	US 12,480,048 B2
	Etchant
Ming-Yen Chung, Kawasaki (JP)
Assigned to TOKYO OHKA KOGYO CO., LTD., Kawasaki (JP)
Filed by TOKYO OHKA KOGYO CO., LTD., Kawasaki (JP)
Filed on May 5, 2023, as Appl. No. 18/313,122.
Claims priority of application No. 111117526 (TW), filed on May 10, 2022.
Prior Publication US 2023/0365864 A1, Nov. 16, 2023
Int. Cl. C09K 13/06 (2006.01); C09K 13/00 (2006.01); C23F 1/14 (2006.01); C23F 1/26 (2006.01); H01L 21/306 (2006.01); H01L 21/311 (2006.01); H01L 21/3213 (2006.01); C09K 13/04 (2006.01)

CPC C09K 13/06 (2013.01) [C09K 13/00 (2013.01); C23F 1/14 (2013.01); C23F 1/26 (2013.01); H01L 21/30604 (2013.01); H01L 21/311 (2013.01); H01L 21/31105 (2013.01); H01L 21/31111 (2013.01); H01L 21/32134 (2013.01); C09K 13/04 (2013.01)]

5 Claims

1. An etchant for selectively removing, from a semiconductor substrate, a tungsten-containing hard mask having compatibility with silicon germanium (SiGe) or silicon phosphorus (SiP), the etchant comprising:

an organic solvent (A);

a sulfur-containing salt (B) containing ammonium hydrogen sulfate ((NH₄) HSO₄) or ammonium sulfate ((NH₄)₂SO₄); and

an oxidant (C) which is hydrogen peroxide,

wherein the etchant contains 5% to 85% by weight of the organic solvent (A), 0.010% to 0.05% by weight of the sulfur-containing salt (B), 5% to 10% by weight of the oxidant (C), and a remainder consisting of water.