Piezoresistive n-Type 4H-SiC Pressure Sensor with Membrane Formed by Mechanical Milling

A 4H-SiC pressure sensor with piezoresistive transducers, for harsh environment applications, e.g., high temperature (~650°C) and/or in corrosive chemicals is presented. The sensing membrane, 1 mm in diameter and 50 µm in thickness, was formed by milling (drilling) a bulk single crystal SiC wafer. Both transverse and longitudinal piezoresistors were formed on the membrane out of an n-type SiC epitaxial layer. Ohmic contacts were obtained with Ta/Ni/Pt metallization followed by annealing at 1000°C for 20 min. The sensor was assembled on a small board and characterized under hydrostatic pressures up to 60 bar at room temperature. The obtained pressure sensitivity was 268 µV/V/bar. The sensor chip was exposed in air at 600°C for 165 hours and changes in bridge resistance were measured.

Published in:
Proceedings of IEEE Sensors, 1, 222-225
Presented at:
IEEE Sensors 2011, Limerik, Ireland, October 28-31, 2011
Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa

 Record created 2011-11-21, last modified 2018-01-28

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