JP4085485B2 - Wafer transfer mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wafer transfer mechanism in a semiconductor manufacturing apparatus.
[0002]
[Prior art]
When performing a process in a semiconductor manufacturing apparatus, it is necessary to heat the wafer evenly. Therefore, the entire wafer is heated by bringing the wafer into close contact with the upper surface of the heater in the vacuum chamber. For this reason, the upper surface of the heater is flat to match the surface of the wafer. However, if the upper surface of the heater is completely flat, it is not possible to secure a space for removing the fork that carries the wafer. I can't deliver it. Therefore, conventionally, when the wafer is placed on the upper surface of the heater, the wafer is delivered by moving the fork up and down.
FIG. 5 shows a conventional wafer transfer mechanism.
In FIG. 5, reference numeral 1 denotes a vacuum chamber, and a slide bearing 2 is attached to the bottom of the vacuum chamber 1. The sliding bearing 2 passes through an elevating shaft 4 that moves up and down as shown by an arrow A by a driving device 3 (not shown). The elevating shaft 4 has a through hole (not shown) at the center and a flat plate portion 5 formed integrally at the upper end. The flat plate portion 5 has a heater (not shown) on the upper surface. The wiring of the heater is made through the through hole. Reference numeral 6 denotes a plurality of, for example, three pin holes, which are formed by perforating the flat plate portion 5 in the vertical direction. A plurality of wafer support pins 7 are attached to the bottom surface of the vacuum chamber 1 and are arranged so as to penetrate the pin holes 6 provided in the flat plate portion 5 from below. Reference numeral 8 denotes a transfer port formed on a side surface of the vacuum chamber 1, and a fork 9 attached to the tip of an arm of a wafer transfer robot (not shown) so as to be able to move up and down enters and exits with the wafer 10 placed thereon. .
Hereinafter, the operation of the wafer transfer mechanism configured as described above will be described.
First, the fork 9 on which the wafer 10 is placed enters the vacuum chamber 1 from the transfer port 8 and stops at the set position. At the same time as the fork 9 stops, the fork 9 descends to place the wafer 10 on the wafer support pins 7.
Next, the fork 9 is moved out of the transfer port 8, and at the same time, the elevating shaft 4 is raised to place the wafer 10 on the heater of the flat plate portion 5.
When the wafer 10 is placed on the flat plate portion 5, the wafer 10 is heated with a heater. When the heating of the wafer 10 is finished, the elevating shaft 4 is lowered and the wafer 10 is placed on the wafer support pins 7. When the wafer 10 is placed on the wafer support pins 7, the fork 9 again enters the vacuum chamber 1 from the transfer port 8, picks up the wafer 10 and goes out of the transfer port 8.
[0003]
[Problems to be solved by the invention]
However, in such a prior art, since it is necessary to provide the raising / lowering mechanism of a fork separately, there existed the following problems.
(1) This will cause the fork to move, reducing the position accuracy of the fork.
(2) Since the fork vibrates, the wafer may be damaged.
(3) The mechanism of the wafer transfer device becomes larger and the cost increases.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a wafer transfer mechanism that keeps the position accuracy of the fork high, does not give vibration to the fork, and can reduce the size of the mechanism portion of the wafer transfer device. .
[0004]
[Means for Solving the Problems]
In order to solve the above problem, the wafer transfer mechanism of the present invention is slidably fitted to a vacuum chamber having a transfer port on the side and a slide bearing extending in the vertical direction on the bottom, and the slide bearing. And an elevating shaft formed with a flat plate portion having a plurality of pin holes drilled in the vertical direction at the upper end protruding into the vacuum chamber, and a movable wafer support pin attached to the bottom surface of the vacuum chamber, A movable wafer support pin is attached to a bottom surface of the vacuum chamber, and is attached to an upper portion of the base. A pin through hole is formed in a central portion, and a slide bearing is attached to the pin through hole. A pin support body having a stopper having a pin passage hole on the lower surface side of the pin and a pin formed of a heat-resistant material and formed on the flat plate portion of the lifting shaft A small-diameter portion that moves up and down, a medium-diameter portion that slides in the slide bearing and has an outer diameter larger than the diameter of the pin hole, and an outer diameter that is larger than the pin through hole of the stopper The pin is composed of a large-diameter portion, and an elastic body that is interposed between the base and the pin and constantly pushes the pin upward.
This makes it possible to easily form a space between the fork and the wafer by the vertical movement of the lifting shaft. When the wafer is transferred from the fork to the upper surface of the flat plate portion, or from the upper surface of the flat plate portion to the fork. When changing, it is not necessary to move the fork up and down.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a side sectional view showing a main part of a wafer transfer mechanism in an embodiment of the present invention, and shows a state where a wafer has been transferred into a vacuum chamber and stopped. FIG. 2 is an enlarged cross-sectional view showing details of the movable wafer support pins, and FIG. 3 is a side cross-sectional view showing the main part of the wafer transfer mechanism in the embodiment of the present invention. Shows the state. FIG. 4 is also a side sectional view showing a state where the lifting shaft is raised by another stage and the wafer is placed on the upper surface of the flat plate portion of the lifting shaft.
The wafer transfer mechanism of the present invention is basically the same as the conventional wafer transfer mechanism, except that the wafer support pins are configured to be movable.
In FIG. 1, reference numeral 11 denotes a movable wafer support pin, which is attached to the bottom surface of the vacuum chamber 1. Reference numeral 12 denotes a base of the movable wafer support pin 11, which is attached to the bottom surface of the vacuum chamber 1, and a pin support 13 having a U-shaped cross section is attached to the upper part. The pin support 13 is formed with a pin through-hole 14 at the center, and a slide bearing 15 is attached to the pin through-hole 14, and the lower surface side of the slide bearing 15 of the pin support 13 is formed from the inner diameter of the slide bearing 15. Also, a stopper 17 having a pin through hole 16 having a slightly larger inner diameter is attached. 18 is a pin made of a heat-resistant material such as ceramics, and slides in a small diameter portion 19 that moves up and down in a pin hole 7 formed in the flat plate portion 5 of the elevating shaft 4, and in the slide bearing 15. The outer diameter is composed of a medium diameter portion 20 formed larger than the diameter of the pin hole 7, and a large diameter portion 21 larger in outer diameter than the pin passage hole 16 of the stopper 17, and has a tapered shape. Yes. Reference numeral 22 denotes an elastic body such as a spring interposed between the base 13 and the pin 19 and always pushes the pin 18 upward.
Hereinafter, the operation of the wafer transfer mechanism configured as described above will be described.
First, as shown in FIG. 1, the fork 9 on which the wafer 10 is placed enters the vacuum chamber 1 from the transfer port 8 and stops at the set position. At this time, the elevating shaft 4 is lowered to the lowest part, and the stepped portion of the medium diameter portion 20 of the pin 19 is pressed by the lower surface of the flat plate portion 5. The pin 19 has a small-diameter portion 20 protruding from the upper surface of the heater of the flat plate portion 5, and a dimension l ₁ from the tip of the pin 18 to the lower surface of the wafer 10 is a step of the large-diameter portion 21 of the pin 18 from the lower surface of the stopper 17. It is set to be shorter than the dimension l ₂ to the part.
Next, as shown in FIG. 3, the elevating shaft 4 is raised by one step, that is, the dimension l ₂ , and the wafer 10 is placed on the tip of the pin 18, and the wafer 10 is moved from the fork 9 by the dimension l ₂ −l _1. Float. In this state, the fork 9 is pulled back and moved out of the vacuum chamber 1 from a transfer port (not shown).
Next, the fork 9 is moved out of the conveying port, and at the same time, the elevating shaft 4 is raised by another dimension, that is, a dimension exceeding the dimension L ₃ from the upper surface of the flat plate portion 5 to the tip of the pin 18 protruding. Then, the wafer 10 is placed on the flat plate portion 5. As shown in FIG. 4, when the wafer 10 is placed on the flat plate portion 5, the wafer 11 is heated by the heater. When the heating of the wafer 10 is finished, on the contrary, the elevating shaft 4 is lowered by one step and the wafer 10 is placed on the pins 18. When the wafer 10 is placed on the pins 18, the fork 9 is again entered into the vacuum chamber 1 from the transfer port, and is stopped in the space between the wafer 10 and the flat plate portion 5.
In this state, the elevating shaft 4 is lowered one more stage to place the wafer 10 on the fork 9. When the wafer 10 is placed on the fork 9, the fork 9 is moved so as to come out of the vacuum chamber 1.
Thus, the wafer transfer mechanism of the present invention moves the fork 9 up and down when the wafer 10 is transferred from the fork 9 to the flat plate portion 5 or when the wafer 10 is transferred from the flat plate portion 5 to the fork 9. Since it is not necessary, the positional accuracy of the fork 9 can be kept high.
Further, since there is no need to provide an elevating mechanism for the fork 9, the fork 9 is not vibrated, the wafer 10 is not damaged, and the mechanism portion in the wafer transfer device is not increased in size. Can also be reduced [0006]
【The invention's effect】
As described above, according to the present invention, since there is no need to provide a fork lifting mechanism, the following effects can be obtained.
(1) Since the fork does not cause any excessive movement, the position accuracy of the fork can be kept high.
(2) Since the fork does not vibrate, the wafer is not damaged.
(3) The mechanical part of the wafer transfer device is not increased in size and the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing a main part of a wafer transfer mechanism in an embodiment of the present invention, showing a state where a wafer has been transferred into a vacuum chamber and stopped.
FIG. 2 is an enlarged cross-sectional view showing details of a movable wafer support pin in an embodiment of the present invention.
FIG. 3 is a side sectional view showing a main part of a wafer transfer mechanism in an embodiment of the present invention, and shows a state in which a lift shaft is raised by one stage to lift a wafer from a fork.
FIG. 4 is a side sectional view showing the main part of the wafer transfer mechanism in an embodiment of the present invention, showing a state in which the lift shaft is raised by another stage and the wafer is placed on the upper surface of the flat plate portion of the lift shaft. ing.
FIG. 5 is a side sectional view showing a wafer transfer mechanism in the prior art.
[Explanation of symbols]
1 vacuum chamber,
2 plain bearings,
3 Drive unit,
4 Lifting shaft,
5 Flat plate part,
6 pin holes,
7 Wafer support pins,
8 Transport port,
9 Forks,
10 wafers,
11 Movable wafer support pins,
12 base,
13 pin support,
14 pin through hole,
15 plain bearing,
16 pin through hole,
17 stopper,
18 pins,
19 Small diameter part,
20 medium diameter part,
21 Large diameter part,
22 Elastic body

Claims (1)

A vacuum chamber having a conveying port on the side and a sliding bearing extending in the vertical direction on the bottom;
An elevating shaft that is slidably fitted to the slide bearing and has a flat plate portion having a plurality of pin holes drilled in the vertical direction at the upper end protruding into the vacuum chamber;
A movable wafer support pin attached to the bottom surface of the vacuum chamber;
A base on which the movable wafer support pins are attached to the bottom surface of the vacuum chamber;
A pin support that is attached to the upper part of the base, has a pin through hole formed in the central portion thereof, a slide bearing is attached to the pin through hole, and a stopper having a pin through hole is attached to the lower surface side of the slide bearing. When,
It is made of a heat-resistant material, and has a small-diameter portion that moves up and down in the pin hole formed in the flat plate portion of the elevating shaft, and slides in the slide bearing and has an outer diameter larger than the diameter of the pin hole. A pin composed of a medium diameter part and a large diameter part having an outer diameter larger than the pin through hole of the stopper;
A wafer transfer mechanism comprising an elastic body interposed between the base and the pins and constantly pushing the pins upward.

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