Self-aligned gate gallium nitride enhanced vertical power device based on suspension field plate

Abstract

The invention relates to a self-aligned gate gallium nitride enhanced vertical power device based on a suspension field plate. The self-aligned gate gallium nitride enhanced vertical power device comprises a drain; a self-supporting Si doped GaN substrate located on the drain electrode; an n-type GaN layer located on the self-supporting Si doped GaN substrate; an n-type GaN transition layer located on the n-type GaN layer; an n-type GaN channel layer located on the n-type GaN transition layer; a first dielectric layer located on the n-type GaN transition layer; a grid electrode located on then-type GaN transition layer; a second dielectric layer located on the n-type GaN transition layer; the suspension field plate located on the second dielectric layer; an n-type GaN contact layer located on the n-type GaN channel layer; and a source electrode positioned on the n-type GaN contact layer. According to the embodiment of the invention, the vertical power device with high breakdown voltage, low on-resistance and high reliability is realized through the organic combination of the annular self-aligned gate structure, the suspension field plate and an n-type doped material.

Description

technical field [0001] The invention belongs to the technical field of semiconductors, and in particular relates to a self-aligned gate gallium nitride enhanced vertical power device based on a floating field plate. Background technique [0002] In recent years, the third-generation wide-bandgap semiconductors represented by SiC and GaN have attracted widespread attention due to their large bandgap, high breakdown electric field, high thermal conductivity, and high saturated electron velocity. [0003] The current research on GaN power devices is mainly based on AlGaN / GaN HEMTs, and power devices with this structure generally have low breakdown field strength. In 2000, Naiqian Zhang of UCSB in the United States obtained an AlGaN / GaN HEMT with a breakdown voltage of 570V by using a gate field plate structure. After that, Panasonic adopted AlN passivation, field plate technology, through-hole technology and other technologies, and the breakdown voltage was as high as 10400V w...

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Problems solved by technology

In 2016, Panasonic used the regrown p-type GaN layer to prepare a GaN-based vertical power device, with a breakdown voltage of 1.7kV and a characteristic on-resistance of 1.0mΩ·cm 2 ; Vertical structure devices need to adopt p-type GaN material regrowth technology if they want to achieve enhanced type. Usually, p-type GaN needs to be doped with Mg, and the activation energy of magnesium is high, so it is not easy to form a high hole concentration. The production cost of p-type GaN vertical structure devices is relatively high, and the yield and stability are difficult to guarantee

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