Method of manufacturing semiconductor device, and etching gas

Abstract

In one embodiment, a method of manufacturing a semiconductor device includes etching a film with etching gas that includes a chain hydrocarbon compound expressed as CxHyFz where C, H and F respectively denote carbon, hydrogen and fluorine, “x” denotes an integer of three or more, and “y” and “z” respectively denote integers of one or more. Furthermore, the CxHyFz is the chain hydrocarbon compound in which each of terminal carbon atoms on a carbon chain of the chain hydrocarbon compound is bonded only to fluorine atoms out of hydrogen and fluorine atoms.

1 . A method of manufacturing a semiconductor device, comprising:
 etching a film with etching gas that includes a chain hydrocarbon compound expressed as C x H y F z  where C, H and F respectively denote carbon, hydrogen and fluorine, “x” denotes an integer of three or more, and “y” and “z” respectively denote integers of one or more,   wherein the C x H y F z  is the chain hydrocarbon compound in which each of terminal carbon atoms on a carbon chain of the chain hydrocarbon compound is bonded only to fluorine atoms out of hydrogen and fluorine atoms.   
     
     
         2 . The method of  claim 1 , wherein the etching gas includes the chain hydrocarbon compound expressed as the C x H y F z  where a value of “x” is an integer from 3 to 5 and y≤z. 
     
     
         3 . The method of  claim 1 , wherein the C x H y F z  includes at least any of C 3 HF 5 , C 4 H 4 F 6 , C 4 H 3 F 7 , C 4 H 2 F 8 , C 4 HF 9 , C 5 H 6 F 6 , C 5 H 5 F 7 , C 5 H 4 F 8 , C 5 H 3 F 9 , C 5 H 2 F 10  and C 5 HF 11 . 
     
     
         4 . The method of  claim 1 , wherein the etching gas further includes at least any of oxygen gas, rare gas, and fluorocarbon compound gas expressed as C a F b  where“a” and “b” respectively denote integers of one or more. 
     
     
         5 . The method of  claim 4 , wherein the C a F b  includes at least any of CF 4 , C 2 F 4 , C 3 F 6 , C 4 F 6  and C 4 F 8 . 
     
     
         6 . The method of  claim 1 , wherein the etching gas includes two or more kinds of chain hydrocarbon compounds expressed as the C x H y F z . 
     
     
         7 . The method of  claim 1 , wherein the etching gas includes a linear chain-type chain hydrocarbon compound expressed as the C x H y F z . 
     
     
         8 . The method of  claim 1 , wherein the film is etched with plasma generated from the etching gas including the chain hydrocarbon compound expressed as the C x H y F z . 
     
     
         9 . The method of  claim 8 , wherein
 the plasma includes a first radical generated by eliminating only hydrogen atom(s) out of hydrogen and fluorine atoms from a molecule of the chain hydrocarbon compound expressed as the C x H y F z , a second radical generated by eliminating only fluorine atom(s) out of hydrogen and fluorine atoms from a molecule of the chain hydrocarbon compound expressed as the C x H y F z , and a third radical generated by eliminating both hydrogen and fluorine atoms from a molecule of the chain hydrocarbon compound expressed as the C x H y F z , and   a concentration of the first radicals in the plasma is larger than a total concentration of the second and third radicals in the plasma.   
     
     
         10 . The method of  claim 8 , wherein a density of the plasma in a chamber is 5.0×10 9  to 3.0×10 11  quantity/cm 3 . 
     
     
         11 . The method of  claim 1 , wherein the film includes a plurality of first films and a plurality of second films alternately formed on a substrate. 
     
     
         12 . The method of  claim 1 , wherein a concave portion with 10 or more of aspect ratio is formed in the film during the etching. 
     
     
         13 . The method of  claim 1 , wherein during the etching, a concave portion is formed in the film and another film including a fluorocarbon compound expressed as C m F n  is formed in the concave portion where “m” and “n” respectively denote integers of one or more. 
     
     
         14 . Etching gas comprising:
 a chain hydrocarbon compound expressed as C x H y F z  where C, H and F respectively denote carbon, hydrogen and fluorine, “x” denotes an integer of three or more, and “y” and “z” respectively denote integers of one or more,   wherein the C x H y F z  is the chain hydrocarbon compound in which each of terminal carbon atoms on a carbon chain of the chain hydrocarbon compound is bonded only to fluorine atoms out of hydrogen and fluorine atoms, and   wherein the C x H y F z  includes at least any of C 3 HF 5 , C 4 H 4 F 6 , C 4 H 3 F 7 , C 4 H 2 F 8 , C 4 HF 9 , C 5 H 6 F 6 , C 5 H 5 F 7 , C 5 H 4 F 8 , C 5 H 3 F 9 , C 5 H 2 F 10  and C 5 HF 11 .   
     
     
         15 . The gas of  claim 14 , wherein the etching gas includes the chain hydrocarbon compound expressed as the C x H y F z  where a value of “x” is an integer from 3 to 5 and y≤z. 
     
     
         16 . The gas of  claim 14 , wherein the etching gas further includes at least any of oxygen gas, rare gas, and fluorocarbon compound gas expressed as C a F b  where “a” and “b” respectively denote integers of one or more. 
     
     
         17 . The gas of  claim 16 , wherein the C a F b  includes at least any of CF 4 , C 2 F 4 , C 3 F 6 , C 4 F 6  and C 4 F 8 . 
     
     
         18 . The gas of  claim 14 , wherein the etching gas includes two or more kinds of chain hydrocarbon compounds expressed as the C x H y F z . 
     
     
         19 . The gas of  claim 14 , wherein the etching gas includes a linear chain-type chain hydrocarbon compound expressed as the C x H y F z . 
     
     
         20 . The gas of  claim 14 , wherein the etching gas is capable of being used so as to generate plasma from the chain hydrocarbon compound expressed as the C x H y F z .