JPH06163668A - Moving apparatus for vacuum - Google Patents

Abstract

PURPOSE:To prevent deformation of a moving part, which moves back and forth in vacuum. CONSTITUTION:A base stage 7 is driven with a driving part 8 and moves back and forth. A moving part 22 is attached to the base stage 7 and moves back and forth in a main vacuum chamber 21. A front-side wall part 16 forms a front-side vacuum chamber 14, which communicates with the main vacuum chamber 21 at a front 10 of the base stage 7. A rear-side wall part 24 forms a rear-side vacuum chamber 23, which communicates with the front-side vacuum chamber 14, at a rear surface 15 of the base stage 7. These parts are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving device for vacuum,
For example, the present invention relates to a vacuum transfer device for moving a wafer or the like back and forth in a vacuum in a semiconductor manufacturing process.

[0002]

2. Description of the Related Art In a semiconductor manufacturing process, storage and transportation of wafers and the like in processes such as processing and various treatments are often carried out in a consistent vacuum. This is because if a semiconductor product is contaminated with impurities, the quality of the product is likely to be poor. Therefore, it is preferable to store and convey the semiconductor product in a highly cleaned vacuum from the viewpoint of preventing contamination.

FIG. 5 is a diagram showing the overall structure of a conventional vacuum moving device 1. In this vacuum moving device 1, a vacuum chamber 3 surrounded by a wall portion 2 is placed in a vacuum state and a carrier 4 is housed in the vacuum chamber 3. A large number of semiconductor products such as wafers are loaded on the carrier 4. The carrier 4 is placed on a carrier pedestal 5, and the carrier pedestal 5 is horizontally supported by a support rod 6 extending downward. The lower end of the support rod 6 is fixed to the base 7. The base 7 is integrally attached to a drive unit 8, and the drive unit 8 can move up and down along a rail 9 as shown by an arrow B. An expandable bellows 12 is hermetically attached between the front surface 10 of the base 7 and the bottom surface 11 of the wall 2 to isolate the vacuum chamber 3 from the outside 13.

In the vacuum moving device 1 having the above structure, when the drive unit 8 moves up and down along the rail 9 as shown by the arrow B, the base 7 attached to the drive unit 8 also moves up and down.
As a result, the support rod 6 and the carrier support 5 attached to the base 7 move up and down in the vacuum as shown by arrow C, and the carrier 4
Moves up and down in a vacuum. The bellows 12 expands and contracts as the base 7 moves up and down to keep the vacuum chamber 3 airtight.

[0005]

The inner space 14 of the bellows 12 is in a vacuum state because it communicates with the vacuum chamber 3. Therefore, the front surface 10 of the base 7 is in contact with the internal space 14 in a vacuum state, and the back surface 15 is in contact with the outside 13 at atmospheric pressure. Therefore, a pressure difference is generated between the front surface 10 and the back surface 15 of the base 7, and the base 7 is pushed upward by the pressing force P and tilts. As a result, there is a problem that the support rod 6, the carrier cradle 5, and the carrier 4 are entirely tilted as shown by the chain line in the figure.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a moving device for vacuum which can prevent deformation of a moving member which moves back and forth in a vacuum.

[0007]

A vacuum moving device according to the present invention comprises a base which is driven by a drive unit to move back and forth, and a moving unit which is attached to the base and moves back and forth in a main vacuum chamber. A front side wall portion forming a front side vacuum chamber communicating with the main vacuum chamber on the front surface of the base, and a back side wall portion forming a back side vacuum chamber communicating with the front side vacuum chamber on the back surface of the base. It is characterized by having.

[0008]

In the present invention, the front side of the base to which the moving member is attached is in a vacuum state because it communicates with the main vacuum chamber, while the back side vacuum formed on the back side of the base. The chamber also communicates with the main vacuum chamber. Therefore, both the front surface and the back surface of the base are in contact with the vacuum space of the same pressure, and there is no pressure difference between the front surface and the back surface of the base.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vacuum moving device according to the present invention will be described below with reference to FIGS.

FIG. 1 is a schematic configuration diagram showing the principle of a vacuum moving device according to this embodiment, FIG. 2 is a front view showing the overall configuration of a vacuum moving device embodying this, and FIG. 3 is shown in FIG. FIG. 4 is an enlarged side view of the removed moving part, and FIG. 4 is a view taken along the line IV-IV in FIG.

As shown in FIG. 1, a vacuum moving device 20 according to the present invention includes a base 7 which is driven by a drive unit 8 to move back and forth, and a main vacuum chamber which is attached to a front surface 10 of the base 7. A moving part 22 that moves back and forth in the inside 21 and a front side vacuum chamber 14 that is attached to the front face 10 of the base 7 and communicates with the main vacuum chamber 21.
And a rear side vacuum chamber 23 attached to the rear side 15 of the base 7 and communicating with the front side vacuum chamber 14.
And a rear side wall portion 24 that forms

The main vacuum chamber 21 is a sealed space surrounded by the wall portion 2, and the moving part 22 moves up and down in the main vacuum chamber 21 which has been evacuated as indicated by an arrow C. Moving part 22
The support pipe 25 is fixed to the front surface 10 of the base 7 upward, and the carrier receiving base 5 on which the carrier 4 is detachably mounted. A large number of semiconductor products such as wafers are stored in the carrier 4. Between the bottom surface 11 of the wall 2 and the front surface 10 of the base 7, flanges 26, 27 are provided.
The upper bellows 12 is hermetically attached via. The upper bellows 12 and the front surface 10 of the base 7 form a front side wall portion 16 that forms the front side vacuum chamber 14. The front vacuum chamber 14 of the bellows 12 communicates with the main vacuum chamber 21 through the holes 28 and 29 in the wall 2 and the flange 26, respectively. The base 7 is attached to a drive unit 8, and the drive unit 8 constitutes an elevating mechanism that ascends and descends along a vertically arranged rail 9 as shown by an arrow B.

A blind flange 31 is fixed to the main body 30 of the moving device 20 for vacuum. A lower bellows 35 is hermetically attached via flanges 33 and 34 between the rear surface 15 of the base 7 and the front surface 32 of the blind flange 31.
The lower bellows 35, the back surface 15 of the base 7 and the blind flange 31 constitute a back side wall portion 24 forming the back side vacuum chamber 23. The back side vacuum chamber 23, which is partitioned by the back side wall 24 from the outside 13 at atmospheric pressure, supports the hole 7a formed in the base 7, the inside 36 of the support pipe 25 communicating with this hole 7a, and the support. It communicates with the main vacuum chamber 21 through a hole 37 formed in the wall surface of the pipe 25, the front side vacuum chamber 14 inside the upper bellows 12, and holes 28 and 29.

Therefore, when the gas in the main vacuum chamber 21 is sucked from the discharge port 2a formed in the wall portion 2 of the main vacuum chamber 21, the gas in the upper bellows 12 is discharged through the holes 28, as shown by the arrow in the figure. It flows through 29 to the main vacuum chamber 21. on the other hand,
Part of the gas in the rear vacuum chamber 23 of the lower bellows 35 is
While flowing into the main vacuum chamber 21 through the hole 7a, the tube interior 36 and the hole 37, the remaining gas flows into the tube interior 36, the hole 37,
Front side vacuum chamber 14 and hole 2 inside the upper bellows 12
It flows into the main vacuum chamber 21 through 8, 29. As a result, the gas in the entire space communicating with the main vacuum chamber 21 is exhausted from the exhaust port 2a to create a vacuum state.

Next, the vacuum moving device 2 having the above structure
The operation of 0 will be described. When the drive unit 8 to which the base 7 is attached moves up and down along the rail 9 as shown by an arrow B, the support pipe 25 fixed to the base 7 moves up and down, and the carrier receiving base 5 and the carrier 4 are in a vacuum state. The main vacuum chamber 21 is moved up and down as shown by arrow C. Both the bellows 12 and 35 also expand and contract as the base 7 moves up and down to maintain the vacuum state. In this case, the front side vacuum chamber 14 in contact with the front surface 10 of the base 7 and the rear side vacuum chamber 2 in contact with the back surface 15
Since both 3 are in communication with the main vacuum chamber 21, there is no pressure difference between the front surface 10 and the back surface 15, and therefore no force due to atmospheric pressure is applied to the back surface 15.

As described above, in the apparatus 20 of this embodiment,
The pressure difference between the front surface 10 and the back surface 15 of the base 7 is eliminated to eliminate the imbalance of force, and the base 7 is prevented from tilting upward. Therefore, the carrier cradle 5 and the carrier 4 placed on the carrier cradle 5 move up and down in the vacuum chamber 21 with high accuracy. For example, in the conventional device 1 as shown in FIG. 5, the base 7 is deformed by 1/10 mm or more, but the base 7 in the device 20 of the present embodiment is deformed by 1/100 mm or less. .

2 to 4 show the structure of a vacuum moving device 20 embodying the principle shown in FIG. 2 to 4, members having the same functions as those in FIG. 1 will be described with the same reference numerals. In the vacuum moving device 20, as shown in FIG. 2, the inside of the vacuum container 41 is a main vacuum chamber 21. An exhaust port 42 is formed in the vacuum container 41, and the gas in the main vacuum chamber 21 is exhausted from the exhaust port 42.

A support pipe 25 for supporting the carrier cradle 5.
A plurality of holes 37 are formed in the hole. An upper bellows 12 is attached between the base 7 to which the lower end of the support pipe 25 is attached and the vacuum container 41. Vacuum moving device 2
A fixing base 43 is fixed to the main body 30 of 0, and a blind flange 31 is fixed to an upper portion of the fixing base 43.
A lower bellows 35 is attached between the base 7 and the blind flange 31. The front side vacuum chamber 14 inside the upper bellows 12 communicates with the main vacuum chamber 21, while the back side vacuum chamber 23 inside the lower bellows 35 includes the pipe interior 36 of the support pipe 25, the hole 37, and the front side vacuum chamber. 14 to communicate with the main vacuum chamber 21. A linear motor is built in the drive unit 8 to which the base 7 is attached, and the linear motor can be moved up and down along a linear guide 44 as a rail.

As shown in FIG. 3, a carrier pedestal 5 is attached to the upper end of the support pipe 25 attached to the base 7, and the carrier 4 is placed on the carrier pedestal 5. The carrier 4 is provided with a large number of supporting pieces 45, and a large number of semiconductor products such as wafers are supported and stacked by the supporting pieces 45.

Therefore, by driving the linear motor of the drive unit 8, the base 7 is moved up and down, whereby the carrier 4 placed on the carrier receiving base 5 is also moved up and down. In this case, since there is no pressure difference between the front surface and the back surface of the base 7, the base 7 is not deformed, and therefore the carrier receiving base 5 and the carrier 4 are vertically moved up and down with high accuracy.

Although the above embodiment has been described with respect to the case where the moving unit 20 moves up and down, the moving direction is not limited to this.

[0022]

Since the vacuum moving device according to the present invention is configured as described above, a pressure difference is not generated between the front surface and the back surface of the base, and therefore, the moving member that moves back and forth in the vacuum is provided. Displacement or deformation can be prevented.

[Brief description of drawings]

1 to 4 are views showing an embodiment of a moving device for vacuum according to the present invention, and FIG. 1 is a schematic configuration diagram showing the principle of the present invention.

FIG. 2 is a front view showing the overall configuration of a vacuum moving device that embodies the principle shown in FIG.

3 is an enlarged side view of a moving part of the apparatus shown in FIG.

4 is a view taken along the line IV-IV in FIG.

5 is a schematic configuration diagram showing the principle of a conventional vacuum moving device, and is a diagram corresponding to FIG. 1. FIG.

[Explanation of symbols]

 7 Base 8 Drive 10 Front of Base 15 Back of Base 20 Moving Device for Vacuum 21 Main Vacuum Chamber 22 Moving Part 23 Rear Side Vacuum Chamber 24 Back Side Wall

Claims (1)

[Claims] 1. A base that is driven by a drive unit to move back and forth, a moving unit that is mounted on the base and moves back and forth in a main vacuum chamber, and a front surface of the base that communicates with the main vacuum chamber. A vacuum moving device comprising: a front side wall portion forming a side vacuum chamber; and a back side wall portion forming a back side vacuum chamber communicating with the front side vacuum chamber on a back side of the base.