Composite silicon carbide MOSFET cellular structure and device

The invention discloses a compound silicon carbide MOSFET cellular structure and device, which integrates a planar gate and a trench gate into one MOSFET to generate a double-channel structure, optimize a current path, effectively prevent current crowding, effectively improve current density and reduce on-resistance. Whether three contact regions are arranged in the first cellular structure or one contact region is arranged in the second cellular structure, a body diode can be formed, a diode reverse mode is generated, and high breakdown voltage and depletion expansion towards the first conductive type drift layer can be supported. Besides, the invention provides two cellular structures, the first cellular structure adopts the separated trench gate and the planar gate, so that a wide unit pitch and a larger cellular size can be realized, and the second cellular structure adopts the trench gate and the planar gate which are connected with each other, so that a narrow unit pitch and a smaller cellular size can