US 12,444,613 B2
Etching processing method
Takashi Hattori, Tokyo (JP); Masaki Yamada, Tokyo (JP); and Keisuke Akinaga, Tokyo (JP)
Assigned to HITACHI HIGH-TECH CORPORATION, Tokyo (JP)
Appl. No. 18/026,095
Filed by HITACHI HIGH-TECH CORPORATION, Tokyo (JP)
PCT Filed Feb. 14, 2022, PCT No. PCT/JP2022/005550
§ 371(c)(1), (2) Date Mar. 13, 2023,
PCT Pub. No. WO2023/152941, PCT Pub. Date Aug. 17, 2023.
Prior Publication US 2024/0312789 A1, Sep. 19, 2024
Int. Cl. H01L 21/311 (2006.01); H01J 37/32 (2006.01); H01L 21/324 (2006.01)
CPC H01L 21/31116 (2013.01) [H01J 37/32522 (2013.01); H01J 37/32816 (2013.01); H01L 21/324 (2013.01); H01J 2237/3344 (2013.01); H01J 2237/3346 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A dry etching processing method for etching a film structure without the use of plasma by supplying gas for process into a process chamber, the film structure being a structure in which a side wall of a groove or a hole is constituted by respective end parts of laminated film layers formed in advance on a wafer placed inside the process chamber, the laminated film layers including silicon oxide films each sandwiched between silicon nitride films in an up-down direction, the etching processing method comprising:
a step of etching the silicon oxide films laterally from the end parts by supplying hydrogen fluoride gas with a pressure of the process chamber being maintained at 600 Pa and a temperature of the wafer being maintained at a value within a range from −25° C. to −60° C., desirably from −25° C. to −50° C.,
wherein the silicon oxide films are etched laterally from the end parts with a partial pressure of the hydrogen fluoride gas being set to 400 Pa.