JP5858901B2 - Carrier transport member in heat treatment furnace and heat treatment furnace - Google Patents

Description

  The present invention relates to a carrier transport member in a heat treatment furnace and a heat treatment furnace.

  The heat treatment furnace is an apparatus that forms an oxide film on the surface of a wafer or diffuses impurities, for example. There are a vertical furnace and a horizontal furnace in the heat treatment furnace. In the case of a horizontal furnace, the core tube has a cylindrical shape with a gas introduction part. The boat loaded with wafers in this core tube (support) is placed on a parent boat (carrier) with wheels to reduce friction with the core tube, and hook hooks provided on the parent boat A hook rod is hooked on the main boat, and the parent boat carrying the wafer is carried in and out of the core tube. When the heat treatment is performed, the wafer is heat treated after being transported to the optimum position for the heat treatment in the furnace core tube.

  If the core tube and the main boat are distorted or tilted when the heat treatment furnace is loaded into or removed from the main boat, or if the core tube and the parent boat wheel do not touch each other, the main boat does not move straight and the cylindrical core tube The parent boat may rotate along. Also, because the position of the hook rod that carries the parent boat and the position of the parent boat are not the same every time, the fulcrum to which force is applied and the center of gravity of the parent boat are not straight to the core tube. It is. If this rotation is large, it will run over the guide of the tray at the part where it is transferred to the tray during unloading, causing damage to the quartz parts and wafers, or causing the parent boat to fall over.

  In view of this, a heat treatment furnace has been proposed in which two guide tubes are installed inside the core tube so as to sandwich the wheels so as to improve straightness (see, for example, Patent Document 1).

JP-A-9-181008

  However, according to the above-described conventional technology, the core tube of the heat treatment furnace is mainly made of quartz, and there is a problem that the cost is increased if a complicated structure in which a guide tube is installed. Further, when the parent boat is caught on the guide pipe, there is a risk of breakage, and there is a possibility that the guide pipe gets over.

  The present invention has been made in view of the above, and an object thereof is to obtain a carrier transport member and a heat treatment furnace in a heat treatment furnace in which a parent boat can go straight without having a complicated structure in the core tube of the heat treatment furnace. To do.

In order to achieve the above-described object, a transport table transport member for a heat treatment furnace according to the present invention is a transport table transport member for a heat treatment furnace that transports a transport table carrying a wafer between a tray and a cylindrical core tube. A hook rod connected to a carriage, a hook bar for reciprocating the carriage between the tray and the core tube, and the carriage moving in the core tube rotate in the circumferential direction of the core tube A hook bar support member that supports the hook bar so as to exert a force on the hook bar in a direction opposite to the rotation of the hook bar, and the hook bar is supported at the position supported by the hook bar support member. , Having a support plate projecting from the surface of the hook bar on both sides in a predetermined direction, the hook bar support member in a direction substantially orthogonal to the position of the support plate when the hook bar is inserted, Rotate the hook rod A shaft support for supporting the said hook bar when subjected to rotational force, characterized in that it have a, an elastic member to produce a rotational force in the opposite direction with respect to the support plate.

  According to the present invention, when the wafer is inserted into the core tube, even if the parent boat advances spirally, it is corrected to the original direction by the restoring force, so that there is an effect that straightness is improved. In addition, the structure of the core tube does not become complicated as in the case where a guide tube is installed inside the core tube, and the straightness of the parent boat in the core tube is not affected by the risk of contact and damage between the guide and the parent boat. And the quartz part or the wafer due to the collision can be prevented, and the parent boat loaded with the wafer can be prevented from falling.

FIG. 1 is a diagram schematically illustrating a configuration of a heat treatment furnace according to an embodiment. FIG. 2 is an exploded perspective view showing a schematic configuration of a transport table and its transport member in the heat treatment furnace according to the embodiment. FIG. 3 is a top view showing an example of the structure of the hook hooking portion. FIG. 4 is a cross-sectional view schematically showing the configuration of the hook bar support portion. FIG. 5 is a perspective view schematically showing another configuration example of the hook bar support portion. FIG. 6 is a diagram schematically showing how the wafer is carried in and out of the heat treatment furnace. FIG. 7 is a perspective view schematically showing a general carriage and its conveying member. FIG. 8 is a diagram schematically showing problems during transportation in a general case. FIG. 9 is a diagram illustrating a mechanism for suppressing the rotation of the parent boat according to the embodiment. FIG. 10 is a diagram illustrating another example of the hook bar support portion.

  With reference to the accompanying drawings, a carrier transport member and a heat treatment furnace in a heat treatment furnace according to an embodiment of the present invention will be described in detail below. It should be noted that the present invention is not limited to the embodiments and can be appropriately changed without departing from the gist of the present invention. In the drawings shown below, the scale of each member may be different from the actual scale for easy understanding. The same applies between the drawings.

  FIG. 1 is a diagram schematically illustrating a configuration of a heat treatment furnace according to the embodiment, and FIG. 2 is an exploded perspective view illustrating a schematic configuration of a transport table and its transport member in the heat treatment furnace according to the embodiment. 3 is a top view showing an example of the structure of the hook hooking portion, FIG. 4 is a cross-sectional view schematically showing the configuration of the hook bar support portion, and FIG. 5 is another configuration of the hook bar support portion. It is a perspective view which shows an example typically. In the following drawings, the conveyance direction of the main boat 23 is the X axis, the height direction is the Z axis, and the direction perpendicular to the X axis and the Z axis is the Y axis.

  The heat treatment furnace 10 is a horizontal diffusion furnace and includes a cylindrical quartz core tube 11 that heats the wafer 21. The wafers 21 are loaded on the sub boat 22 every predetermined number of times, and the sub boat 22 is further mounted on the main boat 23 to which wheels 23a are attached. Wheels 23 a are attached to the parent boat 23 so as to be movable in the axial direction of the cylindrical core tube 11. In the figure, the axis of the core tube 11 is arranged so as to coincide with the X-axis direction, and wheels 23a are attached so that the main boat 23 can move in the X-axis direction. Further, a hook hooking portion 24 is provided at the end of the parent boat 23 in the negative X-axis direction (the end of the core tube 11 on the wafer loading / unloading port 11a side). In this example, although the wheel 23a is attached to the parent boat 23, the wheel 23a may not be attached.

  A wafer door 11a of the core tube 11 is provided with a quartz door (not shown) for covering the core tube 11 with a lid. Further, a tray 31 for placing the parent boat 23 to be transferred is provided on the wafer carry-in / out entrance 11 a side of the core tube 11. The position of the upper surface of the tray 31 is adjusted so as to be the same height as the inner bottom surface of the core tube 11.

  Further, the heat treatment furnace 10 is provided with a transport table transport member 40 for taking the parent boat 23 into and out of the core tube 11. The carriage transport member 40 includes a hook bar 41 extending in the X-axis direction, a hook 42 provided at the end of the hook bar 41 in the X-axis positive direction, and a hook at the end of the hook bar 41 in the X-axis negative direction. And a hook bar support portion 43 that supports the bar 41.

  A support plate 44 that protrudes in a predetermined direction is provided at a portion of the hook bar 41 that is supported by the hook bar support portion 43. In this example, support plates 44 are provided in the positive and negative directions of the Y axis of the hook bar 41.

  As shown in FIG. 4, the hook bar support portion 43 is configured by a support portion main body 431 having a cavity 433 in a peripheral region through which the hook bar 41 passes. Near the central portion of the cavity 433 in the Y-axis direction, a shaft support portion 432 protruding in the Z-axis direction that supports the hook bar 41 is fixed to the support portion main body 431. The shaft support part 432 supports the hook bar 41 inserted from the X-axis direction of the support part main body 431. The hook bar 41 is fixed by the shaft support portion 432 so that the extending direction of the support plate 44 is the Y-axis direction in the initial state. The contact point between the hook bar 41 and the shaft support part 432 is sufficiently smooth, and the hook bar 41 is rotatably supported in a plane perpendicular to the insertion direction.

  Further, by inserting the hook bar 41 so that the support plate 44 is arranged in the Y-axis direction, the cavity 433 in the support portion main body 431 is divided into four regions 433 a to 433 d by the shaft support portion 432 and the support plate 44. It is divided into. Then, the elastic member 434 is fitted into the four regions 433a to 433d. The elastic member 434 is a material having elasticity, and examples thereof include a spring. As described above, the hook bar 41 can rotate in a plane perpendicular to the insertion direction. Therefore, when the hook bar 41 rotates in that direction, the support plate 44 provided on the hook bar 41 causes the elastic member 434 to move. Compress. At this time, the elastic member 434 is disposed so as to exert a force in a direction to resist the compressive force. Note that one end of the elastic member 434 may be fixed to the inner wall of the support portion main body 431 constituting the cavity 433, and the other end may be fixed to the support plate 44, or one or both may not be fixed.

  In FIG. 2, the hook bar 41 is supported by one hook bar support part 43, but as shown in FIG. 5, the hook bar support part 43 and the hook bar support part 43 in the X-axis direction The hook rod 41 may be supported by two stoppers 51 provided on both sides. The stopper 51 is provided with an opening 51a only in a portion where the hook bar 41 is inserted. As a result, even if the hook bar 41 moves in the X-axis direction, the support plate 44 contacts the stopper 51, so that the hook bar 41 can be prevented from slipping in the X-axis direction.

  As shown in FIG. 3, the hook hooking portion 24 according to this embodiment has a structure in which the hook 42 of the hook bar 41 can be inserted from above (Z-axis positive direction). Hook fixing portions 242 provided continuously from the hook insertion portion 241 on both sides in the X-axis direction of the portion 241. The hook insertion portion 241 is designed to be wider than the size of the hook 42 so that the hook 42 is caught by the hook hook portion 24 even if the position of the hook bar 41 (hook 42) is slightly shifted. As the distance from the hook insertion portion 241 along the X-axis direction increases, the width of the region into which the hook 42 is inserted becomes narrower, and there is no play of rotation of the hook 42 at the hook fixing portion 242 at both ends. As a result, the rotation of the parent boat 23 and the hook bar 41 is synchronized. When carrying in, it fits into the hook fixing part 242 at the end in the X axis positive direction, and when carrying out, it fits into the hook fixing part 242 at the end in the X axis negative direction.

  Next, the state of heat treatment using such a heat treatment furnace 10 will be described. FIG. 6 is a diagram schematically showing how a wafer is carried in and out of the heat treatment furnace, FIG. 7 is a perspective view schematically showing a general transport table and its transport member, and FIG. It is a figure which shows typically the problem at the time of conveyance in a general case, and FIG. 9 is a figure explaining the mechanism which suppresses rotation of the parent boat by embodiment.

  In FIG. 6, in the diffusion process or thermal oxidation process of impurities (for example, phosphorus) in the solar cell manufacturing process, the main boat 23 carrying the wafer 21 to be heat-treated to the core tube 11 of the horizontal diffusion furnace is carried in / out. It represents the situation. Here, as the wafer 21 to be heat-treated, for example, a p-type silicon wafer having an antireflection unevenness formed on the surface can be used. Due to the high temperature during the thermal diffusion process, the process is performed by placing the wafer 21 on the parent boat 23 made of quartz.

  First, as shown in FIG. 6A, the child boat 22 loaded with the wafers 21 to be heat-treated is placed on the tray 31 at a predetermined position on the parent boat 23. Thereafter, the hook 42 of the hook bar 41 is hooked on the hook hooking portion 24 provided at the end of the parent boat 23 in the negative X-axis direction. The hook 42 is inserted into the hook hooking portion 24 from above the Z axis.

  Next, as shown in FIG. 6 (b), the hook rod 41 is pushed in the direction of inserting the parent boat 23 into the core tube 11, and as shown in FIG. 6 (c), the parent boat 23 with wheels 23a is It is stopped at a predetermined position in the core tube 11. Thereafter, the hook 42 is removed from the hook hooking portion 24, and the hook bar 41 is returned to its original position. Then, the wafer loading / unloading port 11a of the core tube 11 is closed by a door (not shown), and heat treatment is performed with the inside of the core tube 11 as a predetermined gas atmosphere.

  After the heat treatment, the door is opened, the hook bar 41 is inserted from the wafer loading / unloading port 11 a of the core tube 11, and the hook 42 is hooked on the hook hooking portion 24 of the parent boat 23. Next, as shown in FIG. 6 (d), by moving the hook bar 41 in the negative direction of the X-axis, the parent boat 23 is unloaded from the core tube 11, and as shown in FIG. 6 (e), the tray It is conveyed to a predetermined position on 31. After the hook bar 41 is removed on the tray 31 and cooled to a predetermined temperature, the child boat 22 is moved to the next process. Thus, the processing of the wafer 21 using the heat treatment furnace 10 is completed.

  As shown in FIG. 7, in the general parent boat 23, a U-shaped hook hook portion 24 is attached so that a space larger than the diameter of the hook 42 of the hook bar 41 is formed in the negative direction of the X axis. ing. In such a structure, when the hook 42 is inserted into the hook hooking portion 24, the connecting portion between the hook 42 and the hook hooking portion 24 comes into contact with a point. Therefore, when the main boat 23 is pushed into the core tube 11 with the hook rod 41 in this state, the main boat 23 may be rotated in the direction of the arrow in FIG.

  On the other hand, in this embodiment, as shown in FIG. 3, when the parent boat 23 is transported, the hook 42 is fitted to the hook fixing portion 242 of the hook hooking portion 24 without any play of rotation. As a result, the parent boat 23 and the hook rod 41 are fixed with respect to the rotation direction of the parent boat 23, and the rotation is synchronized. Therefore, it becomes difficult for the main boat 23 to rotate in the core tube 11 as shown in FIG. Thus, the rotation suppression effect of the parent boat 23 can be expected only by synchronizing the rotation of the hook rod 41 and the parent boat 23. However, since the hook bar 41 and the parent boat 23 are generally made of quartz, there is a risk of damage if the force is too strong.

  Therefore, in this embodiment, as shown in FIG. 4, the regions 433 a to 433 d that are partitioned by the two support plates 44 and the shaft support portion 432 that extend perpendicularly from the surface of the hook bar 41 in the Y-axis direction are elastic. Member 434 was installed. As a result, when the parent boat 23 rotates as shown in FIG. 8 and the hook bar 41 also rotates synchronously, a force is applied in the reverse rotation direction, and at the same time, the sudden force is reduced.

  FIG. 9 schematically shows the inside of the hook bar support portion 43 when the parent boat 23 and the hook bar 41 are rotated counterclockwise in synchronization. When the hook bar 41 rotates counterclockwise, the support plate 44 attached to the hook bar 41 also rotates counterclockwise. As a result, the elastic member 434b in the region 433b is compressed between the support plate 44 and the upper surface portion of the cavity 433, and a force F in the direction in which the elastic member 434b extends (clockwise) is applied to the support plate 44. work. In addition, when one end of the elastic member 434c in the region 433c is connected to the support plate 44, the elastic member 434c is extended, and the elastic plate 434c is contracted in the direction in which the elastic member 434c contracts (clockwise). Power will work.

  Similarly, the elastic member 434d in the region 433d is compressed between the support plate 44 and the lower surface portion of the cavity 433, and a force F in the direction in which the elastic member 434d extends (clockwise) acts on the support plate 44. . Further, when one end of the elastic member 434a in the region 433a is connected to the support plate 44, the elastic member 434a is extended, and the support plate 44 is in a direction (clockwise) in which the elastic member 434a contracts. Power will work.

  As a result, even if the main boat 23 rotates around the X axis in the core tube 11, a force acts on the hook bar 41 in a direction to cancel it, so that the main boat 23 is placed in a predetermined position in the core tube 11. It is possible to fit in.

  4 and 9, the support plate 44 of the hook bar 41 is disposed so as to protrude in the Y-axis direction, and the shaft support portion 432 formed in the cavity 433 of the support portion main body 431 protrudes in the X-axis direction. Although the example arrange | positioned is shown, it is not limited to this. The shaft support portion 432 can be formed in any direction, and the support plate 44 of the hook bar 41 may be disposed in a direction substantially orthogonal to the shaft support portion 432.

  FIG. 10 is a diagram illustrating another example of the hook bar support portion. In FIG. 10, one end of the elastic member 434 is connected to the end of the support plate 44, and the other end is connected to the side surface constituting the cavity 433, and the elastic member 434 is substantially parallel to the protruding direction of the support plate 44. The structure is arranged as follows. Even in such a structure, a force in the direction of reverse rotation can be exerted on the hook bar 41 when the main boat 23 rotates in the core tube 11.

  In this embodiment, the hook 42 is inserted into the hook insertion part 241, and the hook hooking part 24 configured to fit the hook fixing part 242 without play of rotation of the hook 42 when the parent boat 23 is transported is provided. As a result, the hook bar 41 can be freely rotated to some extent, so that the hook bar 41 can be fitted at a predetermined position even if the parent boat 23 is slightly rotated initially. In addition, since the rotation of the main boat 23 in the core tube 11 and the rotation of the hook rod 41 can be synchronized, the straightness of the main boat 23 is improved, the quartz parts and the wafer 21 are damaged by the collision, the wafer This has the effect of preventing the parent boat 23 loaded with 21 from falling.

  In this embodiment, the hook bar 41 is inserted in the vicinity of the center of the cavity 433 in the support body 431, and the shaft support part 432 in the cavity 433 that supports the hook bar 41 is substantially perpendicular to the shaft support part 432. The support plate 44 provided on the surface of the hook bar 41 and the elastic member 434 arranged in the four regions 433a to 433d defined by the shaft support portion 432 and the support plate 44 are provided. Thus, when the hook bar 41 rotates, a force in the direction opposite to the compression direction acts on the support plate 44 by the elastic member 434 compressed in the rotation direction. As a result, the straight traveling performance of the parent boat 23 is improved, and it is possible to prevent damage to the quartz component and the wafer 21 due to the collision and the overturning of the parent boat 23 on which the wafer 21 is loaded.

  As described above, the carrier transport member of the heat treatment furnace according to the present invention is useful for a horizontal heat treatment furnace that performs heat treatment on a wafer.

  DESCRIPTION OF SYMBOLS 10 Heat treatment furnace, 11 Core tube, 11a Wafer carry-in / out entrance, 21 Wafer, 22 Sub boat, 23 Parent boat, 23a Wheel, 24 Hook hook part, 31 Tray, 40 Carriage carrier member, 41 Hook bar, 42 Hook, 43 Hook Rod support part, 44 support plate, 51 stopper, 51a opening, 241 hook insertion part, 242 hook fixing part, 431 support part main body, 432 shaft support part, 433 cavity, 433a-433d region, 434, 434a-434d elastic member.

Claims (5)

In the carrier transport member of the heat treatment furnace that transports the carrier carrying the wafer between the tray and the cylindrical core tube,
A hook rod connected to the carriage, and a hook bar for reciprocating the carriage between the tray and the core tube;
A hook bar support member for supporting the hook bar so as to exert a force on the hook bar in a direction opposite to the rotation when the carrier moving in the core tube rotates in a circumferential direction of the core tube ;
With
The hook bar has a support plate that protrudes on both sides in a predetermined direction from the surface of the hook bar at a position supported by the hook bar support member;
The hook bar support member is
A shaft support part that rotatably supports the hook bar in a direction substantially orthogonal to the arrangement position of the support plate when the hook bar is inserted;
An elastic member that generates a rotational force in the opposite direction to the support plate when the hook bar receives a rotational force;
Carriage carrying member of the heat treatment furnace, characterized by have a. The elastic member is conveyed in the heat treatment furnace according to claim 1, characterized by being arranged to expand and contract in the shaft supporting the rotational direction of the support plate in the clearance defined by the support plate of the hook bar Stand conveying member. The furnace tube;
The carriage,
The carrier transport member according to claim 1 or 2 ,
A heat treatment furnace comprising: The carriage is as claimed in claim 3, characterized in that it comprises a hook connecting portion having a hook fixing part for fixing the said hook in the absence play rotation of the hook during the reciprocation of the carriage Heat treatment furnace. The hook connecting portion further has a hook insertion portion for inserting the hook, which is larger than the size of the hook,
5. The heat treatment furnace according to claim 4 , wherein the hook fixing part is continuously provided on both sides of the hook insertion part in the moving direction of the carriage on the both sides of the hook insertion part.

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