US 12,237,174 B2
Etching method
Kazunori Shinoda, Tokyo (JP); Hirotaka Hamamura, Tokyo (JP); Kenji Maeda, Tokyo (JP); Kenetsu Yokogawa, Tokyo (JP); Kenji Ishikawa, Aichi (JP); and Masaru Hori, Aichi (JP)
Assigned to HITACHI HIGH-TECH CORPORATION, Tokyo (JP)
Appl. No. 17/642,356
Filed by Hitachi High-Tech Corporation, Tokyo (JP)
PCT Filed Apr. 22, 2021, PCT No. PCT/JP2021/016333
§ 371(c)(1), (2) Date Mar. 11, 2022,
PCT Pub. No. WO2022/224412, PCT Pub. Date Oct. 27, 2022.
Prior Publication US 2024/0047222 A1, Feb. 8, 2024
Int. Cl. H01L 21/311 (2006.01); H01L 21/02 (2006.01); H01L 21/3065 (2006.01)
CPC H01L 21/31122 (2013.01) [H01L 21/02183 (2013.01); H01L 21/3065 (2013.01)] 5 Claims
OG exemplary drawing
 
1. An etching method for etching a film layer as a processing object containing nitride of transition metal including tantalum nitride, the film layer being disposed on a surface of a wafer, the method comprising the steps of:
supplying reactive particles containing fluorine and hydrogen but containing no oxygen to a surface of the film layer to form a reaction layer which mainly contains a tantalum-fluorine bond and nitrogen-hydrogen bond and has a self-saturating tendency on the surface of the film layer; and
eliminating the reaction layer by heating the film layer.