Manufacturability and reliability optimization for metallization of SiC piezoresistive pressure sensors

In this paper, we adopt Ni-based ohmic contacts of n-type 4H-SiC (silicon carbide), basing its applications on SiC pressure sensors, to explore the manufacturability and high temperature reliability problems of SiC metallization process, including the adhesion of metal layers, the influence of surface treatment on ohmic contact formation way between metal and SiC wafers, the failure problem caused by the thermal stress between the metal and the SiC wafer at high temperature and the high temperature reliability of the ohmic contact metal structure. By optimizing the process details, the specific contact resistance (ρc) can reach 2.05E-5 Ω·cm2; moreover, both ohmic contact and metal wiring structure can keep stable performance in 300 °C 60 h air environment.