Patent ID: 11476124

Abstract:
A method of etching a cobalt-containing member in a semiconductor structure includes providing an etchant including a fluorine-free acid and an alkaline solution having a pH value between 8.5 and 13, and etching the cobalt-containing member in the semiconductor structure using the etchant, wherein a rate of etching the cobalt-containing member by the etchant is substantially greater than a rate of etching a nitride-containing member by the etchant. An etchant for etching a cobalt-containing member in a semiconductor structure includes a fluorine-free acid, and an alkaline solution having a pH value between 8.5 and 13; wherein a rate of etching a cobalt-containing member by the etchant is substantially greater than a rate of etching a nitride-containing member by the etchant, and a level of dissolved oxygen of the etchant is substantially less than or equal to 100 ppb.