TWI633265B - Heat treatment apparatus - Google Patents

Abstract

A door is provided at the mouth of the quartz tube, and the door can be opened and closed by an opening and closing mechanism. The door has a quartz plate disposed on the side of the quartz tube, a heat insulating material held on the inner side of the door, and a door frame for holding the quartz plate and the heat insulating material. The opening and closing mechanism has a driving arm that supports the door frame at the front end and is driven together with the door to a direction close to or away from the quartz tube, and a driving means for driving the driving arm, and drives the door by the driving force of the driving means, and the quartz tube is driven The mouth of the furnace is opened or locked. The door tilt adjusting member is supported in a tiltable manner at the front end of the driving arm, and is mounted on the door frame, and supports the door in an adjustable tilt manner.

Description

Heat treatment device

The present invention relates to a heat treatment apparatus for heat-treating a workpiece such as a ruthenium substrate.

In the manufacturing process of a solar cell or the like, heat treatment such as diffusion treatment for diffusing impurities on the surface of a workpiece, that is, a germanium substrate (semiconductor wafer), is performed. The heat treatment apparatus for performing this heat treatment is provided with a reaction tube and a heater for storing a workpiece and performing heat treatment.

The reaction tube is, for example, a quartz tube, and houses therein a wafer boat in which a predetermined gap is provided to hold a plurality of semiconductor wafers. The heater is disposed around the outer side of the reaction tube and heats the inside of the reaction tube to a predetermined temperature.

In the configuration disclosed in Japanese Laid-Open Patent Publication No. 2001-185501, an opening for the entrance and exit of the boat is formed at one end of the reaction tube, and a door for opening and closing the opening is provided. The inside of the reaction tube can be sealed by blocking the opening of the door.

At the time of diffusion processing of the semiconductor wafer, a gas such as phosphorus trichloride (POCl ₃ ) or boron tribromide (BBr ₃ ) is introduced into the sealed reaction tube.

The inner surface of the door is exposed to the high temperature reaction tube, and the outside is cooled by the outside air. Therefore, if sufficient insulation is not achieved between the inner surface and the outer surface of the door, the vicinity of the opening of the reaction tube is cooled by the door during the heat treatment.

Further, if the inner surface of the door is insufficiently adhered to the end surface of the reaction tube, the vicinity of the opening of the reaction tube is cooled by entering the air outside the reaction tube from the gap between the two. When the diffusion of the semiconductor wafer is cooled, if the vicinity of the opening of the reaction tube is cooled, the following situation may occur, that is, phosphorus pentaphosphorus (P _{2 ) is} precipitated from POCl ₃ near the inner surface of the door and the opening of the reaction tube. O ₅ ).

In addition, the phosphoric acid aqueous solution generated by the reaction between the water vapor contained in the air outside the reaction tube and the POCl ₃ and P ₂ O _{5 in} the reaction tube may cause corrosion of the metal frame supporting the door, or Contamination of the workpiece inside the reaction tube.

It is an object of the present invention to provide a heat treatment apparatus which can suppress the corrosion of a frame and the contamination of a workpiece by reliably insulating the inner surface of the door from the outer surface and improving the airtightness of the inner surface of the door and the end surface of the reaction tube. The generation of the by-product of the cause.

The heat treatment apparatus of the present invention includes a reaction tube, a door, an opening and closing mechanism, and a door tilt adjusting member.

The reaction tube has a cylindrical shape and is closed at one end, and an opening (furnace mouth) is formed at the other end, and the workpiece to be heat-treated is housed inside through the opening. The door system opens and closes the opening of the reaction tube.

The door has an inner surface member, a heat insulating material, and a door frame. The inner surface member is disposed on the reaction tube side. The heat insulating material is disposed on the outer side of the inner surface member. The door frame is disposed on the outer side of the heat insulating material for holding the inner surface member and the heat insulating material.

The opening and closing mechanism has a driving arm and a driving means. The drive arm is attached to the front end to support the door frame. The driving arm is moved toward the direction of one of the reaction tubes and away from the door The tube is driven in the other direction. The driving means drives the driving arm by its driving force to cause the door to operate to open or close the opening of the reaction tube.

The door tilt adjusting member adjusts the door to be tilted. Also, it is supported obliquely at the front end of the door drive arm and mounted on the door frame.

1‧‧‧ Heat treatment unit

2‧‧‧Reaction tube (quartz tube)

2A‧‧‧ mouth

3‧‧‧Diffusion

4‧‧‧The boat

5‧‧‧Exhaust pipe

7‧‧‧heater

10‧‧‧

11‧‧‧Quartz plate

12‧‧‧Insulation materials

13‧‧‧ door frame

14‧‧‧stops

20‧‧‧Opening and closing institutions

21‧‧‧ drive arm

23‧‧‧ Driving means

24‧‧‧1st shaft

25‧‧‧2nd shaft

26‧‧‧1st link

27‧‧‧Fixed bracket

28‧‧‧2nd link

30‧‧‧Door tilt adjustment member

31‧‧‧ rod end bearing

32‧‧‧Shake axis

33‧‧‧Angle adjustment head

34‧‧‧Angle adjustment block

34A‧‧‧ openings

40‧‧‧Door rotation limiting member

41‧‧‧Rotary limit plate

41A‧‧‧ openings

42‧‧‧Rotary limit head

43‧‧‧Support block

131‧‧‧Disc

132‧‧‧Cylinder

231‧‧‧Cylinder tube

232‧‧‧ piston rod

241‧‧ ‧ pillar

242‧‧‧ casing

311‧‧‧Spherical inner ring

321‧‧‧Fixed parts

411, 412‧‧‧ both ends

G‧‧‧ arrow

R1, R2‧‧‧ arrows

W‧‧‧Workpiece

Fig. 1 is a plan view showing a main part of a heat treatment apparatus according to an embodiment of the present invention.

2 is a partially cutaway plan view showing the door and the drive arm.

Fig. 3 is a cross-sectional view showing the constitution of the door tilt adjusting member and taken along the line III-III of Fig. 2.

Fig. 4 is an explanatory view for explaining the operation of the door tilt adjusting member.

Fig. 5 is a cross-sectional view showing the configuration of the door rotation restricting member and taken along the line V-V of Fig. 2.

Fig. 6 is a front view showing the configuration of an opening and closing mechanism, a door tilt adjusting member, and a door rotation restricting 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 has a configuration in which the quartz tube 2, which is a reaction tube of the present invention, is disposed horizontally in a horizontal direction as a horizontal furnace, and has an opening and closing mechanism as shown in Fig. 1 . The opening and closing of the door 10 is a basic structure in which the opening (furnace) 2A of the quartz tube 2 in which the diffusion chamber 3 of the workpiece W is accommodated is formed. The workpiece W is, for example, a rectangular crucible substrate for a solar cell unit. Crystal boat 4 The workpiece W is placed in a state in which a plurality of pieces are vertically arranged at equal intervals, and the workpiece W is carried out and carried into the diffusion chamber 3 through the furnace opening 2A by the travel of the transmission wheel.

In the diffusion chamber 3, a diffusion gas flow introducing device (not shown) provided on one side of the closed end of the quartz tube 2 (not shown) in FIG. 1 is introduced, and a diffusion gas containing a diffusion source (for example, POCl ₃ ) is introduced. .

Specifically, the gas flow introducing means for diffusion is configured to bubbling a liquid diffusion source by a source gas, and combining a source gas of a saturated vapor containing a liquid diffusion source with a carrier gas as a gas flow for diffusion This diffusion gas flow is introduced from one end of the quartz tube 2 as indicated by an arrow G.

An exhaust pipe 5 is connected to the circumferential surface of the quartz tube 2 near the furnace opening 2A. The gas for diffusion for processing the workpiece W is discharged from the exhaust pipe 5 to the outside of the furnace. In order to prevent leakage of the diffusion gas from the furnace opening 2A, the diffusion chamber 3 is under a negative pressure.

A heating device is disposed on the outer circumference of the quartz tube 2. The heating device has a configuration including a heater 7 as shown, for example. The diffusion source is introduced into the diffusion chamber 3 heated by the operation of the heating device by the gas introduction device for diffusion, and a process of diffusing impurities (for example, phosphorus) to the workpiece W is performed. Further, the heating device may further include a soaking tube between the quartz tube 2 and the heater 7.

The furnace opening 2A of the quartz tube 2 is closed by the opening and closing door 10. The door 10 is opened and closed by the opening and closing mechanism 20 which will be described later.

As shown in FIG. 2, the door 10 is provided with the quartz plate 11, the heat insulating material 12, and the door frame 13. The quartz plate 11 is a disk made of quartz, which 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 when the door 10 is closed, it is pressed against the furnace opening 2A of the quartz tube 2.

The door frame 13 is formed by integrally forming the disk portion 131 and the tubular portion 132. Shaped component. 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 tubular portion 132 constitutes a side portion of the door 10.

The heat insulating material 12 is filled in a space surrounded by the tubular portion 132 of the door frame 13. The heat insulating material 12 is held by the disk portion 131 of the door frame 13 and the quartz plate 11, and is attached to a plurality of portions in the circumferential direction of the outer peripheral surface of the tubular portion 132 of the door frame 13 and the peripheral portion of the quartz plate 11. The stopper 14 is fixed. Thus, the quartz plate 11 and the heat insulating material 12 are assembled to the door frame 13. On the door 10, the heat insulating material 12 is disposed on the opposite side of the quartz plate 11 from the diffusion chamber 3 (see Fig. 1).

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 means 23. The driving arm 21 is brought toward the direction of the quartz tube 2 by the driving means 23 (see the direction of the arrow R1 in FIG. 1) and the other direction away from the quartz tube 2 (refer to the direction of the arrow R2 in the same figure). drive. Thus, by driving the driving arm 21, the door 10 is driven to open or lock the furnace opening 2A of the quartz tube 2.

In the present embodiment, the drive means 23 is constituted by a cylinder mechanism including a piston rod 232 that reciprocates and a cylinder tube 231 that houses the piston rod 232, and receives a supply of fluid pressure to cause the piston rod 232 advances and retreats with respect to the cylinder tube 231 to transmit power. Here, the cylinder mechanism uses a pneumatic cylinder.

The drive arm 21 is provided to extend substantially parallel to the face of the door 10 that closes the mouth 2A of the quartz tube 2.

The base end of the drive arm 21 is coupled to the front end of the piston rod 232 via the first link 26 and the second link 28.

A fixing bracket (fixing member) 27 is fixed to the side of the furnace opening 2A of the quartz tube 2 with respect to the heat treatment device. The long side direction of the fixing bracket 27 is defined as a stone The direction of the axial direction of the British tube 2 is orthogonal. The fixing bracket 27 is disposed such that one end portion is located closer to the quartz tube 2 than the other end portion. The first rotating shaft 24 and the second rotating shaft 25 are provided at one end and the other end of the fixed bracket 27 in the longitudinal direction.

The first rotating shaft 24 is composed of a cylindrical pillar 241 fixed to the fixed bracket 27 and a cylindrical sleeve 242 rotatably disposed around the pillar 241. At one end of the fixed bracket 27, the base end portion of the drive arm 21 and one end portion of the first link 26 are rotatably supported by the first rotating shaft 24 to rotate the drive arm 21 together with the first link 26.

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

The second rotating shaft 25 is realized by a simple concave-convex fitting by providing a pin protruding from the fixing bracket 27 and providing a hole for fitting the pin to the cylinder tube 231 or the like. At the other end of the fixed bracket 27, the cylinder tube 231 is rotatably supported by the second rotating shaft 25.

The drive means 23 is a means for automating the rotation of the drive arm 21. Then, with respect to the driving means 23, when the piston rod 232 advances from the cylinder tube 231, the driving arm 21 rotates to approach the furnace opening 2A of the quartz tube 2 to rotate the door 10 in the closing direction. Then, the door 10 is pressed against the furnace opening 2A to seal the inside of the quartz tube 2.

On the other hand, if the piston rod 232 retreats with respect to the cylinder tube 231, the drive arm 21 rotates away from the furnace opening 2A of the quartz tube 2 to rotate the door 10 in the opening direction. Furthermore, if the drive means 23 is controlled by a controller not specifically shown, the drive of the drive arm 21 can be automatically controlled.

The door frame 13 is tilted and adjusted by a door disposed at the front end of the driving arm 21 The member 30 can be tilted (shaken) to be freely supported.

Specifically, as shown in FIG. 3 , the door tilt adjusting member 30 includes a rod end bearing 31 and a rocking shaft 32 . The rod end bearing 31 is attached to the front end of the drive arm 21. The rocking shaft 32 is supported by the rod end bearing 31 to tilt the shaft. The rocking shaft 32 is fixed to the center of the door frame 13 by using the fixing fitting 321 . The rocking shaft 32 fixed to the door frame 13 by the fixing fitting 321 is inserted into the spherical inner ring 311 of the rod end bearing 31 mounted on the front end of the driving arm 21.

The rod end bearing 31 can be configured by using a known rod end bearing (Japanese Laid-Open Patent Publication No. 2003-247540, Japanese Laid-Open No. Hei 2-78808), and can be swayably held in a spherical mounting hole formed inside. Inner ring 311. The rocking shaft 32 is held obliquely together with the spherical inner ring 311.

An angle adjusting head 33 is provided on the other end of the rocking shaft 32 opposite to the one end of the door frame 13. An angle adjustment block 34 is attached to the front end of the drive arm 21. An opening 34A through which the angle adjusting head 33 passes is formed in the angle adjusting block 34. The size of the opening 34A is set to a size that allows the inclination of the angle adjusting head 33.

With the above configuration of the door tilt adjusting member 30, as shown in FIG. 4, the door 10 is slantably supported with respect to the driving arm 21. The maximum angle α of the inclination angle of the door 10 is limited (adjusted) by the relative relationship between the outer diameter of the angle adjustment head 33 and the inner diameter of the opening 34A of the angle adjustment block.

Further, the door frame 13 and the driving arm 21 are provided with a door rotation restricting member 40 that restricts the rotation of the center of the door 10. As shown in FIG. 6, the door rotation restricting member 40 is disposed at a position deviated from the center of the face of the door 10 close to the furnace opening 2A of the quartz tube 2, and restricts the rotation of the door 10.

In the present embodiment, as shown in FIG. 5, the door rotation restricting member 40 includes a rotation restricting head 42 and a rotation restricting plate 41. The rotation restricting head 42 is fixed to the driving arm 21. The rotation restricting plate 41 is fixed to the door frame 13. Further, conversely, the rotation restricting head 42 may be fixed to the door frame 13 to fix the rotation restricting plate 41 to the driving arm 21.

The rotation restricting plate 41 is produced by bending a metal plate having a reed shape into a substantially zigzag shape at two locations in the longitudinal direction. The rotation restricting head 42 is attached to the support block 43 so as to protrude toward the door 10, and the support block 43 is vertically fixed to the opposite side of the drive arm 21 from the door 10.

The rotation restricting plate 41 is fixed to the disk portion 131 of the door frame 13 by screwing or the like using one of the end plates 411 and 412 which are parallel to each other. A rotation restricting head 42 is inserted through the opening 41A 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 limits the rotation of the rotation restricting head 42 within a certain range. Specifically, the inclination angle of the door 10 is adjusted by the rotation restricting head 42 and the opening 41A so that the rotation restricting head 42 can be detachably inserted into the opening 41A within the range of the angle α described above.

With the above configuration of the door rotation restricting member 40, the rotation of the door 10 about the rocking shaft 32 is restricted. Thereby, the reproducibility of the sliding connection 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 incorporated in the door 10, even if there is a temperature difference between the inside and the outside of the door 10, the temperature drop of the quartz plate 11 on the inner surface of the door can be suppressed. Thereby, it is possible to prevent the by-product generated from the gas for diffusion from being deposited in the vicinity of the furnace opening 2A of the quartz tube 2.

The door 10 holds the heat insulating material between the door frame 13 and the quartz plate 11 Construction. Therefore, even if the door 10 has the structure of the heat insulating material 12, the door 10 can be opened and closed without any trouble by the drive arm 21 supporting the door frame 13 on the outside of the door to be rotatably opened and closed.

Further, the driving arm 21 is biased toward the furnace opening 2A side of the quartz tube 2 by the driving means 23, and the door frame 13 is supported by the door tilt adjusting member 30 provided at the front end of the driving arm 21, so that the inner surface of the door can be made. The quartz plate 11 follows the shape of the furnace opening 2A of the quartz tube 2 to improve the hermeticity of both. Thereby, it is possible to prevent the atmosphere from intruding from the furnace opening 2A of the quartz tube 2, and it is possible to prevent the occurrence of by-products by reacting with the atmosphere, thereby preventing corrosion of the door and contamination in the furnace, and lengthening the maintenance period.

The description of the above embodiments is illustrative in all respects and should not be construed as limiting. The scope of the present invention is not disclosed by the above embodiments but by the scope of the claims. Further, all changes that come within the meaning and range of equivalence of the claims are intended to be included within the scope of the invention.

Claims (7)

A heat treatment apparatus comprising: a quartz tube having one end closed, an opening formed at the other end, and a heat-treated workpiece being accommodated through the opening; and a door opening and closing the opening of the quartz tube And an opening and closing mechanism that opens and closes the opening, wherein the door has an inner surface member that is formed of quartz and disposed on the side of the quartz tube, and is disposed outside the inner surface member. a heat insulating material and a door frame disposed on the outer side of the heat insulating material to hold the inner surface member and the heat insulating material, wherein the opening and closing mechanism has a driving arm that is driven to approach one of the quartz tubes and away from the above Another direction of the quartz tube; a driving means for driving the driving arm; and a door tilt adjusting member for supporting the door at a front end of the driving arm in a tiltable manner; and capable of being accompanied by the driving arm The opening of the quartz tube is opened and closed by the movement of the door generated by the driving, and the door tilt adjusting member includes: a front end portion of the driving arm; and a rocking shaft having the door frame attached to one end portion thereof, and the other end portion being held by the inner ring of the bearing and capable of engaging with the above-mentioned driving arm The relative rotation of the inner ring causes tilting together with the door frame, and the opening and closing mechanism further has a door rotation restricting member that restricts rotation about the center of the door, the door rotation restricting member being disposed with respect to the length of the driving arm The side direction restricts the rotation of the rocking shaft only at a position on one side with respect to the above-mentioned rocking axis, When the opening and closing mechanism moves the door so as to close the opening of the quartz tube, the inner surface member is pressed against the periphery of the opening of the quartz tube, and the door inclination adjusting member is formed by the inner surface member The inclination of the door is adjusted so as to surround the opening of the quartz tube, 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 trichloride or boron tribromide for heat-treating the workpiece is introduced into the quartz tube. The heat treatment device of claim 1, wherein the bearing is a rod end bearing. The heat treatment device according to any one of claims 1 to 3, wherein the door tilt adjusting member further includes: an angle adjusting head provided at the other end of the rocking shaft; and an angle adjusting block, The front end portion of the driving arm is formed with an opening through which the angle adjusting head passes, that is, an opening allowing the inclination of the angle adjusting head. The heat treatment apparatus according to any one of claims 1 to 3, wherein the door rotation restricting member includes: a rotation restricting head provided in one of the door frame or the driving arm; and a rotation limit The plate is provided on the other of the door frame or the drive arm, and is formed with an opening through which the rotation restricting head passes, that is, an opening whose size is limited to a rotation within a certain range. The heat treatment device according to any one of claims 1 to 3, wherein the driving means is a cylinder mechanism including a piston rod that reciprocates and a cylinder tube that houses the piston rod, and receives a supply of fluid pressure And causing the piston rod to move forward and backward with respect to the cylinder tube, thereby transmitting the driving force. The base end portion of the drive arm is coupled to the piston rod. The heat treatment device of claim 6, wherein the driving arm extends substantially parallel to a surface that closes an opening of the quartz tube, and a base end portion of the driving arm and an end portion of the first link are The driving arm is rotatably supported at one end of the fixing bracket in a manner of being rotated together with the first link, and the cylinder tube is rotatably supported at the other end of the fixing bracket, and the first link is The other end portion is rotatably coupled to the front end portion of the piston rod, and the fixing bracket is disposed such that one end portion is positioned closer to the quartz tube than the other end portion.