US 12,243,751 B2
Chemical solution, etching method, and method for manufacturing semiconductor device
Hakuba Kitagawa, Yokkaichi Mie (JP); Tatsuhiko Koide, Kuwana Mie (JP); and Hiroshi Fujita, Mie Mie (JP)
Assigned to KIOXIA CORPORATION, Tokyo (JP)
Filed by Kioxia Corporation, Tokyo (JP)
Filed on Sep. 3, 2021, as Appl. No. 17/466,273.
Claims priority of application No. 2021-049124 (JP), filed on Mar. 23, 2021.
Prior Publication US 2022/0310401 A1, Sep. 29, 2022
Int. Cl. H01L 21/311 (2006.01); C23F 1/26 (2006.01); H01L 21/306 (2006.01); H01L 21/321 (2006.01); H01L 21/3213 (2006.01)
CPC H01L 21/31111 (2013.01) [C23F 1/26 (2013.01); H01L 21/30608 (2013.01); H01L 21/32134 (2013.01); H01L 21/3212 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method, comprising:
selectively etching a molybdenum layer using a chemical solution to remove a portion of the molybdenum layer, wherein the chemical solution includes (i) a mixed acid including an inorganic acid, an oxidizing agent, a carboxylic acid, and water, and (ii) and a polyethyleneimine of a concentration in the chemical solution in a range of 0.05 wt % to 10 wt %,
wherein the molybdenum layer comprises elemental molybdenum in an amount of not less than 99 atom %; and
a concentration of the inorganic acid in the chemical solution is higher than a concentration of the polyethyleneimine and the concentration of the inorganic acid in the chemical solution is higher than a concentration of the water in the chemical solution.