GaN-based enhanced vertical HEMT device and preparation method thereof

Abstract

The invention provides a GaN-based enhanced vertical HEMT device and a preparation method thereof. The device structurally comprises a drain electrode, a substrate, a drift region, a vertical channel barrier layer, a channel layer, a barrier layer, a passivation layer, a trench gate and a source electrode in sequence from bottom to top. The GaN channel layer, the AlGaN barrier layer on the upper side of the GaN channel layer and the Al<x>Ga<1-x>N vertical channel barrier layer below the GaN channel layer form a double-heterojunction structure, and the structure forms a barrier layer in the vertical channel direction through a GaN / AlGaN heterostructure, so that the transport of carriers in the vertical direction is blocked under the off-state condition, the channel is further turned off, and the enhanced characteristic is realized. The structure can effectively avoid negative effects caused by a traditional Mg-doped p-GaN barrier layer, and the designed device has the remarkable characteristics of low on-resistance, high drain current density and high threshold voltage.

Description

technical field [0001] The invention belongs to the technical field of semiconductor devices, and in particular relates to a GaN-based enhanced vertical HEMT device and a preparation method thereof. Background technique [0002] Wide bandgap semiconductor materials play an increasingly important role in high-frequency, high-power and optoelectronic fields due to their advantages such as large bandgap width and high bonding energy. GaN high electron mobility transistor (HEMT) with lateral structure is its main structure in the field of power device applications, and its core is AlGaN / GaN heterojunction. Compared with traditional GaN lateral devices, GaN-based vertical power field effect transistors have the advantages of high area efficiency, lower thermal resistance, easier packaging, small edge effect of electric field, and lower on-resistance. [0003] In order to alleviate the current collapse effect and improve the reliability of the device, the high-field region of GaN...

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Problems solved by technology

The etching damage of these two methods is large, the process is extremely complicated, the activation rate of Mg is low, and the defect states introduced are high, so it is difficult to fabricate high-performance and high-reliability GaN vertical devices

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