US 12,381,092 B2
Etchant for etching a cobalt-containing member in a semiconductor structure and method of etching a cobalt-containing member in a semiconductor structure
Ren-Kai Chen, Hsinchu (TW); Li-Chen Lee, Hsinchu (TW); Shun Wu Lin, Taichung (TW); Ming-Hsi Yeh, Hsinchu (TW); and Kuo-Bin Huang, Hsinchu County (TW)
Assigned to TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD., Hsinchu (TW)
Filed by TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD., Hsinchu (TW)
Filed on Jul. 27, 2022, as Appl. No. 17/815,240.
Application 17/815,240 is a division of application No. 17/141,882, filed on Jan. 5, 2021, granted, now 11,476,124.
Prior Publication US 2022/0367206 A1, Nov. 17, 2022
Int. Cl. H01L 21/3213 (2006.01); C09K 13/06 (2006.01); C09K 13/10 (2006.01); H10D 62/83 (2025.01); H10D 64/62 (2025.01)
CPC H01L 21/32134 (2013.01) [C09K 13/06 (2013.01); C09K 13/10 (2013.01); H10D 62/83 (2025.01); H10D 64/62 (2025.01)] 20 Claims
OG exemplary drawing
 
1. An etchant for etching a cobalt-containing member in a semiconductor structure, comprising:
a fluorine-free acid; and
an alkaline solution,
wherein a pH value of the etchant ranges between 2 and 6, a rate of etching the cobalt-containing member by the etchant is greater than a rate of etching a nitride-containing member by the etchant, the fluorine-free acid is selected from a group consisting of: aliphatic monocarboxylic acids having 1 to 18 carbon atoms, aliphatic dicarboxylic acids having 2 carbon atoms, aromatic carboxylic acids, sulfonic acids having 1 to 20 carbon atoms, hydrobromic acid, sulfuric acid, sulfurous acid, phosphoric acid, phosphorous acid, polyphosphoric acid and perchloric acid, and the alkaline solution includes an alkaline compound, and the alkaline compound is selected from a group consisting of: choline, pyrrole, piperidine, 1,8-diazabicyclo-[5,4,0]-7-undecene, sodium carbonate, sodium bicarbonate, and sodium silicate.