JPH07235508A - Treatment apparatus - Google Patents

Abstract

PURPOSE:To provide the treatment apparatus capable of detecting the deformation of a wafer boat holding workpieces (wafers) popping, etc., of the workpieces. CONSTITUTION:Within the treatment apparatus wherein a plurality of workpieces (W) are shifted to a wafer boat 10 which is contained in a treatment chamber 12 for heat treatment, for example, an abnormality detecting sensor 68 comprising e.g. a distance sensor is arranged above the wafer boat 10. Next, the periphery of the sensor 68 is irradiated with e.g. laser beams in the long direction thereof to detect the reflected beams thereby enabling the deformation of the wafer boat 10 or the popping, etc., of the workpieces (W) to be detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing apparatus for heat-treating semiconductor wafers and the like, and more particularly to a processing apparatus capable of detecting deformation of a wafer boat and protrusion of a semiconductor wafer.

[0002]

2. Description of the Related Art Generally, in a manufacturing process of a semiconductor integrated circuit or the like, an oxide film is formed on a semiconductor wafer to be processed, a thin film is formed by a thermal CVD method, and an impurity concentration region is formed by a thermal diffusion method. Various processing devices are used for this purpose.

As a type of these various processing apparatuses, instead of the conventional horizontal type in which the processing furnace is arranged in the horizontal direction,
A vertical processing device in which a processing furnace is erected is often used. In this type of vertical heat treatment apparatus, in order to improve the processing efficiency, a large number of wafers, for example, about 100 wafers are stacked at equal intervals on a wafer boat made of, for example, quartz, and each wafer boat is formed into a substantially cylindrical shape. The wafer is subjected to various kinds of processing by being inserted into a vertical processing chamber (process tube) and being heated in a processing chamber under a predetermined processing gas.

As shown in FIG. 7, the wafer boat has two
The columnar quartz end plates 2 and 2 are connected at their peripheral portions by, for example, four support rods 4A to 4D made of quartz, and each support rod 4A to 4D is provided with a predetermined length along its length direction. It is configured by forming a large number of wafer supporting grooves 6 having a width capable of accommodating the peripheral portion of the wafer W at intervals. Each wafer W has a wafer supporting groove 6 formed at the same horizontal level.
It is supported by inserting and removing the peripheral edge portion of the transfer arm 8 from the horizontal direction.

[0005]

By the way, each time the wafer boat 10 is subjected to heat treatment, the temperature of the wafer boat 10 is raised and lowered repeatedly. Therefore, the wafer boat 10 is made of quartz having high heat resistance. However, the wafer boat itself is deformed due to long-term use. This deformation particularly appears in the form of bending deformation of the supporting rods 4A to 4D which are weak in strength, and the heat treatment temperature is about 110 as in the heat diffusion.
It becomes more prominent as the temperature is increased to as high as 0 ° C.

Further, this type of wafer boat 10 has
For example, wet cleaning with a cleaning liquid is performed regularly or irregularly to remove a film or the like attached to the wafer. However, the wafer boat itself may be deformed by repeating this kind of cleaning operation. .

When the wafer boat 10 is deformed in this way, the wafer support grooves 6 formed on the support rods 4A to 4D are partially different in pitch, or the support rods are deformed to cause the wafer support grooves 6 to be deformed. The position shifts in the horizontal direction, and as a result, the relative position with respect to the transfer arm 8 shifts, which makes it difficult to carry the wafer W in and out of the wafer boat 10, and holds the wafer sufficiently in the wafer support groove 6. In some cases it could not be done. In particular, when the deformation is severe, the arm 8 and the wafer boat 10 interfere with each other to damage the arm 8 during wafer transfer, or in the worst case, the wafer boat 10 itself is tilted to damage the wafer boat and the wafer. There was also the problem of doing it.

Even when the wafer boat 10 is not deformed, when the wafer boat 10 on which the wafers W are stacked is moved by the boat elevator or the boat transfer, the wafer W is not supported by the wafer support groove of the wafer boat 10 due to vibration or the like. Wafer W after jumping out of 6
In some cases, the wafer W cannot be transferred smoothly or the wafer W is damaged due to a transfer error.

As a related technique, Japanese Patent Laid-Open No. 4-658 is known.
As disclosed in Japanese Patent Laid-Open No. 55-55, there is disclosed a technique for detecting the installation posture of a boat by laser light to prevent the damage and the like. However, in this technique, the deformation of the boat itself, the protrusion of the wafer, etc. are not accurate. I can't figure it out.

The present invention focuses on the above problems,
It was created to solve this effectively. An object of the present invention is to provide a processing apparatus that can detect deformation of a holding body that holds an object to be processed, protrusion of the object to be processed, and the like.

[0011]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention transfers a plurality of objects to be processed to a holder and stores the transferred objects to be processed in a processing chamber. In a processing device that heat-treats this, an abnormality detection sensor section for detecting the displacement of the holding body or the holding state of the object to be processed is provided.

[0012]

Since the present invention is constructed as described above, the abnormality detection sensor unit, for example, a laser beam is provided along the longitudinal direction on the outer peripheral portion of the holding body with or without the object to be processed. By radiating light and detecting the reflected light, the deformation of the holder and the holding state of the object to be processed, for example, the presence or absence of this protrusion is detected.

In this case, by using, for example, a distance sensor as the sensor unit, when there is a deformed portion of the holding body or a protrusion of the object to be processed, the laser beam is reflected at that portion, and as a result, Since the distance shorter than the reference distance in the normal state is detected, it is possible to recognize the deformation or the protrusion. In particular, by providing this sensor section on the carry-in / carry-out side for carrying in and carrying out the object to be processed with respect to the holding body,
It is possible to almost certainly recognize the protrusion of the object to be processed.

Furthermore, by arranging a plurality of abnormality detecting sensor portions along the circumferential direction of the holder in this way, it is possible to almost certainly recognize the deformation of the holder in any direction. it can.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a processing apparatus according to the present invention will be described below in detail with reference to the drawings. 1 is a schematic sectional view of a processing apparatus according to the present invention, FIG. 2 is a layout view showing a layout relationship between a holder and an abnormality detection sensor section in a holder housing chamber, FIG. 3 is a partially enlarged view of the holder, and FIG. FIG. 5 is a diagram showing a planar arrangement state of the abnormality detection sensor unit, FIG. 5 is an explanatory view for explaining abnormality detection when the holding body is deformed, and FIG. 6 is abnormality detection when the object to be processed jumps out of the holding body. It is an explanatory view for explaining.

The processing apparatus of the present invention includes a process tube 12 which is a processing chamber for performing a predetermined process on a semiconductor wafer W which is an object to be processed, and a large number of, for example, 100 wafers W for the process tube 12. A load lock chamber 12 having an insertion / removal mechanism 14 for inserting / removing the stored wafer boat 10 and a wafer in which unprocessed wafers or processed wafers are arranged in parallel in the load lock chamber 12. A holder housing chamber 16 for waiting the boat 10;
A wafer transfer chamber 18 for transferring wafers between the wafer boat 10 that is provided in parallel in the holder housing chamber 16 and is on standby and a cassette C that can accommodate a plurality of wafers, for example, 25 wafers Parts are made up.

A front automatic door 20 is provided between the holder housing chamber 16 and the transfer chamber 18 and the load lock chamber 12.
And a rear auto door 22 are provided so as to be openable and closable, respectively, and these front and rear auto doors 20, 22 are provided.
When is closed, the inside of the holding body accommodating chamber 16 is maintained in a sealed state. In this holder housing chamber 16,
A vacuum pipe 24 connected to a vacuum pump (not shown) is connected, and N connected to an N ₂ gas supply source (not shown) is connected.
_{The 2} gas introduction pipe 26 and the N ₂ gas discharge pipe 28 are connected to each other. Therefore, the inside of the holder housing chamber 16 can be replaced with a vacuum atmosphere or an N ₂ gas atmosphere.

Process tube 1 constituting the above processing chamber
Reference numeral 2 denotes a vertical substantially cylindrical quartz container having an inverted U-shaped cross section. A heater 30 is provided on the outer periphery of the process tube 12 so as to surround it, and a cooling pipe is further provided on the outer periphery thereof. Protective cover 3 with built-in insulation
2 is coated. A manifold 34 made of, for example, stainless is connected to the lower end of the opening of the process tube 12. The manifold 34 has a cylindrical shape with upper and lower flanges, and as shown in FIG. 1, a peripheral wall portion of the manifold 34 is provided with a gas introducing pipe 36 for introducing a predetermined processing gas into the process tube 12 and a post-processing. The exhaust pipes 38 for exhausting the gas are connected respectively. In this case, the gas introduction pipe 36 is connected to a predetermined gas supply source and a N ₂ gas supply source via a gas switching valve (not shown), and introduces the processing gas and the N ₂ gas into the process tube 12 as necessary. You can do it.

[0019] The load lock chamber 12, for example either a stainless steel panel for circumferential welding, or O-ring seal has a sealed closed structure at its upper and lower suitably not shown in position, for example N ₂ The N ₂ gas introduction pipe 40 and the N ₂ gas discharge pipe 42 connected to the gas supply source are connected to each other, so that a predetermined amount of N ₂ gas is constantly supplied into the load lock chamber 12 to create a controlled atmosphere. The loading / unloading mechanism 14 arranged in the load lock chamber 12 is composed of a boat elevator 10A for mounting and holding the wafer boat 10 and a ball screw 10B for moving the boat elevator 10A up and down. In this case, since the load lock chamber 12 does not need to be in a vacuum state, it is not necessary to give the panel forming the load lock chamber 12 high rigidity. Therefore, the ball screw 10B of the insertion / removal mechanism 14 may be fixed to the wall of the load lock chamber 12 instead of being self-supporting.

A transfer mechanism 44 for transferring the wafer boat 10 between the insertion / removal mechanism 14 and the holding body accommodating chamber 16 is disposed on the side of the insertion / removal mechanism 14. The transport mechanism 44 is provided outside the load lock chamber 12 for horizontal rotation (turning) and ascending / descending drive unit 44A.
And a multi-joint arm 44B connected to the rotary shaft of the drive unit 44A and located inside the load lock chamber 12, and the arm 44B holds and transfers the wafer boat 10. The load lock chamber 12
An auto shutter 46 that opens and closes the openings of the load lock chamber 12 and the process tube 12 is provided at the furnace opening provided in the upper part of the.

On the other hand, in the transfer chamber 18, a mounting table 48 for mounting a cassette to be carried in from the outside, is located between the mounting table 48 and the holding body accommodating chamber 16,
A wafer transfer 50 that transfers the wafer W between the cassette C on the mounting table 48 and the wafer boat 10 in the holder housing chamber 16 is arranged. This table 48
The plurality of, for example, four cassettes C can be arranged vertically or horizontally. The wafer transfer 50 is composed of a transfer arm 8 which is rotatable and expandable.
And a wafer elevator 52 for moving it vertically.
The transfer chamber 18 and the holder housing chamber 1
The wafer is held by the transfer arm 8 and the front door 20 for partitioning the wafer 6 is opened.
A loading / unloading door 56 for loading / unloading the cassette C to / from the outside is airtightly provided on the partition wall 54 partitioning the transfer chamber 18 so as to be opened / closed. The partition wall 54 is not shown. N ₂ gas supply tube 5 for connecting the N ₂ supply source
8 and an exhaust pipe 60 connected to an exhaust pump (not shown) for exhausting the internal atmosphere.

On the other hand, the wafer boat 10 for accommodating a large number of wafers W has, for example, two disk-shaped quartz end plates 2 and 2 separated by a predetermined distance as shown in FIGS. It is constituted by connecting four support rods 4A to 4D made of quartz, and is made of quartz in its entirety to have heat resistance. The end portions of the support rods 4A to 4D are connected to the peripheral portion of the end plate 2 and the two support rods 4A and 4D located on the side for loading / unloading the wafer W, that is, the loading / unloading port 62 side, It is separated by a distance slightly smaller than the diameter of the wafer to be housed, and in a direction opposite to the direction in which the other support rods 4B, 4C are provided, and slightly separated from the center G when the wafer is placed. It is located. And in each support rod 4A-4D,
Wafer supporting grooves 6 formed at the same horizontal level are formed at equal pitches along the length direction as many as the number of wafers to be mounted (see FIG. 3). Therefore, when the wafer is properly placed with the orientation flat 64 of the wafer facing the support rods 4B, 4C, the wafer is prevented from falling out of the wafer support groove 6. The groove width of each wafer support groove 6 is formed to be slightly wider than the wafer thickness so that a vertical error at the time of transfer by the transfer arm 8 can be absorbed to some extent. The wafer boat 10 thus formed is mounted on the boat mounting table 16 with the loading / unloading port 62 facing the wafer transfer 50 side of the transfer chamber 18 in the holder housing chamber 16.

When the wafer boat 10 is heated and cooled repeatedly every time the wafer is heat-treated and is subjected to a large thermal stress, the boat itself is deformed due to long-term use and the above-mentioned inconvenience occurs. There is. Therefore, the holder housing chamber 16 is provided with an abnormality detection sensor section 68 for detecting the deformation of the boat and the wafer holding state.

Specifically, this abnormality detection sensor unit 68
2 and 4, as shown in FIGS. 2 and 4, above the wafer boat 10 installed on the boat mounting table 66 and at a position slightly outside the peripheral portion of the end plate 2, the circumferential direction thereof is A plurality of them are arranged at a predetermined interval along. Each sensor unit 68 is fixed to a sensor mounting member 70 that is provided horizontally extending above the boat from the side wall of the storage chamber.
In the illustrated example, four detection sensor units 68A to 68D are arranged at the portions corresponding to the support rods 4A to 4D in order to detect the deformation of the support rods 4A to 4D, and the wafer loading / unloading port. A pop-out detection sensor portion 68E for mainly detecting the pop-up of the wafer is disposed on the side, and five sensor portions are provided as a whole. The number of the sensor units 68 is not limited to this, and may be larger or smaller than this. In this case, at least the pop-out detection sensor unit 68E for detecting the pop-up of the wafer
It is preferable to provide two or three or more including the above, and it is also preferable to provide them corresponding to the position of the support rod in order to detect the displacement of the rod early. As the detection sensor unit 68, it is preferable to use a laser distance sensor capable of accurately detecting the distance to a reflecting object by reflecting the laser light and detecting the reflected light. With this sensor, for example, a wavelength of 670 nm is used. By radiating the laser beam, the distance to the reflecting object can be measured with an accuracy of about 2 μm. Therefore, each sensor unit 68 has a laser emitting unit 7 for reflecting the laser light.
2A and a laser light receiving portion 72B for receiving the reflected laser light are paired, and the laser light is efficiently reflected below the boat mounting table 66 and vertically below the detection sensor portions 68A to 68E. For reflectors 74A-7
4E are provided. Therefore, the distance between the detection sensor unit 68 and the reflection plate becomes a reference distance, and for example, due to the deformation of the support rod or the protrusion of the wafer, these interrupt the laser optical path and become an obstacle to the laser light. When the laser light is reflected, the detection distance is shortened, so that it is possible to judge whether the rod is deformed or the wafer pops out. In this case, in order to detect this only when the rod is displaced beyond the allowable value of the displacement amount of the support rod or the protrusion amount of the wafer or when the wafer protrudes, each sensor unit 68 has its laser optical path. The wafer boat, which has no displacement, is positioned and provided so as to pass a position located outside by the above-mentioned permissible value with respect to the position set on the boat mounting table 66 as a reference. Normally, the error range in which the transfer arm 8 can be transferred smoothly without failing to remove the wafer, and the arm can be moved without interfering with the wafer boat is, for example, about 2 mm. The supporting rods 4A to 4D corresponding to the respective sensor units 68 are located at positions where the displacement of the supporting rod of 2 mm can be detected.
Alternatively, the distance to the edge of the reference wafer is determined. still,
In this embodiment, the reflectors 74A to 74A for the laser light are used.
Although E is provided, the laser light may not be reflected under normal conditions without providing E. According to this, the reference is at the infinite distance.

The outputs of the detection sensor units 68A to 68E are output from the distance determining unit 7 including, for example, a microcomputer.
6, the distance to the reflecting object is obtained based on the time from the laser emission to the reflected light input.
This result is input to the processing unit 78. When the reflected light is not detected, the distance is infinite. In the processing unit 76, it is determined whether the wafer is popping out or the support rod is deformed based on the above detection result. If the wafer is popping out, the number of the wafer popping out from the top or the bottom. The warning system 80 warns and displays this result on the warning display unit 80, and immediately stops the wafer transfer drive system, for example, the drive system 82 of the wafer transfer 50. The processing unit 78 includes
In order to obtain the protruding position of the wafer and the displacement of the support rod, necessary information such as the height level of each wafer under normal conditions and position information in the height direction of the support rod is stored in advance.

Next, the operation mode of the present embodiment configured as described above will be described. First, the overall flow of the object to be processed will be described. The loading / unloading door 56 of the transfer chamber 18 is opened, and the cassette C containing the unprocessed wafer W is placed on the placing table 48. The mounting table 48 has a structure in which, for example, four cassettes C can be arranged in the vertical direction or in the horizontal direction, and the number of wafers that can be accommodated in one wafer boat can be mounted. Further, the transfer chamber 18 is filled with an N ₂ gas atmosphere to prevent the formation of a natural oxide film on the wafer surface.

Next, the wafer boat 1 is placed in the holding chamber 16.
In the state where 0 is accommodated, the front automatic door 20 on the carry-in / out side of the holder housing chamber 16 is opened to communicate the holder housing chamber 16 and the transfer chamber 18. In this state, the wafers 50 in the wafer carrier C on the mounting table 48 are transferred to the wafer boat 10 in the holding chamber 16 by the wafer transfer 50, and a predetermined number of wafers W, for example, 100 wafers W are transferred to the wafer boat 10. After being housed, the front automatic door 20 is closed to make the inside of the holding body housing chamber 16 airtight. Then, the inside of the holding body accommodating chamber 16 is evacuated to a predetermined vacuum pressure state, or the wafer boat 10 and the wafer W are completely shielded from the atmosphere by N ₂ flow at normal pressure, N ₂ flow at reduced pressure, or the like. Thus, formation of a natural oxide film on the wafer W is prevented.

When the inside of the holding body accommodating chamber 16 is evacuated for a predetermined time as described above, N ₂ gas is introduced into the holding body accommodating chamber 16 so that the N ₂ gas is always introduced. The rear auto door 22 is opened in the same atmosphere as the lock chamber 12. Then, the transfer mechanism 44 is driven to drive the wafer boat 10 in which the wafers W in the holder storage chamber 16 are stored.
Are transferred and held on the boat elevator 10A.

Next, the boat elevator 10A rises, the wafer boat 10 is inserted into the process tube 12, and the lid 84 of the boat elevator 10A abuts on the lower end flange of the manifold 34 to cause the process tube 12 to come into contact.
The inside is sealed. Then, the N ₂ gas in the process tube 12 is discharged using the exhaust pipe 38, and when the inside of the process tube 12 reaches a predetermined vacuum degree, the gas introduction pipe 36
Then, the processing gas is introduced to perform the desired processing.

After the processing is completed, the processing gas in the process tube 12 is discharged using the exhaust pipe 38, and when the inside of the process tube 12 reaches a predetermined vacuum degree, N ₂ gas is introduced by the gas introduction pipe 36. To do. Thereafter, when the pressure of the N ₂ gas is the same as the pressure of N ₂ gas of the load lock chamber 12, the wafer boat 10 is lowered to take out the processed wafers W in the loading procedure in reverse.

Therefore, the transfer chamber 18 and the load lock chamber 12
Since the holding body accommodating chamber 16 is disposed between the transfer chamber 18 and the process tube 12, the unprocessed wafer W loaded into the process tube 12 is constantly exposed to an inert gas atmosphere that is shielded from the atmosphere. Formation of a native oxide film on the surface is prevented.

By the way, when the heat treatment as described above is repeatedly performed, the wafer boat 10 made of quartz is deformed due to thermal stress due to repeated heating and cooling. Further, such deformation of the wafer boat also occurs due to repeated boat cleaning, particularly wet cleaning.
Furthermore, when the wafer boat 10 is moved by the insertion / removal mechanism 14 or the transfer mechanism 44, the wafer W may be ejected from the wafer boat 10 by a slight distance due to the vibration of the movable part, etc. Induces misprints.

In order to detect such a state in advance,
A plurality of abnormality detection sensor units 68 are arranged in the holder housing chamber 16. In the holding body accommodation chamber 16, the wafer boat 1 mounted at a predetermined position on the boat mounting table 66.
Laser light L from each laser emission section 72A of each abnormality detection sensor section 68A to 68E provided above the outer periphery of 0.
A is emitted, and the reflected light is received by the laser light receiving portion 72B.

Here, all the wafers W are wafer boats 1.
When the wafer boat 10 itself is normally held without jumping out from 0, and the wafer boat 10 itself is not displaced or deformed more than the permissible amount, as shown in FIG.
.. 68E (only some of the sensor parts are shown as representatives in FIG. 5) laser light LA corresponding to a reflecting plate 74A installed below the boat without being reflected by obstacles on the way.
Reflected at ~ 74E. The distance determination unit 76 calculates the distance according to the time from the emission of the laser light to the reception of the reflected light, and the processing unit 78 substantially determines the calculated distance from the previously stored distance between the sensor unit and the reflector. If they are the same, it is determined to be normal.

Further, due to the heat stress, the wafer boat 10
If the support itself is deformed, for example, as shown in FIG. 5A, the support rods 4A to 4D are bent and deformed slightly in one direction, but the upper end plate 2 of the wafer boat 10 is horizontally displaced. In this case, the abnormality detection sensor portion located in the displacement direction, for example, the laser light LA from the sensor portion 68D is reflected by the upper end plate 2, or is bent and deformed outward to the support rod 4A. The laser light LA from 68A is reflected, and as a result, the distance obtained by these reflected lasers is smaller than the reference distance, so the processing unit 78 recognizes that it is in an abnormal state and displays an alarm. The unit 80 is notified of that fact, an error is displayed, an alarm is issued to the operator, and a stop command is output to the drive system 82 of the wafer transfer 50 to transfer the wafer. 0 to stop the drive of. As a result, the transfer arm 8 of the wafer transfer 50 interferes with the wafer boat 10 and the wafer boat 10 falls over.
Alternatively, it is possible to prevent the wafer transfer error from occurring due to the deformation of the wafer boat 10.

Further, the peripheral edge of the wafer W is not sufficiently fitted into the wafer support groove 6 of the support rod 4A due to a transfer error during transfer by the transfer arm 8 or vibration during transfer of the wafer boat. When this slightly protrudes to the carry-in / carry-out port side, the peripheral edge of the wafer WA from which the laser beam LA emitted from the projecting detection sensor portion 68E provided on the carry-in / carry-out port 62 side of the boat projects as shown in FIG. It will hit the part and be reflected. Since the distance L1 between the detection sensor unit 68E and the protruding wafer WA is obtained based on the reflected light, the processing unit 78 recognizes how many wafers are protruding from above or below. As a result, the alarm display section 80 is instructed to issue an alarm and the information about the popped-out wafer WA is displayed, and at the same time, the drive system 82 of the wafer transfer 50 receives the information. Give an instruction to stop driving. As a result, the operator manually performs an appropriate recovery operation. The detection sensor unit 68
It goes without saying that the deformation of the wafer boat can also be detected by E.

The inspection by the detection sensor unit 68 as described above can be performed whenever necessary when the wafer is accommodated in the wafer boat or not accommodated therein. Immediately before transferring the wafer, when the transfer of the wafer to the boat is completed, the inspection is performed immediately before transferring the processed wafer from the boat.

As described above, when the wafer boat itself is deformed by the heat stress and the cleaning caused by heating and cooling, or when the wafer is jumping out of the wafer boat due to the vibration of the wafer boat, this should be properly detected. You can Therefore, the transfer arm 8 and the wafer boat 10 do not interfere with each other when the wafers are transferred due to the deformation of the wafer boat itself, so that the wafer boat 10 falls and a very expensive boat or a wafer that has been mounted. Etc. or the transfer arm 8 made of alumina, SiC or the like can be prevented from being damaged. Furthermore, since the jumping out of the wafer can be detected,
It is possible to prevent a transfer error such as a pinch failure at the time of transferring a wafer and prevent damage to the wafer and the like.

The wafer W pops out or the wafer boat 1
The amount of protrusion or the amount of deformation that can be tolerated when 0 is deformed is determined by the allowable error range in which the transfer arm 8 can properly transfer the wafer. In the present embodiment, as described above, the amount of protrusion or the amount of deformation is 2 mm. The mounting position of each detection sensor unit 68 is determined so that it can be detected if it occurs. Further, by providing the plurality of detection sensor units 68, when the wafer boat itself is deformed, it is possible to easily recognize in which direction the wafer boat is deformed, and maintenance can be easily performed. .

In the above embodiment, the processing apparatus provided with the transfer chamber 18, the holder housing chamber 16 and the load lock chamber 12 has been described as an example, but an apparatus for housing a large number of wafers in a wafer boat to perform heat treatment. Then, all can be applied. Further, in this embodiment, a plurality of wafer boats are provided and the wafer is transferred in a portion other than directly below the process tube 12, for example, in the holding chamber 16, but directly below the process tube 12. In the case of a processing apparatus of the type in which wafers are transferred in the load lock chamber, the abnormality detection sensor unit 68 described above is arranged in this load lock chamber. In this case, since the abnormality detection sensor unit 68 is arranged above the wafer boat, the sensor unit interferes with the wafer boat when the wafer boat is loaded / unloaded from / to the process tube. To avoid this, the sensor mounting member 70 (see FIG. 2) that holds the detection sensor unit 68 may be configured to be movable, for example, in the horizontal direction so that it can be retracted.

Further, in the present embodiment, the vertical type processing device in which the process tube is erected has been described as an example, but the present invention is not limited to this and is similarly applied to a horizontal type processing device in which the process tube is arranged in the horizontal direction. be able to. Furthermore, although a distance sensor that reflects laser light is used as the abnormality detection sensor unit, any sensor may be used as long as it can detect the presence or absence of an obstacle with good directivity, for example, ultrasonic waves are used. Sensors can also be used.

Further, although the present invention has been described by taking a semiconductor wafer as an example of the object to be processed, it can be applied to other objects to be processed, for example, a processing apparatus such as a glass substrate or an LCD substrate.

[0043]

As described above, according to the processing apparatus of the present invention, the following excellent operational effects can be exhibited. For example, since an abnormality detection sensor unit including a distance sensor can be provided to detect the displacement of the holding body that holds the object to be processed and the protrusion of the object to be processed, a transfer error is eliminated, and the cost of the holding body to fall is high. The damage to the holder and the damage to the object to be processed can be significantly suppressed. By providing a plurality of the abnormality detection sensor portions along the circumferential direction of the holding body, it is possible to reliably grasp the deformation of the holding body in any direction. Further, by providing the abnormality detection sensor unit on the carry-in / carry-out port side where the object to be processed is carried in and out, it is possible to reliably grasp the protruding of the object to be processed from the holder.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a processing apparatus according to the present invention.

FIG. 2 is a layout diagram showing a layout relationship between a holder and an abnormality detection sensor section in a holder accommodating chamber.

FIG. 3 is a partially enlarged view of a holder.

FIG. 4 is a diagram showing a planar arrangement state of an abnormality detection sensor unit.

FIG. 5 is an explanatory diagram for explaining abnormality detection when the holder is deformed.

FIG. 6 is an explanatory diagram for explaining abnormality detection when the object to be processed jumps out of the holder.

FIG. 7 is a diagram showing a general state when a semiconductor wafer is transferred onto a wafer boat.

[Explanation of symbols]

 2 End Plates 4A to 4D Support Rods 6 Wafer Support Grooves 8 Transfer Arms 10 Wafer Boats (Holders) 12 Process Tubes (Process Chambers) 14 Insertion / Removal Mechanisms 16 Holder Hold Chambers 18 Transfer Chambers 50 Wafer Transfers 52 Wafer Elevators 62 Carry-in / carry-out port 68 Abnormality detection sensor unit (distance sensor) 72A Laser light emitting unit 72B Laser light receiving unit 74A to 74E Reflector plate 76 Distance determining unit 78 Processing unit 80 Warning display unit 82 Drive system C cassette LA Laser light W Semiconductor wafer (processing target) body)

Claims (4)

[Claims] 1. A processing apparatus in which a plurality of objects to be processed are transferred to a holder, and the transferred objects to be processed are accommodated in a processing chamber and subjected to heat treatment. A processing apparatus comprising an abnormality detection sensor unit for detecting a holding state of a processing body. 2. The abnormality detection sensor unit comprises a distance sensor that detects an abnormality by emitting a laser beam in the length direction of the holder and detecting a reflected light. Processing equipment. 3. The processing apparatus according to claim 1, wherein a plurality of the abnormality detection sensor units are arranged at predetermined intervals along the circumferential direction of the holder. 4. The processing apparatus according to claim 1, wherein the abnormality detection sensor unit is arranged on a loading / unloading side of the object to be processed with respect to the holder.