Vertical gallium nitride based nitride heterojunction field effect transistor with polarized doped current barrier layer

Abstract

The invention provides a vertical gallium nitride based nitride heterojunction field effect transistor with a polarized doped current barrier layer, which sequentially and mainly comprises a drain electrode, an n<+>-GaN substrate, an n-GaN buffer layer, a GaN channel layer, an AlGaN barrier layer, a source electrode on the AlGaN barrier layer and a grid electrode on the AlGaN barrier layer from bottom to top, wherein the source electrode and the drain electrode are both in ohmic contact, the grid electrode is in Schottky contact, the vertical gallium nitride based nitride heterojunction field effect transistor further comprises the polarized doped p-AlGaN current barrier layer between the n-GaN buffer layer and the GaN channel layer, and an Al component in the current barrier layer increases gradually in the y direction. According to the vertical gallium nitride based nitride heterojunction field effect transistor with the polarized doped current barrier layer, a polarized electric field, produced by the gradual change of the Al component in the current barrier layer, increases the activation rate of p-type impurities and the hole concentration of the current barrier layer, so that the breakdown voltage of an element is increased.

Description

technical field [0001] The invention relates to the field of semiconductor devices, in particular to a vertical GaN-based heterojunction field effect transistor with a polarized doped current blocking layer. technical background [0002] Gallium nitride-based heterojunction field effect transistor (Heterojunction Fiele-Effect Transistor, HFET) not only has a large band gap, a high critical breakdown electric field, a high electron saturation velocity, good thermal conductivity, radiation resistance and good chemical stability, etc. Excellent characteristics, 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 It is one of the most potential transistors for power electronics applications. [0003] The existing high withstand voltage GaN HFET...

AI Technical Summary

Problems solved by technology

Among the known p-type impurities in GaN materials, the Mg impurity has the lowest activation energy, about 200meV, but it is still much higher than the thermoelectric potential (about 26meV) at room temperature. Excessively high impurity activation energy leads to The activation rate of p-type impurities is very low, only about 1%, and it will decrease sharply with the decrease of temperature. When the material is AlGaN or AlN, the activation rate of p-type impurities will further decrease due to the further increase of activation energy.

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