JP6426816B2 - Heat treatment equipment - Google Patents

Description

  The present invention relates to a heat treatment apparatus for performing a heat treatment on a work such as a silicon substrate.

  In a manufacturing process of a solar battery cell or the like, heat treatment such as diffusion processing is performed to diffuse impurities on the surface of a silicon substrate (semiconductor wafer) which is a work. The heat treatment apparatus for performing this heat treatment includes a process tube and a heater for accommodating the work and performing the heat treatment.

  The process tube is, for example, a quartz tube, and accommodates therein a boat in which a plurality of semiconductor wafers are held with a predetermined gap therebetween. The heater is disposed to surround the outside of the process tube and heats the inside of the process tube to a predetermined temperature.

  At one end of the process tube, an opening for taking in and out the boat is formed, and a door for opening and closing the opening is provided. By closing the opening with the door, the inside of the process tube is sealed (see, for example, Patent Document 1).

During the diffusion process of the semiconductor wafer, a gas such as phosphorus oxychloride (POCl ₃ ) or boron tribromide (BBr ₃ ) is introduced into the sealed process tube.

JP, 2001-185501, A

The door is exposed to the outside air and cooled while the inside surface is exposed in the hot process tube. For this reason, if the insulation between the inner surface and the outer surface of the door is not sufficient, the vicinity of the opening of the process tube is cooled through the door during the heat treatment process. In addition, if the adhesion between the inner surface of the door and the end surface of the process tube is not sufficient, the open air in the vicinity of the opening of the process tube is cooled by the outside air that intrudes into the process tube from the gap between the two. When the vicinity of the opening of the process tube is cooled during the diffusion processing of the semiconductor wafer, precipitation of phosphorus pentoxide derived from POCl ₃ (P ₂ O ₅ ) is caused on the inner surface of the door or in the vicinity of the opening of the process tube. In addition, an aqueous solution of phosphoric acid generated by the reaction of water vapor contained in the process tube with POCl ₃ or P ₂ O ₅ in the process tube causes the metal frame supporting the door to corrode, There is a risk of contaminating the work in the process tube.

  The object of the present invention is to ensure insulation between the inner surface and the outer surface of the door and to improve sealing between the inner surface of the door and the end surface of the process tube to cause corrosion of the frame and contamination of the work. It is providing the heat processing apparatus which can suppress generation | occurrence | production of a product.

  The heat treatment apparatus of the present invention comprises a process tube, a door, an opening and closing mechanism, and a door inclination adjusting member.

  The process tube has a tubular shape, one end is closed, and an opening (furnace port) is formed at the other end, and a workpiece to be heat-treated is accommodated inside through the opening. The door opens and closes the opening of the process tube.

  The door has an inner surface member, a heat insulating material and a door frame. The inner member is disposed on the process tube side. The heat insulating material is disposed outside the inner surface member. The door frame is disposed outside the heat insulating material to hold the inner member and the heat insulating material.

  The opening and closing mechanism has a drive arm and drive means. The drive arm supports the door frame at its tip. The door arm is driven with the door in one direction approaching the process tube and in the other direction away from the process tube. The drive means is configured to drive the drive arm by the drive force to operate the door to open or close the opening of the process tube.

  The door inclination adjusting member supports the door in an adjustable manner. The tip of the door drive arm is tiltably supported and attached to the door frame.

  According to this configuration, since the heat insulating material is built in the door, even if there is a temperature difference between the inside and the outside of the door, a decrease in the temperature of the inner surface member of the inside surface of the door is suppressed. This prevents the deposition of byproducts derived from the diffusion gas in the vicinity of the furnace opening of the process tube.

  The heat insulating material and the inner surface member are structures held by the door frame. Therefore, even if the door has a heat insulating material, the door can be opened and closed without any trouble by the open / close mechanism that supports the door frame on the outer surface of the door on the tip of the drive arm and allows it to rotate.

  Further, by the door inclination adjusting member provided at the tip of the drive arm and supporting the door in an inclinable manner, the sealing property can be enhanced in a manner that the inner member of the inner surface of the door follows the shape of the furnace opening of the process tube. . This prevents the entry of air from the furnace opening of the process tube, and prevents the generation of by-products that react with the air and are generated, which cause the door to be corroded and the inside of the furnace to be contaminated. it can.

  The door inclination adjusting member may include a rod end bearing attached to the tip of the drive arm, and a swinging shaft whose axis is tiltably supported by the rod end bearing. The swing shaft is attached to the door frame.

  The door inclination adjusting member may additionally additionally include an angle adjusting head and an angle adjusting block as follows. The angle adjustment head is provided at the other end opposite to the one end attached to the door frame in the swing shaft. An opening is formed in the angle adjustment block. The size of the opening is set to allow the angle adjusting head to pass through and to allow the angle adjusting head to tilt.

  The door frame and the drive arm are provided with a door rotation restricting member for restricting the rotation around the center of the door at a position eccentric to the center of the surface of the door closing the opening of the process tube.

  According to this, the door inclination adjusting member is realized simply. On the other hand, the angle adjusting head attached to the swinging shaft is allowed to rotate about the swinging shaft within the opening of the angle adjusting block, whereby the inner member of the process tube furnace opening and the inner surface of the door It is conceivable that the sealing property is lowered by repeating the opening and closing as the state of the sliding contact with the sheet is changed.

  Therefore, by providing a door rotation restricting member for restricting the rotation of the door to the door frame and the drive arm, the reproducibility of the sliding fit between the furnace opening of the process tube and the inner member of the inner surface of the door is maintained, and the sealing performance is lowered. You can prevent. Since the door rotates around the center of the door, it is desirable to provide the door rotation restricting member at a position eccentric to the center of the surface closing the process tube opening in the door.

  The structure of the said door rotation control member is a structure provided with the following rotation control head and a rotation control board. The rotation restricting head is provided on either the door frame or the drive arm. The rotation restricting plate is provided on the other of the door frame or the drive arm, and the rotation restricting head penetrates, and an opening having a size that restricts the rotation of the rotation restricting head within a certain range is formed.

  The drive means is constituted by the following cylinder mechanism. The cylinder mechanism includes a reciprocating piston rod and a cylinder tube that accommodates the piston rod, and is supplied with fluid pressure so that the piston rod advances and retracts relative to the cylinder tube to generate a driving force. The proximal end of the drive arm is connected to the piston rod, and the drive force is transmitted to the drive arm.

  The configuration for realizing the rotation of the drive arm is as follows. The drive arm is provided to extend substantially parallel to the surface of the door closing the opening of the process tube. The drive arm proximal end is provided with a first link that rotates with the drive arm. The fixing bracket is fixed to the heat treatment apparatus. The proximal end of the drive arm and the one end of the first link are rotatably supported at one end of the fixed bracket. The cylinder tube is rotatably supported at the other end of the fixed bracket and the other end of the fixed bracket. The other end of the first link is rotatably connected to the tip of the piston rod. The fixing bracket is provided such that one end is closer to the process tube than the other end.

  According to this invention, the furnace port of the process tube and the inner surface member of the door inner surface can be sealed while suppressing the temperature decrease of the inner surface member of the door inner surface. As a result, both the deposition of by-products derived from the diffusion gas in the vicinity of the furnace opening of the process tube and the intrusion of air from the furnace opening are suppressed, and the generation of the causative agent of the door corrosion and the furnace contamination is prevented. , It is possible to prolong the maintenance cycle.

It is a top view which shows the principal part of the heat processing apparatus which concerns on embodiment of this invention. It is a partially broken plan view which shows a door and a drive arm. It is the arrow III-III sectional view taken on the line of FIG. 2 which shows the structure of a door inclination adjustment member. It is a figure explaining operation | movement of a door inclination adjustment member. It is the arrow VV sectional view taken on the line of FIG. 2 which shows the structure of a door rotation control member. It is a front view which shows the structure of an opening-and-closing mechanism, a door inclination adjustment member, and a door rotation control member.

  Hereinafter, a heat treatment apparatus according to an embodiment of the present invention will be described with reference to the drawings.

  As an example, the heat treatment apparatus 1 is configured as a horizontal furnace in which the quartz tube 2 which is the process tube of the present invention is horizontally disposed in the longitudinal direction, and as shown in FIG. A door 10 is provided at an opening (furnace port) 2A of the quartz tube 2 in which the third portion 3 is formed, and can be opened and closed using an opening and closing mechanism 20. The workpiece W is, for example, a rectangular silicon substrate for solar cells. The boat 4 holds a plurality of workpieces W vertically arranged at equal intervals, travels by the traveling wheels, and carries the workpieces W into and out of the diffusion chamber 3 through the furnace port 2A.

The diffusion chamber 3 includes a diffusion source (for example, POCl ₃ ) using a diffusion gas air flow introduction device (not shown) installed on the closed end side of the quartz tube 2 omitted in FIG. Gas is introduced.

  Specifically, the diffusion gas flow introducing device causes the liquid diffusion source to bubble by the source gas, merges the source gas containing saturated vapor of the liquid diffusion source with the carrier gas, and makes it a diffusion gas flow, and this diffusion gas The air flow is configured to be introduced from one end of the quartz tube 2.

  An exhaust pipe 5 is connected to a peripheral surface near the furnace port 2A of the quartz tube 2. The diffusion gas provided for processing the workpiece W is exhausted from the exhaust pipe 5 to the outside of the furnace. The diffusion chamber 3 has a negative pressure in order to prevent the gas leakage of the diffusion gas from the furnace port 2A.

  A heating device is disposed on the outer periphery of the quartz tube 2. As the heating device, for example, a configuration provided with a heater 7 as shown in FIG. The diffusion source is introduced from the diffusion gas introduction device into the diffusion chamber 3 heated by the operation of the heating device, whereby a process (impurity, for example, phosphorus) is diffused to the work W is performed. The heating device can also include a heat equalizing pipe between the quartz tube 2 and the heater 7.

  The furnace port 2A of the quartz tube 2 is closed by an openable door 10. The door 10 is rotated by an opening and closing mechanism 20 described later to open and close the furnace port 2A.

  As shown in FIG. 2, the door 10 includes a quartz plate 11, a heat insulator 12 and a door frame 13. The quartz plate 11 is a disk made of quartz and corresponds to the inner surface member of the present invention. The door frame 13 holds the quartz plate and the heat insulating material. The quartz plate 11 is present on the inner surface side of the door 10, and is pressed against the furnace port 2A of the quartz tube 2 when the door 10 is closed.

  The door frame 13 is a member having a shape in which the disk portion 131 and the cylindrical portion 132 are integrated. The door frame 13 is formed of a rigid material such as stainless steel. The disk portion 131 is present on the outer surface side of the door 10. The cylindrical portion 132 constitutes a side surface portion of the door 10.

  The heat insulating material 12 is filled in a space surrounded by the cylindrical portion 132 of the door frame 13. The heat insulating material 12 is sandwiched between the disk portion 131 of the door frame 13 and the quartz plate 11, and the stoppers 14 are attached to plural places in the circumferential direction of the outer peripheral surface of the cylindrical portion 132 of the door frame 13 and the peripheral portion of the quartz plate 11. Fixed by Thus, the quartz plate 11 and the heat insulating material 12 are assembled to the door frame 13. In the door 10, the heat insulating material 12 is disposed on the opposite side to the diffusion chamber 3 (see FIG. 1) of the quartz plate 11.

  Next, the configuration of the opening and closing mechanism 20 will be described. The opening and closing mechanism 20 includes a drive arm 21 and a drive unit 23. The driving arm 21 is driven by the driving means 23 in one direction approaching the quartz tube 2 together with the door 10 (see arrow R1 direction in FIG. 1) and in the other direction away from the quartz tube 2 (see arrow R2 direction in FIG. 1). . By driving the drive arm 21 in this manner, the door 10 is driven and the furnace port 2A of the quartz tube 2 is opened or closed.

  In the present embodiment, the drive means 23 includes a reciprocating piston rod 232 and a cylinder tube 231 accommodating the piston rod 232, and the supply of fluid pressure causes the piston rod 232 to advance relative to the cylinder tube 231. It is configured by a cylinder mechanism that retracts to transmit the driving force. Here, an air cylinder is used as a cylinder mechanism.

  Drive arm 21 is provided to extend substantially in parallel with the surface of door 10 closing furnace port A of quartz tube 2.

  The proximal end of the drive arm 21 is connected to the distal end of the piston rod 232 via the first link 26 and the second link 28.

  A fixing bracket (fixing tool) 27 is fixed to the heat treatment apparatus at the side of the furnace port 2A of the quartz tube 2. The longitudinal direction of the fixing bracket 27 is defined in the direction orthogonal to the axial direction of the quartz tube 2. The fixing bracket 27 is provided such that one end is closer to the quartz tube 2 than the other end. A first pivot shaft 24 and a second pivot shaft 25 are provided at one end and the other end of the fixed bracket 27 in the longitudinal direction, respectively.

  The first pivot shaft 24 is composed of a columnar support 241 fixed to the fixed bracket 27 and a cylindrical sleeve 242 rotatably disposed around the support 241. The proximal end of the drive arm 21 and one end of the first link 26 can be rotated by the first pivot shaft 24 so that the drive arm 21 and the first link 26 rotate in unison with one end of the fixed bracket 27 Supported by

  The other end of the first link 26 is rotatably connected to the tip of the piston rod 232. The other end of the first link 26 and the tip of the piston rod 232 are connected via a second link 28 rotatable relative to the first link 26.

  The second pivot shaft 25 can be realized by a simple concavo-convex fitting such as providing a pin on the fixed bracket 27 and providing a hole in which the pin is fitted to the cylinder tube 231. The cylinder tube 231 is rotatably supported by the second pivot shaft 25 at the other end of the fixed bracket 27.

  The drive means 23 is a device that automates the rotation of the drive arm 21. When the piston rod 232 advances from the cylinder tube 231, the drive arm 21 rotates so as to approach the furnace port 2A of the quartz tube 2, and the door 10 rotates so as to close. Then, the door 10 is pressed against the furnace port 2A, and the inside of the quartz tube 2 is sealed.

  On the other hand, when the piston rod 232 retracts relative to the cylinder tube 231, the drive arm 21 rotates away from the furnace port 2A of the quartz tube 2, and the door 10 rotates so as to open. When the piston rod 232 retracts with respect to the cylinder tube 231, the drive arm 21 rotates away from the furnace port 2A of the quartz tube 2, and the door 10 rotates so as to open. If the drive means 23 is controlled by a controller (not shown) in particular, the drive of the drive arm 21 can be automatically controlled.

  The door frame 13 is tiltably (swayably) supported by a door tilt adjustment member 30 disposed at the tip of the drive arm 21.

  Specifically, as shown in FIG. 3, the door inclination adjusting member 30 includes a rod end bearing 31 and a rocking shaft 32. The rod end bearing 31 is attached to the tip of the drive arm 21. The rocking shaft 32 is supported by the rod end bearing 31 so that the axial center can be inclined. The swinging shaft 32 is fixed to the center of the door frame 13 using a fitting 321. The swinging shaft 32 fixed to the door frame 13 by the metal fitting 321 is inserted into the spherical inner ring 311 of the rod end bearing 31 attached to the top end of the drive arm 21.

  The rod end bearing 31 can be configured using a known rod end bearing (Japanese Patent Application Laid-Open No. 2003-247540, Japanese Utility Model Application Laid-Open No. 2-78808), and in the spherical mounting hole formed inside, The spherical inner ring 311 is held swingably. The rocking shaft 32 is held tiltably together with the spherical inner ring 311.

  An angle adjusting head 33 is provided at the other end of the swinging shaft 32 opposite to the one end attached to the door frame 13. An angle adjustment block 34 is attached to the tip of the drive arm 21. The angle adjustment block 34 is formed with an opening 34A through which the angle adjustment head 33 passes. The size of the opening 34A is set to allow the tilt of the angle adjustment head 33.

  Due to the above-described configuration of the door inclination adjusting member 30, as shown in FIG. The maximum α of the inclination angle of the door 10 is regulated (adjusted) by the relative relationship between the outer diameter of the angle adjusting head 33 and the inner diameter of the opening 34A of the angle adjusting block.

  Furthermore, the door frame 13 and the drive arm 21 are provided with a door rotation restricting member 40 that restricts the rotation of the door 10 about the center thereof. As shown in FIG. 6, the door rotation restricting member 40 is provided at a position deviated from the center of the surface of the quartz tube 2 in the door 10 closing the furnace port 2A, and restricts the rotation of the door 10.

  In the present embodiment, the door rotation restricting member 40 includes a rotation restricting head 42 and a rotation restricting plate 41, as shown in FIG. The rotation restricting head 42 is fixed to the drive arm 21. The rotation restricting plate 41 is fixed to the door frame 13. Alternatively, it is also possible to adopt a configuration in which the rotation restricting head 42 is fixed to the door frame 13 and the rotation restricting plate 41 is fixed to the drive arm 21.

  The rotation restricting plate 41 is manufactured, for example, by bending a strip-like sheet metal at two places in the longitudinal direction into a substantially Z shape. The rotation restricting head 42 is attached to a support block 43 vertically fixed on the opposite side of the drive arm 21 to the door 10 so as to protrude toward the door 10.

  The rotation restricting plate 41 is fixed to the disc portion 131 of the door frame 13 with screws or the like using one of the end pieces 411 of the both end pieces 411 and 412 parallel to each other. The rotation restricting head 42 passes through the opening 41 </ b> A formed in the other end piece 412 of the rotation restricting plate 41. The size of the opening 41A is set to a size that restricts the rotation of the rotation restricting head 42 within a certain range. Specifically, the rotation restricting head 42 and the opening 41A are adjusted such that the rotation restricting head 42 is inserted into the opening 41A so that the inclination angle of the door 10 can be changed within the range of the angle α.

  The rotation of the door 10 around the swinging shaft 32 is restricted by the configuration of the door rotation restriction member 40 described above. Thereby, the reproducibility of the sliding contact between the furnace opening 2A of the quartz tube 2 and the quartz plate 11 on the inner surface of the door can be maintained according to the present invention, since the heat insulating material 12 is built in the door 10 Even if there is a temperature difference on the outside, the temperature decrease of the quartz plate 11 on the inner surface of the door is suppressed. Thereby, it is prevented that the by-product derived from the gas for diffusion is precipitated in the vicinity of the furnace port 2A of the quartz tube 2.

  The door 10 has a structure in which a heat insulating material is sandwiched between the door frame 13 and the quartz plate 11. Therefore, even if the door 10 has a heat insulating material 12, the door 10 can be opened and closed without any trouble by the open / close mechanism 20 which supports the door frame 13 on the outer surface of the door by the drive arm 21 and makes it freely rotatable.

  Further, the drive arm 21 is urged toward the furnace port 2A of the quartz tube 2 by the drive means 23, and the door frame 13 is supported by the door inclination adjustment member 30 provided at the tip of the drive arm 21. By sealing the quartz plate 11 on the inner surface of the door along the shape of the furnace opening 2A of the quartz tube 2, the sealing property of the both can be enhanced. Thereby, the penetration of air from the furnace port 2A of the quartz tube 2 can be prevented, generation of by-products by reaction with the air can be prevented, and corrosion of the door and contamination in the furnace can be prevented.

  The above description of the embodiments should be considered in all respects as illustrative and not restrictive. The scope of the present invention is indicated not by the embodiments described above but by the claims. Further, the scope of the present invention is intended to include all modifications within the scope and meaning equivalent to the claims.

W work 1 heat treatment device 2 quartz tube (process tube)
2A furnace opening 3 diffusion chamber 4 boat 5 exhaust pipe 6 soaking pipe 7 heater 10 door 11 quartz plate (inner surface member)
12 Thermal insulation 13 Door frame 14 Stopper 20 Opening and closing mechanism 21 Drive arm 23 Drive 26 First link 27 Fixing bracket 28 Second link 30 Door inclination adjustment member 31 Rod end bearing 32 Swing shaft 33 Angle adjustment head 34 Angle adjustment block 40 Door rotation regulating member 41 rotation regulating plate 42 rotation regulating head 43 support block

Claims (7)

One end of which is open port formed on the other end with closed, and the quartz tube workpiece to be heat treated is accommodated through the opening, a door for opening and closing the opening of the quartz tube, the to open and close the opening door and a switching mechanism for operating the,
The door, an inner surface member disposed on the quartz tube side is formed of quartz, and the heat insulating member disposed on the outside of the inside member, said inside member and the insulation arranged outside of the heat insulating material It has a door frame that holds wood and,
The opening and closing mechanism is
A drive arm that is driven in the other direction away from one and the quartz tube approaching the quartz tube,
Drive means for driving the drive arm ;
A door inclination adjusting member for inclinably supporting the door at a tip end portion of the drive arm;
And the opening of the quartz tube can be opened and closed by the movement of the door accompanying the drive of the drive arm ,
The door inclination adjusting member
A bearing attached to the tip of the drive arm;
The door frame is attached to one end, and the other end is held by the inner ring of the bearing, and can swing along with the door frame according to relative rotation of the inner ring with respect to the drive arm Axis,
Is included,
The opening and closing mechanism further includes a door rotation restricting member that restricts rotation around the center of the door, and the door rotation restricting member is only at a position on one side with respect to the swing axis in the longitudinal direction of the drive arm. It is provided to limit the rotation of the swing shaft,
When the opening and closing mechanism moves the door such that the opening of the quartz tube is closed, the inner surface member is pressed by the periphery of the opening of the quartz tube, whereby the door inclination adjusting member is the quartz tube A heat treatment apparatus , wherein the inclination of the door is adjusted so that the inner surface member is along the periphery of the opening, whereby the inner surface member is in close contact with the periphery of the opening of the quartz tube .   The heat treatment apparatus according to claim 1, wherein a diffusion gas containing phosphorus oxychloride or boron tribromide for heat-treating the work is introduced into the quartz tube.   The heat treatment apparatus according to claim 1, wherein the bearing is a rod end bearing. The door inclination adjusting member
An angle adjusting head provided at the other end of the rocking shaft,
An angle adjustment block provided at the tip of the drive arm, the opening through which the angle adjustment head passes, and having an opening sized to allow inclination of the angle adjustment head ;
The heat treatment apparatus according to any one of claims 1 to 3 , further comprising Wherein the door rotation restricting member,
A rotation restricting head provided on one of the door frame and the drive arm;
A rotation restricting plate which is provided on the other of the door frame and the drive arm, and which is an opening through which the rotation restricting head passes , and which has an opening having a size for restricting the rotation of the rotation restricting head within a predetermined range; ,
It includes heat treatment apparatus according to claim 1. It said drive means includes a piston rod which reciprocates a cylinder mechanism having a cylinder tube accommodating the piston rod, advancing the piston rod is supplied with fluid pressure to the cylinder tube, retracting transmitting the driving force by,
Before Symbol proximal end of the drive arm to the piston rod is connected, the heat treatment apparatus according to any one of claims 1 to 5. The drive arm extends substantially parallel to the plane of the Close the opening of the quartz tube,
As with the previous SL drive arm and the first link is rotating together, the proximal end portion of the drive arm and the one end portion of the first link is rotatably supported on one end of the fixing bracket,
With the previous SL cylinder tube is rotatably supported on the other end of the fixing bracket, the other end of the first link is rotatably connected to the distal end of the piston rod,
The heat treatment apparatus according to claim 6, wherein the fixing bracket is provided such that one end is closer to the quartz tube than the other end.

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