A novel 4H-SiC merged P-I-N Schottky (MPS) with floating back-to-back diode (FBD),named FBD-MPS,is pro-posed and investigated by the Sentaurus technology computer-aided design (TCAD) and analytical model.The FBD fea-tures a trench oxide and floating P-shield,which is inserted between the P+/N-(PN) junction and Schottky junction to eliminate the shorted anode effect.The FBD is formed by the N-drift/P-shield/N-drift and it separates the PN and Schottky active region independently.The FBD reduces not only the Vturn to suppress the snapback effect but also the Von at bipolar operation.The results show that the snapback can be completely eliminated,and the maximum electric field (Emax) is shifted from the Schottky junction to the FBD in the breakdown state.