US 11,953,460 B2
Monolithic humidity sensor devices and methods of manufacture
Ricky Alan Jackson, Richardson, TX (US); and Wai Lee, Dallas, TX (US)
Assigned to Texas Instruments Incorporated, Dallas, TX (US)
Filed by Texas Instruments Incorporated, Dallas, TX (US)
Filed on Mar. 31, 2022, as Appl. No. 17/709,692.
Claims priority of provisional application 63/186,950, filed on May 11, 2021.
Prior Publication US 2022/0365018 A1, Nov. 17, 2022
Int. Cl. G01N 27/22 (2006.01); H01L 23/31 (2006.01); H01L 23/64 (2006.01)
CPC G01N 27/225 (2013.01) [H01L 23/3171 (2013.01); H01L 23/642 (2013.01)] 20 Claims
OG exemplary drawing
 
9. An integrated circuit, comprising:
a silicon substrate;
circuitry on or over said silicon substrate, the circuitry including top-level metal interconnects;
a primary passivation barrier over said top-level metal interconnects;
conductive vias through said primary passivation barrier to said top-level metal interconnects;
a capacitor above said primary passivation barrier and electrically coupled through said conductive vias to said circuitry, said capacitor comprising interdigitated metal fingers with spaces therebetween;
a secondary passivation barrier over said capacitor; and,
a hygroscopic material layer over said secondary passivation barrier, wherein said capacitor is operable to exhibit a capacitance value responsive to moisture present in said hygroscopic material layer and said circuitry is operable to generate a signal responsive to said capacitance value.