DocumentCode :
2783560
Title :
Failure Mechanisms in MEMS Based Silicon Carbide High Temperature Pressure Sensors
Author :
Okojie, R.S. ; Nguyen, P. ; Nguyen, V. ; Savrun, E. ; Lukco, D. ; Buehler, J. ; McCue, T.
Author_Institution :
NASA Glenn Res. Center, Cleveland, OH
fYear :
2007
fDate :
15-19 April 2007
Firstpage :
429
Lastpage :
432
Abstract :
The paper reports recent results of the long term reliability evaluation of single crystal silicon carbide (SiC) piezoresistive pressure sensors operated up to 500 degC. In-depth failure analysis was performed to identify the mechanisms responsible for their failures. Accelerated stress test (AST) that was developed specifically for high temperature operating devices was initially performed to extract the stable operating parameters of the transducers, which allowed for extracting the operating parameters. After the AST that included several hours of cyclic pressure and temperature excursions, the recorded maximum drift of the zero pressure offset voltage at room temperature, VOZ(25 degC), was 1.9 mV, while the maximum drift at 500 degC was 2.0 mV. The maximum recorded drift of the full-scale pressure sensitivity after ten hours of thermal cycling at 500 degC was plusmn1 muV/V/psi. In all cases, the observed failures during field validation were associated with the detachment of the Au die-attach from the sensor bondpads.
Keywords :
failure analysis; microsensors; pressure sensors; reliability; silicon compounds; wide band gap semiconductors; 1.9 mV; 500 C; MEMS based silicon carbide; SiC; accelerated stress test; failure analysis; gold die-attach; high temperature pressure sensors; long term reliability evaluation; piezoresistive pressure sensors; pressure sensitivity; single crystal silicon carbide; Failure analysis; Life estimation; Micromechanical devices; Performance evaluation; Piezoresistance; Silicon carbide; Stress; Temperature sensors; Testing; Transducers; High Temperature; Pressure Sensors; Reliability; Silicon Carbide;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Reliability physics symposium, 2007. proceedings. 45th annual. ieee international
Conference_Location :
Phoenix, AZ
Print_ISBN :
1-4244-0919-5
Electronic_ISBN :
1-4244-0919-5
Type :
conf
DOI :
10.1109/RELPHY.2007.369928
Filename :
4227669
Link To Document :
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