Thin edge carrier ring

Abstract

A PECVD deposition chamber with a circular pedestal with a recessed portion in the outer top surface of the pedestal. A PECVD deposition chamber with a circular wafer carrier ring with a recessed portion in the outer top surface of the wafer carrier ring.

1 . A PECVD deposition chamber, comprising:
 a circular wafer pedestal with a top surface diameter larger than a wafer diameter and with an outer recessed portion of said top surface where said recessed portion is outside said wafer diameter and where said recessed portion underlies an interface between a plasma edge and chamber ambient in said PECVD deposition chamber.   
     
     
         2 . The chamber of  claim 1  where said circular wafer pedestal further comprises a wafer carrier ring and where said outer recessed portion is the outer portion of said wafer carrier ring. 
     
     
         3 . The chamber of  claim 2  where a width of said outer recessed portion is in the range of 0.5 to 0.8 inches and a depth of said outer recessed portion is in the range of 0.03 to 0.06 inches. 
     
     
         4 . The chamber of  claim 3  where said width is about 0.6+/−0.005 inches and said depth is about 0.0425+/−0.005 inches. 
     
     
         5 . The chamber of  claim 1  where a pressure during a deposition in said PECVD deposition chamber is greater than 12 Torr. 
     
     
         6 . The chamber of  claim 1  where a deposition in said PECVD deposition chamber is an OSG deposition. 
     
     
         7 . A PECVD deposition chamber, comprising:
 a wafer carrier ring with a recessed portion on the outer top side of said wafer carrier ring and where said recessed portion underlies an interface between a plasma edge and chamber ambient in said PECVD deposition chamber.   
     
     
         8 . The chamber of  claim 7  where a width of said recessed portion is in the range of 0.5 to 0.8 inches and a depth of said recessed portion is in the range of 0.03 to 0.06 inches. 
     
     
         9 . The chamber of  claim 8  where said width is about 0.6+/−0.005 inches and said depth is about 0.0425+/−0.005 inches. 
     
     
         10 . The chamber of  claim 7  where a pressure during a deposition in said PECVD deposition chamber is greater than 12 Torr. 
     
     
         11 . The chamber of  claim 7  where a deposition in said PECVD deposition chamber is an OSG deposition.