JP2004253507A - Locally cleaned wafer processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a locally cleaned wafer processing apparatus which can efficiently process a wafer having a different size from the wafer housed in a pod. <P>SOLUTION: The locally cleaned wafer processing apparatus 20 includes a first loading port in which the pod for housing the wafer of a mechanism closely mounted in the apparatus for opening a cover is placed; and a second loading port having a cassette placing base for placing an open cassette containing the wafer, and a window 3 of the size capable of conveying the wafer into the apparatus 20 and having an opening/closing door 3a in the locally cleaned wafer processing apparatus 20 corresponding to the wafer outlet of the open cassette. When the pod is placed in the first loading port, the wafer housed in the pot in the state that the opening/closing door 3a is closed is conveyed. When the open cassette is placed on the cassette placing base, the wafer housed in the open cassette is conveyed in the state that the opening/closing door 3a is opened. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a locally cleaned wafer processing apparatus, and more particularly, to perform a predetermined process on a semiconductor wafer in a device to manufacture a semiconductor or inspect a semiconductor in a local cleaning for locally creating a clean space. In a so-called mini-environment handling system (hereinafter referred to as a mini-en system), it is possible to process a conventional open cassette storage wafer transported in a clean room and a closed pod storage wafer dedicated to the mini environment system. The present invention relates to a locally cleaned wafer processing apparatus capable of efficiently processing wafers having different sizes.
[0002]
[Prior art]
When the wiring pattern formed on the wafer is miniaturized and the process becomes 0.25 μm or more, and when the diameter of the wafer becomes a large diameter of 12 inches (about 300 mm), the influence of foreign matter increases accordingly. To that extent, the yield of the wafer itself and of the chips formed on the wafer is also reduced. Therefore, it is not enough to clean only the room where the conventional semiconductor manufacturing apparatus is installed. No matter how much the cleanliness of the room is increased, there is a limit, so the processing of the semiconductor wafer is performed by the mini-en system.
The local cleaning device is usually a device with a high degree of sealing, and keeps the inside at a positive pressure to prevent foreign matter from entering from the outside. The degree of cleanliness is reduced to about class 0.01. The internal positive pressure is generated by sending clean air into the inside of the air from a fan through a filter.
The loading and unloading of a workpiece to be processed, such as a wafer, into and out of the apparatus is usually carried out in a sealed pod.The pod is independently closed and tightly mounted on the apparatus, and the lid is closed. A FOUP (Front Opening Unified POD), which is an opening mechanism, is provided (see Patent Document 1).
[0003]
FIG. 3 is an external view of the wafer transfer device 10 of the mini-en system. A fan unit 11 for sending air into the apparatus is provided at an upper portion, and a filter for purifying air is provided at a front surface on an air blowing side. 12a and 12b are pods storing 13 or 25 wafers, and are mounted on FOUP openers 13a and 13b.
The pods 12a and 12b have a security cover at an opening on the front side of the apparatus. The lid is opened by each opener when the pods 12a and 12b are mounted on the FOUP openers 13a and 13b.
Here, the work loaded from the pod 12a is unloaded to the original pod 12a after the inspection is completed. Similarly, the pod 12b is loaded from the pod 12b, and the work is unloaded to the original pod 12b. Note that one may be used as a load-side pod and the other may be used as an unload-side pod.
[0004]
FIG. 4 is a schematic diagram illustrating an internal state of the device 10. Reference numeral 14 denotes a wafer handling unit, for example, which takes out a wafer after inspection from the inspection stage 16 and transfers it to the pod 12a, takes out the next inspection wafer from the pod 12a, sends it to the pre-alignment stage 15, and performs pre-alignment. Later, the wafer is transferred to the inspection stage 16.
Incidentally, the inspection stage 16 described above is often provided in an independent wafer inspection device as a local cleaning device. Reference numeral 20 in FIGS. 2 and 3 indicates this case, and the dotted frame portion is the wafer inspection apparatus 20, which is locally cleaned independently. In this case, the above-described wafer transfer device 10 becomes an independent wafer handling device as a local cleaning device, and the wafer handling device 10 docks with the independent wafer inspection device 20. Windows that are opened and closed are provided at the respective docking positions for transferring wafers, and wafers are transferred between the apparatuses through these windows. When each device is independent, each window is closed, thereby ensuring each device confidentiality.
[0005]
On the other hand, conventional wafers of 12 inches (300 mm) or less, for example, 6-inch and 8-inch wafers, are stored in an open cassette, handled and transported in a clean room, and are processed through this open cassette. For example, it is carried into a wafer inspection device. Here, the wafer is taken out of the open cassette by a wafer handling device provided in or near the inspection device and is placed on a table of the inspection device or the like in the device. In this case, the inspection device and the like are not locally cleaned with the above-described cleanliness.
By the way, it has been proposed that a conventional 12-inch wafer stored in an open cassette stored in a clean room and a 12-inch wafer stored in a closed pod dedicated to a mini-en system are processed by a mini-en system.
This is different from the FOUP type local cleaning device in that a clean box for mounting and cleaning an open cassette is provided in front of the local cleaning device to clean an open cassette loaded with 12-inch (300 mm) wafers. After being loaded into a box, it is cleaned with a clean box in a closed state, and an open cassette in the clean box in a closed state is carried into a wafer processing apparatus as a FOUP type (see Patent Document 2).
[0006]
[Patent Document 1]
JP 2001-284428 A [Patent Document 2]
JP, 2002-110762, A
[Problems to be solved by the invention]
However, in the latter local cleaning device using the open cassette in the FOUP system, the system is for a 12 inch (300 mm) used in the FOUP system, and a closed clean box or an equivalent interface is used. Will be needed. Handling of wafers of 12 inches or less, for example, 6-inch or 8-inch wafers, is not considered.
On the other hand, for handling 6-inch or 8-inch wafers, the conventional cassette transfer in a clean room is sufficient, and in particular, cleanliness for cleaning in a closed state is not required. However, apart from processing a 12-inch wafer, it is necessary to separately provide equipment for a wafer processing apparatus for these small-diameter wafers. This leads to increased costs.
Therefore, similarly to Patent Document 2, it is conceivable to process a 6-inch or 8-inch wafer by using a local cleaning device using an open cassette. However, the use of a clean box has a problem of increasing the size of the system. . In addition, cleaning a wafer with a clean box lowers the processing efficiency of 6-inch and 8-inch wafers, and requires switching to the FOUP method when handling both wafers.
An object of the present invention is to solve such a problem of the related art, and can process a conventional open cassette storage wafer for transfer in a clean room and a closed pod storage wafer dedicated to a mini-en system, In particular, it is an object of the present invention to provide a locally-cleaned wafer processing apparatus capable of efficiently processing a wafer having a size different from that of a wafer stored in a pod.
[0008]
[Means for Solving the Problems]
The feature of the locally cleaned wafer processing apparatus of the present invention for achieving such an object is a locally cleaned wafer processing apparatus for processing a wafer while maintaining the inside of the apparatus at a positive pressure with respect to an external pressure.
A first load port, on which a pod storing wafers is mounted, of a mechanism which is securely mounted on the apparatus and the lid is opened, a cassette mounting table on which an open cassette storing wafers is mounted, and a wafer pick-up of the open cassette; A second load port having an opening / closing door provided in the local cleaning wafer processing apparatus corresponding to the outlet and having a window having a size capable of carrying a wafer into the apparatus;
When the pod is mounted on the first load port, the wafer stored in the pod is loaded with the opening / closing door closed, and when the open cassette is mounted on the cassette mounting table, the opening / closing is performed. The door is opened and the wafer stored in the open cassette is carried in.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
As described above, according to the present invention, since the first load port for the FOUP type pod and the second load port for the open cassette are provided, both the wafers can be mounted without providing a special switching mechanism. Can be processed by the same mini-en system.
When the wafer is processed at the second load port, the opening / closing door is opened. However, no problem occurs because the mini-en system side is at a positive pressure and does not drop below the cleanness of the open cassette. .
In particular, by storing a wafer different from the inch size of the FOUP system in the open cassette of the second load port, it is possible to easily process a conventional wafer having a different size of 6 inches or 8 inches.
As a result, in the mini-en system, it is possible to process the wafer even in the open cassette, and it is possible to easily store a wafer having a different inch size in the open cassette and easily process the wafer in the local cleaning process capable of processing the wafer. Can be realized.
[0010]
【Example】
FIG. 1 is an external view of a wafer transfer apparatus according to an embodiment to which a locally cleaned wafer processing apparatus according to the present invention is applied, and FIG. 2 is an open cassette mounting apparatus for mounting an open cassette accommodating wafers having different inch sizes. It is explanatory drawing of a mounting table. In each of the drawings, the same components are denoted by the same reference numerals, and description thereof will be omitted.
In FIG. 1, reference numeral 1 denotes a wafer transfer device of the mini-en system, which corresponds to the wafer handling device (or the transfer device 10) shown in FIGS. 3 and 4, but the FOUP opener 13b side is connected to the open cassette mounting table 13. Has been replaced. A window frame (opening) 3 is provided behind the open cassette mounting table 13 similarly to the case of the FOUP opener 13b, and an opening / closing door 3a provided in the window frame 3 opens and closes. ing. The opening / closing door 3a is a door that opens and closes by moving up and down, and its opening / closing mechanism is provided below the window frame 3 inside the wafer transfer device 1, but is not shown in the drawing. The size of the opening of the window frame 3 corresponds to or larger than the opening for taking in and out the wafer from the open cassette storing the largest size wafer.
Although the design of the FOUP opener 13a is changed in FIG. 1 in accordance with the open cassette mounting table 13, the function is the same as that in FIG. The FOUP opener 13a is provided with the moving plate 2 for bringing the pod 12a placed on the FOUP opener 13a into close contact with the window frame of the FOUP opener 13a.
The internal configuration of the wafer transfer apparatus 1 is the same as that shown in FIG. 4, and the description thereof is omitted. However, the FOUP opener 13a and the open cassette are a loader and an unloader, respectively.
[0011]
As shown, the position of the open cassette receiving surface of the open cassette mounting table 13 substantially matches the receiving surface of the pod 12a of the FOUP opener 13a. Then, loader plates 2a and 2b having a thickness corresponding to the moving plate 2 of the FOUP opener 13a are mounted according to the open cassettes storing the respective 8-inch and 6-inch wafers.
FIG. 2 is an explanatory diagram showing the relationship between the loader plates 2a and 2b and the open cassette mounting table 13.
FIG. 2A shows a state where the loader plate is not mounted. As shown in FIG. 2A, the open cassette mounting table 13 receives an open cassette 18a of 12-inch wafer indicated by a dotted line. Three pins 17a, 17b, 17c are planted at the positions of the vertices of an inverted triangle whose one side is parallel to the window frame 3. Further, a switch 4 for detecting a cassette is provided between the pin 17a and the pin 17b, and an operation member 4a thereof protrudes.
Openings 6a and 6b are provided on the front side of the open cassette mounting table 13 on both front sides of the pins 17a and 17b, and a photo sensor 7a embedded in the open cassette mounting table 13 is provided behind these openings 6a and 6b. , 7b are fixed. Light from the light emitting elements of the photosensors 7a and 7b is projected through openings 6a and 6b, respectively, and reflected light from the object is received by the light receiving elements of the photosensors 7a and 7b to detect the mounting of a specific plate. Is done.
FIG. 2B shows a state in which the loader plate 2 a of an 8-inch wafer is mounted on the open cassette mounting table 13. In this case, since there is no specific plate and the open cassette 18a is directly mounted on the open cassette mounting table 13, the photosensors 7a and 7b do not receive reflected light, and no detection signal is generated from them.
The loader plate 2a is a plate detachably mounted on the open cassette mounting table 13 via the pins 17a, 17b, 17c, and is, for example, a rectangular plate made of aluminum. The open cassette 18b for the 8-inch wafer is indicated by a dotted line. The loader plate 2a is provided with holes 8a, 8b, 8c fitted to the pins 17a, 17b, 17c corresponding to the pins 17a, 17b, 17c, and provided with a hole 9 through which the operating element 4a of the cassette detecting switch 4 passes. ing. Further, a hole 9a through which light from the photosensor 7a passes is opened corresponding to the position of the photosensor 7a. The light from the photo sensor 7b has no hole in the loader plate 2a and is blocked by the hole. As a result, the photosensor 7a does not receive the reflected light and thus does not generate a detection signal, but the photosensor 7b receives the reflected light from the loader plate 2a and generates a detection signal.
Reference numeral 19 denotes a cassette guide claw for easily and detachably fixing the open cassette to a fixed position.
[0012]
FIG. 2C shows a state in which the loader plate 2b of a 6-inch wafer is mounted on the open cassette mounting table 13.
The loader plate 2b is a plate that is detachably mounted on the open cassette mounting table 13 via the pins 17a, 17b, and 17c, like the loader plate 2a, and is a rectangular plate made of aluminum. The open cassette 18c for 6-inch wafers is shown by a dotted line.
The loader plate 2b is provided with holes 8a, 8b, 8c that fit into the pins 17a, 17b, 17c, respectively, and a hole 9 through which the operator 4a of the cassette detection switch 4 is provided. However, the hole 9a is not provided. Therefore, the difference from the loader plate 2a is that the light from the photo sensors 7a and 7b both receives the reflected light from the loader plate 2b. Therefore, both the photo sensors 7a and 7b generate detection signals.
As a result, depending on ON / OFF of a signal detected by the light receiving signals of the photosensors 7a and 7b, one of the states of FIG. 2A, the state of FIG. 2B, and the state of FIG. State can be detected. Further, it is possible to determine whether any of the open cassettes 18a to 18c is set based on this and the ON / OFF of the switch 4.
Also, regardless of which cassette is mounted on the open cassette mounting table 13, the operator 4a of the switch 4 for detecting the cassette descends and the switch 4 is turned on to detect the mounting of the cassette. In response, the opening / closing door 3a is lowered, the window frame 3 is opened, and the wafer handling unit 14 can start operation.
The detection of the mounting of the open cassette 18a of the 12-inch wafer shown in FIG. 2A is performed in combination with or instead of the differential of the cassette detecting switch 4 in accordance with the SEMI standard in accordance with the dotted line in FIG. The light emitting elements 30a and 30b and the light receiving elements 31a and 31b are provided, and one of the lights from the light emitting elements 30a and 30b is passed through the open cassette 18a and received by the light receiving elements 31a and 31b, and one of them is turned ON. By obtaining a combination detection signal in which the other is turned off, it may be detected that the open cassette 18a is mounted on the open cassette mounting table 13.
[0013]
Thus, the size of the open cassette mounted on the open cassette mounting table 13 is determined, and the wafer handling unit 14 (see FIG. 4) of the wafer transfer device 1 turns ON / OFF the light receiving signals of the photo sensors 7a and 7b. When the switch 4 is turned on, the open cassette mounted on the open cassette mounting table 13 is determined, and the wafer in the cassette is handled accordingly. Then, the wafer is loaded on the inspection table 16 of the inspection apparatus 20, and the wafer after the inspection is received from the inspection apparatus 20 and returned to the cassette.
In this case, the wafer transport device 1 of the mini-en system does not become a mini-en system having a high degree of cleanness because the window frame 3 is in the open state, but the wafer transport device 1 has a positive pressure inside the wafer handling unit 14. , A sufficient degree of cleanness can be ensured for wafers of 12 inches or less.
By the way, a 12-inch open cassette is not used in a normal production line because of its reduced cleanliness. However, in a laboratory or the like where a specially high cleanness is set, a 12-inch open cassette is simply used for analyzing the condition of wafers. Used as a simple system. In other words, it can be used in an environment where sufficient cleanliness as a mini-en system is not required.
[0014]
By the way, when any one of the cassettes mounted on the open cassette mounting table 13 is removed from the mounting table, the operator 4a of the cassette detection switch 4 is raised, the switch 4 is turned off, and the cassette is turned off. Since the removal is detected, the wafer handling unit 14 returns to the initial position according to the detection signal. Then, the operation is stopped, the opening / closing door 3a rises, and the window frame 3 is closed.
In a state where the opening / closing door 3a of the window frame 3 is closed, the pod 12a is mounted on the FOUP opener 13a side, and the wafer stored in the pod 12a is locally cleaned as in the related art. Is loaded on the inspection stage 16 of the inspection apparatus 20, inspected, and the wafer after inspection is unloaded and returned to the pod 12a.
[0015]
As described above, in the embodiment, an example in which 6-inch, 8-inch, and 12-inch wafers are stored is described as an open cassette, but the open cassette in the present invention is limited to the size of these wafers. Of course not.
In the embodiment, the discrimination of 6 inches, 8 inches, and 12 inches is performed by mounting a plate, but the open cassette mounting table 13 may be a mounting table dedicated to any one of them. Of course, in such a case, particularly, in such a case, it is preferable to use a mounting table dedicated to a cassette that stores wafers having a size different from the wafer size of the FOUP pod.
Further, in the embodiment, a processing apparatus in which a transfer apparatus for processing a wafer in a mini-en system and an inspection apparatus are combined as an example, but the present invention is not limited to such an apparatus.
In the embodiment, both the FOUP opener 13a and the open cassette mounting table 13 are described as the load and unload ports, respectively. However, the discharge of the wafer may be performed from another port. Need not be.
[0016]
【The invention's effect】
As can be understood from the above description, the present invention includes the first load port for the FOUP type pod and the second load port for the open cassette, so that a special switching mechanism is provided. Instead, both wafers can be processed by the same mini-en system.
In particular, by storing a wafer different from the inch size of the FOUP system in the open cassette of the second load port, it is possible to easily process a conventional wafer having a different size of 6 inches or 8 inches.
As a result, in the mini-en system, it is possible to process the wafer even in the open cassette, and a local cleaning wafer processing apparatus capable of storing wafers having different inch sizes in the open cassette and processing the wafer is facilitated. Can be realized.
[Brief description of the drawings]
FIG. 1 is an external view of a wafer transfer apparatus according to an embodiment to which a locally cleaned wafer processing apparatus according to the present invention is applied.
FIG. 2 is an explanatory diagram of an open cassette mounting table for mounting an open cassette that stores wafers of different inch sizes.
FIG. 3 is an external view of a conventional wafer transfer device of a mini-en system.
FIG. 4 is a schematic diagram illustrating an internal state of the device of FIG. 3;
[Explanation of symbols]
1,10 ... wafer transfer device,
2 moving plate, 2a, 2b loader plate,
3 ... window frame, 3a ... opening and closing door,
4 ... switch, 4a ... operator of switch 4,
5a, 5b ... light receiving element,
6a, 6b ... opening,
7a, 7b: photo sensor, 9, 9a: hole,
11 ... fan unit,
12a, 12b ... pod,
13b, 13a ... FOUP opener,
14 ... wafer handling unit,
15 Pre-alignment stage
16… Inspection stage,
17a, 17b, 17c ... pins,
18a, 18b, 18 ... open cassette,
19 ... Cassette guide claw,
20: Wafer inspection device.

Claims (4)

In a locally cleaned wafer processing apparatus for processing a wafer while maintaining the inside of the apparatus at a positive pressure with respect to the external pressure,
A first load port on which a pod storing the wafer is placed, wherein the first load port is a mechanism that is securely mounted on the apparatus and the lid is opened;
A cassette mounting table on which an open cassette containing the wafers is mounted, and a size capable of carrying a wafer into the apparatus having an opening / closing door provided in this locally-cleaned wafer processing apparatus corresponding to a wafer outlet of the open cassette; A second load port having a window and a second load port;
When the pod is placed on the first load port, loading of the wafer stored in the pod is performed with the opening and closing door closed,
When the open cassette is mounted on the cassette mounting table, the opening / closing door is opened and the wafer stored in the open cassette is carried in, and the locally cleaned wafer processing apparatus. The second load port has a detector for detecting that the open cassette is mounted on the cassette mounting table, and the open / close door is opened according to a detection signal of the detector, and the cassette mounting 2. The local cleaning wafer processing apparatus according to claim 1, wherein the open cassette storing the wafer having a different size from the wafer stored in the pod is mounted on the mounting table. A plate is mounted on the cassette mounting table, and the open cassette accommodating the wafers having the different sizes is mounted via the plate, and the size of the wafer in the open cassette is determined by mounting the plate. Item 3. A locally cleaned wafer processing apparatus according to Item 2. A plurality of the plates are provided corresponding to the open cassettes storing the wafers having different sizes, and one of the plates is selectively mounted on the cassette mounting table, and The size of the wafer is determined by the difference in the form, the cassette mounting table has a plurality of pins fitted into a plurality of holes arranged in a distributed manner, the detector is a switch having an actuator, and a plurality of switches. 4. The local cleaning wafer processing apparatus according to claim 3, wherein the plate has a plurality of holes fitted into the plurality of pins and a hole through which the actuator penetrates.

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