Plasma processing apparatus and processing method

Abstract

The present invention provides a plasma processing apparatus and processing method capable of maintaining a constant processing profile. The plasma processing apparatus for providing a plasma processing to a wafer placed in a processing chamber comprises a processing vessel 1a constituting the processing chamber 1, process gas supply devices 3, 4 for supplying processing gas to the processing chamber 1, and a plasma generating means 2 for generating plasma by supplying electromagnetic energy to the processing chamber and dissociating the process gas supplied to the processing chamber, wherein the apparatus further comprises a processing chamber surface temperature control unit 15 for controlling the inner surface temperature of the processing chamber, the control unit controlling the temperature by heating the inner surface of the processing chamber by generating plasma in the chamber for a predetermined processing time based on a processing history after terminating a cleaning process and prior to performing the wafer processing.

Description

[0001] The present application claims priority from Japanese patent application No. 2004-54229 filed on Feb. 27, 2004, the content of which is hereby incorporated by reference into this application. FIELD OF THE INVENTION [0002] The present invention relates to a plasma processing apparatus and processing method, and more specifically, to a plasma processing apparatus and processing method preferably applied to the micromachining of semiconductor devices. DESCRIPTION OF THE RELATED ART [0003] A plasma processing apparatus is a device for forming fine patterns on a surface of a wafer to be fabricated into a semiconductor device or the like. One typical example of the plasma processing apparatus is a plasma etching apparatus. The plasma etching apparatus is equipped with a processing chamber for processing the wafer, a sample stage for placing the wafer disposed in the processing chamber, and a gas supply system including, for example, a shower plate for introducing the gas used for e...

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Benefits of technology

[0027] In view of the above-mentioned problems, the present invention offers a plasma processing apparatus and processing method capable of maintaining a constant processing profile.

Problems solved by technology

However, the reaction products will gradually deposit in the processing chamber during repeated wafer processing, and cause the state of the inner surface of the processing chamber (the surface of the processing chamber exposed to plasma and radicals, and the surface of components disposed in the processing chamber) to change.

The states of the plasma and radicals contained in the processing chamber are easily affected by the surface state of the processing chamber, and therefore, the processing profiles of the semiconductor devices gradually vary during repeated etching even under the same processing conditions, causing the performance of the semiconductor devices to deteriorate.

If the deposits in the processing chamber are left unremoved, the thickness of the deposits increases gradually, and the repeated thermal stress of plasma heating causes the thick deposits to crack and create fine contaminants.

If the contaminants fall on the wafers, they obstruct the etching process and cause process defects that lead to malfunction of the processed devices.

If oxygen gas is used as one of the etching gases, it causes the processing chamber surface to oxidize, and if halogen gas is used, it causes the surface to be halogenated.

However, most of these measures were not sufficient, and the processing profiles of the semiconductor devices were still gradually varied.

Therefore, it was necessary to replace or to clean the components of the processing apparatus before the fluctuation of the processing profiles caused problems.

However, they are not capable of suppressing the fluctuation of processing profiles of the wafers.

Thus, it is difficult to maintain a constant plasma and radical state and to maintain a fixed processing profile just by removing the deposits in the processing chamber.

However, the state of radicals cannot be made constant simply by coating the inner surface of the processing chamber with polymer.

Thus, it is difficult to uniformly control the surface temperature thereof which has the greatest influence on surface reaction.

In other words, the inner surface temperature of the processing chamber may be left substantially uncontrolled, and this may cause the fluctuation of the radical state.

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