JPH06302679A - Material-to-be-treated conveying box and treating apparatus - Google Patents

Abstract

PURPOSE:To prevent adhesion of the atmosphere, gaslike impurity, etc., to a material to be treated by carrying in/carrying out of a treating apparatus without exposing the material to be treated to the atmosphere by providing a cover to be switched to be opened or closed for maintaining an inert gas atmosphere in a box for detachably containing the material to be treated by blocking the box in a sealed state. CONSTITUTION:A material-to-be-treated conveying box 9 contains a cassette 11 for containing to hold many semiconductor wafers 5 in a parallel state and is conveyed. The box 9 has a box body 12, a cover 14 for blocking the body 12 in a sealed state through a sealing material 13 at a bottom and to be operated to be opened or closed, and a normally closed inert gas vent valve 15 at a sidewall. The wafers 5 contained in an N2 gas atmosphere are placed on the cover 14 of the box 9, covered with the body 12, inner N2 gas is suitably sucked by the valve 15, and sealed. Thus, the wafers 5 contained in the cassette 11 can be conveyed to a treating apparatus without exposure to the atmosphere.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an object transfer box and a processing apparatus used in, for example, a semiconductor device manufacturing process.

[0002]

2. Description of the Related Art In a semiconductor process, various kinds of processes such as forming an oxide film on a semiconductor wafer as an object to be processed, forming a thin film by a thermal CVD method, forming a high impurity concentration region by a thermal diffusion method, etc. The processing device is performed. Recently, a vertical heat treatment apparatus has been widely adopted for these various kinds of processing.

In this vertical heat treatment apparatus, a cassette (a cage-shaped carrier) in which a large number of semiconductor wafers are aligned and stored
When the wafer is carried into the main body of the equipment by the transfer device, the cassette is placed on the transfer stage in the main equipment by the transfer, and the semiconductor wafers in the cassette are transferred one by one or five by the transfer machine. Each of them is transferred to the wafer boat in the loading area and held in a multi-stage state, and then the wafer boat is lifted up by the boat elevator to carry the semiconductor wafer into the process container, and the process container is sealed to a predetermined processing gas atmosphere. Then, the semiconductor wafer is subjected to required processing by heating while being replaced with.

The processed semiconductor wafer is pulled out from the inside of the process container together with the wafer boat, and then returned to the carrier on the transfer stage by the transfer machine, and the carrier is taken out of the apparatus main body through the loading / unloading port. It is carried out to the next processing equipment.

In the processing operation in such a heat treatment apparatus, when a semiconductor wafer is inserted into or removed from a process container, there is a considerably high temperature atmosphere even in the vicinity of the furnace opening on the way. A natural oxide film is formed on the surface of the semiconductor wafer due to O ₂ therein.
If gaseous impurities such as carbon and particulate impurities such as oil mist and dust are present in the main body of the device, these impurities may adhere to the semiconductor wafer or cause chemical reaction (chemical contamination), and This causes deterioration of device characteristics and yield.

For this reason, the apparatus main body has a closed system structure, and an inert gas such as N ₂ gas is supplied by a gas supply / discharge means so that a positive pressure high-purity inert gas atmosphere (non-oxygen atmosphere) is always provided. It is desired to remove impurities such as air (O ₂ ) and particles from the inside of the main body of the apparatus by substituting and maintaining the above).

[0007]

However, even if the inside of the apparatus main body is replaced with an inert gas atmosphere such as N ₂ gas as described above, the atmosphere (O ₂ ) along with the semiconductor wafer carried in from the outside is maintained. In particular, a large number of semiconductor wafers, which are aligned and housed in a basket-like cassette, are exposed to the atmosphere during transportation to the main body of the apparatus, and narrow gaps between the wafers and gas impurities and particles (particles) are likely to be small. Impurities enter the gap and are brought into the device body as they are. It is difficult to remove these impurities, and a large amount of N ₂ purge gas is required, which is uneconomical and time consuming, leading to a decrease in processing efficiency.

The present invention has been made in view of the above circumstances and can be carried in and out of a processing apparatus in an inert gas atmosphere without exposing an object to be processed such as a semiconductor wafer to the atmosphere. It is an object of the present invention to provide an object-to-be-processed transfer box and a processing apparatus which are effective in preventing O ₂ ), gaseous impurities and particulate impurities (particles) from adhering to an object to be processed and entering the processing apparatus. To do.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the object transporting box of the present invention has a box main body in which the object to be processed is detachably inserted, and the box main body is sealed. A lid that can be opened and closed to close the inside of the box to maintain an inert gas atmosphere is provided, and the object to be processed is stored in the box body, and the lid is closed to keep the inside of the box body in the inert gas atmosphere. It is characterized in that it is configured to be carried in and out of the processing device.

On the other hand, the processing apparatus according to the present invention has a door that opens and closes inside and outside the processing apparatus main body which is replaced and maintained in an inert gas atmosphere, and the object transfer box according to claim 1 can be carried in and out from the outside. And a gas supply / discharge means for replacing the inside of the pass box with an inert gas, and a lid removing mechanism for automatically opening and closing the lid of the object transfer box within the pass box in an inert gas atmosphere. And a transfer means for transferring the object to be processed in the object transfer box to the inside of the apparatus main body.

By using the object transfer box and the processing apparatus having the above-described structure, the object such as a semiconductor wafer can be transferred while being stored in the inert gas atmosphere in the object transfer box without exposing to the atmosphere, Only the outside door of the object transport box is received in the pass box of the processing apparatus.

Although the atmosphere temporarily enters the pass box, the outer door is closed in the same manner as the inner door, and the inert gas is supplied into the pass box by the gas supply / exhaust means so that the atmosphere and the object are covered. Impurities that have adhered to the outer surface of the processed product transport box are expelled. Since the pass box has a small capacity, and the object transfer box has a simple outer shape with no irregularities, it is possible to increase the temperature from the atmosphere by supplying a relatively small amount of gas from the gas supply / discharge means. Can be quickly replaced with a pure inert gas atmosphere.

In this way, with the inside of the pass box replaced with the inert gas atmosphere, the lid of the workpiece transfer box is opened by the lid removing mechanism, and only the inside door of the pass box is opened, and the inside of the pass box is opened. The object to be processed in the object-to-be-processed transfer box is transferred to the processing chamber in the main body of the processing apparatus, which is maintained in the inert gas atmosphere, by the transfer means to perform the required processing operation. The processed object is stored in the inert gas atmosphere in the object transfer box in the pass box and carried out to the next processing step in the reverse order of the above.

Thus, the object to be processed can be carried in and out of the processing apparatus in an inert gas atmosphere without exposing it to the atmosphere, and the atmosphere (O ₂ ) and gaseous impurities and particulate impurities (particles) can be carried out. It is possible to easily and surely prevent the above) from adhering to the object to be processed and entering the inside of the processing apparatus.

Further, in the processing apparatus of the present invention, the object transfer box according to claim 1 is bonded to the object transfer box of the processing apparatus main body, which is replaced and maintained in an inert gas atmosphere, in an airtight state from the outside. With a box holding mechanism to, and in normal times the processing object carry-in / out port is closed from the inside, and the processing object carrying box is joined to the processing object carry-in / out port,
A lid-removing door mechanism for removing the lid of the box and opening the inside of the processing apparatus main body together, and a transfer means for transferring the object to be processed in the object transfer box into the apparatus main body. Characterize.

If this processing apparatus and the above-described object transfer box are used, when the object transfer box is sent while the object is stored in the inert gas atmosphere as described above, The box holding mechanism directly joins the object transfer box to the object inlet / outlet of the processing apparatus body in an airtight state, and in this state, the lid removal door mechanism inside the apparatus body removes the lid of the object transfer box. Open the inside of the processing unit together. As a result, the inside of the processing object transfer box and the inside of the processing apparatus main body are in communication with each other while being isolated from the atmosphere, and the processing object inside the processing object transfer box is directly transferred to the processing chamber inside the processing apparatus main body by the transfer means. And perform the required processing work. As a result, the same effect as the above can be obtained, and the pass box can be omitted.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of an object carrying box and a processing apparatus according to the present invention will be described below with reference to FIGS. Here, a vertical heat treatment apparatus used as an oxidation apparatus or a CVD apparatus for forming an insulating film on a semiconductor wafer is exemplified.

FIG. 1 is a vertical sectional view of a vertical heat treatment apparatus,
2 is a horizontal sectional view taken along the line AA of FIG. 1, FIG. 3 is a sectional view taken along the line BB of FIG. 1, FIG. 4 is a longitudinal sectional view taken along the line CC of FIG. 1, and FIG. It is the schematic which shows the gas control system of the whole processing apparatus.

First, as shown in FIGS. 1 to 4, the vertical heat treatment apparatus according to this embodiment has an apparatus main body 1. The apparatus main body 1 has a box-shaped structure using a housing panel 1a, and its front part faces the clean room 2 in the factory, and most of the other parts are installed in a maintenance room 4 separated by a partition wall 3. Has been done.

A processing chamber 6 for performing a predetermined process on a thin disk-shaped semiconductor wafer 5 as an object to be processed is defined by a partition wall 7 in a substantially upper half portion of the apparatus main body 1, and this process is performed. The loading area 8 is N directly below the chamber 6.
It is constructed with airtightness so that it can be replaced and maintained in an inert gas atmosphere such as ₂ gases. Further, a pass box 10 for inserting / removing an object transfer box 9 containing a semiconductor wafer 5 is provided on the front surface of the apparatus main body 1.

To describe the details of the respective parts, first, as shown in FIG. 1 to FIG. 3, the object transport box 9 is a cassette (a basket-like) which holds and holds a large number of semiconductor wafers 5 which are objects to be processed in parallel. A box body 12 having a hat shape of an appropriate size with an open bottom surface, and a lid 14 joined to the bottom surface of the box via a sealing material 13, which is used for carrying the carrier 11. The side wall of the main body 12 is provided with a normally closed inert gas vent valve 15.

By injecting an inert gas such as N ₂ gas through the ventilation valve 15, the entire interior can be replaced and maintained with an inert gas atmosphere, and the inert gas inside can be sucked out from the ventilation valve 15. By setting the inside to an appropriate negative pressure state, the lid 14 is adsorbed to the box body 12 via the seal member 13 to be blocked and held, and the inert gas is supplied from the ventilation valve 15 to release the negative pressure state. By pulling the box body 12 upward, the box body 12 is opened apart from the lid 14, and in this state, the cassette 11 containing the semiconductor wafer 5 can be inserted and removed, and the semiconductor wafer 5 in the cassette 11 can be inserted and removed. There is.

The pass box 10 is a small (small-capacity) vertically elongated box body integrally assembled with the front housing panel 1a of the apparatus main body 1, and has front and rear portions (inside the processing apparatus main body 1). The automatic doors 20 and 21 that are opened and closed in a sliding manner are provided in and. Each of the automatic doors 20 and 21 has its own opening / closing drive unit, which can be opened alternately and at the same time can be hermetically closed by a seal member to hermetically seal the entire interior. When the outside auto door 20 is opened, the object transfer box 9 containing the semiconductor wafer 5 is opened.
Can be smoothly inserted / removed / stored in the pass box 10 by an appropriate transfer means from the outside, and the inside of the automatic door 21 allows the pass box 10 to internally communicate with the loading area 8 in the processing apparatus body 1. There is.

The pass box 10 is connected to a gas introduction pipe 24 and an exhaust pipe 25 as gas supply / discharge means for replacing the inside of the box with an inert gas. This gas introduction pipe 24 is provided with a valve 26 and a regulator 2 as shown in FIG.
It is connected to the inert gas supply device 28 via 7, and N ₂ gas, for example, as an inert gas can be introduced into the pass box 10 from the gas introduction pipe 24. On the other hand, the exhaust pipe 25 is connected to a factory exhaust device 30 with a suction blower via an automatic damper 29 so that the gas in the pass box 10 can be sucked and exhausted.

The pass box 10 is provided with a lid removing mechanism 33. The lid removing mechanism 33 includes an elevating air cylinder 34 standing on the upper plate of the pass box 10.
An opening / closing air cylinder 35 supported at the lower end of the piston rod, and a pair of left and right clamp arms 36 supported at both ends of the piston rod of the opening / closing air cylinder 35.
And the left and right clamp arms 36 approach each other by the opening and closing air cylinders 35 in the inert gas atmosphere in the pass box 10 to grip the box body 12 of the object transfer box 9 from the left and right, By pulling the box body 12 upward by the lifting air cylinder 34, the box body 12 is opened apart from the lid 14 at the lower end.

The lid removing mechanism 33 has a valve operating portion 37 in the form of a protrusion at the lower end of one of the left and right clamp arms 36.
And the left and right clamp arms 36 when opening the lid.
At the same time as grasping the box main body 12 of the object-to-be-processed box 9, the valve operating section 37 pushes open the normally closed inert gas ventilation valve 15 of the box main body 12, so that the inside of the object-to-be-processed box 9 is appropriately opened. By setting the pressure to the same atmospheric pressure as that in the pass box 10, the lid 14 for the box body 12
Is designed to be released.

On the other hand, a vertical process container 41 is installed in the processing chamber 6 in the upper half of the processing apparatus main body 1. The process container 41 is a heating furnace called a process tube formed of, for example, quartz, and has an inverted U-shaped cross section, that is, a vertical substantially cylindrical shape with an upper end closed.
The heater 4 surrounds the outer periphery of the process container 41.
2 is provided, and the periphery thereof is covered with a protective cover 43 incorporating a cooling pipe, a heat insulating material and the like.

A manifold 44 is connected to the lower end of the opening of the process container 41. The manifold 44 is in the shape of a rectangular cylinder with upper and lower flanges. As shown in FIG. 2, an exhaust pipe 45 with an automatic damper 45a for exhausting the gas in the process container 41 is connected to the peripheral wall portion, and the tip of the exhaust pipe 45 is attached. It is led out of the apparatus body 1 and connected to the factory exhaust device 30. Further, a gas introduction pipe 46 for introducing new gas into the process container 41 via the manifold 44 is provided. The tip of the gas introduction pipe 46 is led out of the apparatus main body 1, and
As shown in FIG. 3, a predetermined process gas (process gas) supply device 48 and the inert gas device 2 are provided via an automatic switching valve 47.
8 and the N ₂ gas as the inert gas can be alternately introduced into the process container 41.

Further, around the manifold 44 under the process container 41, an annular chamber-shaped scavenger 51 is constituted by the partition wall 7 and a square dish-shaped case 51a fixed to the lower surface thereof. A heat exhaust pipe 52 that constantly discharges heat and unnecessary gas accumulated around the lower part of the process container 41 is led out, and its tip is led out of the apparatus main body 1 and connected to the factory exhaust device 30. A branch pipe 54 with an automatic damper 54a is provided in the processing chamber 6 in the middle of the heat exhaust pipe 52.

The case 5 of the scavenger 51
The central portion of the bottom surface of 1a is opened so as to communicate with the lower end of the manifold 44, and constitutes the furnace opening 41a of the process container 41. An auto shutter 56 is installed in the loading area 8 to close the furnace opening 41a from the lower surface side in an airtight state via an O-ring. The automatic shutter 56 is moved up and down and rotated laterally by the opening / closing drive unit 57 to open / close the furnace opening 41a.

In the loading area 8, a wafer boat 61 and a boat elevator 62 are installed as a loading mechanism for inserting / removing the semiconductor wafer 5 into / from the process container 41 of the processing chamber 6. This wafer boat 6
Reference numeral 1 denotes a vertically-oriented quartz-shaped wobble, which has a structure in which a large number of semiconductor wafers 5 are stored and held in multiple stages in a horizontal state with vertical intervals.

The wafer boat 61 is vertically supported by the boat elevator 62 just below the furnace opening 41a of the process vessel 41. This wafer boat 61
In the state where a large number of semiconductor wafers 5 are accommodated, the boat elevator 62 raises and inserts it into the process container 41 with the opening of the shutter 56, and conversely lowers and pulls out from the process container 41. To do. It should be noted that the wafer boat 61 is raised and the process container 41 is raised.
When inserted into the process vessel 41, the flange 61a at the bottom of the wafer boat 61 closes the furnace opening 41a in place of the auto shutter 56, so that the inside of the process container 41 can be sealed.

A transfer machine (wafer transfer) 63 is used as a transfer means for transferring an object to be processed inside the apparatus body between the wafer boat 61 in the loading area 8 and the pass box 10. The elevator 64 is installed so as to be capable of moving up and down. In this transfer machine 63, when the automatic door 21 inside the pass box 10 is opened,
The semiconductor wafers 5 are taken out one by one from the cassette 11 in the open object transfer box 9 located in the pass box 10 and stored and held in the wafer boat 61 in the loading area 8 or vice versa. Boat 6
It serves to return the semiconductor wafer 5 from 1 to the cassette 11.

Further, in order to replace / maintain the inside of the loading area 8 in the apparatus main body 1 with a positive pressure inert gas atmosphere, a gas introduction pipe 71 and an exhaust pipe 7 as gas supply / discharge means.
2 and are provided. The gas introduction pipe 71 is connected to the primary side (suction side) of the blower fan 82 in the middle of the return path 81 installed under the floor of the apparatus body 1 as a gas circulation cooling and purification system described later. The gas introduction pipe 71 is led out of the apparatus main body 1 and is connected to an inert gas supply device 28 via a flow rate adjusting valve 73 and a regulator 74 as shown in FIG. 5, and N ₂ gas as an inert gas is used as the return path. It can be introduced into the loading area 8 via 81. The exhaust pipe 72 is led out from the downstream side in the loading area 8, is equipped with an automatic damper 72a on the way, and is connected to the above-described factory exhaust device 30.

At the time of initial replacement in the loading area 8, the automatic damper 72a is opened to evacuate the loading area 8 by the factory exhaust device 46, and N ₂ gas is introduced at about 200 to 400 liters / min. In the steady state after the replacement, the N ₂ gas introduction amount is set to 50
The auto-damper 72a of the exhaust pipe 72 is closed by squeezing it to about 1 liter / min, and the inside of the loading area 8 is maintained at a proper positive pressure N ₂ gas atmosphere by the clearance exhaust of the loading area 8 or the pressure adjustment damper. ing. The leak gas due to the clearance exhaust is factory exhausted from the branch pipe 54 with the automatic damper 54a of the heat exhaust pipe 52 of the scavenger 51.

The gas circulation cooling and purification system maintains the N ₂ gas atmosphere in the loading area 8 at a high purity and prevents an abnormal temperature rise even when the semiconductor wafer 5 is repeatedly processed. As this system configuration,
First, a return path 81 is provided under the floor of the apparatus body 1 for taking out N ₂ gas from the loading area 13 once to the outside of the system, purifying and cooling it, and then returning it to the loading area 8 again. 82 is installed, a gas purifier 83 is installed on the secondary side of the blower fan 82, and a gas cooler 84 is installed on the secondary side.

The gas purifier 83 is a chemical filter in which a metal getter such as zirconia that absorbs gaseous impurities (moisture, oxygen, hydrocarbons, etc.) is replaceably incorporated according to the application. Further, the gas cooler 84 is a radiator type in which radiating fins are provided on a water-permeable cooling pipe, and has a cooling capacity such that the secondary side blown-out gas temperature becomes 50 ° C. or lower.

A filter 85 that receives the N ₂ gas from the return path 81 and blows it into the loading area 8 is provided on one side surface of the loading area 8. The filter 85 is a vertical-type ULPA grade absolute filter, N together with the ₂ particulate impurities in the gas (particle such as dust) and filtered collecting, one side to the N ₂ gas loading area 8 Blow out into a horizontal laminar flow from. Further, in order to make the horizontal laminar flow state of the N ₂ gas more reliable, a straightening plate 86 having a large number of holes formed on the other side surface in the loading area 8
Is vertically provided so as to face the filter 85, and N ₂ gas is sucked and conducted from the rear surface space 87 to the return path 81 through the straightening plate 86.

A gas shower mechanism 90 is provided above the loading area 8. This gas shower mechanism 90 is connected to the inert gas supply device 28 via the valve 91 and the regulator 27 as shown in FIG. 5, and the case of the scavenger 51 connected to the tip of this gas introduction pipe 92. A special nozzle 94 fixed to the lower surface of 51a via a bracket 93 is provided.

The special nozzle 94 is flat and has a width dimension capable of covering the entire area of the wafers having a diameter of 200 mm and a shape having the landing (running) distance as long as possible, and the wafer boat 61 is inserted into and removed from the process container 41 (loading). (/ Unloading), the N ₂ gas is made to flow horizontally from right next to the lower side of the furnace opening 41a of the process vessel 41 at 50 to 100 liter / min, and the ULPA filter 85 is used.
The wind velocity from the horizontal laminar wind (0.75m /
sec) and the semiconductor wafers 5 held in the wafer boat 61 in multiple stages by this N ₂ shower.
Impurities such as O ₂ and hot air are expelled from each other.

Further, as shown in FIG. 5, gas-conducting pipes 111 and 112 as oxygen concentration detecting means in the loading area 8 and the pass box 10 are provided, and these are a common oxygen concentration meter ( O ₂ sensor) 113
It is connected to the. The oxygen concentration meter 113 has a built-in three-way switching valve and a gas outlet pump, and measures whether the oxygen concentration in the loading area 8 and the pass box 10 is 20 PPm or less.

Further, the controller 11 receives the signal from the oxygen concentration meter 113 and the signal from the pressure sensor 114 for measuring the atmospheric pressure in the loading area 8.
5 are provided. In response to a control command from the controller 115, the automatic dampers 29, 45a, 5
4a, 72a, valves 26, 47, 73, 91, automatic doors 20, 21 and automatic shutter 56, transfer machine 63, boat elevator 62, etc. Has become.

The operation of the vertical heat treatment apparatus and the object transfer box 9 having such a structure will be described. First, since the loading area 8 in the apparatus main body 1 is relatively narrow, it serves as a gas supply / discharge means at the time of initial replacement. The auto-damper 72a of the exhaust pipe 72 is opened to perform exhaust by the factory exhaust device 30, and N ₂ gas is introduced from the gas introduction pipe 71 at about 400 liters / min. Thus relatively less N ₂
The amount of gas supply makes it possible to easily replace the atmosphere with an inert gas.

In the stationary state after the replacement, the N ₂ gas introduction amount from the gas introduction pipe 71 is reduced to a small amount of about 50 liters / min, the auto-damper 72a of the exhaust pipe 72 is closed, and the clearance in the loading area 8 is exhausted. or high enough 0.2MmH ₂ O from moderate positive pressure (clean room 2 pressure within the loading area 8 by the pressure adjustment damper 1MmH ₂ O
Maintained in a N ₂ gas atmosphere of about ₂ ). In addition, the leak gas due to the gap exhaust is the heat exhaust pipe 52 of the scavenger 51.
Factory exhaust is always performed from the branch pipe 54 with the automatic damper 54a.

On the other hand, the pass box 10 is constantly supplied with 50 l / min from the gas introduction pipe 24 as a gas supply / discharge means.
N ₂ gas is continuously introduced, and the inside of the pass box 10 is N ₂ while exhausting so as to be pushed out from the exhaust pipe 25.
Replace with gas atmosphere.

In such a state, first, a large number of semiconductor wafers 5 as the objects to be processed are held in parallel in a cassette in a N ₂ gas atmosphere chamber at a different position and stored, and the lid 14 of the object transfer box 9 is directly stored. The box body 12 is placed on the box body 12, and the inside N ₂ gas is appropriately sucked out from the ventilation valve 15 so as to be in a negative pressure state. In this way, the semiconductor wafer 5 placed in the cassette 11 is transferred to the processing apparatus by an appropriate transfer means such as a robot while being stored in the inert gas atmosphere in the processing object transfer box 9 without being exposed to the atmosphere.

When the object transfer box 9 is transferred, only the automatic door 20 outside the pass box 10 of the processing apparatus is opened to receive the object transfer box 9. As a result, the atmosphere temporarily enters the pass box 10, but the outer auto door 20 is replaced by the inner auto door 21.
In the same manner as described above, the amount of N ₂ gas introduced from the gas inlet pipe 24 is increased to expel the impurities adhering to the atmosphere in the pass box 10 and the outer surface of the object transfer box 9 from the N ₂ gas. Replace with atmosphere.

Since the pass box 19 has a small capacity and the object transfer box 9 has a simple outer shape with few irregularities, a relatively small amount of gas is supplied from the gas introduction pipe 24. Only by doing so, the air and impurities can be surely expelled and the atmosphere can be quickly replaced with a high-purity inert gas atmosphere.

After this, the lid removing mechanism 33 descends, and the left and right clamp arms 36 grip the box body 12 of the object-to-be-processed box 9, and at the same time, the valve operating section 37 vents the normally closed inert gas. The valve 15 is pushed open to bring the inside of the object-to-be-processed box 9 from the negative pressure state to the same atmospheric pressure as the inside of the pass box 10 to release the suction of the lid 14, and then the box body 12 is pulled up and opened.

At this point, the automatic door 21 inside the pass box 10 is opened, the transfer machine 63 as a transfer means extends the hand into the pass box 10, and the transfer machine 63 on the lid 14 of the open object transport box 9 is opened there. The semiconductor wafers 5 in the cassette 11 are taken out one by one to the loading area 8 and transferred to the wafer boat 61.

The large number of semiconductor wafers 5 transferred to the wafer boat 61 are inserted into the process container 41 of the processing chamber 10 by the auto elevator 56 opening and being raised together with the wafer boat 61 by the boat elevator 62. To be done. Then, with the furnace opening 41a closed with the lower flange 61a, the N ₂ gas atmosphere in the process container 41 is exhausted by the exhaust pipe 45, and the process gas is introduced into the process container 41 from the gas introduction pipe 46. The semiconductor wafer 5 is subjected to the required processing by heating the heater 42.

After the process, the process gas in the process container 41 is exhausted through the exhaust pipe 45 and N ₂ gas is supplied from the gas introduction pipe 46 in the reverse order of the above procedure to supply the process gas inside the process container 41. Same N ₂ as in loading area 8
Replace with gas atmosphere. Then, the boat elevator 62 descends and the processed semiconductor wafer 5 is returned to the loading area 8 together with the wafer boat 61. At that time, the automatic door 21 inside the pass box 10 again
Only, the transfer machine 63 is operated, the processed semiconductor wafer 5 in the wafer boat 61 is taken out, and the pass box 1
Return to 0 inside cassette 11.

Then, the automatic door 32 inside the pass box 10 is closed, and the lid removing mechanism 33 is lowered to cover the box body 12 of the object transfer box 9 with the lid 14.
Close up. At this time, the inert gas vent valve 15 is kept open by the valve operating portion 37, and in this state, the N ₂ gas in the pass box 10 is sucked from the exhaust pipe 25 through the auto damper 29 by the suction blower, The inside of the box 10 and the object transport box 9 is set to an appropriate negative pressure state (atmospheric pressure of about 760 mmH ₂ O).

After that, the lid removing mechanism 33 opens the box body 12 and moves up to close the ventilation valve 15,
The inside of the pass box 10 is returned to normal pressure again. As a result, the inside of the object transport box 9 is in a negative pressure state rather than the surroundings, so that the lid 14 is suction-held to the box body 12 and the closed state is maintained.

In this state, only the automatic door 20 outside the pass box 10 is opened, and the object transfer box 9 is opened.
While the processed semiconductor wafer 5 is stored in the internal N ₂ gas atmosphere via the cassette 11, the semiconductor wafer 5 is properly taken out by the carrying means and carried out to the next processing step or the like.

As described above, the semiconductor wafer 5 can be carried in and out of the processing apparatus from the outside in an inert gas atmosphere without exposing the semiconductor wafer 5 to the atmosphere, and the atmosphere (O ₂ ) and gaseous impurities and particulate impurities can be carried out. It becomes possible to easily and surely prevent (particles) from adhering to the semiconductor wafer 5 and entering the inside of the processing apparatus, and the total consumption of the inert gas can be reduced, and the cost can be reduced. In addition, the inside of the loading area 8 can be maintained in a high-purity inert gas atmosphere at a positive pressure, and a natural oxide film is generated during loading / unloading of the semiconductor wafer 5 into the process container 41 and impurities in the semiconductor wafer 5 are generated. It greatly helps to suppress the adhesion and chemical reaction.

As the semiconductor wafer processing operation described above is repeated, gaseous impurities such as carbon are generated in the N ₂ gas atmosphere in the loading area 8, and particulate impurities such as oil mist and dust (particles) are generated. )
Occurs or the process container 4 is opened by opening the furnace opening 41a.
There is a possibility that the N ₂ gas atmosphere in the loading area 8 will rise due to the release of hot air from inside 1 or the radiant heat from the processed semiconductor wafer 5 heated to a high temperature (about 1000 ° C.).

However, while the clean N ₂ gas is continuously supplied as the purge gas from the gas introduction pipe 71 as described above, the gas circulation cooling and purification system is constantly operated, and the N ₂ gas in the loading area 8 is mixed with the impurities. The blower fan 82 once makes the return passage 81 pass through the straightening plate 86, and the gas purifier 83 absorbs gaseous impurities (moisture, oxygen, hydrocarbons, etc.), and the N ₂ gas Through the gas cooler 84 at 50 ° C
Cooling is performed as follows, and further, particulate impurities (particles such as dust) in the N ₂ gas are collected by filtration with an ULPA grade absolute filter 85.
Since the N ₂ gas is blown into the loading area 8 from one side in a horizontal laminar flow state to be refluxed, the N ₂ gas atmosphere in the loading area 8 is maintained at a high purity and an abnormal temperature rise occurs. To be prevented.

Further, at the time of loading / unloading the wafer boat 61 into / from the process vessel 41 (load / unload), the gas shower mechanism 90 is operated, and the N ₂ gas from the special nozzle 94 is rapidly moved to the vicinity of the lower side of the furnace opening 41a. Impurities such as O ₂ and hot air between the semiconductor wafers 5 that are horizontally held in a multi-stage manner on the wafer boat 61 are expelled by the N ₂ shower blown out in a horizontal flow right from the side.

As a result, when the semiconductor wafer 5 is inserted into or removed from the process container 41, gaseous impurities such as carbon or particulate impurities (particles) such as oil mist or dust are attached or chemical reaction (chemical contamination) is caused. ), The deterioration of the characteristics and yield of the semiconductor element is not caused.

Next, a second embodiment of the processing apparatus of the present invention will be described with reference to FIG. In the figure, the same components as those shown in FIGS. 1 to 5 are designated by the same reference numerals to simplify the description.

In this embodiment, the processing apparatus main body 1 of the vertical heat treatment apparatus has a front-rear width dimension larger than that of the above-described embodiments, and in addition to the above-described structure, a plurality of cassettes 11 for storing objects to be processed are provided inside. This is a configuration including a cassette stock stage 120 that can be kept on standby.

That is, in the processing apparatus main body 1, a substantially upper half of the rear portion is partitioned by the partition wall 7 as a processing chamber 6 for performing a predetermined process on the semiconductor wafer 5 as the object to be processed as described above. The area directly below is a loading area 8, and the front side of the processing chamber 6 and the loading area 8 is an area (I / O area) 1 for loading and unloading objects to be processed.
It is said to be 21.

A pass box 10 similar to the above is installed in the front part of the inside / outside area 121 for loading and unloading of the object to be processed, and the cassette transfer 122 is provided immediately behind the pass box 10.
The cassette stock stage 120 is installed so as to be able to move up and down via 23, and a cassette stock stage 120 is provided in the upper half part thereof. The cassette stock stage 120 has multiple stages (for example, a configuration having four upper and lower cassette storage shelves 120a,
The semiconductor wafer 5 together with the cassette 11 is taken in from the inside of the pass box 10 by the cassette transfer 122 and placed.

Also, this cassette stock stage 12
Directly below 0, a transfer stage 124 is supported by a stand 125 of an appropriate height and arranged in two upper and lower stages, and the cassettes 11 are taken out from the cassette stock stage 120 by a cassette transfer 122 on the respective upper surfaces. It is designed to be placed. A large number of semiconductor wafers 5 in the cassette 11 placed on the transfer stage 124 are taken out one by one while the transfer machine (wafer transfer) 63 similar to the above is moved up and down, and the wafer boat 61 in the loading area 8 is taken out. Or transfer it to
On the contrary, the processed semiconductor wafer 5 from the wafer boat 61
Can be returned to the cassette 11 on the transfer stage 124. The other structure is the same as that of the first embodiment.

In the first and second embodiments, the ventilation valve 15 is provided in the box body 12 of the object transfer box 9.
The lid 14 is fusion-held to the box body 12 to maintain the closed state by providing a negative pressure (decompression) through the ventilation valve 15, that is, a vacuum system is used. Although not shown, the box body 12 is provided by a mechanical clamping mechanism or an adsorption method using an electromagnet.
On the other hand, it is also possible to adopt a configuration in which it is held closed so that it can be opened and closed.
By doing so, the ventilation valve 15 can be omitted.

Next, a third embodiment of the present invention will be described with reference to FIG. This embodiment is an example in which the object transfer box 9 is also used as a pass box and the pass box 10 provided in the processing apparatus is omitted.

That is, FIG. 7 is an enlarged sectional view of the front panel portion of the housing panel 1a of the processing apparatus main body 1 of the vertical heat treatment apparatus similar to FIG. 1, and the pass box 10 is omitted. Instead, a processing object loading / unloading port 130 is formed on the front panel portion of the processing apparatus main body 1, a box holding mechanism 131 is provided below the outer surface of the processing object loading / unloading port 130, and the loading / unloading port 130 is provided on the inner surface side. A lid removing door mechanism 140 that is closed from one side is provided.

The box holding mechanism 131 has an air cylinder 133 whose lower end is pivotally attached to the outer surface of the front panel of the processing apparatus main body 1 via a hinge 132, and this air cylinder 13
3 is provided with a support arm 135 which is supported on the upper end of the piston rod and is vertically rotatable about a hinge 134 on the outer surface of the processing apparatus main body 1 as a fulcrum. Then, the object transfer box 9 which is transferred from the outside by an appropriate means is received by the support arm 135, and the box 9 is transferred.
It functions to hold the rear end side of the loading / unloading port 130 in an airtight state.

The object-carrying box 9 used in this embodiment is a laterally oriented box body capable of accommodating a cassette 11 in which the rear end face is opened and a large number of semiconductor wafers 5 as objects to be processed are held in parallel. 12, a lid 14 joined to the open surface with the rear end flange 12a of the box body 12 via a sealing material 13, and a normally-closed inert gas vent valve 15 provided in the center of the lid 14. The configuration is such that the box holding mechanism 131 causes the box body 1
The rear end flange 12 a is joined and held in an airtight state to the peripheral portion of the carry-in / out port 130 of the front panel portion of the processing apparatus body 1 via the sealing material 136, and at this time, the lid 14 on the rear surface is housed in the carry-in / out port 130. It has become.

On the other hand, the lid removing door mechanism 140 has an air cylinder 142 whose upper end is pivotally attached to the inner surface of the front panel of the processing apparatus main body 1 via a hinge 141, and the processing apparatus supported by the lower end of the piston rod of the air cylinder 142. Body 1
A support arm 144 that is vertically rotatable around a hinge 143 of the inner surface of the support fulcrum, and is fixedly supported by the support arm 144.
A flip-up type door 14 that is closely joined and closed via 45
6 and.

Further, the flip-up type door 146 of the lid removing door mechanism 140 is integrally provided with a convex portion 147 at the central portion of the front surface, and the convex portion 147 is the carrying-in / out port 13 described above.
The ventilation valve 15 of the lid 14 of the object transfer box 9 which is housed in 0 is pushed open. The door 146 has an electromagnetic valve 14
8 is provided, which opens when the ventilation valve 15 is opened so that the inside of the object transfer box 9 and the inside of the processing apparatus main body 1 are in communication with each other to eliminate a pressure difference therebetween.
Further, the suction cup 149 is formed on the front surface of the convex portion 147 of the door 146.
And a vacuum suction nozzle 150 are provided.
0 is connected to a suction blower or the like via a hose 151.

The operation of the third embodiment will be described. As described above, a large number of semiconductor wafers 5 as the objects to be processed are accommodated in the object transfer box 9 via the cassette 11, and the box 9 is accommodated therein. The inside is set to a proper negative pressure state of an inert gas (for example, N ₂ gas) atmosphere, and the lid 14 is brought into a sealed state in which the box body 12 is adsorbed and held. In this state, when the object transfer box 9 is properly transferred by the transfer means, the object transfer box 9 is received by the support arm 135 of the box holding mechanism 131, and the air cylinder 133 is pushed up to rotate the object. As shown in FIG. 7, the rear end flange 12a of the box 9 is directly joined to the object loading / unloading port 130 of the processing apparatus main body 1 in an airtight state.

As a result, the lid 14 of the object-to-be-processed transport box 9 is inserted into the carry-in / out port 130, so that the carry-in / out port 130 is closed from the inside until then.
The ventilation valve 15 is pushed open to the convex portion 147 of the. At the same time, the electromagnetic valve 148 is opened, and the workpiece transfer box 9 is opened.
The inside and the inside of the processing apparatus main body 1 are brought into communication with each other to eliminate a pressure difference between them. Further, the suction cup portion 149 on the front surface of the convex portion 147 of the door 146 is joined to the lid 14, and the lid 14 is vacuum chucked by suction from the vacuum suction nozzle 150.

In this state, the cylinder 142 of the lid removing door mechanism 140 is pulled up to open the door 146 together with the lid 14 via the support arm 144 so as to flip up inside the processing apparatus main body 1.

As a result, the inside of the box main body 12 of the object transfer box 9 and the inside of the processing apparatus main body 1 are brought into communication with each other while being isolated from the atmosphere, and the semiconductor wafer 5 in the cassette 11 inside the box main body 12 is kept as it is. Then, it is taken out into the inside of the processing apparatus main body 1 by the transfer machine 63 as a transfer means, transferred to the wafer boat and inserted into the processing chamber as shown in FIG. The processed semiconductor wafer 5 is taken out in the reverse order of the above and is transferred to the next processing step or the like.

Thus, the object to be processed can be carried in and out of the processing apparatus in an inert gas atmosphere without exposing it to the atmosphere, and the atmosphere (O ₂ ) and gaseous impurities and particulate impurities (particles) can be carried out. It is possible to easily and surely prevent the above) from adhering to the object to be processed and entering the inside of the processing apparatus.
Moreover, in this embodiment, the pass box 10 can be omitted.

The configuration of the third embodiment is also applicable to the processing apparatus having the cassette stock stage of the second embodiment shown in FIG. Also in this third embodiment, the ventilation valve 15 of the object transfer box 9 is eliminated, and the lid 14 is openably and closably held by the box body 12 by a mechanical clamping mechanism or an adsorption method using an electromagnet. Also, in the lid removing door mechanism 140, the lid 14 is gripped by a mechanical clamping mechanism or an adsorption method using an electromagnet in addition to performing vacuum lid chucking of the lid 14 with a suction cup portion. It may be configured to open and close together with.

Further, in each of the above-described embodiments, an oxidizer or C for forming an insulating film on the semiconductor wafer 5 as an object to be processed.
Although the vertical heat treatment apparatus used as the VD apparatus has been illustrated, the kind of the object to be processed and the kind of the processing are not particularly limited, and it goes without saying that the processing apparatus may be a processing apparatus that performs another kind of processing. Is. An inert gas other than the above-mentioned N ₂ gas may be supplied depending on the type of these treatments.

[0080]

As described above in detail, by using the object transfer box and the processing apparatus of the present invention, the object such as a semiconductor wafer is exposed to the atmosphere in an inert gas atmosphere without exposing the object to the processing apparatus. It can be carried in and out, and the atmosphere (O
₂ ) and gaseous impurities and particulate impurities (particles) can be prevented from adhering to the object to be processed and entering the processing equipment, reducing the consumption of inert gas and processing the object to the processing chamber. It is very useful for suppressing the generation of a natural oxide film during loading / unloading, the adhesion of impurities to the object to be processed, and the chemical reaction, and it is very economical and can achieve high performance.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a vertical heat treatment apparatus and an object transfer box according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional view taken along the line AA of FIG.

3 is a sectional view taken along the line BB of FIG.

FIG. 4 is a vertical cross-sectional view taken along the line CC of FIG.

FIG. 5 is a schematic diagram showing a gas control system of the entire processing apparatus.

FIG. 6 is a vertical cross-sectional view showing a vertical heat treatment apparatus and an object transfer box according to a second embodiment of the present invention.

FIG. 7 is a vertical cross-sectional view showing a part of a vertical heat treatment apparatus and an object transfer box according to a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Processing apparatus main body, 5 ... Processed object (semiconductor wafer), 6
... processing chamber (41 ... process container), 8 ... loading area, 9 ... object transport box, 10 ... pass box, 11 ... cassette, 12 ... box body, 14 ... lid,
15 ... Vent valve, 20, 21 ... Door, 33 ... Lid removing mechanism,
24, 25 ... Gas supply / discharge means (24 ... Gas introduction pipe, 25 ...
Exhaust pipe), 63 ... Transfer means (transfer machine), 130 ... Processing object loading / unloading port, 131 ... Box holding mechanism, 140 ... Lid removing door mechanism.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tamotsu Tanifuji 1-24-1 Machiya, Shiroyama-cho, Tsukui-gun, Kanagawa Prefecture Tokyo Electron Sagami Co., Ltd. Sagami Business Office

Claims (4)

[Claims] 1. A box main body comprising a box main body for removably accommodating an object to be processed, and an openable / closable lid for hermetically closing the box main body to maintain the inside in an inert gas atmosphere. An object-to-be-processed transfer box, characterized in that the object to be processed is stored in the container, the lid is closed, and the box body is carried into and out of the processing apparatus while maintaining an inert gas atmosphere. 2. A normally closed inert gas vent valve is provided in either the box body or the lid, and the inert gas in the box body is sucked out through the vent valve to make a negative pressure in the body. The object-to-be-processed transfer box according to claim 1, wherein the lid is sucked and held in a closed state. 3. A pass box for accommodating an object transfer box according to claim 1, which has a door that opens and closes inside and outside a processing apparatus main body that is replaced and maintained in an inert gas atmosphere, Gas supply / discharge means for replacing the inside of the pass box with an inert gas, a lid removing mechanism for automatically opening and closing the lid of the object transfer box within the pass box in an inert gas atmosphere, and the object transfer A processing apparatus, comprising: a transfer unit that transfers an object to be processed in a box to the inside of the apparatus main body. 4. A box holding mechanism for joining the workpiece transfer box according to claim 1 in an airtight state from the outside with respect to the workpiece inlet / outlet of the processing apparatus main body which is replaced and maintained in an inert gas atmosphere; Covers the processing object loading / unloading port from the inside, and when the processing object transporting box is joined to the processing object loading / unloading port, removes the lid of the box to open the inside of the processing apparatus body together. A processing apparatus comprising a door mechanism and a transfer means for transferring an object to be processed in the object transfer box to the inside of the apparatus main body.