Vertical GaN heterojunction field-effect transistor with P type GaN island

Abstract

The invention discloses a vertical GaN heterojunction field-effect transistor with a P type GaN island. The field-effect transistor comprises an AlGaN barrier layer, wherein a source electrode and a grid electrode are arranged on the AlGaN barrier layer, and a GaN channel layer, a p-GaN current blocking layer, an n-GaN buffer layer, an n+-GaN substrate and a drain electrode are arranged under the AlGaN barrier layer in sequence. A hole with the caliber of LAP is formed in the center of the p-GaN current blocking layer and nested to the n-GaN buffer layer, the p-GaN island is arranged in the n-GaN buffer layer, and the p-GaN island is located between the p-GaN current blocking layer and the n+-GaN substrate. In the GaNPI-VHFET, by using the p-GaN island layer, extra p type impurities are introduced into the n-GaN buffer layer, and the n-GaN buffer layer area is exhausted in the off state, so that the buffer area is equivalent to an intrinsic region during voltage resistance. Therefore, the problem that the vertical electric field intensity is continuously decreased when current moves far away from an interface of the p-GaN current blocking layer and the n-GaN buffer layer is solved to increase breakdown voltage of a device. Meanwhile, leaked current of the drain electrode is also decreased in the off state.

Description

technical field [0001] The invention relates to the field of semiconductor high withstand voltage devices, in particular to a vertical GaN-based heterojunction field effect transistor with P-type GaN islands. Background technique [0002] Gallium nitride-based heterojunction field effect transistor (GaN Heterojunction Fiele-Effect Transistor, GaN HFET) not only has a large band gap, high critical breakdown electric field, high electron saturation velocity, good thermal conductivity, radiation resistance and good chemical stability At the same time, gallium nitride (GaN) materials can form a two-dimensional electron gas heterojunction channel with high concentration and high mobility with materials such as aluminum gallium nitride (AlGaN), so it is especially suitable for high-voltage, high-power And high temperature applications, it is one of the most potential transistors for power electronics applications. [0003] The existing high withstand voltage GaN HFET structure is...

AI Technical Summary

Problems solved by technology

However, the electric field between the source and drain of this structure presents a zigzag distribution, and when the electric field at the interface of each p-n junction reaches the critical electric field, the electric field at other positions is still lower than the critical breakdown electric field, and the withstand voltage still has the potential to be further improved.

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