JP3341978B2 - Cleaning system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning system for cleaning an object to be processed such as a semiconductor wafer and an LCD substrate.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process,
2. Description of the Related Art A cleaning system is used to remove contamination such as particles and organic contaminants on the surface of a semiconductor wafer (hereinafter, referred to as “wafer”). Among them, a wet-type cleaning system that cleans a wafer by immersing it in a cleaning solution in a processing bath has an advantage that particles attached to the wafer can be effectively removed.

[0003] This wet type cleaning system comprises an interface section on which a cassette containing wafers is placed,
A cleaning unit for cleaning and drying the wafer, and a transfer device for loading and unloading the cassette between the interface unit and the cleaning unit are provided. A loading / unloading port is formed in the interface unit, and a cassette transported by an AGV (automated guided vehicle) is supplied and unloaded to and from the cleaning system via the loading / unloading port. The cleaning section is provided with a loader for taking out the wafer from the cassette, various cleaning tanks for cleaning the wafer, a drying tank for drying the wafer, and an unloader for storing the wafer in the cassette. . Then, when the cassette is placed on the interface unit by a robot or the like, the cassette is carried into the cleaning processing unit by the transfer device. Next, the wafer is taken out of the cassette by the loader of the cleaning section. Then, for example, 50 wafers stored in two cassettes are collectively washed with various liquids while being conveyed to each washing tank. Further, in the drying tank, the water on the wafer surface is subjected to IPA using, for example, IPA (isopropyl alcohol).
A is removed at the same time as the volatilization of A.

[0004] The cleaning system configured as described above is
It is generally installed in a clean room with high cleanliness. The inside of this clean room is maintained in a clean atmosphere in which generation of impurities such as dust, gas, and chemicals generated from the human body and frictional sliding parts of mechanical devices is minimized. On the other hand, in the cleaning section of the wet type cleaning system, various chemicals are used for cleaning and drying the wafer, so that the vapor of the chemical and the vapor such as IPA used in the drying tank remain inside the cleaning system. Could be. If these vapors leak out of the cleaning system from the loading / unloading port of the interface section, the inside of the clean room will be contaminated.

[0005] Therefore, by setting the inside of the cleaning system to a negative pressure atmosphere and setting the pressure in the clean room to be higher than the atmosphere in the cleaning system by, for example, about +0.38 mmHg, the atmosphere in the cleaning system is changed to the interface section. It prevents leakage from the loading / unloading port to the outside.

[0006]

However, when a differential pressure is formed between the clean room and the cleaning system as described above,
An airflow that flows from the clean room into the cleaning system through the loading / unloading port of the interface unit is formed. Then, particles enter the cleaning system with this air flow, or the air flow in the system is disturbed,
There is a problem that particles and mist re-attach to the washed wafer. Further, if an air current enters a drying tank in which the wafer is dried using the IPA vapor, the IPA vapor cannot be satisfactorily supplied to the wafer surface, and adverse effects such as leaving a watermark on the wafer surface will occur.

On the other hand, attempts have been made to provide a baffle plate between the interface section and the cleaning section in order to suppress the generation of such an air flow. However, if such a baffle plate is provided, the baffle plate must be bypassed when the wafer is transferred between the interface unit and the cleaning unit.
The transport path cannot be made linear. For this reason, it takes a long time to transfer the wafer, the tact time becomes longer, and the throughput is reduced.

Accordingly, it is an object of the present invention to provide a cleaning system capable of preventing an airflow from flowing into a cleaning system from inside a cooling room without reducing throughput.

[0009]

In order to solve the above problems, the present invention comprises an interface section for supplying and unloading an object to be processed and a cleaning section for cleaning the object to be processed. In the cleaning system, the cleaning processing unit is in a standby state.
Section, unloader, drying tank, washing tank and loader.
The standby unit is disposed at the forefront of the cleaning unit.
A first shutter that can be opened and closed is provided at a loading / unloading port that supplies and unloads the object to be processed to and from the interface unit, and a second shutter that can be opened and closed is provided between the interface unit and the standby unit . It is characterized by the following.

According to this cleaning system, the first shutter and the second shutter are opened only when the object is transported, and are closed when the object is not transported. Thus, it is possible to prevent the airflow from flowing into the cleaning system. That is, when the first shutter is opened, the second shutter is opened.
By closing the first shutter and closing the first shutter when the second shutter is opened, the atmosphere in the cooling room and the atmosphere in the cleaning system are not directly communicated with each other. Can be prevented. Incidentally, the driving portion of the first shutter, as well as disposed below the transfer port for supplying and carrying-out of the object to interface unit, the driving portion of the second shutter,
It is preferable to dispose the object to be processed between the interface unit and the standby unit below a transport path for supplying and unloading the object. Further, when the first shutter is lowered, the loading / unloading port for supplying and unloading the object to be processed to / from the interface section is in an open state, and when the second shutter is lowered, the interface section is connected to the interface section. It is preferable that the transfer passage for supplying and unloading the object to and from the standby unit be open.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described based on a cleaning system 1 for cleaning a wafer W as an example of an object to be processed. FIG. 1 is a perspective view of a cleaning system 1 installed in a clean room. The cleaning system 1 includes an interface unit 2 on which a cassette C is mounted by an unshown AGV (automated guided vehicle) or the like running in a clean room, a cleaning processing unit 3 for cleaning and drying a wafer, and an interface for these. A transfer device 4 that carries in and out the cassette C between the unit 2 and the cleaning unit 3 is provided. The cassette C stores a plurality of wafers W as objects to be cleaned in the cleaning system 1.

A loading / unloading port 5 is formed on a side surface of the interface unit 2. A cassette C transported by an AGV (not shown) is loaded into the cleaning system 1 via the loading / unloading port 5, and the loading / unloading port 5 is provided. It is carried out of the cleaning system 1 through the outlet 5. In the cassette C carried into the cleaning system 1, a wafer W to be cleaned by the cleaning processing unit 3 is stored. Also,
In the cassette C carried in from the cleaning system 1, the wafers W already cleaned by the cleaning processing unit 3 are stored.

As shown in FIG. 2, four rails 8, 9, 10, and 11 are provided on the upper surface of the interface section 2. The cassette C is configured to be moved left and right on these rails 8, 9, 10, and 11.
In the illustrated embodiment, a cassette C containing wafers W having been cleaned by the cleaning system 1 is placed on the two rails 8 and 9 located at the rear. On these rails 8 and 9, the cassette C transported from the cleaning section 3 by the arm 13 of the transfer device 4, which will be described in detail later, is placed on the rails 8 and 9 at the right side in the drawing. It has become. Thus, the cassette C placed at the right position on the rails 8 and 9
Is then moved on rails 8 and 9 and transported to the left position on rails 8 and 9.
In the illustrated embodiment, a cassette C containing a wafer W to be cleaned by the cleaning system 1 is mounted on the two rails 10 and 11 located at the front. On these rails 10 and 11, A
The cassette C transported by the GV or the like
0 and 11 are placed at the left side position in the figure. The cassette C placed at the left position on the rails 10 and 11 is then moved on the rails 10 and 11 and transported to the right position on the rails 10 and 11. FIG. 2 shows a state in which the cassette C on the rails 8 and 9 has been moved to the left position on the rails 8 and 9. Further, the cassette C on the rails 10 and 11 has been conveyed to the right position on the rails 10 and 11.

As shown in FIG. 2, a guide rail 12 extending back and forth is arranged on the upper surface of the transfer device 4.
Arm body 14 running along the guide rail 12
An arm 13 that can be raised and lowered and that is rotatable is mounted on the upper surface of the device. The operation of the arm 13 causes the rail 1
The cassettes are picked up from above 0 and 11, the cassettes are carried into the standby section 15 of the cleaning section 3 described below, and the cassette C is picked up from the standby section 15 and the cassette C is mounted on the rails 8 and 9. The cassette C is carried in and out between the interface unit 2 and the cleaning processing unit 3 by being placed.

At the foremost side of the cleaning section 3, there is disposed a standby section 15 in which the transfer of the cassette C by the arm 13 of the transfer apparatus 4 described above is performed. In the cleaning processing unit 3, an unloader 16 is disposed behind the standby unit 15, and various cleaning tanks 17 and a drying tank 18 for cleaning and drying the wafer W are arranged in series behind the unloader 16, and are arranged in series. A loader 19 is disposed at the rear. As described above, when the cassette C is carried into the standby unit 15 of the cleaning unit 3 from the rails 10 and 11 of the interface unit 2 by the arm 13, the cassette C is removed by the lifter (not shown). After being lifted upward, it is conveyed to the rearmost position of the cleaning section by the liner, and further lowered by a lifter (not shown).
The cassette C containing the wafers W before cleaning is transported to the loader 19. Then, the wafer W is taken out of the cassette C by the loader 19, and the wafer W is sequentially transported to each of the cleaning processing units 3 in a batch manner to perform cleaning and drying. It is supplied to the unloader 16. On the other hand, the cassette C from which the wafer W has been taken out by the loader 19 and emptied is lifted again above the cleaning processing unit 3 by the lifter, and then transported to the forefront of the cleaning processing unit 3 by the liner. The cassette C that has been emptied by being lowered by the lifter that is not used is transported to the standby unit 15. The cassette C thus transported to the standby section 15 is thereafter supplied to the unloader 16. Then, the unloaded cassette 16 stores the washed wafer W in the empty cassette C.
Is stored again. The cassette C containing the washed wafers W is transported to the standby unit 15 and then placed on the rails 8 and 9 of the interface unit 2 by the operation of the arm 13 as described above. Has become.

In the cleaning system 1 as described above, as shown in FIG.
A first shutter 20 for opening and closing the shutter and a second shutter 22 for opening and closing between the interface unit 2 and the cleaning unit 3 are provided. FIG. 1 shows a state where the first shutter 20 is lowered and the second shutter 22 is raised.

As shown in FIG. 3, below the loading / unloading port 5 of the interface section 2, a first drive section 21 for driving the first shutter 20 up and down is arranged. The first drive unit 21 is configured by, for example, a cylinder, a motor, or the like.
In the case of a motor, an encoder is directly connected to the drive shaft, and the rotation amount of the motor is controlled by a pulse signal. Then, for example, a stepping motor driven by a pulse signal is used as the first drive unit 20, and by controlling the rotation amount, the first shutter 20 is raised to close the loading / unloading port 5, and The shutter 20 is lowered so that the carry-in / out port 5 is opened. Although not shown, for example, a sensor such as a photo sensor or a proximity sensor is provided so that the elevation of the first shutter 20 can be recognized, and the opening and closing of the loading / unloading port 5 is detected by the sensor. The first shutter 20 indicated by a solid line in FIG.
1 shows a state in which it is lowered by operation. When the first shutter 20 is lowered in this way, the loading / unloading port 5
Is in an open state, and a cassette C conveyed by an AGV or the like (not shown) can be carried in and out of the interface unit 2. On the other hand, when the first shutter 20 is raised by the operation of the first drive unit 21, the first shutter 20 moves to the position shown by the one-dot chain line 20 'in FIG. The exit 5 is closed. As described above, the loading / unloading port 5 is controlled by the first shutter 20.
Is closed, the air in the clean room does not flow into the interface unit 2 of the cleaning system 1.

Next, as shown in FIG.
Between the interface unit 2 and the cleaning unit 3
The partition plate 25 has a transport passage 24 for carrying in and out the cassette C between the interface unit 2 and the cleaning unit 3. And
The above-described second shutter 22 is supported by a second drive unit 23 disposed below the transport path 24. Similarly, the second drive unit 23 is also formed of, for example, a motor or a cylinder, and the second shutter 22 is moved up and down by the operation of the second drive unit 23. Note that, similarly to the first driving unit 21 described above, by controlling the elevation of the second shutter 22, the second shutter 22 is elevated to close the transport passage 24, and the second shutter 22 is closed. The shutter 22 is moved down to open the transport passage 24. Similarly, the opening and closing of the second shutter 22 is detected by, for example, a photo sensor or a proximity sensor. In FIG. 4, the second shutter 22 indicated by a solid line has been lowered by the operation of the second drive unit 23. When the second shutter 22 is lowered as described above, the transport path 24 is opened, and the cassette C supported by the arm 13 of the transfer device 4 described above is transferred to the interface unit via the transport path 24. It is in a state where it can be supplied and unloaded between the cleaning processing unit 2 and the cleaning processing unit 3. on the other hand,
When the second shutter 22 is raised by the operation of the second drive unit 23, the second shutter 22 moves to the position indicated by the one-dot chain line 22 'in FIG.
The transport passage 24 is closed. When the transfer path 24 is closed by the second shutter 22 in this manner,
The air does not flow between the interface unit 2 and the cleaning unit 3.

The first shutter 20 and the second shutter
The second shutter 22 is configured such that when the first shutter 20 opens, the second shutter 22 closes, and when the second shutter 22 opens, the first shutter 20 closes. That is, the first driving unit 21 and the second
Of the first shutter 21 is the first shutter 2
0, the second drive unit 2
3 operates to lower the second shutter 22, and when the second drive unit 23 operates to raise the second shutter 22, the first drive unit 21 operates the first shutter 20. The control is performed so as to move down.

Now, the steps of cleaning the wafer W in the above-described cleaning system 1 will be described step by step as follows.

First, a cassette C containing wafers W that have not been cleaned is transported to the front of the interface unit 2 of the cleaning system 1 by an AGV (not shown). At this stage, both the first shutter 20 and the second shutter 22 are still raised, and the carry-in / out port 5 on the side surface of the interface unit 2 and the transport passage 24 between the interface unit 2 and the cleaning unit 3 are all in the state. It is closed. When the AGV travels to the front of the interface unit 2 and stops at a predetermined position, a signal is transmitted to the cleaning system 1 by, for example, control means (not shown), and after confirming that the second shutter 22 is closed. , First drive unit 2
The first shutter 20 is lowered by the operation of 1, and the loading / unloading port 5 is opened. Thereafter, the cassette C conveyed by the AGV is carried into the interface unit 2 via the carry-in / out port 5, and in the example shown in the figure, the two cassettes C are mounted on the left sides of the rails 10 and 11, respectively. Thus, the cassette C to the interface unit 2
Is completed, the first shutter 20 is raised by the operation of the first drive unit 21, and the carry-in / out port 5 is closed.

Next, on the rails 10 and 11, the cassette C
Is moved to the right position. After confirming that the first shutter 20 is closed, the second shutter 22 is lowered by the operation of the second drive unit 23, and
4 is open. Then, the cassettes C placed on the rails 10 and 11 are picked up one by one by the operation of the arm 13 of the transfer device 4, and are sequentially loaded into the standby unit 15 of the cleaning processing unit 3. Thus, 2
After the two cassettes C are loaded into the standby section 15, the second shutter 22 is raised by the operation of the second drive section 23, and the transport path 24 is closed again. Thereafter, the two cassettes C are lifted upward by a lifter (not shown) in the cleaning processing unit 3, conveyed to the rearmost position of the cleaning processing unit 3 by the liner, and further lowered by the lifter (not shown) to be cleaned. The cassette C containing the previous wafer W is transported to the loader 19. Then, in the loader 19, the wafers W are transferred from the two cassettes C.
Are taken out, and the wafers W are sequentially transported to the respective cleaning processing units 3 in a batch manner to perform cleaning and drying. The wafers W that have completed the processing such as the cleaning are supplied to the unloader 16.

On the other hand, the cassette C, from which the wafer W has been taken out by the loader 19 and emptied, is again lifted above the cleaning section 3 by the lifter, and then transported to the forefront of the cleaning section 3 by the liner. Further, the cassette C that has been emptied by being lowered by a lifter (not shown) is transported to the standby unit 15. Thus, the standby unit 15
The cassette C transported to the unloader 16
Supplied to Then, the wafer W that has been subjected to the cleaning process described above is stored again in the cassette C by the unloader 16. Then, the cassette C containing the wafers W that have been subjected to the cleaning process as described above is transferred from the unloader 16 to the standby unit 15.

Next, the second shutter 22 is lowered by the operation of the second drive unit 23, and the transport passage 24 is opened. Then, by the operation of the arm 13 of the transfer device 4, the cassettes C placed on the standby unit 15 are picked up one by one, and are sequentially transported to the right positions on the rails 8 and 9 of the interface unit 2. After the two cassettes C are conveyed on the rails 8 and 9 in this manner, the second shutter 22 is raised by the operation of the second drive unit 23, and the conveyance path 24 is closed again.

Next, the cassette C is moved to the left position on the rails 8 and 9. Then, the first driving unit 21
The first shutter 20 is lowered by the operation of
The loading / unloading port 5 is opened. In this manner, the cassette C containing the wafers W having been subjected to the cleaning process and placed at the left position on the rails 8 and 9 is then placed in an AGV (not shown).
And transported to the next step as appropriate.

In the cleaning system 1 of the embodiment described above, one of the loading / unloading port 5 of the interface unit 2 and the transport path 24 between the interface unit 2 and the cleaning processing unit 3 is always in contact. Since the cassette C is in the closed state, the cassette C is not loaded into the cleaning section 3 or when the cassette C is loaded.
When the air is carried out from the inside, the air in the clean room does not directly enter the cleaning processing unit 3. Therefore, there is no concern that particles or the like floating in the clean room enter the cleaning section 3 of the cleaning system 1 and the wafer W
Can be cleaned in a clean environment. In addition, since unnecessary airflow is not generated in the cleaning processing unit 3, adverse effects such as a watermark remaining on the surface of the wafer W during IPA drying in the drying tank 18 do not occur, and the reliability of the cleaning processing of the wafer W is improved. Becomes possible.
Further, compared to the case where a baffle plate or the like is installed as in the prior art, the transport path of the cassette C can be made linear,
The time for carrying the cassette C can be reduced. As a result, it is possible to improve the operation efficiency of the entire system.

In the above embodiment, the cleaning system 1 for cleaning a wafer W has been mainly described as an example. However, the present invention is applicable to a cleaning system for handling another object to be processed such as an LCD substrate. It is also possible to make it.

[0028]

According to the present invention, by providing the first shutter and the second shutter which can be opened and closed, when cleaning the object to be processed, an adverse effect caused by air entering the system from the external environment. Can be eliminated and the cleaning processing time can be shortened, so that the reliability and operation efficiency of the entire system can be improved. Therefore, according to the present invention, the object to be processed can be cleaned smoothly, and for example, the production efficiency in the manufacture of semiconductor devices can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a cleaning system.

FIG. 2 is a plan view of an interface unit.

FIG. 3 is an explanatory diagram of a first shutter.

FIG. 4 is an explanatory diagram of a second shutter.

[Explanation of symbols]

 C cassette W wafer 5 loading / unloading port 20 first shutter 21 first drive unit 22 second shutter 23 second drive unit 24 transfer passage 25 partition plate

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H01L 21/304 B08B 3/04

Claims (11)

(57) [Claims] An interface for supplying and unloading an object to be processed
Cleaning unit with a cleaning unit for cleaning the base unit and the object to be processed.
In the purification system,The cleaning section includes a standby section, an unloader, a drying tank, a cleaning section,
Equipped with a tank and a loader, The standby unit is located at the forefront of the cleaning unit.
,  Supplies and unloads the object to be processed to the interface
A first shutter that can be opened and closed at the loading / unloading port, andThe standby unitCan be opened and closed between
A cleaning system provided with a second shutter;
M 2. The cleaning processing section, wherein:
The unloader is located behind and the back of the unloader is cleaned
Tank and drying tank are arranged in series, and a loader is arranged at the rearmost position
The cleaning system according to claim 1, wherein
Tem. 3. A cassette accommodating an object to be processed is inserted into the cassette.
Transfer device for loading and unloading between the interface unit and the standby unit
Device is provided on the interface unit.
The cleaning system according to claim 1. 4. When the first shutter is opened,
When the second shutter is closed and the second shutter is opened
Wherein the first shutter is closed.
The cleaning system according to claim 1, 2, or 3. 5. A stage in which a cassette containing an object to be processed is transported by an AGV to a position in front of an interface unit.
4. The system according to claim 1, wherein the first shutter and the second shutter are both closed.
Or the cleaning system according to any one of 4. 6. When the AGV travels to the front of the interface and stops at a predetermined position, the first shutter is opened after confirming that the second shutter is closed. The cleaning system according to any one of claims 1, 2, 3, 4, and 5. 7. When the loading of the cassette containing the object to be processed into the interface section is completed, the first shutter is closed, and after confirming that the first shutter is closed, the second shutter is opened. 3. The method according to claim 1, wherein:
The cleaning system according to any one of 3, 4, 5, and 6. 8. The method according to claim 8, wherein the second shutter is closed after the cassette accommodating the object to be processed is carried into the standby unit from the interface unit, and thereafter, the cleaning processing is performed in the cleaning processing unit. Claims 1, 2, 3, 4, 5, 6, or 7
The cleaning system according to any one of the above. 9. After the cassette accommodating the object to be processed is transported from the standby section to the interface section , the second shutter is closed, the first shutter is opened, and the cassette is moved to the interface section. 2. The method according to claim 1, wherein
The cleaning system according to any one of 2, 3, 4, 5, 6, 7, and 8. 10. A device which is carried into a standby unit from an interface unit.
Transports the loaded cassette to the loader,
The object to be processed is taken out of the set and processed by the loader.
Remove the empty cassette from the body to the standby unit
4. The method according to claim 1, wherein the transfer is performed.
The cleaning system according to 6, 7, 8 or 9. 11. An empty cassette conveyed to the standby section.
Is supplied to the unloader, and the cassette is
11. The method according to claim 10, wherein the processing body is stored again.
On-board cleaning system.