US 11,929,327 B2
Liner-free conductive structures with anchor points
Hsu-Kai Chang, Hsinchu (TW); Keng-Chu Lin, Hsinchu (TW); Sung-Li Wang, Zhubei (TW); Shuen-Shin Liang, Hsinchu (TW); and Chia-Hung Chu, Taipei (TW)
Assigned to Taiwan Semiconductor Manufacturing Co., Inc., Hsinchu (TW)
Filed by TAIWAN SEMICONDUCTOR MANUFACTURING CO., LTD., Hsinchu (TW)
Filed on Jul. 22, 2020, as Appl. No. 16/936,335.
Claims priority of provisional application 62/967,278, filed on Jan. 29, 2020.
Prior Publication US 2021/0233861 A1, Jul. 29, 2021
Int. Cl. H01L 23/532 (2006.01); H01L 21/768 (2006.01); H01L 23/522 (2006.01)
CPC H01L 23/53257 (2013.01) [H01L 21/76805 (2013.01); H01L 21/76883 (2013.01); H01L 21/76888 (2013.01); H01L 23/5226 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method, comprising:
depositing an etch stop layer on a cobalt contact disposed on a substrate;
depositing a dielectric layer on the etch stop layer;
etching the dielectric layer and the etch stop layer to form an opening to expose a top surface of the cobalt contact;
etching the exposed top surface of the cobalt contact to form a recess in the cobalt contact, wherein the recess extends laterally under the etch stop layer;
depositing a ruthenium metal to substantially fill the recess and the opening; and
annealing the ruthenium metal to convert a portion of the ruthenium metal that is in physical contact with the dielectric layer into a conductive ruthenium oxide layer along interfaces between the ruthenium metal and the dielectric layer and to limit cobalt concentration to less than about 6 atomic percent along grain boundaries in the ruthenium metal.