Plasma processing method and apparatus

Abstract

A plasma processing method includes evacuating a vacuum chamber while supplying a gas into the vacuum chamber, thereby controlling an interior of the vacuum chamber to a pressure, and supplying a high frequency power of a frequency of 50 MHz-3 GHz to an antenna which is set opposite to a substrate placed at a substrate electrode in the vacuum chamber and which has a structure with a dielectric member held between a wall face of the vacuum chamber opposite to the substrate and a metallic plate, thereby generating plasma inside the vacuum chamber and processing the substrate, wherein the high frequency power is supplied to satisfy a relation 3r<c/(f·∈ ½ )<9r when c is a light velocity (m/sec), f is a frequency (Hz) of the high frequency power, ∈ is a relative permittivity of the dielectric member, and r is a half (m) of a longer line of a shape of the dielectric member.

What is claimed is:  
     
         1 . A plasma processing apparatus comprising: 
 a vacuum chamber;    a gas supply device for supplying a gas into the vacuum chamber;    an evacuation device for evacuating the vacuum chamber;    a substrate electrode used for placing a substrate in the vacuum chamber;    an antenna in a structure having a dielectric member held between a wall face of the vacuum chamber opposite to the substrate electrode and a metallic plate; and    a high frequency power source capable of supplying a high frequency power of a frequency of 50 MHz-3 GHz to the antenna,    the plasma processing apparatus being constituted to supply the high frequency power to satisfy a relation 3r<c/(f·∈ ½ )<9r wherein c is a light velocity (m/sec), f is a frequency (Hz) of the high frequency power, ∈ is a relative permittivity of the dielectric member, and r is a half (m) of a longer line of a shape of the dielectric member.    
     
     
         2 . A plasma processing apparatus according to  claim 1 , wherein the plasma processing apparatus is constituted to supply the high frequency power to satisfy a relation 3r<c/(f·∈ ½ )<9r wherein c is alight velocity (m/sec), f is a frequency (Hz) of the high frequency power, ∈ is a relative permittivity of the dielectric member, and r is a radius (m) of a circular shape of the dielectric member.  
     
     
         3 . A plasma processing apparatus according to  claim 1 , wherein the plasma processing apparatus is constituted to supply the high frequency power to satisfy a relation 3r<c/(f·∈ ½ )<9r wherein c is alight velocity (m/sec), f is a frequency (Hz) of the high frequency power, ∈ is a relative permittivity of the dielectric member, and r is a half (m) of a diagonal line of a rectangular shape of the dielectric member.  
     
     
         4 . A plasma processing apparatus according to  claim 1 , wherein the plasma processing apparatus is constituted to supply the high frequency power to satisfy a relation 3r<c/(f·∈ ½ )<9r wherein c is a light velocity (m/sec), f is a frequency (Hz) of the high frequency power, ∈ is a relative permittivity of the dielectric member, and r is a half (m) of a major axis of an ellipse shape of the dielectric member.  
     
     
         5 . A plasma processing apparatus according to  claim 1 , wherein the plasma processing apparatus is constituted to supply the high frequency power to satisfy a relation 4r<c/(f·∈ ½ )<8r wherein c is alight velocity (m/sec), f is a frequency (Hz) of the high frequency power, ∈ is a relative permittivity of the dielectric member, and r is a half (m) of a longer line of a shape of the dielectric member.  
     
     
         6 . A plasma processing apparatus according to  claim 1 , wherein the plasma processing apparatus is constituted to supply the high frequency power to satisfy a relation 5r<c/(f·∈ ½ )<7r wherein c is a light velocity (m/sec), f is a frequency (Hz) of the high frequency power, ∈ is a relative permittivity of the dielectric member, and r is a half (m) of a longer line of a shape of the dielectric member.  
     
     
         7 . A plasma processing apparatus according to  claim 1 , wherein a high frequency voltage is supplied to the metallic plate via a through hole formed in a vicinity of a center of the dielectric member, thereby shortcircuiting the metallic plate and the wall face of the vacuum chamber opposite to the substrate via through holes formed to a plurality of points different from the center and a periphery of the dielectric member.  
     
     
         8 . A plasma processing apparatus according to  claim 7 , wherein each of the points to be shortcircuited to the vacuum chamber is almost isotropically arranged to the center of the antenna.  
     
     
         9 . A plasma processing apparatus according to  claim 1 , wherein a surface of the antenna is covered with an insulating cover.  
     
     
         10 . A plasma processing apparatus according to  claim 1 , wherein a ring and groove-shaped plasma trap is set between the antenna and vacuum chamber.