JP2003168729A - Purging unit for semiconductor wafer storing clean box - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that an open-close unit for a clean box and a clean box purging unit are separately required when the clean box is purged with nitrogen, and in this case, a general-purpose clean box can not be used, and a clean box fit for the nitrogen purging unit is required. <P>SOLUTION: A purging device is used for purging a clean box with gas, and the clean box is equipped with a main body provided with an opening at its lower part and an open-close lid which is equipped with shelves for semiconductor wafers inside and stops up the opening from below. The purging device is equipped with a wall which is capable of descending down till the internal surface of the open-close lid is located above a gas inlet and a gas outlet and also ascending up till the internal surface of the open-close lid is located below the gas inlet and the gas outlet. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for purging the inside of a clean box in a clean atmosphere when the semiconductor wafer is replaced, and an apparatus used therefor.

[0002]

2. Description of the Related Art It is necessary to manufacture wafers used for semiconductor devices and the like in an environment where high cleanliness is guaranteed, and it is common to carry out in a clean room where the entire room is kept at high cleanliness. It was target. However, in order to keep the entire room that occupies a large volume in high cleanliness, a large amount of capital investment and maintenance cost are required, and once the capital investment is made, a large facility investment is required again when the room layout is changed due to the manufacturing process change. It is uneconomical because it requires investment. Therefore, in recent years, by keeping the inside of the semiconductor wafer processing apparatus at a high level of cleanliness as a microenvironmental space (hereinafter referred to as the mini environment section) without keeping the level of high cleanliness of the entire room, A method is known in which the same effect as when it is maintained is obtained (hereinafter, such a processing device is referred to as a clean device). That is, the semiconductor wafer processing apparatus is laid out in a room where manufacturing is performed, and a wafer storage container (hereinafter, referred to as a clean box) whose inside is kept highly clean is transferred between the clean apparatuses. Then, a clean box is connected to a predetermined wafer loading / unloading port provided in the semiconductor wafer processing apparatus so as to prevent dust from entering from the outside, and the wafer is delivered through the loading / unloading port of the wafer, whereby manufacturing is performed. This means that it is possible to maintain a high level of cleanliness in all environments to which wafers are exposed, without increasing the cleanliness of the room. As a result, it is possible to obtain the same effect as when the entire room is made a clean room, and it is possible to reduce equipment investment and maintenance costs and realize an efficient production process.

The clean box will be described with reference to FIG. 7a. The clean box 11 includes a main body 11a having an opening in the downward direction, and an opening / closing lid 11b which is fitted into the opening of the main body 11a and closes the opening from below.
The opening / closing lid 11b has a constant thickness, and its outer surface and inner surface are substantially parallel to each other. The side surface is fitted into the inner surface of the main body 11a to seal the clean box 11. The main body 11a can be separated by pulling it out in the vertical direction with respect to the opening / closing lid 11b. A shelf 13 for storing semiconductor wafers is provided on the inner surface of the opening / closing lid 11b. Clean box 1
1 moves in a state where the outer surface of the opening / closing lid 11b is kept horizontal so that the opening / closing lid 11b is on the lower side when the operation is performed by an arbitrary apparatus. It An opening / closing lid 11b is provided on the outer surface of the opening / closing lid 11b.
A latch mechanism is provided to prevent falling off from 1a. This latch mechanism will be described with reference to FIG. 7b. FIG. 7b is a view showing a latch mechanism inside the opening / closing lid 11b. The latch mechanism is a circular rotary cam plate 10 which is arranged at a substantially central position of the opening / closing lid 11b so as to be rotatable around the central axis in a direction perpendicular to the opening / closing lid 11b.
1 is provided. At the center of the rotary cam plate 101, there is a peripheral hole which is an engaging means for engaging the rotary cam plate 101 with an opening / closing device for rotating the rotary cam plate 101 and for rotating the rotary cam plate 101 around the central axis. 101c is formed. The peripheral hole 101c serving as an engaging means is arranged on the outer surface side of the opening / closing lid 11b. The peripheral hole 101c is the rotary cam plate 10.
1 is a groove-shaped hole having a constant width in a part of the circumference having a predetermined radius from the center of 1. In addition, the rotating cam plate 10
Two cam grooves 101a and 101b are formed in the No. 1. The latch mechanism is also a slide type latch member 10.
3 and a latch member 104. Latch member 1
03 and the latch member 104 are slidably opened and closed by the guide member 107 and the guide member 108 so that the tip 103a and the tip 104a respectively project from the side surface of the opening / closing lid 11b in opposite directions along the surface direction of the opening / closing lid 11b. It is arranged on the lid 11b. Latch member 1
03 and the latch member 104 in the direction perpendicular to the rotary cam plate 101, respectively.
6 is attached. The cam pin 105 and the cam pin 106 are engaged with the cam groove 101a and the cam groove 101b. Thereby, the latch member 103 and the latch member 104 are guided by the cam groove 101a and the cam groove 101b, and can slide so as to project or retract from the side surface of the opening / closing lid 11b in the surface direction of the opening / closing lid 11b (vertical direction in the drawing).

The cam grooves 101a and 101b are formed in such a shape that the distance from the center of the rotary cam plate 101 changes according to the circumferential position. With this cam shape,
When the rotary cam plate 101 is fully rotated counterclockwise to the position shown in FIG. 7, the latch member 103 and the latch member 104 respectively have a tip 103 a and a tip 10.
Slide 4a to the outermost position. Open / close lid 1
When 1b is attached to the main body portion 11a, the protruding front end portion 103a and the protruding front end portion 104a have the main body portion 11a.
The opening / closing lid 11b is latched to the main body portion 11a by engaging with a tab (not shown) arranged in a so as to overlap. On the contrary, when the rotary cam plate 101 is rotated clockwise by 90 degrees from that position, the latch member 103 and the latch member 1 are rotated.
Reference numeral 04 slides to the innermost position and becomes the position indicated by the chain double-dashed line in the figure. In this state, the tips 103a and 104a of the latch member 103 and the latch member 104 are retracted from the periphery of the opening / closing lid 11b, and are not engaged with the tab (not shown) of the main body.

Conventionally, the clean box 11 as described above is used.
Then, only by making the inside of the clean box 11 highly clean, that is, by reducing the amount of dust per unit volume, the lid of the clean box is closed and sealed to prevent dust particles from adhering to the semiconductor wafer. Was there. However, as semiconductor design requirements fall below 0.25 micron in recent years, it becomes necessary to control the film thickness of wafers on the order of angstroms. When a semiconductor wafer is exposed to air, its surface is oxidized and a native oxide film is formed on the surface of the wafer. Therefore, there is a problem that the surface of the semiconductor wafer is oxidized by the air filled in the clean box 11 to form a natural oxide film only by keeping the clean box in a high degree of cleanliness. When the natural oxide film is formed on the semiconductor wafer as described above, it becomes difficult to control the film pressure of the semiconductor wafer in the subsequent steps.

[0006]

As a method of preventing the oxidation of the film on the semiconductor wafer, there is a method of purging the air inside the clean box with nitrogen gas. In a typical method of this method, an inlet port and an outlet port for introducing nitrogen gas for purging with nitrogen gas prepared in a clean box are prepared in advance, and nitrogen gas is introduced into the clean box from the inlet port and the outlet is provided. The air in the clean box, specifically oxygen, is reduced by the method of discharging from the port. This method requires a plurality of steps of placing a semiconductor wafer on a clean box in advance, sealing the clean box with a lid, and then purging with nitrogen gas of high cleanliness. In particular, in order to realize this with a device, a plurality of devices, that is, a device for transferring semiconductor wafers (clean box opener),
A separate clean box nitrogen purge was required. Also, a general-purpose clean box cannot be used, and a clean box suitable for the nitrogen purging device is required. Therefore, there has been a demand for a method capable of simultaneously carrying out nitrogen purging while placing a semiconductor wafer in a clean box, and an apparatus capable of realizing the method.

[0007]

According to the present invention, a gas is purged inside a clean box having a main body portion having an opening on the lower side, and an opening / closing lid which closes the opening from the lower side and has a shelf for semiconductor wafers on the inner surface. And a table for engaging the opening / closing lid to mount the opening / closing lid, a flange base for supporting the main body portion in contact with an end of an edge of the opening, and the flange base. And a wall portion surrounding the side surface of the table and having a gas introduction port and a gas discharge port on the inner surface thereof, and forming a closed space by the main body portion, the flange base, the wall surface, and the table. Is possible,
The wall can be lowered until the inner surface of the opening / closing lid is located above the gas inlet and the gas outlet, and the wall is the inner surface of the opening / closing lid in the gas inlet and the gas outlet. The above problem is solved by a purging device characterized in that it can be raised to a lower position. That is, this makes it possible to integrate the conventional clean box opener and the clean box nitrogen purging device and perform processing in a series of steps.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a clean box purge device 1 of the present invention will be described with reference to FIG. FIG. 1 shows a clean box purge device 1 of the present invention. The clean box purging device 1 includes an elevating mechanism section 21 and a pedestal section 22. A ball screw 24 is arranged in the elevating mechanism portion 21 such that its axial direction is vertical, and a slide bush 23 is screwed therein. One end of the ball screw 24 is a servo motor 25.
And the ball screw 24 can be rotated around the axial direction of the ball screw 24. On the slide bush 23, the flange base 2 is attached to the ball screw 2 of the lifting mechanism 1.
It is mounted substantially horizontally so as to project in a direction perpendicular to the axial direction of No. 4.

The pedestal portion 22 has a structure in which the pedestal portion 22 extends vertically from the elevating mechanism portion 21 in the horizontal direction to support the entire apparatus. Four legs 26 are vertically attached to the upper surface 22a of the pedestal portion 22. The table receiving portion 3 is attached to the upper ends of the legs 26. The lower surface of the flange base 2 normally contacts the upper end of the wall portion 3a of the table receiving portion 3.
Then, the elevator rear portion 21 can lower and move the table receiving portion 3 against the biasing force of the spring 27 until the upper surface of the flange base 2 and the substantially upper surface of the table 4 are at the same height. The flange base 2 is set with a position where the upper surface of the flange base 2 and the upper surface of the table 4 are substantially at the same height as the lowest descent point. On the other hand, the flange base 2
Is an opening / closing lid 11 for replacing semiconductor wafers.
In order to raise b significantly, it is possible to move at least upwardly until the lowermost side of the main body 11 is higher than the uppermost part of the shelf 13 of the semiconductor wafer,
The position where the ascending movement is possible is set as the maximum ascending point. The clean box 11 is placed on the flange base 2 and the table 4 with the opening of the clean box 2 facing down.

Next, the structure of the flange base 2 and the table receiving portion 3 will be described in detail with reference to FIG. Figure 2
FIG. 2 is a diagram showing a cross section AA of FIG. 1. The table 4 is fixed to the upper surface 22a of the pedestal portion 22 by table support legs 29 so as to be horizontal. The table 4 has almost the same shape as the opening / closing lid 11b of the clean box 11 and has almost the same size. The table 4 and the side surfaces of the opening / closing lid 11b and the inner surface of the wall 3a are substantially the same in shape and size. ing. And the table receiving part 3 is the table receiving part 3
It is possible to move by ascending or descending in a state that the inner surface of the wall portion 3a of the table 3 is almost in contact with the side surface of the table 4 with only a slight gap. Therefore, the wall 3a of the table receiving portion 3 and the table 4 can be sealed at least to the extent necessary to purge the inside with gas. An opening / closing mechanism 30 for activating the latch mechanism of the opening / closing lid 11b of the clean box 11 is arranged in the center of the table 4. The opening / closing mechanism 30 is mounted in the table 4 so as to be rotatable about a vertical axis. The opening / closing mechanism 30 will be described with reference to FIG. The opening / closing mechanism is rotatable about a vertical direction perpendicular to the table 4 as a central axis, and includes a rod 30a extending below the table 4. A cylindrical opening / closing mechanism support structure 36, which is concentric with the central axis of the rod 30a, is attached to the table 4 facing downward. Bearings 37a and 37b for rotatably supporting the rod 30a are arranged in the opening / closing mechanism support structure 36. As a result, the opening / closing mechanism 30 rotates about the axis of the rod 30a. The lower end of the rod 30a is connected to a latch gear 41 having the same central axis as the rod 30a as the rotation axis. On the upper surface of the opening / closing mechanism 30, pins 31a and 31b for engaging with the engaging means are arranged point-symmetrically with respect to the center of the table so as to extend vertically from the table 4. The distance between the pin 31a and the pin 31b is substantially equal to the diameter of the peripheral hole 101c of the opening / closing lid 11b, and when the opening / closing mechanism 30 is rotated, the peripheral hole 1 serving as the engaging means between the pin 31a and the pin 31b.
01a is brought into contact with the wall surface of the peripheral hole 101b to rotate the rotary cam plate 101 of the opening / closing lid 11b. Subsequently, the drive portion of the opening / closing mechanism will be described with reference to FIGS. 4 (a) and 4 (b).

FIG. 4A shows the lower side of the table 4,
It is the figure which looked at the upper surface 22a of the pedestal part 22 from the upper side. 4B is a view of the flange base 2 and the pedestal portion 22 viewed from the right side of FIG. A rail 48 is attached to the pedestal portion 22 along a direction parallel to one side when the clean box 11 is placed on the table 4. A latch rack 42 is slidably mounted on the rail 48 along the rail. The latch rack 42 engages with the latch gear 41 to form a rack and pinion mechanism. A motor 47 is arranged on the pedestal portion 22, and the motor 47 rotates the motor gear 43. A motor rack 44 is engaged with the motor gear 43 to form a rack and pinion mechanism. A frame guide rail 49 a and a frame guide rail 49 b are arranged on the pedestal 22 in parallel with the rail 48, and the frame 45 is parallel to the pedestal 22 and the frame guide rail 49 a.
And the frame guide rail 49b, the frame guide rail 49 has a shape that extends vertically from the upper surface 22a of the pedestal portion 22 to a position exceeding the height of the flange base 2.
It is mounted slidably along b. The motor rack 44 is attached to the frame 45. A clean box holding pusher 46 is attached to one end of the frame 45 so as to extend vertically upward with respect to the upper surface 22 a of the pedestal portion 22. A rack pusher 45a that abuts the latch rack 42 on the frame 45 and can push the latch rack 42 along the rail.
Is attached. The flange base 2 penetrates the flange base 2 and has a clean box pressing pusher 4
An elongated hole 35 is provided for allowing the 6 to move in the surface direction of the flange base 2 without interfering with the flange base 2. Clean box retainer 28 is provided on the upper surface of the flange base 2.
Are arranged. The clean box holder 28 is one of the opposite sides of the table 4 of the flange base 2 and is an elongated hole 35.
2 are arranged, one each on the periphery of the side on which is arranged, outside the range in which the opening of the clean box 11 is enveloped. The clean box retainer 28 has a shaft 28b arranged so as to extend horizontally along the same direction as the rail 48 of the table 4, and has a hollow portion, and the shaft 28b is slidably supported in the hollow portion. A shaft guide 28c, a cylindrical bracket 28h having a hollow portion fixed to one end of the shaft 28b, and a spring 28f stored inside the bracket 28h.
The spring 28f is mounted on the shaft 2 in the hollow portion of the bracket 28h.
8b is arranged along the axial direction. A spiral guide groove 28e is formed on the inner surface of the shaft guide 28d. The guide groove 28e is engaged with a projecting guide pin 28d extending in a direction perpendicular to the central axis direction of the shaft 28b, and the shaft 28b slides to guide the guide pin 28d into the guide groove 28e. With the spiral shape of the guide groove 28e, the flange base 2 is rotated inward from the outside. An arm 28a is fixed to the shaft 28b, and the arm 28a rotates together with the shaft 28b. The arm 28a is mounted so as to stand upright when the spring contracts and the shaft 28b is pushed into the shaft guide 28c by a predetermined length. The spiral shape of the guide groove 28e is the shaft 28b.
Is pushed for a predetermined length and moves outward from the shaft guide 28c by the force of a spring from a boating state, the arm 28a standing upright is gradually moved to a fall position where the arm 28a is substantially horizontal. The shape is such that the flange base 2 lights up while rotating from the outside to the inside. This allows
When the arm 28a is in the upright position, the clean box 11 can be moved in the vertical direction until its opening is brought into contact with the upper surface of the flange base 2. Clean box 1
When the 1 is placed on the upper surface of the flange base 2, the arm 28
a rotates to the falling position, and the tip of the arm 28a presses the edge of the main body 11a of the clean box 11 downward in the vertical direction to fix the clean box 11.

In the initial state, the clean box holding pusher 46 of the frame 45 contacts the shaft 28b and the shaft 28b is completely pushed into the shaft guide 28c. In this state, the rack pusher 45a
Is not in contact with the latch rack 42,
The frame 45 moves and the clean box pressing pusher 46 causes the shaft 28b to gradually move out of the shaft guide 28c from the initial state. Then, after a lapse of a predetermined time (after the frame 45 has moved by a predetermined distance), the rack pusher 45 a is brought into contact with the latch rack 42.
The position of 5a is set. The latch rack 42 is connected to the end of the rail 48 by a spring, and is biased so as to be pulled in a direction opposite to the direction in which the shaft 28b extends from the shaft guide 28c (the direction in which the shaft 28c is pushed). When the motor gear 43 is rotated by the motor 47, the frame 45 moves to the motor rack 4
4 slides in the direction away from the shaft 28b along the frame guide rails 49a and 49b. With the movement of the clean box pressing pusher 46, the shaft 28b rotates while extending by the force of the spring, and the arm 28 is rotated along with the rotation of the shaft 28b.
a rotates and moves to a fall state. The arm 28a that has moved to the overturned state fixes the clean box 11.
Thereafter, when the frame 45 continues to move further, the rack pusher 45a comes into contact with the latch rack 42 and pushes the latch rack 42. The latch rack 42 moves along the rail 48 against the spring 51 and rotates the opening / closing mechanism 30 together with the latch gear 41. As a result, the pins 31a and 31b fitted in the peripheral holes 101a and 101b of the rotary cam plate 101 rotate, and the peripheral holes 101a and 1
The rotary cam plate 101 of the opening / closing lid 11b is rotated by contacting the wall surface at the end of 01b. By rotating the rotary cam plate 101, the tips 103a and 104a of the latch member 103 and the latch member 104 are retracted from the periphery of the opening / closing lid 11b to be disengaged from the main body 11a and the opening / closing lid 11b can be opened. Become.

A spring 27 is attached to the peripheral surface of the leg 26 on the leg 26 attached to the upper surface 22a of the pedestal portion 22, and urges the table receiving portion 3 upward in the vertical direction. The table receiving portion 3 includes a bottom surface portion 3b capable of contacting the outer peripheral portion of the outer surface of the table 4, and a wall portion 3a extending vertically from the bottom surface portion 3b. The inner surface of the wall 3a of the table receiving portion 3 is substantially in contact with the side surface of the table 4 and the side surface of the opening / closing lid 11b, and the table receiving portion 3 moves up or down along the side surface of the table 4 and the side surface of the opening / closing lid 11b. A groove is arranged on the upper surface of the bottom surface portion 3b so as to surround the outer peripheral portion of the upper surface. A seal member 31 is fitted in this groove. The seal member 31 is fitted so that a part of its cross section is located above the upper surface of the bottom surface portion at an arbitrary position, and the bottom surface portion 3b is pressed against the outer surface of the table 4 so that the seal member 31 is crushed and the table is crushed. It is possible to make the receiving unit 3 and the table 4 to have a sealed state at least to purge the inside with nitrogen gas.

The flange base 2 is arranged so that its lower surface is in contact with the upper end surface of the wall portion 3a. Flange base 2
Between the lower surface of the wall and the upper end surface of the wall 3a.
3 is arranged, the flange base 2 is lowered and pressed against the upper end surface of the wall portion 3a of the table receiving portion 3 so that at least the inside of the flange base 2 and the wall portion 3a of the table receiving portion 3 is filled with nitrogen gas. It is possible to create the required degree of tightness for purging with. A seal member 34 is attached to the upper surface of the flange base 2 over the entire periphery in conformity with the shape of the main body 11a so that the entire periphery of the opening of the main body 11a of the clean box 11 can be attached to the flange base 2 in a sealed state. ing. The clean box retainer 28 moves the main body 11a into the clean box 11
The main body 11a is pressed and fixed to the flange base 2 in a state where the opening of the main body 11a is in contact with the seal member 34. As a result, it is possible to create a sealed state that is necessary for purging the main body 11a, the flange base 2, and at least the inside with nitrogen gas. Finally, at least a sealed space between the main body portion 11a of the clean box 11, the flange base 2, the wall portion 3a of the table receiving portion 3, and the table 4 at least to purge the inside with nitrogen. Is made.

Below the table receiving portion 3, an introduction pipe 9 and a discharge pipe 10 are connected to the peripheral portion of the side so as to face each other. The wall 3a of the table receiving portion 3 is provided with an introduction flow path 7 and a discharge flow path 8, and the introduction pipe 9 and the discharge pipe 10 are connected to the introduction flow path 7 and the discharge flow path 8, respectively. A gas introduction port 5 and a gas discharge port 6 for introducing a purging gas are provided on the inner surfaces of the table receiving section 3 which face each other, and the table receiving section 3 is provided from the introduction flow path 7 and the discharge flow path 8, respectively. Introduces or discharges gas into or from.

Next, the operation of the clean box purging device 1 will be described with reference to FIG. 5 (a), 5 (b) and 5 (c) are diagrams showing an operation sequence of the clean box purge device 1. FIG. 5A shows a state immediately after the clean box 11 is placed on the clean box purge device 1 in the standby state.
In the clean box purging device 1 in the standby state, the flange base 2 is at the lowest position by the lifting mechanism 21.
In this state, the flange base 2 presses the table receiving portion 3 vertically downward, the spring 27 contracts, and the flange base 2 and the table 4 have substantially the same height. When carrying out a semiconductor wafer remounting operation, in this state, as shown in FIG. 5A, the rotary cam plate 101c of the opening / closing lid 11b.
The clean box 11 with the open / close lid 11b facing down on the table 4 so that the pins 31a and 31b are fitted in the
To place. When the clean box 11 is placed on the table 4 in this manner, the edge of the opening of the main body 11a just abuts the seal member 34, and the inside of the clean box 11 is ready to be shielded from the outside.

Subsequently, the motor gear 43 shown in FIG. 4 is rotated to move the frame 45, and the clean box holding pusher 46 pushes the shaft 28b of the clean box retainer 28 to bring down the arm 28a in the upright state until it falls. Body part 11 of the clean box 11
A is fixed as shown in FIG. Further motor gear 4
When 3 rotates, when the latching gear 41 is rotated by a rotatable angle (90 degrees in the case of this embodiment) which is a predetermined angle, the pins 31a and 31b push against the wall surface of the peripheral hole 101c to rotate the cam plate 101. To rotate. Latch member 1
03 and the respective tip ends 103a of the latch members 104
The tip 104a and the tip 104a are retracted from around the opening / closing lid 11b and released from the main body 11a. From here, if the latching gear 41 is rotated more than the rotatable angle of the rotary cam plate 101, the rotary cam plate 101 cannot rotate.
The pins 31a and 31b are pressed against the wall of the peripheral hole 101c and fixed by friction. Thereby, the opening / closing lid 11b can be fixed to the table 4. Then, from this state, the flange base 2 is moved up by the elevating mechanism 21 to the highest position. Then, as the flange base 2 moves up, the spring 27 extends and the table receiving portion 3 gradually moves up and moves. Eventually, as shown in FIG. 5C, the flange base 2 separates from the table receiving portion 3 and rises. Since the main body portion 11a of the clean box 11 is fixed by the clean box retainer 28, the main body portion 11a moves up along with the flange base 2 and moves to the highest position, and then stands by. And
Perform semiconductor wafer remounting work.

After the semiconductor wafer remounting work is completed, the procedure opposite to the above procedure is performed from the state of FIG. 5C, that is, the flange base 2 is moved down. When the flange base 2 descends until it contacts the upper end surface of the wall portion 3a of the table receiving portion 3, the state shown in FIG. 2 is obtained. Here, if the flange base 2 is pressed to the upper end surface of the table receiving part 3 to some extent, a sealed state between the flange base 2 and the table receiving part 3 is secured, and the main body part 11a of the clean box 11, the flange base 2 and the table receiving part 3 are secured. Part 3 and lid 1
A closed space required for purging at least the inside with nitrogen gas is formed between 1b and 1b. In this state, the opening / closing lid 11b is located below the gas inlet 5 and the gas outlet 6, and the gas inlet 5 and the gas outlet 6 communicate with the closed space (the gas inlet 5 and the gas outlet). The outlet 6 is open). Here, the gas to be purged (for example, nitrogen gas or dry air) is introduced from the introduction pipe 9 and exhausted from the discharge pipe 10. The atmosphere filled in the clean box 11 is replaced with nitrogen gas after a lapse of a predetermined time. The pressure of the gas after replacement is preferably 0.05 MPa to 0.15 MPa higher than atmospheric pressure in order to prevent dust from entering the inside of the clean box 11 from the outside. When it is confirmed that the nitrogen gas has been replaced by a predetermined amount, the flange base 2 is further lowered, so that the gas inlet 5 and the gas outlet 6 are blocked by the opening / closing lid 11 and the table 4. When the flange base 2 is further lowered, the gas introduction port 5
And the gas outlet 6 are located outside the hermetically closed space by cutting off the communication with the hermetically sealed space (the gas inlet 5 and the gas outlet 6 are closed)
To do. Then, the opening / closing lid 11b is fitted into the opening of the main body 11a. Therefore, the motor gear 43 is rotated to fix the opening / closing lid 11b to the main body 11a, and the clean box holder 28 is released. The clean box 11 can be removed from the table 4 and moved to the next step.

The gas inlet 5 and the gas outlet 6 are shown in FIG.
It can be an elongated hole as shown in (a). In this case, in order to efficiently introduce the nitrogen gas into the closed space, it is advisable to dispose the blockage 50 inside which the gas introduced from the introduction pipe 9 collides once. By doing so, the gas introduced from the introduction pipe 9 once diffuses in the longitudinal direction of the hole of the gas introduction port 5 in the blockage 50 as shown by the chain double-dashed line in FIG. It is efficient because it is introduced from the mouth 5 into the closed space. The gas inlet 5 may be a set of many holes as shown in FIG. 6 (b). In this case, without arranging the blockage,
Since gas collides with the wall between the holes, an efficient diffusion effect can be expected.

An opening / closing mechanism 30 arranged on the upper surface of the table 4.
It is desirable to provide a rubber lining on the outer circumference of the pins 31a and 31b. As a result, due to the friction of the rubber, the pins 31a and 31b can be firmly fixed to the engaging means of the opening / closing lid 11b. For example, as shown in FIG. 2, when the seal member 11c of the opening / closing lid 11b of the clean box 11 sticks too firmly to the main body portion 11a of the clean box 11, the rotation of the rotary cam plate 101 is prevented. Although it may be difficult to remove the opening / closing lid 11b only by the pressing force of the pin by rotating the opening / closing mechanism 30 over the possible angle, the opening / closing lid 11b can be naturally removed by applying the rubber lining. It is advantageous. In this embodiment, the engaging means is a peripheral hole, and the pin is attached to the engaging means. However, the rotating cam plate 101 is engaged with the rotating cam plate 101 so that the rotating cam plate 101 can be rotated, and the opening / closing lid 11b is provided. The shape is not limited to the peripheral hole and the pin as long as the can be fixed. For example, a simple round hole and pin shape may be used.

Further, in the above-mentioned embodiment, in the present specification, the closed space to the extent that the inside can be purged with nitrogen means, for example, that nitrogen gas is introduced from the gas introduction port 5 to the inside and the gas is discharged to the outside from the gas discharge port 6. In the step of, a closed state is also meant to the extent that the internal pressure can be maintained higher than the external pressure during the work of closing the opening / closing lid 11b. Therefore, it does not necessarily mean a state of a closed space that is high enough to keep the inside vacuum for a predetermined time. That is, it is a concept including a sealed state in which the internal pressure can be maintained higher than the external pressure within a certain time. The state where the internal pressure can be maintained higher than the external pressure is a certain period of time until the pressure becomes the same as the external pressure when the space is filled with purge gas. Is meant to guarantee the degree to which you need. By ensuring at least this degree of hermeticity, the amount of gas required for purging is reduced and the time required for purging is also reduced.

In the above embodiment, the table 4 is fixed to the pedestal 22, and the wall 3a of the table receiving portion 3 is positioned such that the inner surface of the opening / closing lid 11b is located above the gas inlet and the gas outlet. Down to the wall or the wall 3a
Rises until the inner surface of the opening / closing lid 11b is located below the gas inlet 5 and the gas outlet 6 to disconnect (close) or seal the communication between the gas inlet 5 and the gas outlet 6, respectively. It is characterized by communicating (opening) with the space. However, instead of fixing the table 4 to the pedestal portion 22, the table 4 can be moved up and down by a motor or the like, and then the table receiving portion 3 and the flange base 2 are fixed to the pedestal portion 22, so that the table 4 is opened and closed. Rises until the inner surface of the table is located above the gas inlet 5 and the gas outlet 6, or the table 4 descends until the inner surface of the opening / closing lid 11b is located below the gas inlet 5 and the gas outlet 6. By doing so, the same effect can be obtained by disconnecting (closing) or connecting (opening) the gas inlet 5 and the gas outlet 6 to and from the closed space. That is, the wall portion 3a of the table receiving portion 3 or the table 4 is relatively movable until the inner surface of the opening / closing lid 11b is positioned above the gas inlet port 5 and the gas outlet port 6, respectively. 4 is the lid 11
The same effect can be obtained if the inner surface of a can be relatively moved until it is located below the gas inlet 5 and the gas outlet 6.

[0023]

The present invention has the following effects. (1) Since the open / close operation of the clean box and the nitrogen purge can be performed in series, it is possible to perform the nitrogen purge after ensuring high cleanliness. In particular, during the purging operation, the gas inlet for purging and the gas outlet are located above the opening / closing lid, so that dust adhering to the opening / closing lid can be prevented from being wound up on the semiconductor wafer side. (2) Since the open / close work of the clean box and the nitrogen purge can be performed in series, the work time can be shortened. (3) Since the open / close operation of the clean box and the nitrogen purge can be performed in series, programming is possible. Also,
As a result, it becomes easy to manage the time after the flange base descends to create a closed space. (4) The conventional method requires two devices, the open / close device for the clean box and the nitrogen purging device. However, according to the present invention, both processes can be processed by the same machine, and the device is unified. It is possible to further reduce the installation area.

[Brief description of drawings]

FIG. 1 is a diagram showing an entire clean box purging device of the present invention.

FIG. 2 is a view showing a cross section of a clean box in the clean box purging apparatus of the present invention in a finely refined state.

FIG. 3 is a view showing a cross section of a table portion of the clean box purging device of the present invention.

FIG. 4 is a view showing a mechanism unit for opening and closing the clean box of the clean box purging device of the present invention. Here, FIG. 4A shows its upper surface and FIG. 4B shows its side surface.

FIG. 5 is a diagram showing an outline of an operation sequence of the clean box purging device of the present invention. Here, FIG.
FIG. 5A is a state in which a clean box is placed, and FIG.
Shows a state in which the main body portion and the opening / closing portion of the clean box are fixed to the table, respectively, and FIG. 5C shows a state in which the main body portion is separated from the opening / closing lid.

FIG. 6 is a diagram showing an example of a gas introduction port of the clean box purge device of the present invention. Here, FIG. 6A shows a gas inlet of a long hole type, and FIG. 6B shows a gas inlet of a multi-hole type.

FIG. 7a is a view showing a cross section of the clean box of the present invention as seen from the side surface.

FIG. 7b is a view of the opening / closing lid of the clean box of the present invention viewed from the outside (lower side).

[Explanation of symbols]

1 Clean box purging device 2 flange base 3 table receiving part 4 tables 5 gas inlet 6 gas outlets 7 Introduction channel 8 discharge channels 9 introduction pipes 10 discharge pipe 11 clean box 11a main body 11b Open / close lid

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shinichi Kadowaki             1-13-1, Nihonbashi, Chuo-ku, Tokyo             -In DC Inc. F-term (reference) 5F031 CA02 DA08 EA14 EA20 FA01                       FA15 MA17 NA02 NA04

Claims (10)

[Claims] 1. A clean box provided with a main body having an opening on the lower side, a shelf for closing the opening from the lower side and having a shelf for storing a semiconductor wafer on the inner surface, and an engaging means on the outer surface. A purging device for purging, a table for engaging the engaging means to mount the opening / closing lid, a flange base for supporting the main body portion in contact with an end portion of an edge of the opening, A wall portion that is capable of contacting the lower surface of the flange base and whose inner surface is located outside the side surface of the table, and that has a gas inlet port and a gas outlet port on the inner surface; The table is relatively movable until the inner surface of the opening / closing lid is located above the gas introducing port and the gas discharging port, and the wall portion or the table has the inner surface of the opening / closing lid as the gas introducing port and the gas introducing port. Until it is located below the gas outlet A purging device characterized in that it can be relatively moved by. 2. The purging apparatus according to claim 1, wherein the wall portion is moved by lowering until the inner surface of the opening / closing lid is positioned above the gas inlet port and the gas outlet port. The purging device is characterized in that the movement is performed by raising the wall portion until the inner surface of the opening / closing lid is positioned below the gas inlet port and the gas outlet port. 3. The purging device according to claim 1, wherein the table is moved by raising the inner surface of the opening / closing lid to a position above the gas inlet and the gas outlet. The purging device is characterized in that the table is moved by being lowered until the inner surface of the opening / closing lid is positioned below the gas inlet and the gas outlet. 4. The purging device according to claim 1, wherein the wall portion forms a closed space between the main body portion, the flange base, the wall portion, and the table. . 5. The purging device according to claim 1, wherein the wall portion is biased upward by a spring, and the flange base resists the force of the spring. The purging device is characterized in that it is possible to urge the lowering of the portion, and the wall portion can be raised by the force of the spring. 6. The purging device according to claim 1, wherein the gas discharge port is an elongated hole. 7. The purging device according to claim 1, wherein the gas outlet has a plurality of holes. 8. The purging device according to claim 1, wherein the flange base can be raised until the lower side of the main body is higher than the uppermost part of the shelf. apparatus. 9. The purging device according to claim 1, wherein the opening / closing lid is rotatable by a predetermined angle about an axis in a direction perpendicular to the surface of the opening / closing lid, and from the center. The table is provided with a rotary cam plate having a hole at a distant position and a latch member for releasing the engagement in association with the rotation of the rotary cam plate, and the table is rotated about an axis in a direction perpendicular to the surface of the table. An opening / closing mechanism having a pin that can be inserted into the hole, the latch member disengages from the main body by rotating the opening / closing mechanism by the predetermined angle, and A purging device characterized in that the table is fixed to the opening / closing lid by rotating the table by the predetermined angle or more. 10. The purging device according to claim 9, wherein:
A purging device characterized in that the pin has a rubber coating.