US 12,261,050 B2
Method of manufacturing semiconductor device, and etching gas
Takaya Ishino, Yokkaichi (JP); Toshiyuki Sasaki, Yokkaichi (JP); Mitsuharu Shimoda, Shibukawa (JP); and Hisashi Shimizu, Shibukawa (JP)
Assigned to KIOXIA CORPORATION, Tokyo (JP); and KANTO DENKA KOGYO CO., LTD., Tokyo (JP)
Filed by KIOXIA CORPORATION, Tokyo (JP); and KANTO DENKA KOGYO CO., LTD., Tokyo (JP)
Filed on May 30, 2023, as Appl. No. 18/325,640.
Application 18/325,640 is a division of application No. 17/197,544, filed on Mar. 10, 2021, abandoned.
Application 17/197,544 is a continuation of application No. PCT/JP2019/027316, filed on Jul. 10, 2019.
Claims priority of application No. 2018-169983 (JP), filed on Sep. 11, 2018.
Prior Publication US 2023/0307244 A1, Sep. 28, 2023
Int. Cl. H01L 21/306 (2006.01); H01L 21/3065 (2006.01); H01L 21/3213 (2006.01)
CPC H01L 21/3065 (2013.01) [H01L 21/3213 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A method of manufacturing a semiconductor device, comprising:
forming an organic hard mask layer including a pattern, on a film;
forming a concave portion in the film by etching the film with the organic hard mask layer and 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, “y” denotes an integer of one or more, and “z” denotes an integer of two or more; and
forming a charge storage layer and a semiconductor layer in the concave portion,
wherein 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,
the film is etched with plasma generated from the etching gas including the chain hydrocarbon compound expressed as the CxHyFz,
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 CxHyFz, 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 CxHyFz, and a third radical generated by eliminating both hydrogen and fluorine atoms from a molecule of the chain hydrocarbon compound expressed as the CxHyFz, 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.