Patent ID: 11929327
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 17:
18. A method, comprising:
depositing an etch stop layer on a metal contact;
etching the etch stop layer to form an opening, wherein the opening exposes a top surface of the metal contact;
etching the exposed top surface of the metal contact to form a recess in the metal contact with a ratio between a width of the recess and a height of the recess of about 3, wherein the recess exposes a portion of a bottom surface of the etch stop layer;
depositing a ruthenium metal layer to substantially fill the recess and the opening; and
annealing the ruthenium metal layer to convert a portion of the ruthenium metal layer into a conductive ruthenium oxide layer along sidewalls of the ruthenium metal layer and to limit cobalt concentration diffused from the metal contact to less than about 6 atomic percent along grain boundaries in the ruthenium metal layer.