Title :
Long-Term Stability of Metal Lines, Polysilicon Gauges, and Ohmic Contacts for Harsh-Environment Pressure Sensors
Author :
Andrei, Alexandru ; Malhaire, Christophe ; Brida, Sebastiano ; Barbier, Daniel
Author_Institution :
Nat. Inst. of Appl. Sci., Villeurbanne
Abstract :
This paper presents a study on the long-term stability of AlTi (with a TiW diffusion barrier) metal lines, polysilicon gauges, and metal on polysilicon contacts resistances for piezoresistive pressure sensors operating in harsh environments. Test structures have been exposed at 150 degC for a cumulated time of almost five months. Only the polysilicon resistivity proved to be stable over time, metal lines, and ohmic-contacts resistances showing irreversible drifts. Finally, the influence of such drifts over the long-term offset stability of piezoresistive pressure sensors has been discussed
Keywords :
contact resistance; environmental factors; ohmic contacts; piezoresistive devices; pressure sensors; 150 C; AlTi; TiW; harsh-environment pressure sensors; long-term stability; metal lines; ohmic contacts; piezoresistive pressure sensors; polysilicon contacts resistances; polysilicon gauges; thermal aging; Biomembranes; Isolation technology; Mechanical sensors; Ohmic contacts; Packaging; Piezoresistance; Protection; Silicon on insulator technology; Stability; Temperature sensors; Ohmic contacts; polysilicon; pressure sensor; reliability; thermal aging;
Journal_Title :
Sensors Journal, IEEE
DOI :
10.1109/JSEN.2006.884164
