Gallium nitride-based hetero-junction field effect transistor with back electrode structure

Abstract

The invention discloses a gallium nitride-based hetero-junction field effect transistor with a back electrode structure. The gallium nitride-based hetero-junction field effect transistor mainly consists of a substrate, an aluminum nitride nucleating layer, a P-type aluminum-indium-gallium-nitrogen buffering layer, a gallium nitride channel layer, an aluminum nitride inserting layer and an aluminum-indium-gallium-nitrogen barrier layer in sequence from bottom to top; a source electrode, a drain electrode and a gate electrode are formed on the barrier layer; the source electrode and the drain electrode form ohmic contact with the barrier layer; the gate electrode and the barrier layer are in Schottky contact; and the gallium nitride-based hetero-junction field effect transistor further comprises the back electrode in contact with the substrate. The back electrode in the gallium nitride-based hetero-junction field effect transistor provided by the invention modulates potential distribution of a device buffering layer, so as to increase potential difference between the two-dimensional electron gas channel and the P-type aluminum-indium-gallium-nitrogen buffering layer. Therefore, two-dimensional electron gas in the channel and the P-type impurities in the buffering layer are entirely consumed, so that the electric field distribution of the device channel is more uniform, and the breakdown voltage of the device is improved.

Description

technical field [0001] The invention relates to the field of semiconductor devices, in particular to a gallium nitride (GaN)-based heterojunction field effect transistor with a back electrode structure. Background technique [0002] Gallium nitride (GaN) based heterojunction field effect transistor has excellent characteristics such as large band gap, high critical breakdown electric field, high electron saturation velocity, good thermal conductivity, radiation resistance and good chemical stability. (GaN) materials can form two-dimensional electron gas heterojunction channels with high concentration and high mobility with materials such as aluminum gallium nitride (AlGaN), so they are especially suitable for high-voltage, high-power and high-temperature applications, and are the most suitable for power electronics applications. One of the most promising transistors. [0003] figure 1 It is a schematic diagram of a common GaN HFET structure in the prior art, mainly includi...

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Problems solved by technology

but for figure 2 For the common RESURF GaN HFET shown, when the device is in reverse bias, the reverse bias voltage between the two-dimensional electron gas channel and the P-type buffer layer is not enough to make the channel two-dimensional electron gas and the P-type buffer layer Completely depleted, so that the withstand voltage limit of GaN material cannot be reached

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