Terminal cell structure and manufacturing method using metal extension, polycrystalline stop field plate

Abstract

The invention relates to the power electronic technical field and particularly relates to a terminal unit structure with metal extending and polycrystal stopping field plates and a method for manufacturing the terminal unit structure. The terminal unit structure comprises a first conductive type substrate, a second conductive type field limit ring is arranged in a first main side of the first conductive type substrate, and a first insulation layer is arranged on a first main plane of the first conductive type substrate. The two field plates are disposed on the first insulation layer and cover the two sides of the second conductive type field limit ring. The field plates comprise the polycrystal stopping field plate and the metal extending field plate, and one end of the metal field plate is connected with the polycrystal stopping field plate. According to the terminal unit structure, polycrystals are used as the stopping field plate, metal is used as the extending field plate, the electric field stopping effect is good, breakdown of the first insulation layer brought by electric field extending is prevented, and dependency on the thickness of the first insulation layer is small.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a terminal unit structure and a manufacturing method using metal extensions and polycrystalline cut-off field plates. Background technique [0002] In the design and manufacture of power electronic devices, the terminal is an indispensable part. It can smooth the internal depletion region of the device when the device is subjected to high voltage, so that the device can withstand higher voltage. The terminal of traditional power electronic devices is usually prepared by implanting and advancing the field confinement ring on the low-doped bottom; there are also field plates on the outside of the field confinement ring to achieve further smoothing of the electric field. [0003] Compared with the single field limit ring structure, the field limit ring + field plate structure can better smooth the depletion region, so in the same pressure-bearing terminal design, the field...

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Problems solved by technology

[0009] Among them, CN201010246809.4 and CN201010246816.4 are the same as the objects protected by this patent, both of which are a kind of "terminal structure" of the semiconductor device itself, but they are different in the design of the terminal structure and the function of the terminal structure. Both patents reduce the electric field at the field limiting ring through different design of the field limiting ring, so that the breakdown voltage can be increased. Their field plate and the field limiting ring are not connected, and the field plate does not reduce the The role of small electric fields

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