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 degrees C.