Silicon passivation-based p-GaN gate enhanced MIS-HEMT device and preparation method thereof

Abstract

The invention discloses a silicon passivation-based p-GaN gate enhanced MIS-HEMT device and a preparation method thereof, the device comprises a substrate layer, a nucleating layer, a buffer layer, a channel layer and a barrier layer which are sequentially arranged from bottom to top, and isolation regions are respectively arranged on two sides of the barrier layer; the isolation region extends from the upper surface of the barrier layer to the upper surface of the buffer layer; a cap layer, a passivation layer, an oxide layer and a gate electrode are sequentially arranged in the middle of the upper surface of the barrier layer from bottom to top, and a source electrode and a drain electrode are arranged on the two sides of the upper surface of the barrier layer respectively. The passivation layer is deposited on the cap layer, so that the oxide layer and the barrier layer can be isolated, the surface state and defects of the p-GaN material are greatly passivated, the voltage resistance of the p-GaN grid is effectively improved, the threshold voltage drift of the device is improved, the output current is increased, and the leakage current of the grid is reduced.

Description

technical field [0001] The invention belongs to the technical field of semiconductor devices, in particular to a p-GaN gate enhancement type MIS-HEMT device based on silicon passivation and a preparation method thereof. Background technique [0002] High Electron Mobility Transistor (HEMT) based on gallium nitride (GaN) has excellent performance of high electron mobility and high breakdown voltage due to the use of a conductive channel formed by a two-dimensional electron gas structure. Due to the wide band gap characteristics of GaN materials, GaN-based HEMT devices have good high temperature characteristics and radiation resistance characteristics, and are favored in harsh application environments such as high frequency, high voltage, and high power. [0003] The p-GaN gate enhancement mode HEMT device depletes the two-dimensional electron gas under the gate region through the built-in electric field generated by the p-GaN gate structure, and has high threshold voltage, sa...

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Problems solved by technology

[0004] The gate oxide layer of p-GaN gate-enhanced MIS (metal-insulator-semiconductor)-HEMT devices can effectively reduce the gate leakage current, but since the epitaxial growth process of GaN materials is carried out in a non-thermodynamic equilibrium state, the material surface A large number of defects and dangling bonds, the interface state between GaN and the oxide layer can capture or release electrons, causing problems such as device threshold voltage drift, gain reduction, and cut-off frequency reduction, resulting in device parameter degradation and reliability reduction, so p-GaN Gate-enhanced MIS-HEMT devices have not been commercialized

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