Silicon carbide planar gate MOSFET cellular structure and manufacturing method thereof

Abstract

The invention discloses a silicon carbide planar gate MOSFET cellular structure. The structure is covered with a silicon carbide epitaxial layer, a gate electrode and an interlayer dielectric layer from bottom to top. A plurality of first conductive type contact regions and a second conductive type contact region are arranged in the middle of the upper end of the silicon carbide epitaxial layer, and the plurality of first conductive type contact regions are located in the middle of the second conductive type contact region and are distributed at intervals along the length direction of the MOSFET channel. The gate electrode covers the two sides of the upper end of the second conductive type contact region, and the first distance between the gate electrodes on the two sides is smaller than the width of the second conductive type contact region and larger than the width of the first conductive type contact regions. The interlayer dielectric layer covers the gate electrode, and the seconddistance between the interlayer dielectric layers on the two sides is smaller than the width of the first conductive type contact regions. Thus, the cell density can be improved, the channel resistance can be reduced, and the purpose of reducing the on resistance can be achieved.

Description

technical field [0001] The invention relates to the technical field of semiconductor devices, in particular to a silicon carbide planar gate MOSFET cell structure and a manufacturing method. Background technique [0002] Silicon carbide (Silicon Carbide, SiC) material, due to its three times the forbidden band width of silicon (Silicon, Si), high critical breakdown electric field, thermal conductivity and carrier saturation drift velocity, makes it an ideal material for the preparation of power electronics. Excellent material for core power devices. On the other hand, in the family of power devices, MOSFETs are full-control power metal oxide field effect transistors (Metal-Oxide-Semiconductor Field Effect Transistors, MOSFETs), which have the characteristics of fast switching speed, high input impedance, and relatively simple driving. Therefore, SiC-based power MOSFETs (SiC MOSFETs) have the inherent advantages of SiC materials on the one hand, and the advantages of unipola...

AI Technical Summary

Problems solved by technology

Finally, compared with silicon-based MOSFETs, the ratio of the inversion layer channel resistance Rch of silicon carbide MOSFETs to the entire device on-resistance Ron is greatly increased.

Images