Groove type vertical gallium nitride power device with floating island structure

Abstract

The invention relates to the technical field of wide bandgap power electronic devices, particularly to a groove type vertical gallium nitride power device with a floating island structure. The device comprises a Body electrode and an outer shell, wherein a groove is formed in the top end of the outer shell, a gate metal is fixedly connected to the inner side wall of the groove, a gate medium is arranged on the inner side of the gate metal, an N+ substrate, an N type drift region, P type layers and N+ doped layers are sequentially arranged in the inner cavity of the outer shell from bottom to top in a wafer structure, two sets of the P type layers and the N+ doped layers are symmetrically arranged, P type floating islands are symmetrically arranged on the inner side of the N type drift region, source and drain electrodes are symmetrically and fixedly connected to the two ends of the top side of the outer shell. According to the invention, two symmetrical P type floating islands are introduced into a N type drift region, so that the electric field aggregation effect at the gate dielectric at the corner of the bottom of the trench can be avoided, the electric field intensity is reduced due to existence of the P-type floating islands, the device breakdown phenomenon caused by breakdown of the gate dielectric is restrained, and the breakdown voltage can be improved.

Description

technical field [0001] The invention relates to the technical field of wide bandgap power electronic devices, in particular to a trench type vertical gallium nitride power device with a floating island structure. Background technique [0002] It has been reported that there is no floating island structure in the trench structure of the ordinary vertical GaN MOSFET. Under the high voltage of the off-state drain of the device, the above trench structure is easy to introduce a peak electric field inside the gate dielectric at the corners on both sides of the bottom of the trench. , leading to irreversible breakdown of the gate dielectric, therefore, the avalanche breakdown of the GaN material cannot be realized, and the advantages of the GaN wide bandgap semiconductor material cannot be brought into play. Based on this, the present invention designs a trench type with a floating island structure Vertical GaN power devices to solve the above problems. Contents of the invention...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a trench-type vertical gallium nitride power device with a floating island structure, so as to solve the problem that the trench structure is easy to introduce a peak electric field inside the gate dielectric at the corners on both sides of the bottom of the trench in the above-mentioned background technology. It leads to irreversible breakdown of the gate dielectric, and cannot take advantage of the advantages of GaN wide bandgap semiconductor materials

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