JPH0742130U - Stroke position detector for moving body in vacuum chamber - Google Patents

Abstract

(57) [Abstract] [Purpose] By providing the switch outside the vacuum chamber, it is not necessary to consider the severe condition of high vacuum as the usage condition of the switch. [Structure] A moving body stroke position detection device in a vacuum chamber includes a limit position detection switch 21 arranged outside the vacuum chamber, and a switch operating member 22 that operates the switch 21 when the lift A reaches the upper stroke limit. I have it. When the platform A reaches the upper stroke limit, the arm 23 is pushed up by the platform A,
A vertical portion 25 that moves in unison with 23 actuates switch 21.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a moving body stroke position detecting device in a vacuum chamber of a semiconductor manufacturing apparatus or the like.

[0002]

[Prior art]

 For example, in a vertical type LPCVD equipment for semiconductor manufacturing, when a wafer is loaded into or unloaded from a furnace (processing chamber), oxygen, moisture, etc. are added to prevent contamination of the furnace (processing chamber) due to oxygen and impurities in the atmosphere. What is equipped with a vacuum chamber that can remove impurities etc. in advance is used. In this vacuum chamber, there is provided a boat mounting table that moves up and down in order to load and unload wafers and boats holding wafers into and out of the processing chamber. Will be needed.

Conventionally, limit switches, photoelectric switches, and the like have been known as stroke position detecting devices of this type, and the stroke position is detected by arranging them in a vacuum chamber.

[0004]

[Problems to be solved by the device]

 The above-mentioned conventional limit switches, photoelectric switches, etc. are not reliable under high vacuum and high temperature, and the degree of vacuum is lowered or the vacuum chamber is contaminated due to degassing from the resin parts and cable coating used. There was a problem of doing. For this reason, a vacuum limit position detection switch has been developed, but the conventional vacuum limit position detection switch was extremely expensive and difficult to handle.

An object of the present invention is that it is not necessary to consider a severe condition of high vacuum as a use condition of the switch, and therefore it is inexpensive and highly reliable under high vacuum. It is an object of the present invention to provide a moving body stroke position detecting device in a vacuum chamber that does not become contaminated.

[0006]

[Means for Solving the Problems]

 The moving body stroke position detecting device in the vacuum chamber according to the present invention comprises a limit position detecting switch arranged outside the vacuum chamber and an operating member for activating the switch when the moving body reaches the stroke limit. is there.

As the switch, a limit switch, a photoelectric switch, a capacitance type switch, or the like is used.

[0008]

[Action]

 The moving body stroke position detecting device in the vacuum chamber according to the present invention comprises a limit position detecting switch arranged outside the vacuum chamber and an operating member for activating the switch when the moving body reaches the stroke limit. Therefore, it is not necessary to consider the severe condition of high vacuum as the operating conditions of the switch.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. In the following description, up / down / left / right means the up / down / left / right of FIG.

FIG. 1 shows an example of a vertical LPCVD apparatus. The apparatus includes a furnace body (1) having a lower end opened and a heater (2), and a furnace body (1) below the furnace body (1). A vacuum chamber (3) is provided. Inside the furnace body (1), there are provided a quartz outer tube (4) whose lower end is open and whose upper end is closed, and an inner tube (5) which is open at both upper and lower ends and serves as a processing chamber. There is. The lower end of the outer tube (4) is projected below the opening of the furnace body (1), and the lower end of the outer tube (4) and the upper end of the vacuum chamber (3) are connected in a sealed manner. A reaction gas inlet port (10) and a reaction residual gas exhaust port (11) are provided in the lower part of the outer tube (4). In the vacuum chamber (3), a boat mounting table (8) for mounting a boat (6) on which a large number of wafers (7) are vertically supported at predetermined intervals, and a boat mounting table for the boat (6). An elevator (a moving body in a vacuum chamber) (A) that lifts and lowers each (8) and loads it into the inner tube (5) is arranged. A lid (8a) having a diameter larger than the lower end opening of the outer tube (4) is provided at the lower end of the boat mounting table (8), and the lid (8a) is provided at the raised position of the boat mounting table (8). The peripheral portion of the upper surface of the outer tube contacts the lower end of the peripheral wall of the outer tube (4), thereby sealing the inside of the outer tube (4). A vertical screw rod (9) is rotatably supported in the forward and reverse directions near the left edges of the upper and lower walls of the vacuum chamber (3). The vertical screw rod (9) has a screw that is inserted through the lift base (A) so that the screw is fitted, and the lift base (A) moves up and down as the vertical screw rod (9) rotates forward and backward. Then, the elevator (A) reciprocates between the lower stroke limit and the upper stroke limit.

When the lift table (A) is at the lower stroke limit, the vacuum chamber (3) is evacuated from the exhaust port (12) provided under the vacuum chamber (3), and the lift table (A) is stroked. The boat (6) is loaded into the inner tube (5) after being raised to the upper limit, and the wafer (7) is processed by heating by the heater (2) and reaction of the introduced gas.

As described above, the lifting platform (A) reciprocates between the lower stroke limit and the upper stroke limit, but in order to prevent the lifting platform (A) from going too far up and down, the peripheral wall of the vacuum chamber (3) is prevented. An upper stroke position detection device (12) that detects the upper stroke limit of the lifting platform (A) is installed above (3a), and a lower part that detects the lower stroke limit of the lifting platform (A) is located below the same. A stroke position detector (14) is provided.

The upper and lower stroke position detecting devices (13) and (14) have substantially the same configuration, and the upper stroke position detecting device (13) is shown in FIGS. 2 to 4. As shown in the figure, in the upper stroke position detection device (13), the limit position detection switch (21) arranged outside the vacuum chamber (3) and the lift table (A) reached the upper stroke limit. And a switch actuating member (22) for sometimes actuating the switch (21).

The switch (21) is a photoelectric switch, and although not shown in detail, it is provided with a light projector and a light receiver, and if there is a switch that blocks light on the axis of this light, a switching signal is generated. To do.

The switch actuating member (22) is inserted into an opening (15) formed in the peripheral wall (3a) of the vacuum chamber (3) and is swingably supported by the peripheral wall (3a). ), A disk part (24) whose center is fixed to the left end part (outer end part of the outdoor side) of the arm (23), and a disk part (24) that is continuously provided below the disk part (24) and has a tip part of the switch (21) It consists of a vertical part (25) designed to block the light from the projector.

An annular seal flange (26) is attached to the outer edge (15a) of the opening (15) of the peripheral wall (3a) of the vacuum chamber (3). The right end of a stainless steel bellows (27) is attached to the edge of the seal flange (26), and the left end opening of the bellows (27) is closed by the disc part (24) of the switch actuating member (22). As a result, the gap between the arm (23) and the edge (15a) of the opening (15) is sealed. The switch (21) is attached to the seal flange (26) via the bracket (28).

The disk portion (24) of the switch actuating member (22) is sandwiched between a pair of horizontal plates (29), and each horizontal plate (29) is provided on a pair of protrusions provided on the seal flange (26). It is swingably attached to the horizontal plate support portion (30) through a pin (31). This allows the arm (23) to swing about the pin (31) as a fulcrum, and the disc portion (24) and the vertical portion (25) to swing together with the arm (23). You can

When the lifting platform (A) reaches the upper stroke limit position, the arm (23) is pushed up by the lifting platform (A), and the tip of the vertical section (25) moves to the right accordingly. , The light from the floodlight of the switch (21) is blocked, and the stroke upper limit position of the elevator (A) is detected. The bellows (27) is flexible, so that when the arm (23) is pushed up by the lift (A), it can expand and contract like a swing. The inside and outside of the vacuum chamber (3) are always shut off. Although not shown, when the lift table (A) moves away from the stroke upper limit position, the switch operating member (22) is returned to its original state by a spring or the like.

As can be seen from FIG. 1, a device for detecting the vertical stroke position is installed at the upper wall of the vacuum chamber (3), that is, at the boundary between the vacuum chamber (3) and the outer tube (4). However, in the upper stroke position detection device (13) of this embodiment, it can be installed on the wall of the vacuum chamber (3) parallel to the movement direction of the lift table (A). The device can be easily installed.

In the lower stroke position detecting device (14), since the arm (23) is pushed down, the point where the tip of the vertical portion (25) moves to the left is the upper stroke position detecting device (13). They are different, and therefore the switch (21) is extended to the left of the upper stroke position detecting device (13). The lower stroke position detecting device (14) is the same as the upper stroke position detecting device (13) except for the position of the switch (21).

In the above embodiment, the switch (21) is a photoelectric switch. However, the switch (21) is not limited to this, and the shape of the switch operating lever (23) may be slightly changed to provide a limit switch. A switch or a capacitance type switch can also be used.

FIG. 5 shows another embodiment of the upper stroke position detecting device.

The upper stroke position detecting device (16) includes a limit position detecting switch (41) arranged outside the vacuum chamber (3) and a switch when the lift table (A) reaches the upper stroke limit. A switch operating member (42) for operating the switch (41).

The switch (41) is a limit switch and generates a switching signal when the lever (41a) of the switch is driven.

The switch operating member (42) is inserted into an opening (15) formed in the peripheral wall (3a) of the vacuum chamber (3) and is rotatably supported by the peripheral wall (3a) ( 43) and the center of the rotary shaft (43) is fixed to the right end (the end on the indoor side) and is driven by the lift (A) that has reached the upper stroke limit. A part (45) and a substantially semi-disc-shaped outdoor side operating part (44) which is fixed to the left end (outer side end) of the rotating shaft part (43) and drives the switch lever (41a). Consists of.

An annular seal flange (46) is attached to the outer edge (15a) of the opening (15) of the peripheral wall (3a) of the vacuum chamber (3). The right end of a stainless steel bellows (47) with a different diameter is attached to the rim of the seal flange (46), and the left end opening of the bellows (47) is inserted into the rotary shaft (43) through a disc (43). By being closed by 48), the gap between the rotary shaft part (43) and the edge part (15a) of the opening part (15) is sealed. It is of course possible to use the bellows (47) having the same diameter.

The outdoor side of the wall (3a) is provided with an outdoor side bearing (49) that supports a portion slightly to the right of the outdoor side operation part (44), and the indoor side of the wall (3a) is provided. An indoor bearing (50) is provided to support a portion of the rotary shaft portion (43) slightly left of the indoor operation portion (45). The limit switch (41) is attached to the left end surface of the outdoor bearing (49).

When the lift table (A) reaches the stroke upper limit position, the indoor-side operation part (45) is pushed up by the lift table (A), whereby the rotary shaft part (43) rotates, and along with this, the room The inner working part (44) drives the switch lever (41a), and the upper stroke position of the lifting platform (A) is detected. Since the bellows (47) has flexibility, when the rotating shaft (43) is rotated, it can be twisted with the rotation, and the inside and outside of the vacuum chamber (3) can be twisted. It is always shut off. Although not shown, when the lift table (A) is separated from the upper stroke position, the switch operating member (42) is returned to its original state by a spring or the like.

The above-mentioned upper stroke position detecting device (16) can also be used as a lower stroke position detecting device by making some changes. In this case, in the upper stroke position detecting device (16), the indoor side operating part (45) and the outdoor side operating part (44) are provided so that the horizontal part is at the bottom and the arc part is at the top. On the other hand, in the lower stroke position detecting device, the indoor side operating portion (45) and the outdoor side operating portion (44) are provided such that the horizontal portion is on the upper side and the arc portion is on the lower side.

In the above-mentioned embodiment, both the indoor side operating part (45) and the outdoor side operating part (44) are substantially semi-disc shaped, but the indoor side operating part (45) is It only needs to have a shape that projects radially from the part (43) and can be driven by the lifting platform (A) .The outdoor working part (44) facilitates driving the switch lever (41a). For example, it is slightly larger than a half circle. Further, in the above embodiment, the switch (41) is a limit switch, but not limited to this, by slightly changing the shape of the outdoor operation section (44), a photoelectric switch or an electrostatic switch can be used as a switch. Capacitive switches can also be used.

Although the stroke position detecting devices (13), (14), and (16) are provided at the upper stroke limit and the lower stroke limit of the lifting platform (A) in the above two embodiments, the present invention is not limited to this. It can be provided at the front end of stroke and the end of stroke of a moving body that reciprocates back and forth. In any case, since the switches (21) (41) are used in the atmosphere, even under the severe conditions of high vacuum and high temperature in the vacuum chamber (3), it is conventional. The switch can be used.

[0032]

[Effect of device]

 According to the moving body stroke position detection device in the vacuum chamber of the present invention, since it is not necessary to consider the severe condition of high vacuum as the use condition of the switch, it is inexpensive and highly reliable under high vacuum, and the degree of vacuum is high. Does not deteriorate and the vacuum chamber is not contaminated.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an apparatus using a moving body stroke position detecting apparatus in a vacuum chamber according to the present invention.

FIG. 2 is a perspective view showing a moving body stroke position detection device in a vacuum chamber.

FIG. 3 is a vertical sectional view of the same.

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

FIG. 5 is a perspective view showing another embodiment of the moving body stroke position detecting device in the vacuum chamber according to the present invention.

[Explanation of symbols]

 (3) Vacuum chamber (13) (14) (16) Moving body stroke position detector (21) (41) Switch (22) (42) Switch actuating member (A) Lift table (moving body)

Claims (1)

[Scope of utility model registration request] 1. A limit position detection switch (21) (41) arranged outside the vacuum chamber (3) and a switch (21) (41) which is activated when the moving body (A) reaches a stroke limit. A moving body stroke position detection device in a vacuum chamber, comprising: operating members (22) (42).