US 12,094,781 B2
Manufacturing method of three-dimensional semiconductor device
Makoto Miura, Tokyo (JP); Kiyohiko Sato, Tokyo (JP); Yasushi Sonoda, Tokyo (JP); and Satoshi Sakai, Tokyo (JP)
Assigned to HITACHI HIGH-TECH CORPORATION, Tokyo (JP)
Appl. No. 16/971,449
Filed by Hitachi High-Tech Corporation, Tokyo (JP)
PCT Filed Sep. 13, 2019, PCT No. PCT/JP2019/035998
§ 371(c)(1), (2) Date Aug. 20, 2020,
PCT Pub. No. WO2021/048995, PCT Pub. Date Mar. 18, 2021.
Prior Publication US 2021/0082766 A1, Mar. 18, 2021
Int. Cl. H01L 21/8234 (2006.01); H01J 37/32 (2006.01); H01L 29/40 (2006.01); H01L 29/423 (2006.01); H01L 29/786 (2006.01)
CPC H01L 21/82345 (2013.01) [H01J 37/32082 (2013.01); H01J 37/3244 (2013.01); H01J 37/32715 (2013.01); H01L 21/823412 (2013.01); H01L 21/823431 (2013.01); H01L 29/401 (2013.01); H01L 29/42392 (2013.01); H01L 29/78696 (2013.01); H01J 2237/332 (2013.01); H01J 2237/334 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A manufacturing method of a semiconductor device having a plurality of stacked channels in which each of the stacked channels has a shape of a wire or a sheet and is stacked in a direction vertical to a substrate in a gate formation region, wherein
the semiconductor device includes a first structure body including a first FET insulating film and wherein the stacked channels are insulated and isolated by the first FET insulating film, and
the manufacturing method of the semiconductor device comprises:
a first step of forming a gate insulating film and a first work function control metal film on the first structure body, and burying the gate formation region with a mask material;
a second step after the first step of performing anisotropic etching to open the mask material until the first work function control metal film covering an upper end of the first FET insulating film is exposed by a pattern having one end located on the first FET insulating film in a plan view;
a third step of depositing a protective film after the second step;
a fourth step after the third step of performing anisotropic etching to remove the protective film while remaining the protective film deposited on sidewalls of the mask material opened in the second step;
a fifth step of performing isotropic etching after the fourth step to remove the mask material located in the pattern in a plan view selective to the protective film and the first work function control metal film;
a sixth step of removing the protective film deposited on the sidewalls of the mask material and the first work function control metal film exposed by the fifth step after the fifth step;
a seventh step of removing the mask material in the gate formation region after the sixth step; and
an eighth step of forming a second work function control metal film on the exposed first structure body after the seventh step.