Silicon carbide MOSFET device and preparation method thereof

Abstract

The invention discloses a silicon carbide MOSFET device and a preparation method thereof. The silicon carbide MOSFET device comprises, form bottom to top, a leakage electrode, a N+substrate and N-epitaxial layer. The N-epitaxial layer is provided with first P-well areas, a first metal, second well areas and a second metal. The first P-well areas are provided with P+areas and N+areas; first ohmic contact is formed by the first metal, the upper surfaces of the P+areas and part of the upper surfaces of the N+areas; the second P-well areas are arranged between every two adjacent first P-well areas, the second P-well areas and the first P-well areas arranged on two side of the second P-well areas are all provided with first gaps, and grooves are encircled by the second P-well areas; and the second metal covers the surface of the groove to form second ohmic contact and the upper surface of the first gap to form Schottky contact. According to the silicon carbide MOSFET device, the flow-continuing ability is improved, and meanwhile the problem that the leakage current of the Schottky contact area in a high-pressure blockage mode is too large is solved.

Description

technical field [0001] The invention relates to the field of semiconductors, in particular to a silicon carbide MOSFET device and a preparation method thereof. Background technique [0002] In recent years, with the continuous development of power electronic systems, higher requirements have been placed on the power devices in the system. Silicon (Si)-based power electronic devices have been unable to meet the requirements of system applications due to the limitations of the material itself. [0003] As a representative of the third-generation semiconductor material, silicon carbide (SiC) material is far better than silicon material in many characteristics. As a commercialized device in recent years, silicon carbide MOSFET devices have great potential to replace existing IGBTs in terms of on-resistance, switching time, switching loss and heat dissipation performance. [0004] However, due to the large bandgap of silicon carbide materials, the turn-on voltage of the parasit...

AI Technical Summary

Problems solved by technology

[0006] However, there are still many problems in silicon carbide MOSFET devices integrating traditional junction barrier Schottky diodes, mainly in that in order to make the Schottky diodes have better freewheeling capability, a larger Schottky contact area is required

On the one hand, the larger Schottky contact area makes the MOSFET have a larger leakage current when it works normally, on the other hand, it also increases the cell area of ​​the silicon carbide MOSFET device, which increases the cost of chip preparation

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