Sulfur dioxide etch chemistries

Abstract

Methods of forming a semiconductor device structure and sulfur dioxide etch chemistries. The methods and chemistries, which may be plasma chemistries, include use of sulfur dioxide and a halogen-based compound to form a trimmed pattern of a patterning material, such as a resist material, at a critical dimension with low feature width roughness, with low space width roughness, without excessive height loss, and without substantial irregularities in the elevational profile, as compared to trimmed features formed using conventional chemistries and trimming methods.

1 . A sulfur dioxide etch chemistry comprising:
 a plasma comprising:
 sulfur dioxide; and 
 at least one halogen-based compound selected from the group consisting of C 3 F 8 , C 4 F 8 , C 4 F 6 , C 5 F 8 , CF 3 I, SF 6 , BCl 3 , ClF, ClF 3 , and NF 3 . 
   
     
     
         2 . (canceled) 
     
     
         3 . The sulfur dioxide etch chemistry of  claim 1 , wherein the halogen-based compound consists of two elements, one of the two elements comprising fluorine. 
     
     
         4 . The sulfur dioxide etch chemistry of  claim 1 , wherein the halogen-based compound comprises at least one of double-bonded carbon atoms and a carbon ring. 
     
     
         5 . (canceled) 
     
     
         6 . The sulfur dioxide etch chemistry of  claim 1 , wherein the halogen-based compound consists of ClF 3 . 
     
     
         7 . (canceled) 
     
     
         8 . The sulfur dioxide etch chemistry of  claim 10 , wherein the sulfur dioxide etch chemistry comprises from about 0.2 part to about 10 parts SF 6  for every about 1 part sulfur dioxide. 
     
     
         9 . The etch chemistry of  claim 21 , wherein the additive gas comprises at least one of argon, helium, nitrogen, and oxygen. 
     
     
         10 . The sulfur dioxide etch chemistry of  claim 1 , wherein the at least one halogen-based compound consists of SF 6 . 
     
     
         11 . The sulfur dioxide etch chemistry of  claim 1 , wherein the at least one halogen-based compound consists of at least one of BCl 3  and CF 3 I. 
     
     
         12 . The sulfur dioxide etch chemistry of  claim 1 , wherein the at least one halogen-based compound consists of NF 3 . 
     
     
         13 . The sulfur dioxide etch chemistry of  claim 12 , wherein the sulfur dioxide etch chemistry comprises from about 0.2 part to about 10 parts NF 3  for every about 1 part sulfur dioxide. 
     
     
         14 . The sulfur dioxide etch chemistry of  claim 12 , wherein the sulfur dioxide etch chemistry comprises about 2 parts NF 3  for every about 1 part sulfur dioxide. 
     
     
         15 . The sulfur dioxide etch chemistry of  claim 3 , wherein the other of the two elements is one of nitrogen, sulfur, and chlorine. 
     
     
         16 . An etch chemistry consisting of a plasma comprising:
 sulfur dioxide;   a halogen-based compound selected from the group consisting of C 3 F 8 , C 4 F 8 , C 4 F 6 , C 5 F 8 , CF 3 I, SF 6 , BCl 3 , ClF, and ClF 3 ; and   a carrier gas including one or more of argon, helium, nitrogen, and oxygen,   the etch chemistry comprising between about 0.1 part to about 10 parts of the halogen-based compound per 1 part of the sulfur dioxide.   
     
     
         17 . The etch chemistry of  claim 16 , wherein the halogen-based compound consists of at least one of BCl 3  and SF 6 . 
     
     
         18 . The etch chemistry of  claim 16 , wherein the halogen-based compound consists of at least one of ClF and ClF 3 . 
     
     
         19 . The etch chemistry of  claim 16 , wherein the halogen-based compound consists of CF 3 I. 
     
     
         20 . The etch chemistry of  claim 16 , wherein the halogen-based compound consists of at least one of C 3 F 8 , C 4 F 8 , C 4 F 6 , and C 5 F 8 . 
     
     
         21 . An etch chemistry consisting of a plasma of sulfur dioxide, a halogen-based compound, and an additive gas. 
     
     
         22 . The etch chemistry of  claim 21 , wherein the halogen-based compound comprises one of a double bonded carbon atom, a triple-bonded carbon atom, or a carbon ring. 
     
     
         23 . The etch chemistry of  claim 21 , wherein the halogen-based compound is one of C 4 F 8 , C 4 F 6 , and C 5 F 8 .