Mass fabrication of 4H-SiC high temperature pressure sensors by femtosecond laser etching

4H Silicon carbide (4H-SiC) is one of the most promising materials for pressure sensing in harsh environments. Due to the low efficiency and high energy consumption of dry etching process, mass manufacturing of SiC pressure sensors has always been a challenging problem. A Yb:KGW femtosecond laser was used to perform the circular diaphragms of bulk 4H-SiC by parallel straight line scanning. Small dimension errors and low surface roughness in rapid etching process were measured. This indicates the potential of utilising the femtosecond laser scanning approach to mass-fabricate bulk SiC sensor chips for pressure sensing.