JPH0224368B2 - - Google Patents

Description

Detailed Description of the Invention (Technical Field of the Invention) The present invention relates to a process tube in which a boat carrying wafers is advanced and retreated from a process tube provided in a furnace main body in order to perform impurity diffusion and oxidation treatment on wafers. The present invention relates to a boat transport device that transports freely.

(Technical background of the invention and its problems) Today, as this type of boat transport device, an automatic transport device called a boat loader, which can automatically move a boat into and out of a process tube, is in practical use. has been made into

This transfer device includes a movable block that is connected to a wafer boat through a connecting means such as a pull-out rod and is slidably guided within a load station, and reciprocates the block along the transfer direction. The structure is such that boats can be transported. The movement of this block is achieved by rotating a long drive shaft inserted through it with a motor or the like at one end, and applying the rotational force to the transport direction through a motion converting means provided between the shaft and the block. This is done by converting it into linear motion along the block and transmitting it to the block.

However, the above configuration has the following various problems.

In other words, since the drive shaft is long, vibration becomes intense especially when rotating at high speed.
This adversely affects the durability of the shaft, and the vibrations are transmitted to other components such as the movable block, impeding smooth sliding movement.
There were problems such as accelerated wear of each sliding part and increased generation of undesirable particles within the load station.

In addition, since the drive shaft is slidably engaged with a movable block within the load station via a motion converting means, particles of fine metal powder are constantly generated around the shaft due to friction between them. There are problems such as the difficulty of cleaning the shaft because it is located inside the station.

(Object of the Invention) The present invention was conceived in view of the various problems of the conventional art described above, and its purpose is to fundamentally change the driving mode of the drive shaft so that the drive shaft and movable block can be operated even during high-speed conveyance operations. It is an object of the present invention to provide a novel boat transport device that can obtain stable operation, improve the durability of the entire device, and significantly suppress the generation of the above-mentioned particles inside a load station.

(Summary of the Invention) In order to achieve the above object, the present invention basically provides a boat transport device for transporting a wafer boat in a manner that allows it to move forward and backward with respect to a process tube housed in a furnace main body. A movable block guided movably in the boat transport direction within the load station, and a wafer boat provided between the movable block and the wafer boat so as to move the wafer boat in the transport direction in accordance with the movement of the block. a connecting means;
a long drive shaft having one end fixed to the movable block and disposed along the boat transport direction; a rotating body through which the drive shaft is inserted and rotatably disposed in the load station; and the rotating body. A drive motor installed outside the load station to apply rotational force to the load station, and a drive motor attached to the rotating body to transmit the rotation of the rotating body to the drive shaft without causing the drive shaft to rotate around its axis. The free end of the drive shaft can extend the side frame of the load station to the outside of the station and retract it toward the station in accordance with the rotation of the rotating body. This paper proposes a boat transport device having the following configuration.

As in the above configuration, in the present invention, instead of the conventional configuration in which the drive shaft is rotated around the axis, a rotating body through which the drive shaft is inserted is driven to rotate, and this rotational force is transferred through the motion converting means. It is configured to transmit linear motion along the transport direction without rotating the shaft around its axis by transmitting it to the drive shaft, and thereby move the movable block in the load station. By fundamentally changing the driving manner of the drive shaft, the above object is fully achieved.

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment of the Invention) FIGS. 1 and 2 show a horizontal diffusion furnace system to which the boat conveyance device of the present invention is applied. First, in FIG. a furnace body equipped with a process tube 2;
1 is a load station connected to the furnace body 1 via a scavenger 4 and composed of a clean bench; 5 is a control box equipped with a boat elevator, etc.; 6 is a source cabinet that supplies processing gas to the process tube 2. It is.

A heater 8 for heating is arranged in a cabinet 7 of the furnace body 1 so as to surround the process tube 2. Reference numeral 9 denotes a wafer boat on which a large number of wafers 10 to be processed are placed, and reference numeral 11 denotes a pull-out rod connected to the boat 9 at one end and to a movable block 13 through a support arm 12 at the other end. This pull-out rod 11 and support arm 12 constitute a connecting means.

The movable block 13 is slidably guided and supported by a guide bar 14 fixed within the load station 3, and its movement direction is along the boat conveyance direction in the longitudinal direction of the process tube 2.

Therefore, when the movable block 13 moves in the boat transport direction to the left in FIG.
The wafer 10 can be transported into the wafer 10, where it can be diffused and
A predetermined process such as oxidation can be performed, and by moving to the right in the boat unloading direction, the processed wafer 10 can be pulled out from the process tube 2 along with the boat 9. In FIG. 1, the position indicated by the chain line is the original position of the movable block 13 when it is taken out of the boat, and is in this position when the device is not in operation. Further, the solid line position indicates the position during delivery.

Next, a description will be given of a boat transfer device that reciprocates the movable block 13 to transfer the wafer boat 9 to the process tube 2 so as to be able to move forward and backward.

Reference numeral 15 denotes a long drive shaft disposed along the boat conveyance direction, one end of which is attached to the movable block 13, and the other end, that is, the free end, extends outward from the load station 3 to the furnace main body 1. It extends parallel to and faces the rear cabinet side surface 7a. In the embodiment, the drive shaft 15 is fixed to the movable block 13, thereby preventing rotation of the shaft 15 about its axis.

Incidentally, if a means for preventing rotation of the shaft 15 is provided separately, it is not necessary to fix the shaft 15 to the block 13.

A rotating body 17 and a reversible drive motor 18 serving as a driving means for rotationally driving the rotating body 17 are arranged on the side frame 16 of the load station 3. This motor 18 is attached to the side frame 16 by a mounting bracket 19.

The rotating body 17 passes through the drive shaft 15 along its center of rotation. The rotating body 17 has a space between it and the shaft 15.
A motion conversion mechanism 20 is provided as a motion conversion means for converting the rotational force of the drive shaft 15 into linear motion in the boat transport direction P along the axis of the drive shaft 15. The motion conversion mechanism 20 is held by the rotating body 17 so as to rotate together with the rotating body 17.

The structure of this rotating body will be further described later with reference to FIG.

Therefore, when the rotating body 17 is rotated by the drive motor 18, the rotational force causes the drive shaft 15 to move in the boat transport direction P via the motion conversion mechanism 20.
Since force is applied in one direction along the shaft 15, the movable block 13 slides together with the shaft 15 in the same direction. When the drive motor 18 reverses, the movable block 13 and the shaft 15 slide in the other direction along the boat transport direction P by the same force transmission as described above.

In this manner, the movable block 13 is controlled to reciprocate along the boat transport direction by the boat transport device. During this time, the drive shaft 15 slides relative to the rotating body 17 without rotating.

Note that 21 is the cabinet side surface 7a of the furnace body 1.
Driveshaft 1 extends with a guide provided in
The free end of 5 is guided and supported in a loosely fitted state.

The setting of the loading position and the original loading position of the boat 9, as well as movement therebetween, is regulated by controlling the drive motor 18 by an appropriate electric control device (not shown).

As shown in FIG. 2, the system of the embodiment includes three
It has a stage furnace structure, and the configuration explained in FIG. 1 is arranged in parallel in three stages, upper and lower.

In FIG. 2, the movable block 13 is shown in its original position. In this position,
As shown by the solid line in the figure, the free end of the drive shaft 15 is retracted toward the load station and is in a spaced state where it does not face the cabinet side surface 7a of the furnace body. Therefore, the cabinet side 7a
The door can be opened and closed without interfering with the drive shaft 15 when the system is stopped.
Maintenance work such as replacing the heater 8 inside the furnace body can be performed freely.

As shown in FIG. 2, each movable block 13 has a pair of guide bars 14.

Next, the structure of the rotating body 17 will be further explained with reference to FIG.

Reference numeral 25 denotes a support member which is fixed to the side frame 16 with bolts 26 and includes a sleeve portion 25a through which the drive shaft 15 is inserted. Rotor 27 of rotating body 17
is rotatably held on this support member 25 via a bearing 28, and on the outer periphery of the rotor 27,
A driven pulley 29 is provided integrally therewith. This pulley 29 is drivingly connected to a drive-side pulley 30 of the drive motor 18 via an endless drive belt 31, whereby rotational driving force is applied from the motor 18 to the rotating body 17.

The rotor 27 exhibits an inertial effect that stabilizes the rotational movement of the entire rotating body due to its inertia.

The motion conversion mechanism 20 is held by a rotor 27 so as to rotate together with the rotor 27. The mechanism 20 is
The drive shaft 15 is inserted through the drive shaft 15 along the center of rotation, and the drive shaft 15 is constructed of a known friction drive type linear motion bearing having a plurality of drive rollers 20a that rotate in an inclined state around the drive shaft 15.

As an alternative modification, the drive shaft 15 may have the shape of a feed screw shaft, and the motion conversion mechanism may be provided with a ball screw that is screwed into the shaft of the screw shaft.

However, in the friction drive type configuration of the embodiment, the shaft can slip when excessive axial force is applied to the shaft 15, so damage to parts can be avoided, and the shaft is also shaped like a round bar. It has advantages such as being simple.

(Effects of the Invention) As described above, in the present invention, the driving mode of the drive shaft is basically changed, and the rotating body is configured to rotate around the shaft, so that the shaft itself can be reciprocated without rotating. Therefore, we were able to solve the conventional problem of shaft vibration during high-speed rotation. Therefore, the sliding movement of the drive shaft and movable block can be made extremely stable, and in addition to the stability of operation, durability is improved, and it can fully meet the specifications of systems that are longer and operate at higher speeds. .

Furthermore, since the drive shaft is simply attached to the movable block and there is no longer a component that converts motion between the two within the load station, that is, converts rotational motion into axial motion, the load station This reduces the number of sliding parts within the shaft, improves operational stability, and further reduces the generation of undesirable particles due to wear of the sliding parts.

Furthermore, when the boat is brought in, the guide shaft extends outward from the load station for a long time and comes to a position corresponding to the cabinet side of the furnace main body.
In the original position, such as when the system is shut down, the free end of the shaft occupies a retracted position away from the side surface of the cabinet of the furnace body, so that it does not interfere with the maintenance work of the furnace body itself. Furthermore, since the shaft protrudes outward from the load station, the shaft can be easily cleaned from the outside, and the inside of the load station can be kept in a state with fewer particles.
It has various effects.

[Brief explanation of drawings]

Fig. 1 is a top view of a diffusion furnace system to which the boat transfer device of the present invention is applied, Fig. 2 is a rear view of the system of Fig. 1, and Fig. 3 is a main part showing the configuration of the rotating body of the boat transfer device. It is an enlarged sectional view. 1: Furnace body, 2: Process tube, 3: Load station, 9: Wafer boat, 10: Wafer, 13: Movable block, 15: Drive shaft, 17: Rotating body, 18: Reversible drive motor.

Claims (1)

[Scope of Claims] 1. A boat transport device for transporting a wafer boat movably forward and backward with respect to a process tube housed in a furnace main body, the boat transport device being movably guided in the boat transport direction within a load station. a movable block; a connecting means provided between the movable block and the wafer boat so as to move the wafer boat in the transport direction in accordance with the movement of the block; a long drive shaft arranged along the road, a rotating body through which the drive shaft is inserted and rotatably disposed outside the load station, and a rotating body installed outside the load station to impart rotational force to the rotating body. a drive motor attached to the rotating body, and a motion converting means that transmits the rotation of the rotating body to a drive shaft and moves the drive shaft in the boat transport direction without rotating around the axis, A boat transport device characterized in that a free end of a drive shaft can be extended to the outside of a load station through a side frame of the load station and retracted toward the station in response to rotation of a rotating body. 2. The free end of the drive shaft extends to a position facing the side surface of the cabinet of the furnace body at the boat loading position, and is placed at a spaced apart position not facing the cabinet side surface at the original position for boat loading. A boat transport device according to claim 1.