Silicon carbide semiconductor device terminal and manufacturing method thereof

Abstract

The invention relates to the power semiconductor technology field and discloses a silicon carbide semiconductor device terminal and a manufacturing method thereof. A terminal structure comprises a plurality of well region auxiliary rings, a junction terminal extension, a plurality of junction terminal auxiliary rings, a plurality of base region auxiliary rings and a passivation layer. The well region auxiliary rings are located outside a well region, the junction terminal extension is close to the well region, and a depth is smaller than that of the well region. The junction terminal auxiliaryrings are located on an outer side of the junction terminal extension, and the base region auxiliary rings are located on an outer side of the junction terminal auxiliary rings. By using less photoetching times and ion implantation times and through introducing the well region auxiliary rings, the junction terminal auxiliary rings and the base region auxiliary rings, electric field distribution of a high field region is optimized so that a blocking characteristic of the device is improved, and tolerance of a blocking voltage of the device to a terminal doping concentration is improved. The invention also provides a process method of using the terminal structure in a silicon carbide MOSFET device.

Description

technical field [0001] The invention relates to the field of silicon carbide semiconductor device preparation, in particular to a terminal structure and preparation method for high-voltage silicon carbide power devices. The structure is suitable for high-voltage silicon carbide power devices from 1200V to 20kV, and can be injected into the terminal in fewer times. High terminal doping tolerance can be achieved under certain conditions, and the device yield rate can be significantly improved. Background technique [0002] Silicon carbide has excellent physical and electrical properties, low intrinsic carrier concentration, high thermal conductivity, high breakdown field strength, and excellent physical and chemical stability. Therefore, silicon carbide has become an ideal material for high-temperature and high-power semiconductor devices. [0003] However, the material cost and manufacturing cost of SiC-based power devices are much higher than traditional Si-based power devi...

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Problems solved by technology

[0008] In order to solve the problems that the terminal area of ​​high-voltage silicon carbide power semiconductor devices is too large and the tolerance of breakdown voltage to doping concentration is not high, the present invention proposes a terminal structure suitable for high-voltage silicon carbide devices. The terminal structure occupies a small wafer area, And the breakdown voltage has a high tolerance to the terminal doping concentration, and is fully compatible with the existing silicon carbide power device process

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