High Temperature Characteristics of Piezoresistive Silicon Carbide Pressure Sensors Implemented by Leadless Packaging

This paper presents the process of fabricating pressure sensor chip based on N-type 4H-SiC with high doping and realizing leadless packaging. The piezoresistive functional layer of the sensor is fabricated using a 4H-SiC wafer with a double epitaxial layer. The formation of the diaphragms is performed by a deep reactive ion etching (DRIE) process. The nickel-based metallization system is able to withstand high temperatures. Leadless packaging based on sintering of glass frits and nano-particle conductive silver paste realizes high temperature resistant packaging of sensor. The zero temperature drift and high temperature resistance stability lasting about 10 hours are tested at up to 600 °C.