Plasma etching apparatus

Abstract

A plasma etch apparatus is disclosed. The plasma etch apparatus includes an electrostatic chuck for loading a wafer; an insulation portion surrounding the electrostatic chuck; and a focus ring disposed on the electrostatic chuck and the insulation portion. The focus ring has a concave-convex configuration.

1 . An apparatus for plasma etching a wafer, comprising: 
 an electrostatic chuck for loading said wafer in the apparatus;    an insulation portion surrounding the electrostatic chuck; and    a focus ring having a circular shape disposed on the electrostatic chuck and the insulation portion,    a portion of the focus ring having a concave-convex configuration.    
   
   
       2 . The plasma etch apparatus of  claim 1 , wherein the focus ring has a concave-convex configuration at the interface where the focus ring contacts the insulation portion.  
   
   
       3 . The plasma etch apparatus of  claim 1 , wherein the electrostatic chuck comprises: 
 a center portion having a diameter shorter than the diameter of the wafer; and    a peripheral portion having a top surface lower than the center portion and surrounding the center portion.    
   
   
       4 . The plasma etch apparatus of  claim 3 , wherein the insulation portion comprises: 
 a bottom supporter surrounding the electrostatic chuck; and    a cover ring spaced from the electrostatic chuck and disposed on the bottom supporter,    wherein the focus ring covers at least a section of the top surface of the peripheral portion and an inner top surface of the cover ring.    
   
   
       5 . The plasma etch apparatus of  claim 4 , wherein the cover ring comprises: 
 an outer cover ring disposed on an edge of a top surface of the bottom supporter; and    an inner cover ring disposed between the outer cover ring and the focus ring,    wherein the inner cover ring has an extension portion which extends to a bottom of the focus ring.    
   
   
       6 . The plasma etch apparatus of  claim 5 , wherein a top surface and an outer sidewall of the outer cover ring form a curved fan-shaped section.  
   
   
       7 . The plasma etch apparatus of  claim 5 , wherein a bottom surface of the outer cover ring is disposed at a location lower than the inner cover ring.  
   
   
       8 . The plasma etch apparatus of  claim 5 , wherein the outer cover ring is formed of quartz or aluminum coated with yttrium oxide (Y 2 O 3 ), the inner cover ring is formed of quartz or aluminum coated with yttrium oxide (Y 2 O 3 ), and the focus ring is formed of silicon.  
   
   
       9 . The plasma etch apparatus of  claim 1 , wherein the insulation portion has a circular-shaped groove and the focus ring has a circular-shaped protruding portion fittingly engaged within the groove.  
   
   
       10 . The plasma etch apparatus of  claim 5 , wherein the inner cover ring has a circular-shaped groove and the focus ring has a circular-shaped protruding portion fittingly engaged within the groove.  
   
   
       11 . The plasma etch apparatus of  claim 1 , wherein the focus ring has a circular-shaped groove and the insulation portion has a circular-shaped protruding portion fittingly engaged within the groove.  
   
   
       12 . The plasma etch apparatus of  claim 5 , wherein the focus ring has a circular-shaped groove and the inner cover ring has a circular-shaped protruding portion fittingly engaged within the groove.  
   
   
       13 . The plasma etch apparatus of  claim 1 , wherein sections of the focus ring and the insulation portion have complementary configurations comprising ripple patterns which are fittingly engaged with respect to each other.  
   
   
       14 . The plasma etch apparatus of  claim 5 , wherein sections of the focus ring and the inner cover ring have complementary configurations comprising ripple patterns which are fitting engaged with respect to each other.  
   
   
       15 . The plasma etch apparatus of  claim 1 , wherein the focus ring includes at least one protruding portion or at least one groove.  
   
   
       16 . The plasma etch apparatus of  claim 3 , wherein a gap between the focus ring and the center portion is from about 0.01 mm to about 0.2 mm.  
   
   
       17 . The plasma etch apparatus of  claim 1 , wherein a gap between the focus ring and the insulation portion is from about 0.01 mm to about 0.2 mm.  
   
   
       18 . The plasma etch apparatus of  claim 1 , wherein the focus ring includes an inner ring adjacent to the electrostatic chuck and an outer ring adjacent to the insulation portion, wherein a top surface of the inner ring is lower than a top surface of the electrostatic chuck by a distance of from about 0.1 to 0.7 mm.  
   
   
       19 . The plasma etch apparatus of  claim 1 , wherein a top surface of the insulation portion is equal to or lower than an top surface of the focus ring.  
   
   
       20 . An apparatus for plasma etching a wafer, comprising: 
 an electrostatic chuck for loading said wafer in the apparatus;    an insulation portion surrounding the electrostatic chuck;    a focus ring disposed on the electrostatic chuck and the insulation portion, at least a portion of the focus ring comprising a concave-convex configuration;    a center portion having a diameter shorter than the diameter of the wafer;    a peripheral portion having a top surface lower than the center portion and surrounding the center portion;    a bottom supporter surrounding the electrostatic chuck; and    a cover ring spaced from the electrostatic chuck and disposed on the bottom supporter.