Vacuum processing apparatus and method

Abstract

A gas exhaust unit evacuates the inside of a vacuum transfer chamber at a constant exhaust rate. An gas exhaust valve is kept normally open, and a purge gas (N2 gas) is supplied from a purge gas supply source into the vacuum transfer chamber via a mass flow controller (MFC) and an opening / closing valve. A main control unit controls a pressure in the vacuum transfer chamber to be within a specified range through a flow rate set value for the MFC while monitoring a pressure in the vacuum transfer chamber via a vacuum gauge. The main control unit determines occurrence of abnormality when the pressure exceeds a specified upper limit and then takes such actions as changing a flow rate set value for the MFC, giving an alarm and stopping the operation of a vacuum processing apparatus.

Description

[0001]This application is a Continuation Application of PCT International Application No. PCT / JP 2007 / 050271 filed on Jan. 11, 2007, which designated the United States.FIELD OF THE INVENTION[0002]The present invention relates to a vacuum processing apparatus and method for performing a desired process on a target object in a vacuum state; and, more particularly, to a technology for controlling an atmosphere in a vacuum transfer chamber where a target object is transferred to and from a vacuum processing chamber under a reduced pressure.BACKGROUND OF THE INVENTION[0003]In manufacturing a semiconductor device or a flat panel display (FPD), various processes such as a film forming process, a heat treatment process, a dry etching process, a cleaning process and the like are performed in a vacuum vessel by using required processing gases. For example, apparatuses for performing such vacuum processes are disclosed in Japanese Patent Laid-open Publication Nos. 2000-127069 and H3-087386). I...

AI Technical Summary

Benefits of technology

[0007]It is, therefore, an object of the present invention to provide a vacuum processing apparatus and method capable of preventing organic contamination of a target object in a vacuum transfer chamber.

[0009]In accordance with the apparatus of the first aspect, even if organic substances are scattered from organic materials in the vacuum transfer chamber due to degasification, they are diluted by the purge gas supplied from the purge gas supply unit and the amount of the organic substances attached to the target object can be reduced. In particular, under a high vacuum, much more organic substances are likely to be attached to the target object while the amount of the organic substances attached thereto can be significantly reduced by controlling the flow rate of the purge gas. Preferably, an upper limit of the pressure range is set to 66.7 Pa (500 mTorr) or less, and the flow rate of the purge gas is controlled to 10 sccm or more.

[0012]In accordance with the apparatus of the second aspect, even if organic substances are scattered from organic materials in the load-lock chamber due to degasification, they are diluted by the purge gas supplied from the purge gas supply unit and the amount of the organic substances attached to the target object can be reduced. In particular, under a high vacuum, much more organic substances are likely to be attached to the target object while the amount of the organic substances attached thereto can be significantly reduced by controlling the flow rate of the purge gas. Preferably, an upper limit of the pressure range is set to 66.7 Pa (500 mTorr) or less, and the flow rate of the purge gas is controlled to 10 sccm or more. Further, it is preferable to set the internal pressure of the load-lock chamber higher than that of the vacuum transfer chamber in order to prevent the atmosphere in the vacuum transfer chamber close to the vacuum processing chamber from diffusing into the load-lock chamber.

[0014]In accordance with the apparatus of the third aspect, even if organic substances are scattered from organic materials in the vacuum transfer chamber due to degasification, they are diluted by the purge gas supplied from the purge gas supply unit and the amount of the organic substances attached to the target object can be reduced. In particular, under a high vacuum, much more organic substances are likely to be attached to the target object while the amount of the organic substances attached thereto can be significantly reduced by controlling the flow rate of the purge gas. Preferably, a lower limit of the flow rate is set to 10 sccm or more and the internal pressure of the vacuum transfer chamber is controlled to 66.7 Pa (500 mTorr) or less.

[0017]In accordance with the apparatus of the fourth aspect, even if organic substances are scattered from organic materials in the load-lock chamber due to degasification, they are diluted by the purge gas supplied from the purge gas supply unit and the amount of the organic substances attached to the target object can be reduced. In particular, under a high vacuum, much more organic substances are likely to be attached to the target object while the amount of the organic substances attached thereto can be significantly reduced by controlling the flow rate of the purge gas. Preferably, an upper limit of the pressure range is set to 66.7 Pa (500 mTorr) or less, and the flow rate of the purge gas is controlled to 10 sccm or more. Further, it is preferable to set the internal pressure of the load-lock chamber higher than that of the vacuum transfer chamber in order to prevent the atmosphere in the vacuum transfer chamber close to the vacuum processing chamber from diffusing into the load-lock chamber.

Problems solved by technology

However, the vacuum processing apparatus has a problem of organic contamination that organic substances generated from a moving part or a frictional part in the vacuum transfer chamber are attached to the target object.

In particular, if the vacuum processing apparatus has a cluster tool type structure, an overall processing time, i.e. a stay time of the target object, takes long due to many processes in the system.

Such organic attachment or contamination deteriorates the reliability of processes such as film forming and etching processes in the vacuum processing chamber, resulting in a poor production yield.

Furthermore, incubation time increases in the film forming process, which leads to increase of variation in thickness.

Particularly, if organic substances which are produced or scattered from grease applied to a vacuum sealing O-ring or bearing, which are generated from a transfer mechanism, e.g., a transfer belt, or which are detached from surfaces of components in the processing chamber after being attached thereto due to poor cleaning, are attached to the surface of the target object, it is hard to remove the organic substances and a defective area on a target surface becomes larger.