US 11,658,040 B2
Plasma processing method
Masaaki Taniyama, Tokyo (JP); Kenichi Kuwahara, Tokyo (JP); and Satoshi Une, Tokyo (JP)
Assigned to HITACHI HIGH-TECH CORPORATION, Tokyo (JP)
Appl. No. 16/957,878
Filed by Hitachi High-Tech Corporation, Tokyo (JP)
PCT Filed Jun. 26, 2019, PCT No. PCT/JP2019/025449
§ 371(c)(1), (2) Date Jun. 25, 2020,
PCT Pub. No. WO2020/100339, PCT Pub. Date May 22, 2020.
Prior Publication US 2020/0411327 A1, Dec. 31, 2020
Int. Cl. H01L 21/311 (2006.01); H01L 21/3065 (2006.01); H01L 21/3213 (2006.01); H01L 21/308 (2006.01)
CPC H01L 21/31144 (2013.01) [H01L 21/3065 (2013.01); H01L 21/3086 (2013.01); H01L 21/31116 (2013.01); H01L 21/32137 (2013.01); H01L 21/32139 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A plasma processing method in which plasma etching is performed on a film to be etched by using a mask, the plasma processing method comprising:
a deposition step of depositing a deposition film containing a boron element on sidewalls of the mask while a radio frequency power is supplied to a sample table on which a sample formed with the film to be etched is placed, wherein the mask includes a first region with a first pattern density and a second region with a second pattern density that is lower than the first pattern density;
a removing step of removing the deposition film formed on the film to be etched of the second region by using a first plasma after the deposition step such that the deposition film is left on the sidewalls of the mask of the second region; and
an etching step of etching the film to be etched by using a second plasma after the removing step,
wherein, in said deposition step, the deposition film containing the boron element is selectively formed on the sidewalls of the mask of the first region, and the deposition film containing the boron element is formed on the sidewalls and on a surface of the film to be etched of the second region.