JP2005072544A - Wafer supplying/collecting equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent contamination between wafers and contamination of a wafer before process treatment even if the wafer before the process treatment and the wafer, contaminated by the process treatment, after the process treatment exist together in the same FOUP in a semiconductor manufacture. <P>SOLUTION: The wafer supplying/collecting equipment is equipped with the wafer holding container FOUP, a door opener which takes out the wafer from the FOUP and returns it in the FOUP again, and a up-and-down moving clean unit which is located in front of the opening face of the FOUP. In the wafer supplying/collecting equipment, the wafer is taken out from the lowerside of the FOUP in order so as to carry out the process treatment of the wafer sheet by sheet, and the wafer is returned from the lowerside to the original position of the FOUP after process treatment, and the clean unit is also moved upwards sequentially according to the wafer before process treatment in the FOUP to spray clean air from the clean unit only on the wafer before process treatment. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention is an apparatus for supplying and recovering a wafer to a process processing apparatus for manufacturing a semiconductor. In particular, when a FOUP (Front Opening Unified Pod) is used as a wafer storage container, the cleanliness in the FOUP is improved. The present invention relates to prevention of wafer contamination before processing in the FOUP.

The 300 mm wafer is stored in the FOUP, the wafer is taken out from the FOUP and handled, and the wafer is transported in a single wafer manner to supply the wafer to each process processing device. The processed wafer is collected in the FOUP. Yes.
That is, the wafers are sequentially taken out from the lower side of the FOUP containing the φ300 mm wafers, supplied one by one to the process processing apparatus, and after the process processing, the wafers are taken out one by one from the process processing apparatus into the original FOUP from the lower side. Collected sequentially.

  Further, the wafer processed by each process processing apparatus is contaminated by the processing gas in the process processing apparatus. For example, it is contaminated with phosphorus and boron compounds in the case of CVD, and chlorine gas in the case of etching.

Further, the wafer is heated by the process process, and the wafer immediately after the process process has a high temperature and is in a state where the gas is easily generated.
On the other hand, until now, in the case of a wafer having a diameter smaller than φ300 mm, the storage container is not in a sealed structure and is open to the atmosphere.
Even if a wafer before the process and a wafer after the process are mixed in the same container, there is no problem that the wafer before the process is contaminated by degassing from the wafer surface after the process.
Here, the storage container is a FOUP in the case of a wafer having a diameter of φ300 mm, and in the case of a wafer having a diameter smaller than the diameter of φ300 mm, the wafer itself used for supplying and taking out the wafer from the process processing apparatus is directly stored. A cassette.

A wafer supply and recovery apparatus using FOUP as a prior document refers to a semiconductor manufacturing apparatus for growing a film on a semiconductor substrate with reference to the following document, and FOUP is used only for taking out a wafer from here. However, there is no intention to keep the environment around the wafer in the FOUP clean.
JP2002-141293

Conventionally, a storage container for storing a wafer having a diameter of 200 mm or less does not have a sealed structure as described in the background section, and air does not stay in the storage container, but is diffused to the surroundings. Cross contamination was not a problem.
However, the diameter of the wafer becomes larger and SEMI requires the use of FOUP as a storage container for φ300 mm wafers in order to prevent contamination from the atmosphere.

In semiconductor manufacturing, a wafer processed in a single wafer type is generally returned to the original FOUP after the process.
Therefore, both the wafer before the process and the wafer after the process are mixed in the same FOUP, and the wafer before the process is contaminated by the gas generated from the wafer surface after the process.
In addition, as described above, the wafer after the process processing is higher than the normal temperature due to the process processing, and is often in a state where gas is easily generated from the wafer surface. Subsequent wafer contamination.

In general, wafers are processed from the bottom of the FOUP, and after the processing, the wafers are sequentially collected and stored from the bottom of the original position of the FOUP.
Therefore, the gas generating component of the wafer after the high-temperature process processing rises, and the wafer before the process processing at the upper part tends to be contaminated. This is because although the air in the FOUP is in a state where the front lid is open, the other portions are covered with the walls constituting the FOUP, so that there is almost no outflow of air in the FOUP.

  In order to solve the above problems, the present invention provides a wafer storage container FOUP, a door opener for taking out the wafer from the FOUP and collecting it in the FOUP, and a clean unit for driving up and down, on the front surface of the opening of the FOUP. In order to process wafers in a single wafer mode, the wafers are sequentially taken out from the lower side of the FOUP, and after the process processing, the wafers are sequentially recovered from the lower side to the original position in the FOUP. The clean unit is also aligned with the wafer before the process processing so as to blow clean air from the clean unit, and is also moved upward sequentially in accordance with the arm height of the wafer entrance / exit bot. The interior of the FOUP is always purged with clean air to eliminate stagnation of air in the FOUP, and the wafer before the process is always maintained in a clean air atmosphere.

In order to prevent contamination of the wafer before the process, the suction port for sucking the air in the FOUP is provided below the FOUP, and the air is sucked from the lower side of the FOUP.
Moreover, the ascending airflow of the air in the FOUP is suppressed by providing a mechanism for sucking from the lower part.
By providing the suction function, degassing from the processed wafer on the lower side in the FOUP forms an air flow that does not enter the unprocessed wafer on the upper side in the FOUP.
Therefore, the contamination from the residual gas generated by the process generated from the wafer after the process is prevented.

  A gas detector is installed in the exhaust line of the suction port, and the suction air is monitored by the gas detector and the cleanliness in the FOUP is also managed.

  An air nozzle that blows clean air into the FOUP is provided on at least one of the left and right sides of the opening of the FOUP. The generated gas remaining on the wafer after the process is forcibly discharged from the FOUP.

  Two door openers are installed and two FOUPs are used. The loader FOUP and the unloader FOUP are separated, and the wafers before and after the process are separated and stored in separate FOUPs. Cross contamination between the wafer before the process and the wafer after the process is prevented.

  A stock area for temporarily storing the processed wafer is provided in the process processing apparatus. This stock area is composed of, for example, a load lock, and is completely spatially separated from the processing chamber of the process processing apparatus.

The processed wafer is sequentially transferred through the degassing area, the cooling area, and the stock area and stored in the FOUP.
A hot plate is provided in the degassing area, and a cooling plate is provided in the cooling area. The process wafer is sufficiently degassed by the hot plate, and degassing is suppressed by the cooling plate.

  The upper stage is provided with two upper and lower stages having a hot plate and a lower stage with a cooling plate, and the wafer after the process is degassed on the hot plate, and then the wafer after the process is cooled with the cooling plate.

Clean air in the mini enclosure is collected by the hooded hood and sent into the FOUP2.
Further, the hood is moved up and down according to the arm position of the transfer robot. In this method, the residual gas generated from the FOUP 2 can be discharged and the FOUP 2 can be kept clean without providing a dedicated clean unit for blowing clean air into the FOUP 2 separately.

In any case, the wafer supply / recovery device according to the present invention can clean the periphery of the wafer before the process by purging with clean air even if the wafer before the process and the wafer after the process are mixed in the same FOUP. Keep wafers out of process after processing.
Therefore, the wafer before the process processing can be always maintained in a clean atmosphere without being affected by the degassing of the wafer after the process processing, and the prevention from the contamination of the wafer before the process processing can be achieved. it can.

The processed wafer is completely spatially separated from the unprocessed wafer so as not to be affected by the contamination of the processed wafer.
By the above two methods, the periphery of the wafer before the process is maintained in a clean environment, and cross contamination between the wafer before the process and the wafer after the process is prevented.
This method can also prevent the wafer from being contaminated before processing.

Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a first embodiment of the present invention. A FOUP 2 containing a plurality of wafers 1 having a diameter of 300 mm is placed on the loading table 16-1 of the door opner 16. The wafers 1 are sequentially taken out one by one from the lowest position of the FOUP 2 and sent to the process processing device 15 by the transfer device. Process processing such as CVD or dry etching is performed in the process processing apparatus. After the processing is completed, the wafer 1 is sequentially returned from the lowest position of the FOUP 2 to the original position by the transfer device.
At this time, the processed wafer 1 and the unprocessed wafer 1 are mixed in the same FOUP 2.
Further, the wafer 1 after the process is heated during the process, and the surface temperature of the wafer 1 is usually higher than the ambient temperature. Therefore, residual gas adhering during the processing is released from the surface of the wafer 1. This is a cause of contamination of the wafer 1 before processing.

  Further, the processing of the wafer 1 is performed from the lowermost end of the FOUP 2, and since the wafer 1 is stored in the original position of the FOUP 2 as described above, a process contaminated with a high temperature process residual gas is present below the FOUP 2. The processed wafer 1 is stored on the upper side of the FOUP 2 before the process processing. The process residual gas generated from the wafer 1 after the process treatment rises and also contaminates the wafer 1 before the process treatment.

With regard to such a contamination problem, in the case of a wafer having a diameter smaller than that of a wafer having a diameter of 300 mm or less, the storage container is not hermetically sealed. Even if it occurs, there is no problem because it diffuses and evaporates around the container.
However, since a 300 mm wafer is required to use a sealed FOUP of SEMI as a storage container, in the conventional method shown in FIG. 8, although the lid is open, the other walls constituting the FOUP 2 The problem of contamination by this process residual gas could not be solved.

In the present invention, the clean unit 4 that is driven up and down is attached to the door option 16, the process processing device 15, or the mini-environment 18 in front of the opening of the FOUP 2. The process of the wafer 1 is performed from the lowermost end, and after the process, the clean unit 4 is sequentially moved upward along with the step of returning the wafer 1 to the original position of the FOUP 2. In this step, the wafer 1 before the process and the wafer 1 after the process are mixed in the same FOUP 2.
Therefore, as described above, the clean air from the clean unit 4 is blown onto the wafer 1 before the process processing, the environment around the wafer 1 before the process processing is maintained in a clean state, and the residual gas provided by the wafer 1 after the process processing It prevents contamination by. The interior of the FOUP 2 is always purged with clean air to eliminate the retention of air in the FOUP 2. In this way, the wafer 1 before the process processing can always be maintained in a clean air atmosphere.

The upper side of the robot that takes in and out the wafer from the FOUP 2 is spatially vacant, and the clean unit 4 is held there from above.
Further, the clean unit 4 is sequentially raised according to the arm height of the wafer entrance / exit bot. The air from the clean unit 4 forms a laminar flow with respect to the wafer 1 before the process processing, and forms an air current that does not involve the air from the wafer 1 after the process processing.

  Further, in order to more reliably prevent contamination of the wafer 1 before the process processing, an air suction port 5 is provided below the FOUP 2 to suppress an upward air flow in the FOUP 2 and the generated residual gas is drawn by the suction fan 7, Prevent diffusion of gas by convection to the top of FOUP2.

A gas detector 6 is provided in the middle of the line of the suction port 5 and the suction fan 7, and suction air is sent to the gas detector 6 to monitor the remaining amount of residual gas contained in the suction air. It can detect the gas type in the suction air, its concentration, etc., and can be used to manage the cleanliness in the FOUP 2.

  As a second embodiment of the present invention, as shown in FIG. 2, clean air is blown into the wafer 1 before processing by air nozzles 8 on both sides of the opening of the FOUP 2 and is generated from the surface of the wafer 1 after processing. Residual gas is forcibly removed. This is very effective when used in conjunction with the first embodiment.

As a third embodiment of the present invention, as shown in FIG. 3, a dedicated FOUP is provided for each of the wafer 1 before the process and the wafer 1 after the process. The wafer 1 before the process processing is transferred from the FOUPA to the processing chamber (CVD, dry etching, etc.), and the wafer 1 after the process processing enters the FOUPB.
Thus, if two FOUPs are attached and the loader FOUP2 and the unloader FOUP2 are separated, cross contamination can be prevented. Therefore, since the storage container FOUP 2 of the wafer 1 before the process processing and the wafer 1 after the process processing are separated and independent, the residual gas generated from the wafer 1 after the process processing does not contaminate the wafer 1 before the process processing. .

  As a fourth embodiment of the present invention, as shown in FIG. 4, the process processing apparatus 15 is provided with a 25-sheet stock area 9 for temporarily storing processed wafers. The unprocessed wafer 1 taken out from the FOUP 2 is loaded into the process processing apparatus 15 by the transfer robot 10. The wafer 1 is stored in the stock area 9 after processing such as CVD in the processing chamber, and is not immediately collected in the FOUP 2 in which the wafer 1 before the process processing is stored. The processed wafer 1 is collected and stored in the original position of the FOUP 2 after degassing is completed.

Further, in this method, by storing in the stock area 9, the wafer 1 after the process processing can be stored in the FOUP 2 after the wafer 1 before the process processing disappears from the FOUP 2, so that the wafer before the process processing can be returned. 1 is not affected by contamination by the wafer 1 after the process.
The stock area 9 is provided with a load lock in the process processing apparatus 15 to form a region that is completely isolated and shielded from the process processing chamber.

As a fifth embodiment of the present invention, as shown in FIG. 5, a degassing area 11, a cooling area 12, and a stock area 9 are provided side by side, and the wafers 1 after processing are sequentially degassed and cooled to stock. Housed in area 9.
A hot plate and a cooling plate are provided, and the processed wafer 1 is sufficiently degassed with the hot plate, and degassing is suppressed with the cooling plate.

  As a sixth embodiment of the present invention, as shown in FIG. 6, a hot plate 13 is installed in the upper stage and a cooling plate 14 is installed in the lower stage to form a two-stage configuration, and a stock area is provided below the lower cooling plate 14. 9 is installed. The wafer 1 after the process is placed on the hot plate 13 in the upper stage and heated at 150 ° C. for 10 minutes to degas the surface of the wafer 1. Next, the degassed wafer 1 is placed on the lower cooling plate 14 and cooled for 1 minute to suppress the generation of gas still remaining on the surface of the wafer 1. Thereafter, the wafer 1 is stored in the stock area 9 at the bottom.

As a seventh embodiment of the present invention, as shown in FIG. 7, the clean air of the mini-environment 18 is drawn into the FOUP 2 by the funnel-shaped hood 17. The clean air blowing surface of the mini-environment 18 and the door opener 16 are connected by a funnel-shaped hood 17. At this time, the funnel-shaped hood 17 is connected on the door option 16 side so that the outlet is located near the opening of the FOUP 2.
Further, the hood is moved up and down according to the arm position of the transfer robot. In this way, even if a separate clean unit is not provided for purging the gas generated from FOUP2, the residual gas that generated FOUP2 can be discharged to keep FOUP2 clean.

It is the schematic which shows the structure of the 1st Example of this invention. It is the figure which attached the air nozzle to the both right and left sides of the opening part of FOUP which shows the structure of the 2nd Example of this invention. It is a figure which shows arrangement | positioning of the FOUP which each isolate | separated and independent of the wafer before a process and the wafer after a process of 3rd Example of this invention. It is the schematic which shows the structure of the 4th Example of this invention, and is the figure which provided the stock area of the wafer after a process processing apparatus. It is the schematic which shows the structure of the 5th Example of this invention, and is the figure which provided the degassing area, the cooling area, and the stock area. It is the schematic which shows the structure of the 5th Example of this invention, and is the figure which provided the hot plate and the cooling plate in two steps up and down. It is the schematic which shows the structure of the 5th Example of this invention, and is the figure arrange | positioned so that clean air can be drawn in in FOUP by a funnel type | mold hood from a mini environment. It is a figure which shows the state which installed FOUP in the conventional door opener.

Explanation of symbols

1 Wafer 2 FOUP
3 OPNER 4 Clean unit 5 Suction port 6 Gas detector 7 Suction fan 8 Air nozzle 9 Stock area 10 Transport robot 11 Degassing area 12 Cooling area 13 Hot plate 14 Cooling plate 15 Process processing device 16 Door option 16-1 Loading platform 16- 2 Door drive unit 17 Funnel-shaped hood 18 Mini environment

Claims (9)

A wafer storage container FOUP, a door opener that takes out a wafer from the FOUP and collects it in the FOUP, and a clean unit that is driven up and down provided in front of the opening of the FOUP, and processes the wafer in a single wafer process The wafers are sequentially taken out from the lower side of the FOUP, and after the processing, the wafers are sequentially recovered from the lower side to the original position in the FOUP, and clean air from the clean unit is mainly applied only to the wafers before the processing. A wafer supply / recovery device that sequentially moves the clean unit upward along with the unprocessed wafer in the FOUP so as to spray. 2. The wafer supply and recovery apparatus according to claim 1, wherein a suction port for sucking air in the FOUP is provided below the FOUP. 3. The wafer supply and recovery apparatus according to claim 1, wherein a gas detector is provided in an exhaust line of the suction port. 2. The wafer supply and recovery apparatus according to claim 1, wherein air nozzles for blowing clean air into the FOUP are provided on at least one of the left and right sides of the opening of the FOUP. Wafer supply / recovery device that uses independent and dedicated FOUPs to take out and collect wafers before and after processing. A wafer supply / recovery device characterized in that a stock area for temporarily storing a processed wafer is provided in the process processing device. Wafer supply / recovery device that transports wafers after process in order, degassing area, cooling area, stock area, and stores them in FOUP. A wafer supply / recovery device having a function of degassing a wafer after processing, comprising a hot plate in the upper stage and a cooling plate in the lower stage. Wafer supply / collection device that collects clean air in the mini-environment and sends it into the FOUP using a hooded hood.

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