JP2845690B2 - Wafer transfer mechanism in atmospheric pressure CVD equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tray transfer mechanism, and more particularly, to a wafer transfer mechanism in a normal pressure CVD apparatus which is attached to a normal pressure CVD apparatus and transfers and unloads a wafer as a semiconductor substrate to and from the normal pressure CVD apparatus. (Hereinafter simply referred to as a wafer transfer mechanism).

[0002]

2. Description of the Related Art FIGS. 2 (a) and 2 (b) are a diagram showing a configuration of an example of a conventional wafer transfer mechanism and a partial sectional view partially extracted and shown. Conventionally, as shown in FIG. 2, this type of wafer transfer mechanism includes a tray 5 on which a wafer 8 is placed, a tray holder 4 on which the tray 8 is placed, and a tray holder 4 below the dispersion head 12 of the atmospheric pressure CVD apparatus. And an inexpensive chain transport mechanism that continuously feeds and passes.

The chain transport mechanism includes a guide block 3 attached to a link 7a of a chain 7 driven by a sprocket via a shim 6, and a sliding member 10 attached to the guide block 3 to contact the guide block 3.
And a rail 11 for guiding the vehicle.

Further, a sliding member 10 is provided which comes into contact with the rail 11 when the guide block 3 slides on the rail 11 so that the tray holder 4 can be smoothly fed without moving up and down. In order to absorb the inherent vibration, the sliding member 10 is made of a soft resin material having a small hardness.

Next, the operation of the wafer transfer mechanism will be described. First, the processed wafers and the tray 5 on which the wafers are placed are sent by a conveyor (not shown). Then, the wafer and the tray are transferred onto the chain by a handling device (not shown). The tray holder 4 on which the tray 5 is placed is sent by the chain 7, and the guide block 3 of the tray holder 4 is engaged with the rail 11. When the tray holder 4 slides on the rail 11 and reaches the lower part of the dispersion head 12, a growth gas is introduced from a gas introduction pipe to disperse the dispersion head 12.
Sprays a growth gas on the wafer 8 to form a film on the wafer 8. Next, the tray holder 4 is further fed, the guide block 3 is disengaged from the rail, and the tray holder 4 is simply put on the chain 7 and sent as it is. Next, the tray 5 and the wafer 8 of the tray holder 4 placed on the chain 7 are transferred to another conveyor by the handling device.

As described above, the tray and the wafer are placed on the tray holder 4 sequentially fed by the chain 7, and the tray holder 4 is conveyed while being regulated by the precise rail 11, and after the film is formed on the wafer 8, the tray holder 4 is moved to the rail. In a state where the wafer 8 is deviated from the regulation of No. 11 and is held by the chain 7, the wafer 8 is continuously rotated in the direction of the arrow to continuously form a film on the wafer 8.

[0007]

In the above-described conventional wafer transfer mechanism, the tray holder on which the wafer is placed and transferred is regulated by the rail and slides, but as the time elapses, the sliding member wears. Then, a gap is formed between the rail and the sliding member, and the tray moves up and down by the chain drive due to the gap. This vertical movement of the tray holder causes a variation in the thickness of the film formed on the wafer,
There is a problem that the yield is significantly reduced. An object of the present invention is to provide a wafer transfer mechanism in an atmospheric pressure CVD apparatus that can continuously transfer a wafer for a long time without moving the wafer up and down.

[0008]

According to the present invention, there is provided a wafer transfer mechanism in an atmospheric pressure CVD apparatus, which is disposed in a region where a growth gas is jetted, has tapered ends at both ends, and extends along a longitudinal direction. A rail having at least an upper and lower groove, a guide having a plurality of balls that move in the retainer while rotating in engagement with the groove, and a tray on which the wafer is mounted and moved by a chain drive, and the guide is mounted. And a holder.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIGS. 1 (a) and 1 (b) are a partial plan view and a cross-sectional view taken along the line AA showing a sliding mechanism of a tray holder on which a wafer is placed and transported by a chain drive in one embodiment of the wafer transporting mechanism of the present invention. It is. This wafer transfer mechanism
As shown in FIG. 1, a guide 1 for rolling and contacting a tray holder 4 on which a wafer 8 and a tray 5 are placed and conveyed in one direction, and slides the tray holder 4 while contacting the balls of the guide 1 That is, a rail 2 is provided.

On the forward side of the tray holder 4, a roller 14 and a roller supporting member which rotate in contact with the side surface of the rail 2 are provided, so that the tray holder 4 driven by the chain 7 can be easily fitted on the rail 14. So tray holder 4
Are regulated by rollers 14. Further, one end and the other end of the rail 2 are formed in a tapered shape so that they can easily enter the guide 1 and easily come off.

The sliding mechanism formed by the rolling contact composed of the rail 2 and the guide 1 is arranged such that the ball 9 held by the retainer 13 on the inner surface of the guide 1 and the upper, lower, left and right grooves of the rail 2 contact without any gap. Rotates with the travel and moves inside the retainer 13. Also, rail 2
The ball 9 and the ball 9 are both made of hardened steel, and are characterized in that they do not wear even without lubrication.

Although this sliding mechanism is commercially available under the trade name of LM guide, the commercially available LM guide is applied to a mechanism that removes or fits the guide from the rail like this mechanism. Can not. The reason is that the distance between the balls moving inside the retainer is wide, and when the ball comes off the rail, the ball falls off the retainer. Therefore, the sliding mechanism of the present invention is formed so that the distance between the balls is reduced, the opening of the retainer that holds the balls is reduced, and the balls do not fall off. The rail 2 has a tapered end so that it can easily enter the guide 1. This tapered shape plays a role of entry and prevents the ball 9 from impacting and falling off. It is.

Next, the operation of the wafer transfer mechanism will be described. First, as described in the conventional example, as the tray holder 7 conveyed by the chain 7 advances in the direction of the arrow, the roller 14 comes into contact with the side surface of the rail 2 and is conveyed while correcting the trajectory. . Next, the rail 2 enters the guide 1, the ball 9 enters the groove of the rail 9, and the ball 9 contacts the groove of the rail 2 while rotating, and the tray holder 4 is forced into the track of the rail 2, It slides without vertical movement and horizontal swing.

Next, when the tray holder 4 reaches the lower part of the dispersion head, a growth gas is jetted onto the wafer 8 to form a film. Next, when the tray holder 4 on which the film-formed wafer is mounted comes out of the lower part of the dispersion head by the driving of the chain, the tray holder 4 is moved.
The rail 2 is released from the guide 1 attached to the guide block 3a, and the tray holder 4 is released from the restriction of the movement from up, down, left and right, and is further transported by the chain 7 in the up and down direction of the paper (in the direction of the arrow).

As described above, the sliding mechanism for forcibly suppressing the vertical movement and the lateral vibration by the chain drive is provided only in the area passing through the dispersion head, and the wafer can be transported without the vertical movement. Further, in this embodiment, the roller 14 for guiding the tray holder 4 to the rail 2 is provided. However, the roller 14 is not particularly required as long as the tapered portion of the rail 2 formed to be accessible can be lengthened. .

[0017]

As described above, according to the present invention, a high-hardness rail is provided in a lower region of a dispersion head for ejecting a growth gas, at least a groove is formed vertically and both ends are tapered. A sliding portion is mounted on a tray holder, which is driven by a chain drive and on which a wafer is mounted, in contact with the rail groove via a ball, and a sliding portion by rolling is provided. By forcibly following the start-up by the sliding portion, the vertical movement of the wafer passing through the dispersion head was eliminated, and the effect of forming a more uniform film thickness was obtained.

[Brief description of the drawings]

FIGS. 1A and 1B are a partial plan view and a cross-sectional view taken along the line AA, respectively, showing a sliding mechanism of a tray holder on which a wafer is placed and transported by a chain drive in one embodiment of the wafer transport mechanism of the present invention.

FIG. 2 is a diagram showing a configuration of an example of a conventional wafer transfer mechanism and a partial cross-sectional view partially extracted and shown.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Guide 2, 11 Rail 3, 3a Guide block 4 Tray holder 5 Tray 6 Shim 7 Chain 7a Link 8 Wafer 9 Ball 10 Sliding member 12 Dispersion head 13 Retainer 14 Roller

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) H01L 21/205 B65G 49/07 C30B 25/12 H01L 21/31 H01L 21/68

Claims (1)

(57) [Claims] 1. A rail which is disposed in a region where a growth gas is injected, has tapered ends at both ends, and has grooves formed at least vertically along a longitudinal direction, and engages with the grooves. A wafer transport mechanism in an atmospheric pressure CVD apparatus, comprising: a guide having a plurality of balls that rotatably move in a retainer while rotating, and a tray holder on which a wafer is mounted and moved by a chain drive and to which the guide is attached. .