Apparatus and method for dry etching

Abstract

The present invention herein provides an apparatus and a method for dry etching, which can solve such a problem that an object to be processed undergoes cracking during the etching procedures due to the heat deformation thereof and thermal shocks, possibly encountered when subjecting, to dry etching procedures, the object having a high thermal expansion coefficient. A dry etching apparatus is provided with an electrode structure having a convex-shaped surface, the convex-shape is one concentric with the cross section of the electrode structure and the height thereof falls within the range of from 0.2 to 1.0 mm. An object consisting of a material having a thermal expansion coefficient of not less than 30×10 −7 /° C. is subjected to dry etching while using the foregoing dry etching apparatus.

1 . A dry etching apparatus characterized in that it is provided with an electrode structure having a convex-shaped surface. 
   
   
       2 . The dry etching apparatus as set forth in  claim 1 , wherein the convex-shape is one concentric with a cross section of the electrode structure and its height falls within the range of from 0.2 to 1.0 mm. 
   
   
       3 . A dry etching apparatus having the following construction: a plasma-generation section is positioned within and at the upper portion of a vacuum chamber and a substrate electrode section is positioned within and at the bottom portion of the vacuum chamber; a high-frequency antenna coil for generating plasma, which is connected to a first high-frequency power source, is attached to an outside of a side wall of the plasma-generation section, which is constituted by a dielectric material; an electrode structure, to which a high-frequency bias electric power is applied through a second high-frequency power source, is fitted to the substrate electrode section; a counter electrode is arranged within the plasma-generation section in such a manner that it is opposed to the electrode structure; and a magnetic field-establishing coil is positioned on an outside of the high-frequency antenna coil, wherein the electrode structure has a convex-shaped surface. 
   
   
       4 . The dry etching apparatus as set forth in  claim 3 , wherein the convex-shape is one concentric with the cross section of the electrode structure and the height thereof falls within the range of from 0.2 to 1.0 mm. 
   
   
       5 . A the dry etching apparatus having the following construction: a plasma-generation section is positioned within and at the upper portion of a vacuum chamber and a substrate electrode section is positioned within and at the bottom portion of the vacuum chamber; a high-frequency antenna coil for generating plasma, which is connected to a first high-frequency power source, is attached to an outside of a side wall of the plasma-generation section, which is constituted by a dielectric material; an electrode structure, to which a high-frequency bias electric power is applied through a second high-frequency power source, is fitted to the substrate electrode section; a counter electrode is arranged within the plasma-generation section in such a manner that it is opposed to the electrode structure; a magnetic field-establishing coil is positioned on an outside of the high-frequency antenna coil; and a variable condenser serving as a branching device is arranged in the course of an electric power supply path positioned between the antenna coil and the first high-frequency power source so as to ensure the connection of the first high-frequency power source with the counter electrode, wherein the electrode structure has a convex-shaped surface. 
   
   
       6 . The dry etching apparatus as set forth in  claim 5 , wherein the convex-shape is one concentric with the cross section of the electrode structure and the height thereof falls within the range of from 0.2 to 1.0 mm. 
   
   
       7 . A dry etching method comprising the step of dry etching an object to be processed, which consists of a material having a thermal expansion coefficient of not less than 30×10 −7 /° C. using a dry etching apparatus as set forth in any one of  claims 1  to  6 . 
   
   
       8 . The dry etching method as set forth in  claim 7 , wherein the object to be processed is one consisting of a quartz, quartz crystal or glass material.