, as shown in FIG. 2, the wafer transfer device 18 is provided with a lifting arm 23 (movable up and down) provided in a vertical direction along a vertical guide 22 by a ball screw (not shown). (Long in the vertical direction), a horizontal moving base 24 provided so as to be horizontally movable by a ball screw or the like along the longitudinal direction of the elevating arm 23, and can be swiveled horizontally on the horizontal moving base 24 via a turning drive unit 25. And a box-shaped base 21 that is long in the horizontal direction. On this base 21, a moving body 27 that supports the base end of one fork 17 is provided so as to be movable back and forth along the longitudinal direction of the base 21, which is the horizontal direction. A moving mechanism (not shown) for moving the moving body 27 forward and backward is provided. The vertical heat treatment apparatus 1 includes a controller 41 that controls the wafer transfer apparatus 18. In the wafer transfer device 18 in FIG. 3, unlike the wafer transfer device in FIG. 9 (having a reference plate separately from the fork), the fork 17 includes a reference plate.

  The fork 17 is formed in a long plate shape along the longitudinal direction of the base 21. As shown in FIGS. 3 to 4, a gripping mechanism (in this embodiment, an upper gripping mechanism) 28 capable of gripping and supporting the wafer w from the front and rear is provided at the lower portion of the fork 17. The upper gripping mechanism 28 is provided at the front end portion of the fork 17 and supports the front edge side of the wafer w, and the movable support portion 28 is provided at the rear end side of the fork 17 and detachably supports the rear edge side of the wafer w. A support unit 28b and a drive unit, for example, an air cylinder 28c, for driving the movable support unit 28b back and forth (a position for gripping and releasing a wafer) are provided.

  The fixed support portion 28a and the movable support portion 28b are each a vertical portion 28x suspended from the lower surface of the fork 17, and protruded from the vertical portion 28x toward the center of the wafer w, and the upper surface is formed in a tapered shape. The peripheral portion of the wafer w is supported on the upper surface of the hook portion 28y. When aligning the wafer w as described later, the wafer w is floated from the upper surface of the hook portion 28y by the non-contact suction holding unit 30, and the wafer w is horizontally rotated by tangential gas blowing, The rotation of the wafer w is stopped by stopping the gas blowing in the tangential direction and sandwiching the wafer w between the vertical portions 28x. When rotating the wafer w, it is preferable that the wafer w be sufficiently sucked and floated so that the peripheral edge of the wafer w does not contact the hook portion 28y.

  In order to prevent the upper surface (surface to be processed) of the wafer w from coming into contact with the lower surface of the fork 17, a predetermined gap is provided between the lower surface of the fork 17 and the upper surface of the wafer w on the lower surface on the front end side of the fork 17. It is preferable that a spacer 29 having a tapered lower surface receiving the front edge side of the wafer w is provided. As a material of the fixed support portion 28a, the movable support portion 28b, and the spacer 29, a heat resistant resin such as a PEEK (Poly Ether Ether Ketone) material is preferable.

  The ring-shaped support plate 13 is provided with a notch (not shown) for avoiding interference with the fixed locking portion 28a and the movable locking portion 28b when the outer diameter is larger than the wafer w. Preferably it is. The ring-shaped support plate 13 is not necessarily provided with a notch when the outer diameter is smaller than that of the wafer w.

  The fork 17 is provided with a non-contact suction holding part (also referred to as a non-contact suction holding part) 30 that sucks and holds the wafer w through the air layer 50 in a non-contact manner so as not to bend. It has been. The air layer 50 includes a thin film (air film). The non-contact suction holding unit 30 is provided on the lower surface (lower portion) of the fork 17 so as to face the center in the center of the upper surface of the wafer w in the illustrated example. And a gas jet nozzle 32 for forming a negative pressure in the vicinity of the negative pressure forming protrusion 31 by jetting gas from the side to the negative pressure forming protrusion 31. It is configured.

The negative pressure forming projection 31 is formed of a cylinder having a diameter of about 10 mm and a height of about 3 mm, for example, and the gas ejection nozzle 32 is located at a predetermined distance, for example, about 2.5 mm from the negative pressure forming projection 31. It is arranged to face the side surface of the part 31. The diameter of the gas ejection nozzle 32 is, for example, about 1 mm. In order to pressure-feed and supply the compressed gas to the gas ejection nozzle 32, a gas pressure feeding source, for example, a cylinder or a compressor (not shown) is connected to the gas ejection nozzle 32 via a pressure feeding channel 35. The gas may be air, but is preferably an inert gas such as nitrogen (N ₂ ) gas. The pressure feed channel 35 may be a pipe.

  A plurality of, for example, four non-contact suction holding portions, that is, negative pressure forming protrusions 31 are provided in order to secure a suction holding force of a wafer having a large diameter, eg, a 300 mm diameter. In the present embodiment, one (common) protruding gas ejection portion 33 having four gas ejection nozzles 32 at the center is provided, and a plurality of, for example, four negative pressure forming projections are provided around the gas ejection portion 33 at equal intervals. A portion 31 is provided. In the illustrated example, the gas ejection portion 33 is formed of a cylinder, and gas ejection nozzles (gas ejection holes) 32 are formed radially from the center thereof, so that the compressed gas is branched and supplied to the gas ejection nozzles 32 from the pressure feed passage 35. It has become. Note that the horizontal movement of the wafer w by the compressed gas can be suppressed by ejecting the compressed gas in all directions.

  FIG. 5 is a schematic side view for explaining the configuration of the non-contact suction holding portion, and FIG. 6 is an explanatory view for explaining the principle of the non-contact suction holding portion. The principle of the non-contact suction holding unit 30 will be described with reference to these drawings. When gas is ejected from the side with respect to the side surface of the negative pressure forming projection 31, the gas is exposed to the surface of the negative pressure forming projection 31 due to the Coanda effect. A positive pressure Pa is generated on the front surface of the negative pressure forming protrusion 31 facing the gas by Bernoulli's theorem, while flowing along the end surface and the peripheral surface. A negative pressure Pb is generated at 31a, and the wafer w is attracted to the end surface 31a of the negative pressure forming protrusion 31 in a non-contact manner by the negative pressure Pb. In addition to the cylinder, the shape of the negative pressure forming protrusion 31 may be, for example, a polygonal column, an ellipse, or a vertical body (cone, polygonal pyramid).

  In order to perform alignment (alignment) of the wafer w while being supported by the fork 17, a gas, for example, nitrogen gas, is blown onto the fork 17 in a tangential direction on the upper surface of the wafer w to rotate the wafer w around its axis. And a positioning nozzle 37 for detecting a positioning mark (not shown) provided on the wafer w and positioning the wafer w. The rotation blow nozzle 36 may be only one (for rotation in one direction), but it is preferable to arrange two different rotation directions for rotation in both the forward and reverse directions for efficient alignment. An opening / closing valve (electromagnetic valve) 38 is preferably provided between the rotation blowing nozzle 36 and the pressure feed passage 35. The alignment mark may be a notch, but is preferably an inscribed mark on the peripheral surface of the wafer with a laser marker.

  The alignment unit 37 has a sensor for detecting an alignment mark on the wafer w, and the controller 41 controls the gas blowing (including direction) from the rotation blowing nozzle 36 based on the detection signal. At the same time, the upper gripping mechanism 28 is closed to stop the rotation of the wafer w so that the wafer alignment mark is aligned with the position of the alignment portion 37.

  Pockets (accommodating grooves) having a predetermined groove width for accommodating and supporting both side edges of the wafer w in parallel are formed in the hoop 14 at a predetermined pitch. In this case, it is difficult for the upper gripping mechanism 28 to grip the tilted wafer. Therefore, the fork 17 includes a displacement sensor 39 for optically detecting the tilt of the wafer w, and a posture control mechanism 40 for making the fork 17 parallel to the wafer w based on a detection signal from the displacement sensor 39. It is preferable to have. As the displacement sensor 39, for example, a laser type ultra-small displacement sensor is used, and for example, the height and height of three points on the wafer are detected by the displacement sensor 39 so as to obtain the center and inclination of the wafer w.

  FIG. 7 is a schematic side view for explaining the posture control mechanism of the support portion, and FIG. 8 is a schematic front view for explaining the posture control mechanism of the support portion. In the present embodiment, as the attitude control mechanism 40 of the fork 17, a first tilt stage 40a for tilting left and right and a second tilt stage 40b for tilting back and forth are used. The base of the first tilt stage 40a is attached to the moving body 27 in the wafer transfer device 18, the base of the second tilt stage 40b is attached to the output of the first tilt stage 40a, and the output of the second tilt stage 40b. The base end portion of the fork 17 is attached to the above. The fork 17 can be adjusted in angle within a range of a predetermined angle θa, for example, 180 ° + α around the rotation center of the first tilt stage 40a on the center line by the first tilt stage 40a, and the fork 17 can be adjusted by the second tilt stage 40b. The angle 17 can be adjusted within a range of a predetermined angle θb, for example, ± 10 ° around the rotation center of the second stage 40b.

  The controller 41 detects and stores the position information (including tilt) of the wafer w in the hoop 14 or the boat 9 by the displacement sensor 39, and based on the position information, the attitude of the fork 17 by the attitude control mechanism 40. Is set to control. Thereby, for example, when the wafer w in the hoop 14 is tilted, the fork 17 can be tilted in accordance with the tilt of the wafer w, and the wafer w can be reliably gripped upward.

  Obstacle sensors 42 for detecting an obstacle are provided on both sides of the tip of the fork 17. As the obstacle sensor 42, an ultrasonic sensor, a CCD camera, or the like is applicable. When an obstacle is detected in advance by the obstacle sensor 42 and its position is stored in the spatial coordinates of the controller 41, and the wafer is transferred so as to avoid the obstacle, or when an obstacle is detected during transfer. By stopping the transfer of the wafer, collision can be avoided and damage to the wafer and the apparatus can be prevented.

  A mapping sensor (also referred to as a wafer counter) 43 for detecting the presence / absence of the wafer w in the hoop 14 or the boat 9 and storing it as position information is provided at the tip of the base 21 of the wafer transfer device 18. It may be done. The mapping sensor 43 includes a light emitting element 43a that emits infrared light and a light receiving element 43b that receives the infrared light. The mapping sensor 43 is scanned in the vertical direction along the wafers w held in multiple stages in the hoop 14 or the boat 9 to detect the position of the wafers w in each stage in the hoop or the boat 9. Information can be stored (mapped) in the storage unit of the controller 41, and the state of the wafer w before and after processing (for example, whether or not it has popped out) can be detected.

  According to the wafer transfer apparatus 18 or the vertical heat treatment apparatus 1 configured as described above, a fork 17 that is moved above a large-diameter wafer w, and a peripheral portion of the wafer w that is provided on the fork 17 are supported. The fork 17 is provided with a non-contact suction holding portion 30 that holds the upper surface center portion of the wafer w in a non-contact manner so as not to bend. The portion 30 can be sucked and floated in a non-contact manner, and the deflection due to the weight of the center of the wafer during wafer transfer accompanying the ultra-large diameter of the wafer w can be suppressed or prevented. Thereby, generation | occurrence | production of the stress by the bending of the wafer w and the fall of a conveyance precision can be suppressed thru | or prevented.

  The non-contact suction holding unit 30 includes a negative pressure forming projection 31 made of a column or a cone protruding toward the upper surface of the wafer w, and a gas from the side with respect to the negative pressure forming projection 31. Is formed in the vicinity of the negative pressure forming protrusion on the lower surface of the fork 17 with a simple configuration. By the negative pressure, the wafer w can be sucked and lifted and held without contact. The non-contact suction holding unit 30 can suppress vertical vibration (vibration isolation) at the center of the wafer w, and can suppress particle scattering.

  The fork 17 detects the alignment mark provided on the wafer w by blowing a gas in the tangential direction of the upper surface of the wafer w and rotates the wafer w, and a position for aligning the substrate. Since the alignment portion 37 is provided, the wafer can be aligned (positioning and alignment in the crystal direction) during the transfer of the wafer at the position of the fork 17, and thus conventionally provided in the housing. The alignment apparatus and the wafer transfer process to the alignment apparatus are not required, and the structure can be simplified and the throughput can be improved.

  The fork 17 includes a displacement sensor 39 for optically detecting the tilt of the wafer w, and a posture control mechanism 40 for making the fork 17 parallel to the wafer w based on a detection signal from the displacement sensor 39. Therefore, even if the wafer w is tilted in the hoop 14, the fork 17 can be made parallel to the wafer w following the tilted wafer w. It is possible to grab the top. In this case, the attitude control mechanism 40 is capable of biaxial attitude control by the first tilt stage 40a and the second tilt stage 40b, and easily moves the fork 17 to be parallel to the wafer surface so as to move the palm. Therefore, highly accurate wafer conveyance is possible. Even if the wafer is tilted, it can be transferred after being corrected to a horizontal posture, so that the wafer can be transferred softly, and damage to the wafer and generation of particles can be prevented.

  Further, the wafer w can be transferred upside down by the first tilt stage 40a. The position of the fork 17 can be automatically corrected by recognizing the position of the wafer surface by the displacement sensor 39. For example, on the boat side, the position information can be obtained only by recognizing the upper surface position of the uppermost wafer. And the pitch information in the boat makes it possible to accurately recognize coordinates and simplify teaching.

  FIG. 9 is a longitudinal sectional view schematically showing another embodiment of the substrate transfer apparatus. In the embodiment of FIG. 9, the same parts as those of the embodiment of FIG. In the embodiment of FIG. 9, the reference plate 44 is provided below the fork 17, and a displacement sensor 39 that optically detects the tilt of the wafer w is provided on the reference plate 44. The base end portion of the reference plate 44 is attached to the moving body 27 in the wafer transfer mechanism 18, and the tip end portion extends horizontally in a cantilevered manner like the fork 17. The displacement sensor 39 detects the displacement (inclination) of the lower surface of the wafer w, and the attitude of the fork 17 is controlled in parallel with the wafer w by the attitude control mechanism 40 based on the detection signal. According to the wafer transfer apparatus of the present embodiment, the same effects as those of the above-described embodiment can be obtained.

  FIG. 10 is a view showing another example of the non-contact suction holding unit, and FIG. 11 is a schematic view schematically showing a pressure feed channel of the non-contact suction holding unit. The non-contact suction holding unit 30 of the present embodiment is a non-contact suction holding unit including a negative pressure forming protrusion 31 disposed in the center and a gas ejection nozzle 32 that jets gas to the side surface of the negative pressure forming protrusion 31. For example, four U are provided. That is, three units U are arranged at equal intervals around one unit U arranged in the center. In this case, it is preferable that these units U are arranged in a direction in which the gas ejection nozzle suppresses the horizontal movement of the wafer by the compressed gas. In addition, as shown in FIG. 11, a pressure feed channel 35 is connected to the gas ejection nozzle 32 of each unit via a distribution channel 35a.

  The holding force obtained in the performance test of the non-contact suction holding unit 30 is as shown in Table 1.

In Table 1, the flow rate is the flow rate of a gas (for example, dry air or N ₂ gas) that is pumped to the pumping flow path 35 at a predetermined pressure, for example, 0.2 MPa, and the flying height is the wafer in a stable holding position. The distance between the wafer and the non-contact suction holding unit is the distance between the non-contact suction holding unit and the holding force is the force that holds the wafer. is there.

  This performance test was performed using the suction holding force measuring device 60 shown in FIG. The suction holding force measuring device 60 includes a load cell 61 having a wafer w bonded to the upper portion thereof, a non-contact suction holding unit 30 disposed above the wafer w, and the non-contact suction holding unit 30 for the wafer w. Is composed mainly of a height adjustment mechanism (not shown) for adjusting the height of the wafer w with respect to the wafer w and a digital force gauge 62 for outputting and displaying the detection value by the load cell 61.

  The holding force obtained in the above performance test is 137.3 g when the flow rate of the pumped gas is 50 L / min, and the weight of the wafer having a diameter of 300 mm is 120 g, so that the wafer w can be held. The test results were obtained.

  FIG. 13 is a perspective view showing another example of the support portion. In this embodiment, the support part 70 is not a fork but is composed of two horizontal and parallel pipes 70a and 70b. The inside of one pipe 70a forms a pressure feed channel 35. A base member 71 attached to the moving body of the wafer transfer apparatus is attached to the base ends of these tubes 70a and 70b, and the non-contact suction holding part 30 is attached to the distal ends of the tubes 70a and 70b.

  Further, the non-contact suction holding portion 30 is attached with fixed support portions 28a and 28a of an upper gripping mechanism 28 via arms 72a and 72b extending obliquely forward and leftward and rightward. A movable support portion (not shown) of the mechanism 28 is attached. According to the substrate transfer apparatus having the support portion 70 of the present embodiment, the same operational effects as those of the embodiment can be obtained and the structure can be simplified.

  FIG. 14 is a perspective view showing an example of a lower grip type support portion. As shown in FIG. 14, the substrate transfer apparatus includes a support unit 70 that is moved below the wafer w, and a gripping mechanism (also referred to as a lower gripping mechanism) 80 that grips and supports the periphery of the wafer w with a lower grip. The support unit 70 may be provided with a non-contact suction holding unit 30 that sucks and holds the wafer w through the air layer in a non-contact manner so as not to bend. The lower gripping type support part 70 is an upside down version of the upper gripping type support part 70 shown in FIG. According to the substrate transfer apparatus having the lower grip type support portion 70 of the present embodiment, the center portion of the lower surface of the wafer w can be held in a non-contact manner, and the same effects as those of the embodiment can be obtained. Even if the operation of transferring the wafer w to the boat fails, the wafer w can be received on the non-contact suction holding unit 30 to prevent the wafer w from falling off.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention is not limited to the above-described embodiments, and various design changes and the like can be made without departing from the gist of the present invention. is there. For example, as the wafer transfer device, a plurality of forks may be provided in the vertical direction.

1 is a longitudinal sectional view schematically showing a vertical heat treatment apparatus according to an embodiment of the present invention. It is a figure which shows a board | substrate conveyance apparatus schematically, (a) is a front view, (b) It is a side view. It is a longitudinal cross-sectional view of a support part. It is a bottom view of a support part. It is a schematic side view for demonstrating the structure of a non-contact suction holding part. It is explanatory drawing explaining the principle of a non-contact suction holding | maintenance part. It is a schematic side view for demonstrating the attitude | position control mechanism of a support part. It is a schematic front view for demonstrating the attitude | position control mechanism of a support part. It is a longitudinal cross-sectional view which shows other embodiment of a board | substrate conveyance apparatus roughly. It is a figure which shows the other example of a non-contact suction holding | maintenance part. It is a model which shows roughly the pumping flow path of the non-contact suction holding | maintenance part. It is a figure which shows a suction holding force measuring device. It is a perspective view which shows the other example of a support part. It is a perspective view which shows the example of a support part of a lower grip type.

1 Vertical heat treatment equipment w Semiconductor wafer (substrate)
3 Heat treatment furnace 6 Lid 9 Boat (holder)
13 Ring-shaped support plate 14 Hoop (storage container)
17 Fork (supporting part)
18 Wafer transfer device (substrate transfer device)
28 Upper gripping mechanism 30 Non-contact suction holding portion 31 Negative pressure forming projection 32 Gas ejection nozzle 36 Rotating blowing nozzle 37 Positioning portion 39 Displacement sensor 40 Attitude control mechanism 44 Reference plate 50 Air layer 70 Supporting portion 80 Lower gripping mechanism U Non-contact suction holding unit

Claims (8)

  In a substrate transport apparatus having a support portion that is moved above or below a large-diameter substrate and a gripping mechanism that is provided on the support portion and supports the peripheral edge of the substrate, the support portion includes a center of the upper surface of the substrate. One or a plurality of non-contact suction holding parts that suck and hold in a non-contact manner through an air layer so as not to bend the center part or the lower surface center part, and the non-contact suction holding part faces the upper surface or the lower surface of the substrate. In order to form a negative pressure in the vicinity of the negative pressure forming protrusion by ejecting gas from the side to the negative pressure forming protrusion, which is composed of a protruding column or cone. A substrate transfer apparatus comprising: a gas jet nozzle.   The support unit includes a rotation blowing nozzle that rotates the substrate by blowing gas in a tangential direction on the upper surface of the substrate, and an alignment unit that detects the alignment mark provided on the substrate and aligns the substrate. The substrate transfer apparatus according to claim 1, wherein the substrate transfer apparatus is provided.   The support portion includes a displacement sensor for optically detecting the tilt of the substrate, and an attitude control mechanism for making the support portion parallel to the substrate based on a detection signal from the displacement sensor. The substrate transfer apparatus according to claim 1 or 2.   A reference plate provided below the support, a displacement sensor provided on the reference plate for optically detecting the tilt of the substrate, and the support made parallel to the substrate based on a detection signal from the displacement sensor 3. The substrate transfer apparatus according to claim 1, further comprising an attitude control mechanism.   A heat treatment furnace having a furnace port at the bottom, a lid for sealing the furnace port, and a large number of large-diameter substrates provided on the lid are held at predetermined intervals in the vertical direction via a ring-shaped support plate The substrate is in a substantially horizontal state between the holding tool, a lifting mechanism that moves the lid up and down and carries the holding tool into and out of the heat treatment furnace, and a storage container that stores a plurality of substrates at a predetermined interval. And a substrate transport device that supports and transports the upper grip, and the transport device grips and supports a support portion that is moved above or below the substrate, and a peripheral portion of the substrate that is provided on the support portion. In the substrate transport apparatus having a gripping mechanism, one or more non-contact suction holding portions that suck and hold through the air layer in a non-contact manner so as not to bend the central portion of the upper surface or the lower surface of the substrate are provided in the support portion. A plurality of non-contact suction holding portions are provided on the upper surface or the lower surface of the substrate. A negative pressure forming projection consisting of a columnar or cone projecting and a negative pressure is formed in the vicinity of the negative pressure forming projection by jetting gas from the side to the negative pressure forming projection A vertical heat treatment apparatus comprising a gas ejection nozzle for performing   The support unit includes a rotation blowing nozzle that rotates the substrate by blowing gas in a tangential direction on the upper surface of the substrate, and an alignment unit that detects the alignment mark provided on the substrate and aligns the substrate. The vertical heat treatment apparatus according to claim 5, wherein the vertical heat treatment apparatus is provided.   The support portion includes a displacement sensor for optically detecting the tilt of the substrate, and an attitude control mechanism for making the support portion parallel to the substrate based on a detection signal from the displacement sensor. The vertical heat treatment apparatus according to claim 5 or 6.   A reference plate provided below the support, a displacement sensor provided on the reference plate for optically detecting the tilt of the substrate, and the support in parallel with the substrate based on a detection signal from the displacement sensor The vertical heat treatment apparatus according to claim 5, further comprising an attitude control mechanism for performing the operation.

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