JP3628683B2 - Vacuum processing apparatus and substrate transfer processing method - Google Patents

Description

  The present invention relates to a vacuum processing apparatus, and more particularly to a transfer system for a vacuum processing apparatus having a plurality of vacuum processing chambers.

  In a vacuum processing apparatus such as a dry etching apparatus, a CVD apparatus or a sputtering apparatus, a plurality of predetermined substrates to be processed are stored as a unit (generally called a lot) in a substrate cassette and put into the apparatus for processing. It is a common vacuum processing apparatus to improve the production efficiency by storing the collected substrates in the same unit and collecting them in the substrate cassette.

  However, in vacuum processing apparatuses such as those described above, particularly dry etching apparatuses and CVD apparatuses that use a reaction by an active gas, the reaction product adheres and accumulates in the processing container as the processing is performed, so that the vacuum performance In many cases, problems such as deterioration of dust, increase in dust, and decrease in the level of the optical monitor signal occur, and in order to avoid such problems, work for periodically cleaning the inside of the processing container is performed. Cleaning operations include so-called wet cleaning that wipes off deposits with an organic solvent, etc., and dry cleaning that uses active gas or plasma that decomposes deposits. However, dry cleaning is superior in terms of workability and efficiency. These functions are becoming indispensable as production lines become more automated.

  An example of a vacuum processing apparatus having such a function is an apparatus disclosed in Patent Document 1.

Japanese Utility Model Publication No. 63-127125

  For example, in the apparatus disclosed in Patent Document 1, a dummy wafer previously accommodated in a vacuum preparatory chamber is carried into the processing chamber when performing plasma cleaning on the processing chamber. It is made to return to the room. For this reason, the vacuum preliminary chamber for accommodating the dummy wafer requires a large volume and requires a transport mechanism dedicated to the dummy wafer, which causes a problem that the apparatus becomes complicated.

  Further, once the dummy wafer used for the plasma cleaning is returned to the vacuum preliminary chamber again, the normal processing is continued. Therefore, in the vacuum preliminary chamber, the used dummy wafer and the normal processing are going to be received. Unprocessed wafers are mixed, which is not preferable from the viewpoint of product contamination.

  An object of the present invention is to provide a transport system for a vacuum processing apparatus that solves the above-described problems, eliminates product contamination due to generation of dust and residual gas, and realizes high production efficiency and high product yield. .

  In order to achieve the above object, the present invention provides an isolation valve that is connected to a plurality of vacuum processing chambers for vacuum processing each substrate to be processed in a horizontal state and separates each chamber from the vacuum processing chamber. A transfer chamber comprising a single chamber, a plurality of cassette tables for mounting a plurality of cassettes capable of storing a plurality of substrates to be processed, processed substrates or dummy processed substrates in the atmosphere, and connected to the transfer chamber. In order to carry out the substrate between the load lock chamber for carrying the substrate into and out of any vacuum processing chamber through the transfer chamber and the vacuum processing chamber through the transfer chamber. An unload-lock chamber, an atmospheric transfer device that transfers the substrates one by one between the cassette in the atmosphere and both the load-lock chamber and the unload-lock chamber, the load-lock chamber, and the load-lock chamber Unload lock room An isolation valve is provided on each of the atmosphere side and the vacuum side, and is opened and closed each time the load lock chamber and the unload lock chamber are switched to the atmospheric atmosphere or the vacuum atmosphere each time they are loaded and unloaded. is there.

  According to the present invention, a load lock chamber for unloading a substrate to be processed into any one of the vacuum processing chambers, and the processed substrate from the vacuum processing chamber via the transfer chamber and the atmosphere. There is an unload lock chamber for unloading the processed substrate to a cassette of the machine every time a substrate to be processed or a processed substrate is loaded / unloaded in order to switch the load lock chamber and the unload lock chamber to an air atmosphere or a vacuum atmosphere. An isolation valve that is opened and closed is provided. Then, the substrate to be processed or the processed substrate is loaded and unloaded one by one between the load lock chamber and the unload lock chamber in the atmospheric atmosphere and the cassette in the atmosphere, and the load lock chamber and the unload lock in the vacuum atmosphere. A substrate to be processed or a processed substrate is loaded and unloaded one by one between the chamber and one of the vacuum processing chambers.

  Therefore, the time during which the vacuum processing chamber and the load lock chamber or the unload lock chamber are in a conductive state with the loading / unloading of the substrate is short. Therefore, the amount of dust and residual gas adhering to the processed substrate brought into the load lock chamber and unload lock chamber is reduced, eliminating the generation of dust and product contamination due to residual gas, etc., and high production efficiency and high product yield. It is possible to provide a transfer system for a vacuum processing apparatus that realizes the above.

  Advantageous Effects of Invention According to the present invention, there is an effect that it is possible to provide a transfer system for a vacuum processing apparatus that eliminates the generation of dust and product contamination due to residual gas and realizes high production efficiency and high product yield.

  An embodiment of the present invention will be described below with reference to FIG.

  FIG. 1 is a diagram showing an application of a vacuum processing apparatus according to the present invention to an apparatus for performing a dry etching process on a semiconductor wafer.

  The apparatus supplies a processing target to the apparatus in a state where unprocessed wafers (substrates) are stored, and stores a plurality of (normally 25) wafers (substrates) for storing and recovering processed wafers (substrates) in their original positions again. A plurality of cassettes 1a, 1b, and 1c capable of storing a plurality of wafers (substrates), the cassettes 1a, 1b, and 1c are placed, and the positions and postures for determining the positions of introduction / discharge to the apparatus are changed. Equipped with cassette bases 2a, 2b, 2c, a vacuum exhaust device and a gas introduction device (not shown) that are always fixed at a fixed position on a horizontal or nearly horizontal plane, and for introducing a wafer into a vacuum atmosphere A load lock chamber (substrate receiving chamber) 5, an unload lock chamber (substrate extracting chamber) 6 for taking out the wafer into the atmosphere, an etching 11 for etching the wafer, Are arranged between the cassettes 1a, 1b and 1c, and the isolation valve 12 which can be hermetically separated and the load lock chamber (substrate receiving chamber) 5 / unload lock chamber (substrate take-out chamber) 6 and the cassettes 1a, 1b and 1c, respectively. For transferring wafers (substrates) between the load lock chamber (substrate receiving chamber) 5 / unload lock chamber (substrate taking-out chamber) 6 and the cassettes 1a, 1b, 1c having a robot having Z and θ axes. The 1st conveyance apparatus 13 is comprised.

  As an operation of the apparatus, first, cassettes 1a and 1b containing unprocessed wafers (substrates) are supplied from a stocker (not shown) to the apparatus by a robot or an operator and placed on cassette stands 2a and 2b. At this time, since the cassette stands 2a and 2b are on the same horizontal plane, the cassette supply operation can be simplified, and it is easy to cope with automation of the production line. On the other hand, a cassette 1c storing dummy wafers is placed on the cassette table 2c.

  The device can process the wafer by either recognizing the production information given to the cassette itself, based on information sent from the host control device, or by a command input by the operator. .

  An unprocessed wafer (substrate) 20 stored in the cassette 1a is extracted by the first transfer device 13, and a load lock chamber (substrate receiving chamber) 5 disposed on the opposite side of the cassette 1a with respect to the first transfer device 13. Carry in through the isolation valve 12a. At this time, the wafer (substrate) 20 may be stored in any location in the cassette 1a. After the wafer (substrate) 20 enters the load lock chamber (substrate receiving chamber) 5 from the isolation valve 12a and then exits from the unload lock chamber (substrate take-out chamber) 6 from the isolation valve 12b, the atmosphere outside the apparatus is completely Therefore, a partition is provided with the isolation valves 12a and 12b as a boundary, and only the cassette bases 2a and 2b, and the cassettes 1a and 1b and the first transfer device 13 placed thereon are highly clean. It can be placed on the clean room side, and the rest can be placed on the maintenance room side where the cleanliness is low. After the isolation valve 12a is closed, the load lock chamber (substrate receiving chamber) 5 is evacuated to a predetermined pressure by an exhaust device (not shown), then the isolation valve 12b is opened and the wafer (substrate) 20 is The sample is transferred to the etching chamber 11 (11a, 11b, 11c) by a vacuum transfer device (not shown) installed in the transfer chamber 16, and placed on the sample stage 8 (8a, 8b, 8c).

  The wafer (substrate) 20 carried into the etching chamber 11 is subjected to an etching process under predetermined conditions. During this time, the load lock chamber (substrate receiving chamber) 5 is returned to the atmospheric pressure by the gas introducing device 4 with the isolation valves 12a and 12b closed, and is similar to the first wafer from the opened isolation valve 12a. A second wafer (substrate) is carried in by the first transfer device 13 and again evacuated to a predetermined pressure by the exhaust device. When the etching process for the first wafer 20 is completed, the isolation valve 12c is opened, the processed wafer (substrate) 20 is carried out to the unload lock chamber (substrate extraction chamber) 6, and then the isolation valve 12c is closed. Then, the isolation valve 12b is opened, a second wafer (substrate) is loaded from the load lock chamber (substrate receiving chamber) 5, and after the isolation valve 12b is closed, the etching process is started.

  The processed wafer (substrate) 20 carried out to the unload lock chamber (substrate take-out chamber) 6 returns the unload lock chamber (substrate take-out chamber) 6 to atmospheric pressure, and then passes through the first transfer device 13 through the isolation valve 12d. Is taken out into the atmosphere and returned to the original position in the cassette 1a originally stored.

  By repeating the above operation, the processing of the unprocessed wafer stored in the cassette 1a is completed, and when the storage of the unprocessed wafer in the original position is completed, the cassette 1a can be recovered, and a cassette storing another unprocessed wafer In the meantime, the apparatus continues to process the unprocessed wafers in the cassette 1b, and if a cassette containing another unprocessed wafer is supplied before the processing of all the wafers in the cassette 1b is completed. The device can always be operated continuously. At this time, since the cassette 1a and the cassette 1b are on the same horizontal plane, the collection operation of the cassette 1a and the supply operation of the cassette containing another unprocessed wafer can be accessed by the first transfer device 13 to the cassette 1b. It can be done without any effect.

  In the etching chamber 11, the reaction product adheres to and accumulates on the inner wall surface as the processing is repeated. Therefore, it is necessary to remove the adhered material by plasma cleaning and restore the original state. After that, the dummy wafer 30 stored in the cassette 1c is extracted by the first transfer device 13, and thereafter the processing is performed in the same manner as in the case of the processing target wafer 20, and then the dummy wafer 30 is stored in the cassette 1c. The dummy wafer 30 is always stocked in the cassette 1c. When all the dummy wafers 30 in the cassette 1c are used for plasma cleaning, or when the use becomes defective due to several uses, the entire dummy wafer 30 is replaced.

  Accordingly, it is not necessary to treat plasma cleaning as a special processing sequence, and it can be incorporated into a normal etching process and performed as a series of operations, and the period for performing cleaning can be arbitrarily set. There is no need for a dedicated mechanism for plasma cleaning from the hardware of the apparatus, and a cassette (1c in this example) containing a dummy wafer 30 is stored in one of a plurality of cassette stands (2c in this example). For applications that do not require plasma cleaning, it is possible to produce more efficiently by installing a cassette containing a wafer (substrate) 20 to be processed instead of a cassette containing a dummy wafer 30. Needless to say that can be done.

  In addition, since the dummy wafer once used for the plasma cleaning is returned to the original cassette in the atmosphere again, the used dummy wafer in the vacuum chamber and the unprocessed one that is going to receive regular processing from now on. There is no mixing with wafers, and there is no worry of product contamination.

It is a top view of the dry etching apparatus of one Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Substrate cassette, 2 ... Cassette stand, 5 ... Load lock chamber (substrate reception chamber), 6 ... Unload lock chamber (substrate extraction chamber),
DESCRIPTION OF SYMBOLS 8 ... Sample stand, 11 ... Etching chamber, 12 ... Isolation valve, 13 ... 1st transfer apparatus, 16 ... Transfer chamber, 20 ... Wafer (substrate), 30 ... Dummy wafer

Claims (2)

A plurality of vacuum processing chambers for etching a substrate to be processed;
A plurality of cassette stands disposed on substantially the same level surface on which a substrate to be processed or a processed substrate or a cassette capable of storing a plurality of cleaning dummy substrates can be placed in an air atmosphere; and
Atmospheric transfer means configured to be movable up and down so that the substrate to be processed or the dummy substrate can be extracted from any location in any of the cassettes of the plurality of cassette stands;
A room that can be switched to an atmospheric or vacuum atmosphere;
A vacuum transfer means configured to transfer the substrate between the switchable chamber and any of the plurality of vacuum processing chambers;
The substrate or the dummy substrate is taken out from any location in any of the cassettes by the atmospheric transfer means and the vacuum transfer means, and the vacuum is set via the switchable chamber. transported to the processing chamber, wherein either one each etching process visually vacuum processing chamber is the original position twice yield the conveyed original cassette the substrate was subjected to cleaning through the switchable chamber and a means for controlling so,
A substrate processing apparatus, wherein cleaning is incorporated into a substrate etch process in the plurality of vacuum processing chambers to perform a series of operations. A plurality of vacuum processing chambers for etching a substrate to be processed, and a cassette that can store a plurality of substrates to be processed or processed substrates or a plurality of dummy substrates for cleaning can be mounted in an air atmosphere at substantially the same level. A plurality of cassette stands arranged on the surface, and the atmosphere to be movable up and down so that the substrate to be processed or the dummy substrate can be removed from any location in any of the cassette stands. A transfer means, a chamber switchable to an air atmosphere or a vacuum atmosphere, a vacuum transfer means configured to transfer the substrate between the switchable chamber and any of the plurality of vacuum processing chambers, and control And a substrate transport processing method in a vacuum processing apparatus comprising:
By the vertical movement of the atmospheric transfer means, the substrate to be processed or the dummy substrate for cleaning is extracted one by one from any location in any cassette of the plurality of cassette stands,
The substrate to be processed or the dummy substrate for cleaning is carried into any one of the vacuum processing chambers through the air transfer means and the vacuum transfer means via the chamber that can be switched to the air atmosphere or the vacuum atmosphere ,
In each of the vacuum processing chambers, the etching process is performed one by one.
The substrate that has been etched or cleaned in any one of the vacuum processing chambers is transferred from the vacuum processing chamber through the switchable chamber to the atmospheric atmosphere by the atmospheric transfer means and the vacuum transfer means. By unloading and collecting one by one in the original position of the original cassette ,
A substrate transfer processing method, wherein cleaning is incorporated into a substrate etch process in the plurality of vacuum processing chambers to perform a series of operations .

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