JP2891382B2 - Heat treatment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a heat treatment method.

(Prior art) In a general heat treatment method, a carrier containing a wafer is taken in from outside by a robot, the carrier is placed on a mounting table by the robot, and then the wafer in the carrier is taken out by another robot. It is stored in a boat, and the boat is inserted into a furnace for heat treatment.

(Problems to be Solved by the Invention) However, in such a conventional heat treatment method, even if the carrier is placed on the mounting table by a robot, accurate positioning is not performed. There is a problem that it may not be possible.

The present invention has been made in view of such a problem,
An object of the present invention is to provide a heat treatment method capable of accurately positioning a carrier on a carrier mounting table.

[Constitution of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention relates to a heat treatment method for performing heat treatment by loading a boat loaded with a number of wafers from below a vertical furnace. When transferring the wafer between the boat and the wafer carrier, a carrier on which the carrier can be placed, an abutting member to which the carrier is abutted, and the carrier connected to a common driving mechanism After providing a plurality of carrier mounting tables having a lock member capable of pressing, and mounting the carrier on the plurality of carrier mounting tables,
The driving mechanism is driven, the carrier is pressed by the lock member to make contact with the contact member, and the carrier is temporarily fixed between the lock member and the contact member. Wherein the transfer of the wafer is performed.

(Operation) In the present invention, when the wafer is transferred, the carrier is temporarily fixed to a predetermined position, so that the wafer transfer operation can be accurately performed by different robots.

(Embodiment) An embodiment in which the present invention is used in a heat treatment process of a semiconductor wafer will be described below with reference to the drawings.

 First, the configuration of the heat treatment apparatus will be described.

As shown in FIG. 1 and FIG. 2, for example, this apparatus comprises a processing unit 2 comprising a reaction tube 1 having a vertical axis in a vertical heat treatment furnace, a substrate which can be set in the processing unit 2, For example, a plurality of semiconductor wafers 3 in the thickness direction, for example, 10
A boat 4 that is a processing container capable of storing 0 to 150 sheets at predetermined intervals, a lifting mechanism 5 that can move the boat 4 up and down so as to carry it into and out of the reaction tube 1, and a lifting mechanism 5 that moves down A boat moving mechanism 6 capable of supporting and moving the boat 4 between the moved position and the wafer transfer unit 22 and the boat mounting unit 42;
A carrier mounting table 8 on which a plurality of carriers 7 capable of accommodating a plurality of the wafers 3, for example, 25 wafers, and transfer of the wafers 3 between the carrier 7 mounted on the carrier mounting table 8 and the boat 4 , A loading / unloading mechanism for transferring the carrier 7 between the apparatus and an external transport robot, for example, a loading / unloading boat 10, and between the loading / unloading boat 10 and the carrier mounting table 8. And a processing gas supply unit 70 for supplying a reaction gas, a vacuum pumping unit 60 including a vacuum pump, and a process control unit 50 for controlling a heat treatment process and wafer transfer. It is configured.

As shown in FIG. 2, the processing section 2 is provided with a tubular reaction tube 1 having a heat-resistant material which is difficult to react with a processing gas, for example, a quartz glass whose upper surface is sealed, which is made of quartz glass.
The diameter of the boat 4 is longer and longer than the boat 4 so that the boat 4 can be installed in the reaction tube 1. A heating mechanism capable of heating the inside of the reaction tube 1 to a desired temperature, for example, about 600 to 1200 ° C., for example, a coil heater 12 is provided around the reaction tube 1 at a predetermined distance from the reaction tube 1. And is wound in a non-contact state. Although not shown, a gas supply pipe extending upward from the lower portion along the inner wall of the reaction tube 1 is disposed in the reaction tube 1.
It is connected to a gas supply source via a not-shown mass flow controller or the like. An exhaust pipe 14 is connected to a lower portion of the reaction tube 1. The exhaust pipe 14 has a vacuum pump in a vacuum exhaust unit 60 capable of reducing the pressure in the reaction tube 1 to a desired pressure and discharging a processing gas. (Not shown).

The lid 15 is provided so as to be able to contact the lower end of the reaction tube 1 so that the inside of the reaction tube 1 of the processing unit 2 configured as described above is airtightly set. The lid 15 is placed on the elevating mechanism 5 and can be brought into contact with the lower end of the reaction tube 1 by elevating and lowering along a guide 17 driven by a driving mechanism such as a ball screw 16. At the top of the lid 15, a heat insulating cylinder 18
The boat 4 made of a heat-resistant and corrosion-resistant material, for example, quartz glass, can be placed on the heat-retaining cylinder 18 in a substantially vertical state.

The boat moving mechanism 6 has a solder annular arm 19 mounted on a rotating shaft 20, and the rotating shaft 20 can be moved up and down by a moving mechanism (not shown) and rotated about the rotating shaft 20 by a rotating mechanism (not shown). I have. The boat 4 can be supported and transferred between the position where the lifting mechanism 5 is lowered by rotation and vertical movement of the boat moving mechanism 6 and between the wafer transfer unit 22 and the boat mounting unit 42.

The transfer device 9 and the transfer device 9 described above are mounted on the same base (not shown), mounted on a rotating shaft, and moved up and down by driving a ball screw (not shown). At both ends of the transfer machine 9, a pair of carrier support arms 37a and 37b slidable along a guide rail 36 are provided. The carrier support arms 37a and 37b are provided in parallel with each other and are driven in conjunction with each other.
a and 37b are slidable by a driving mechanism (not shown), for example, a motor.

A plurality of, for example, four carriers 7 can be placed on the carrier mounting table 8 in the vertical direction.

FIG. 3 shows one of the carrier mounting tables 8 as viewed from the side. The carrier mounting table 8 has an air cylinder of a base 85 to which a pedestal 83 having an abutment portion 81 is fixed and fixed. A rod 87 of the air cylinder 87 is fixedly mounted, and slidably penetrates a gantry (not shown) provided on the gantry 83 and another carrier installation gantry 8.

The rod 89 is provided with a penetrating rod 97, which is fitted into a hole 95 of a lock member 93 that presses two sides of the carrier 7. This lock member 93 is supported by a shaft 91.

The other carrier mounting table 8 (not shown) is configured in the same manner as described above, and is configured so that one air cylinder 87 can simultaneously drive the lock members 93 of the carrier mounting table 8 provided in four stages.

A filter 54 such as a HEPA filter or a ULPA filter having a fan 53 is provided above the carrier mounting table 8 and the transfer machine 9 and the transfer machine 11. By supplying only the purified air to the wafer 3
It has a structure to prevent contamination.

The boat mounting section 42 is provided with a mounting table 44 that fits with the lower portion of the boat 4 and holds the boat 4 vertically. The mounting table 44 is mounted on a rail 46 by driving a motor and a ball screw (not shown). Are movable in parallel.

The wafer transfer section 22 is provided with a mounting table 24 for vertically holding the boat 4 similarly to the mounting table 44.
Reference numeral 24 is configured to be vertically movable by a moving mechanism (not shown).

As shown in FIG. 4, the boat 4
A supporting member 26 for holding the upper end of the camera is vertically movably provided by a moving mechanism (not shown). Thus, a heat treatment apparatus is configured.

Next, the operation of the above-described heat treatment apparatus and the method of transferring wafers will be described.

The carrier 17 of the loading / unloading boat 10 is transported by the transporter 11 to the carrier mounting table 8.

At this time, the lock member 93 is at the position shown by the two-dot chain line in FIG. Next, the air cylinder 87 is driven, and the rod 89
Moves in the A direction. When the rod 89 moves in the A direction,
The lock member 93 rotates around the shaft 91 in the direction B, and comes to a position shown by a solid line in the drawing. In response to the movement of the lock member 93, the carrier 7 comes from a position indicated by a two-dot chain line to a position indicated by a solid line in FIG.
At this time, the projection 99 provided at the lower end of the carrier 7 is
It comes into contact with the contact portion 81 of 83.

As described above, when the projecting portion 99 abuts on the abutting portion 81 and the rear end is pressed by the lock member 93 and is temporarily fixed to the gantry 83, the carrier 7 is positioned at a predetermined accurate position. It will be provided.

The provisional fixing means has been described as a means for locking at the bottom of the carrier, but the side wall of the carrier may be gripped or sucked.

Next, the wafer 3 stored in the carrier 7 is transferred to the boat 4 by five or one by one by the support mechanism for five or one of the transfer machines 9. At this time, the monitor wafer or the dummy wafer may be transferred as needed. In performing this transfer, the boat 4 is vertically held by the mounting table 24 of the wafer transfer unit 22, and the mounting table 24 is moved upward by a vertical movement mechanism (not shown), or the support member 26 is not shown. The boat 4 is moved downward by the up-down mechanism, the upper end of the boat 4 is held by the support member 26, and the transfer is performed at this position.

As described above, when the carrier 7 is temporarily fixed at a predetermined position, the wafer transfer operation can be automatically performed even if the wafer transfer robot is another robot.

When the transfer is completed, the mounting table 24 is moved downward by the vertical movement mechanism, or the support member 26 is moved upward, and the upper end of the boat 4 is opened by the support member 26.

Next, the boat moving mechanism 6 rotates and the arm 19
Is fitted into the lower concave portion.

As shown in FIG. 4, the boat 4 is moved by moving the arm 19 of the boat moving mechanism 6 upward, or by moving the vertical mechanism (not shown) of the mounting table 24 of the wafer moving section 22 downward.
It is detached by the mounting table 24 of 22.

Next, the arm 19 is rotated to move the boat 4 above the boat mounting section 42, and the arm 19 is moved downward to transfer the boat 4 to the boat mounting section 42.

Next, the mounting table 42 of the boat mounting section 42 is moved in parallel, and the arm 19 is released from the boat 4.

Next, another boat 4, which is in the reaction tube 1 and accommodates the wafer 3 subjected to the predetermined heat treatment, is moved downward by the lifting mechanism 5.

As shown in FIG. 4, the arm 19 is rotatably mounted on the lower concave portion of the boat 4 mounted on the heat retaining cylinder 18 on the elevating mechanism 5, and the arm is moved upward, or the elevating mechanism 5 is moved downward to keep the heat. The boat 4 is detached from the tube 18.

The boat 4 is moved to the wafer transfer section 22 by the rotation of the arm 19 and is mounted on the mounting table 24 in the same manner as described above, and the transfer machine 9 has processed the boat 4 from the boat 4 into the carrier 7 in the opposite manner. Is transferred. Then, the carrier 7 is transported from the loading / unloading boat 10 to the outside by an automatic guided vehicle or the like.

Next, the arm 19 turns to the boat mounting portion 42 and waits, and the boat 4 storing the wafer 3 transferred from the carrier 7 mounted on the mounting table 44 moves on the rail 46, and The arm 19 is fitted in the lower concave portion of the fourth.

The arm 19 is moved upward to release the boat 4 from the mounting table, and the arm 19 is rotated to move onto the heat retaining cylinder 18 placed on the elevating mechanism 5 so that the axes of the boat 4 and the heat retaining cylinder 18 are aligned. In this state, the arm 19 is lowered, or the elevating mechanism 5 is moved upward, the boat 4 is mounted on the heat retaining tube 18, the arm 19 is retracted above the boat mounting part 42, and the elevating mechanism 5 is raised. The lid 15 is brought into contact with the lower side of the reaction tube 1 by this raising, and the inside of the reaction tube 1 is set to be airtight, and at the same time, the boat 4 is installed in the reaction tube 1. Then, the reaction tube 1 is heated by the heater 12.
The inside is heated and controlled at a desired temperature and temperature distribution, and in this state, a predetermined processing gas is supplied from a gas supply pipe (not shown) into the reaction tube 1 to perform predetermined oxidation, diffusion, CVD processing and the like.

After the completion of this process, the supply of the process gas is stopped, and if necessary, the inside of the reaction tube 1 is replaced with an inert gas, for example, N ₂ gas, and then the boat 4 is lowered by the elevating mechanism 5 to complete the process. .

Thus, according to the present embodiment, since the carrier is temporarily fixed, the carrier can be accurately positioned.

Therefore, the carrier mounting table 8 is supported by the support mechanism of the transfer machine 9.
When the wafer in the carrier is transferred, the support mechanism is accurately inserted into a predetermined position in the carrier and the wafer is transferred, so that a mistake in transferring the wafer can be prevented.

In the above embodiment, the present invention is applied to the vertical heat treatment apparatus. However, the present invention is not limited to this. For example, the same effect can be obtained by applying the invention to a horizontal heat treatment apparatus.

Further, in the above embodiment, the semiconductor wafer is used as the object to be processed, but the present invention is not limited to this, and it goes without saying that the present invention may be applied to an apparatus for processing a liquid crystal glass substrate, a ceramic substrate, or the like. .

[Effects of the Invention] As described above, according to the present invention, when a wafer is transferred, the carrier is temporarily fixed to a predetermined position, so that a different robot can transfer the wafer accurately.

[Brief description of the drawings]

1 and 2 are block diagrams of a heat treatment apparatus for explaining an embodiment of the apparatus of the present invention, and FIG.
FIG. 4 is an explanatory view of boat transfer. 3 Wafer 4 Boat 7 Carrier 8 Carrier mounting table 81 Contact part 83 Stand 87 Air cylinder 89 Rod 93 Lock member 99 Projecting part

Claims (1)

(57) [Claims] 1. A heat treatment method for performing heat treatment by loading a boat loaded with a large number of wafers from below a vertical furnace, wherein when transferring the wafers between the boat and a wafer carrier, the carrier is loaded. A plurality of carrier mounting tables including a mountable mount, a contact member with which the carrier is in contact, and a lock member connected to a common drive mechanism and capable of pressing the carrier are provided. After placing the carrier on the carrier mounting table, drive the drive mechanism, press the carrier by the lock member to make contact with the contact member, between the lock member and the contact member A heat treatment method, wherein the carrier is temporarily fixed, and the wafer is transferred in the temporarily fixed state.