US 11,988,625 B2
Capacitive biosensor and fabricating method thereof
Cheng-Ping Chang, Hualien (TW); Chien-Hui Li, Yilan (TW); Chien-Hsun Wu, Hsinchu (TW); Tai-I Yang, Hsinchu (TW); and Yung-Hsiang Chen, Hsinchu (TW)
Assigned to VANGUARD INTERNATIONAL SEMICONDUCTOR CORPORATION, Hsinchu (TW)
Filed by Vanguard International Semiconductor Corporation, Hsinchu (TW)
Filed on Dec. 23, 2020, as Appl. No. 17/133,246.
Prior Publication US 2022/0196586 A1, Jun. 23, 2022
Int. Cl. G01N 27/22 (2006.01); G01N 27/414 (2006.01); G01N 33/543 (2006.01)
CPC G01N 27/226 (2013.01) [G01N 27/4145 (2013.01); G01N 33/5438 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A capacitive biosensor, comprising:
a transistor;
an interconnect structure disposed on the transistor, wherein the interconnect structure comprises:
a first metal structure disposed on the transistor;
a second metal structure disposed on the first metal structure; and
a third metal structure disposed on the second metal structure, wherein the third metal structure comprises a first conductive layer, a second conductive layer, and a third conductive layer that are sequentially stacked, and wherein each of the first conductive layer and the third conductive layer comprises a first conductive coating and a second conductive coating on the first conductive coating;
a passivation layer disposed on the interconnect structure, wherein the passivation layer has an opening exposing a portion of the third metal structure;
a first sidewall spacer disposed on sidewalls of the opening; and
a sensing region disposed on the interconnect structure, wherein the sensing region comprises:
a first sensing electrode formed of the third conductive layer; and
a second sensing electrode disposed on the passivation layer.