US 12,369,327 B2
MFM device with an enhanced bottom electrode
Harry-Hak-Lay Chuang, Zhubei (TW); Fu-Chen Chang, New Taipei (TW); Tzu-Yu Chen, Kaohsiung (TW); Sheng-Hung Shih, Hsinchu (TW); and Kuo-Chi Tu, Hsin-Chu (TW)
Assigned to Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed on Mar. 28, 2022, as Appl. No. 17/705,653.
Prior Publication US 2023/0329001 A1, Oct. 12, 2023
Int. Cl. H10B 53/30 (2023.01)
CPC H10B 53/30 (2023.02) 20 Claims
OG exemplary drawing
 
16. A method of forming a semiconductor structure, comprising:
forming an access device in a substrate;
forming a conductive contact coupled to the access device and a lower metal feature coupled to the conductive contact within a lower dielectric structure over the substrate;
forming a middle dielectric structure over the lower dielectric structure, wherein the middle dielectric structure is formed with an opening that exposes the lower metal feature;
forming a bottom electrode layer within the opening, wherein the bottom electrode layer is formed with molybdenum;
forming a ferroelectric layer on the bottom electrode layer;
forming a top electrode layer on the ferroelectric layer;
performing a patterning process on the bottom electrode layer, ferroelectric layer, and the top electrode layer, to respectively form a bottom electrode, ferroelectric structure, and a top electrode, wherein the bottom electrode is coupled to the access device through the conductive contact; and
wherein a top surface of the bottom electrode is formed with an elevated concentration of nitrogen relative to a bottom surface of the top electrode.