Piezoresistive n-type 4H-SiC pressure sensor with membrane formed by mechanical milling

摘要: 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 diameter and 50 µm thickness, was formed by milling (drilling) a bulk single crystal SiC wafer. Both transverse longitudinal piezoresistors were on the membrane out of an n-type epitaxial layer. Ohmic contacts obtained Ta/Ni/Pt metallization followed annealing at 1000°C 20 min. assembled small board characterized under hydrostatic pressures up to 60 bar room temperature. sensitivity 268 µV/V/bar. chip exposed air 600°C 165 hours changes bridge resistance measured.