JP2002237508A - Method for vacuum processing substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for vacuum processing for realizing a high production efficiency. SOLUTION: In the method for vacuum processing a substrate, an atmospheric conveying unit has a robot disposed at a front side common for a load locking chamber and an unload locking chamber, to convey an unprocessed substrate and a processed substrate. The conveying unit mounts a cassette for housing the unprocessed substrate on a cassette base for housing the cassette, disposed fixedly on a substantially horizontal surface disposed at the predetermined position of a front side of the conveying unit; sequentially conveys the unprocessed substrates at each one from any place in the cassette of the arbitrary base to the load locking chamber, based on production information imparted to the cassette or the information sent from a host controller by the conveying unit; conveys the unprocessed substrate at each one from the load locking chamber to any vacuum processing chamber; processes the substrate; delivers the processed substrate in an arbitrary vacuum processing chamber at each one to the unload locking chamber; and recovers the processed substrate from the unload locking chamber to an original position of the original cassette at each one, by the conveying unit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vacuum processing method for a substrate, and more particularly to a vacuum processing method having a plurality of vacuum processing chambers and a vacuum processing method for a substrate using the same.

[0002]

2. Description of the Related Art 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 housed in a substrate cassette as one unit (generally called a lot). It is a general vacuum processing apparatus transport system and operating method that the efficiency of production is improved by putting the processed substrates into the substrate cassette for each unit and collecting the processed substrates.

However, in the above vacuum processing apparatus, particularly in an apparatus utilizing a reaction by an active gas such as a dry etching apparatus and a CVD apparatus, a reaction product adheres and accumulates in a processing vessel as the processing is performed. Often, problems such as deterioration of vacuum performance, increase of dust, and decrease in the level of an optical monitor signal occur, and in order to avoid such problems, an operation of periodically cleaning the inside of the processing container is performed. Cleaning work includes so-called wet cleaning, which wipes off deposits with an organic solvent, etc., and dry cleaning, which uses active gas or plasma to decompose the deposits. From the viewpoint of workability and efficiency, dry cleaning is superior. These features are becoming essential as production lines become more automated.

An example of a transfer system for a vacuum processing apparatus having such a function is the apparatus disclosed in Japanese Utility Model Laid-Open No. 63-127125.

[0005]

Problems to be Solved by the Invention
In the apparatus disclosed in Japanese Patent No. 127125, a dummy wafer previously housed in a vacuum preparatory chamber is loaded into the processing chamber when performing plasma cleaning of the processing chamber. It has been made to return. For this reason, there is a problem that the vacuum spare chamber for accommodating the dummy wafer requires a large volume and requires a transfer mechanism dedicated to the dummy wafer, which complicates the apparatus.

Further, in order to continue the normal processing after the dummy wafer once used for the plasma cleaning is returned to the vacuum preparatory chamber, the used dummy wafer and the normal processing are received in the vacuum preparatory chamber. The unprocessed wafers to be mixed are mixed, which is not preferable from the viewpoint of product contamination.

An object of the present invention is to solve the above problems,
Eliminate product contamination due to garbage and residual gas,
An object of the present invention is to provide a vacuum processing method for a substrate which realizes high production efficiency and high product yield.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a cassette table on which a plurality of cassettes accommodating a plurality of substrates are placed in an atmosphere, and an atmosphere transfer device operating in the atmosphere. A plurality of vacuum processing chambers for processing substrates one by one, a load lock chamber for loading an unprocessed substrate into any one of the vacuum processing chambers, and unloading a processed substrate from any one of the vacuum processing chambers. A vacuum processing method for a substrate, comprising: an unload lock chamber for removing the unprocessed substrate and the processed substrate, wherein the atmospheric transfer device is located on a front side common to the load lock chamber and the unload lock chamber. A transfer device having a transfer robot, wherein the unprocessed substrate is stored in the cassette table in which a cassette is stored fixedly disposed on a substantially horizontal surface at a predetermined position in front of the atmospheric transfer device. The cassette was placed on, by the atmospheric transfer device, granted production information to the cassette,
Alternatively, based on information sent from a higher-level control device, the unprocessed substrates are transferred one by one from any place in the cassettes of any one of the cassette tables to the load lock chamber, and any unprocessed substrates are transferred from the load lock chamber. The unprocessed substrates are loaded and processed one by one into the vacuum processing chamber, and the substrates that have been processed in any one of the vacuum processing chambers are transported one by one to the unload lock chamber. And collecting the processed substrates one by one from the unload lock chamber to the original position of the original cassette.

According to the present invention, a cassette containing unprocessed substrates is placed on a cassette table. At this time, since the cassette table is horizontal, the supply operation of the cassette can be simplified, and it is easy to respond to automation of the production line.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One 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 is provided with a plurality (usually 25) for supplying an object to be processed to the apparatus in a state where the unprocessed wafers are stored, and storing and processing the processed wafers at the original position again. A plurality of cassettes 1a capable of storing wafers,
1b and 1c, on which the cassettes 1a, 1b, 1c are placed and fixed on a horizontal or near-horizontal plane without changing the position and posture for determining the position of introduction / discharge to the apparatus. Cassette table 2a, 2 fixed in position
b, 2c, a load lock chamber (substrate receiving chamber) 5 for introducing a wafer into a vacuum atmosphere, which is equipped with a vacuum exhaust device and a gas introducing device (not shown), and an unload lock chamber for taking the wafer into the atmosphere ( Substrate unloading chamber) 6,
Etching 11 for performing etching process on wafer
(11a, 11b, 11c), an isolation valve 12 capable of separating them airtightly, and a load lock chamber (substrate receiving chamber) 5 / unload lock chamber (substrate unloading chamber) 6 and cassettes 1a, 1b, 1c. Between the load lock chamber (substrate receiving chamber) 5 / unload lock chamber (substrate unloading chamber) 6 and the cassettes 1a, 1b, 1c provided with a robot having X, Y, Z and θ axes. And a first transfer device 13 for sending and receiving wafers.

As an operation of the apparatus, first, cassettes 1a and 1b storing unprocessed wafers are supplied from a stocker (not shown) to the apparatus by a robot or an operator, and are mounted on the cassette tables 2a and 2b. At this time, since the cassette tables 2a and 2b are on the same horizontal plane, it is possible to simplify the operation of supplying the cassette, and it is easy to respond to automation of the production line. On the other hand, the cassette table 2
On c, a cassette 1c containing a dummy wafer is placed.

[0014] The device recognizes the production information given to the cassette by itself, is based on information sent from a higher-level control device, or is based on a command input by an operator.
The wafer can be processed by any of the methods.

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 device) disposed on the opposite side of the first transfer device 13 from the cassette 1a. To chamber 5) Isolation valve 12a
Carry in through. At this time, the wafer (substrate) 20
It may be stored in any place in the cassette 1a. After the wafer (substrate) 20 enters the load lock chamber (substrate receiving chamber) 5 from the isolation valve 12a and exits the unload lock chamber (substrate unloading chamber) 6 from the isolation valve 12b, the atmosphere outside the apparatus is completely complete. Because it is in a state of being cut off,
A partition is provided between the isolation valves 12a and 12b, and the cassette tables 2a and 2b and the cassettes 1a and 1b mounted thereon are provided.
In addition, only the first transfer device 13 can be placed in the clean room where the cleanliness is high, and the rest can be placed in the maintenance room where the cleanliness is low. After closing the isolation valve 12a, the load lock chamber (substrate receiving chamber) 5 is evacuated to a predetermined pressure by an exhaust device (not shown), and then the isolation valve 12b is opened to transfer the wafer (substrate) 20. The wafer is transferred to each of the etching chambers 11 (11a, 11b, 11c) by a vacuum transfer device (not shown) provided in the chamber 16, and is placed on each of the sample tables 8 (8a, 8b, 8c).

Each of the etching chambers 11a, 11b, 11
In c, an isolation valve 12a ', 12b', 12c '(not shown) is provided between the transfer chamber 16 and the transfer chamber 16 so as to airtightly separate them.

Each of the etching chambers 11 (11a, 11b, 1)
The wafer (substrate) 20 carried into 1c 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 the same as the first wafer from the opened isolation valve 12a. 2
The first wafer is loaded by the first transfer device 13,
It is evacuated again to a predetermined pressure by the exhaust device.
When the etching processing of the first wafer (substrate) 20 is completed, the isolation valve 12c is opened, and the processed wafer (substrate) 20 is carried out to the unload lock chamber (substrate unloading chamber) 6, and then the isolation valve is opened. 12c is closed and the isolation valve 12 is closed.
b is opened, the second wafer is carried in 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 unloading chamber) 6 returns to the atmospheric pressure in the unload lock chamber (substrate unloading chamber) 6, and then passes through the first isolation valve 12d. It is taken out into the atmosphere by the transport device 13 and returned to the original position in the cassette 1a that was initially stored.

By repeating the above operation, the processing of the unprocessed wafers stored in the cassette 1a is completed, and when the wafers are stored again in the original position, the cassette 1a can be collected.
The apparatus is replaced with a cassette containing another unprocessed wafer, but the apparatus continues to process the unprocessed wafers in the cassette 1b, and another unprocessed wafer is processed before all the wafers in the cassette 1b are completely processed. When a cassette containing wafers is supplied, the apparatus can always be operated continuously. At this time, since the cassette 1a and the cassette 1b are on the same horizontal plane, the operation of collecting the cassette 1a and the operation of supplying a cassette containing another unprocessed wafer are not affected by the access to the cassette 1b by the transfer device 13. Can be done without giving.

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 substance by plasma cleaning and restore the original state. In the embodiment, the dummy wafer 30 stored in the cassette 1c is extracted by the first transfer device 13, and thereafter the processing is performed in exactly the same manner as in the case of the processing target wafer (substrate) 20. Can be returned to the original position in the cassette 1c, and the dummy wafers 30 are always stocked in the cassette 1c.

If all of the dummy wafers 30 in the cassette 1c have been used for plasma cleaning or if the dummy wafers 30 have failed due to several uses, the dummy wafers 30 will not be used.
Are exchanged every cassette 1c.

Therefore, it is not necessary to treat the plasma cleaning as a special processing sequence, the plasma cleaning can be performed as a series of operations by incorporating the cleaning into a normal etching process, and the cleaning cycle can be arbitrarily set. is there. There is no need for a special mechanism for plasma cleaning from the hardware of the apparatus, and the dummy wafer 30 is mounted on one of the plurality of cassette tables (2c in this example).
It is only necessary to install a cassette (1c in this example) in which the wafer to be processed 20 is stored instead of the cassette in which the dummy wafer 30 is stored. It is needless to say that the installation enables more efficient production.

Further, the dummy wafer once used for the plasma cleaning is returned to the original cassette in the atmosphere again. Therefore, in the vacuum chamber, the used dummy wafer and the normal dummy wafer are to be processed. Unprocessed wafers are not mixed, and there is no concern about product contamination.

[0024]

According to the present invention, there is provided a vacuum processing which eliminates the generation of dust and contamination of products due to residual gas, realizes a high production efficiency and a high product yield, and a vacuum processing method for a substrate using the same. be able to.

[Brief description of the drawings]

FIG. 1 is a plan view of a dry etching apparatus according to an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Substrate cassette, 2 ... Cassette stand, 5 ... Load lock chamber (substrate receiving chamber), 6 ... Unload lock chamber (substrate unloading chamber), 8 ... Sample table, 11 ... Etching chamber, 12 ... Isolation valve, 13 ... First transfer device, 16: transfer chamber, 20: wafer (substrate), 30: dummy wafer.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tsunehiko Tsune 794 Kazato, Higashitoyoi, Kudamatsu-shi, Yamaguchi Prefecture Inside the Kasado Plant, Hitachi, Ltd. (72) Inventor Wenji Ito 794 Kazato, Higashitoyoi, Kudamatsu-shi, Yamaguchi Inside the Kasado Plant of Hitachi, Ltd.

Claims (1)

[Claims] 1. A cassette table on which a plurality of cassettes accommodating a plurality of substrates are placed in an atmosphere, an atmosphere transfer device operating in the atmosphere, a plurality of vacuum processing chambers for processing substrates one by one, and A vacuum processing method for a substrate comprising: a load lock chamber for carrying a processing substrate into any one of the vacuum processing chambers; and an unload lock chamber for carrying out a processed substrate from any one of the vacuum processing chambers. The atmosphere transfer device is a transfer device that is located on a front side common to the load lock chamber and the unload lock chamber and has a robot that transfers an unprocessed substrate and a processed substrate, and the front side of the atmosphere transfer device. The cassette storing the unprocessed substrate is placed on the cassette table in which the cassette is stored by being fixedly disposed on a substantially horizontal surface at a predetermined position, The unprocessed substrates are transferred one by one to the load lock chamber from any place in the cassette of any one of the cassette tables based on the production information given to the cassette or information sent from a higher-level control device. Then, the unprocessed substrates are loaded one by one from the load lock chamber to one of the vacuum processing chambers and processed, and the substrates that have been processed in any one of the vacuum processing chambers are processed one by one in the unload lock chamber. A method of vacuum processing a substrate, comprising: unloading the processed substrate from the unload lock chamber to the original position of the original cassette one by one by the atmospheric transfer device.