YAlN/GaN high-electron-mobility transistor and manufacturing method thereof

Abstract

The invention relates to a YAlN / GaN high-electron-mobility transistor and a manufacturing method thereof, and mainly solves the problems of low working frequency and high material dislocation density of an existing nitride microwave power device. The transistor comprises a substrate, a nucleating layer, a GaN channel layer, an AlN insertion layer and a YAlN barrier layer from bottom to top, wherein an InAlN cap layer is arranged between the insertion layer and the barrier layer; a barrier protection layer and an insulated gate dielectric layer are sequentially arranged at the upper part of the barrier layer, and ohmic contact regions for manufacturing a source electrode and a drain electrode are arranged on two sides from the InAlN cap layer to the insulated gate dielectric layer. A nucleating layer, a GaN channel layer, an AlN insertion layer and an InAlN cap layer in the structure are grown by adopting MOCVD; and the YAlN barrier layer and the barrier protection layer are grown by adopting MBE. The material is high in polarization intensity, high in device working frequency, high in reliability, simple in manufacturing process and high in consistency, and can be used for a high-frequency microwave power amplifier and a microwave millimeter wave integrated circuit.

Description

technical field [0001] The invention belongs to the technical field of semiconductor devices, and in particular relates to a transistor with high electron mobility, which can be used for making high-frequency microwave power amplifiers and microwave millimeter-wave monolithic integrated circuits. Background technique [0002] Group III nitride semiconductor materials have excellent properties such as wide bandgap, high critical breakdown field strength, and high electron saturation drift velocity. There are unique advantages in application. Since the first GaN high electron mobility transistor (HEMT) prototype device was successfully prepared in 1993, significant progress has been made in device performance and reliability, and it has gradually entered the field of commercial application from experimental research. With the deepening of research and the advancement of material epitaxy technology and device manufacturing process, the GaN device structure has been continuousl...

AI Technical Summary

Problems solved by technology

[0004]One is that the heteroepitaxial GaN material has high-density dislocation defects, which will form leakage channels to reduce the breakdown voltage of the device and capture Electrons cause device current collapse;

[0005]The second is that the AlGaN barrier layer and the GaN channel layer have tensile strain caused by lattice mismatch, and the device produces reverse in the AlGaN barrier layer when it is working at high voltage. Piezoelectric effect, which creates lattice defects and reduces device reliability;

[0006]Third, the two-dimensional electron gas concentration generated by the polarization effect at the AlGaN / GaN heterojunction interface is not high enough, which limits the further shortening of the gate length of the device and the increase of the operating frequency ;

[0007]Fourth, if the AlGaN barrier layer is not protected, surface states will be generated on the surface of the barrier layer, which will reduce the concentration of two-dimensional electron gas and affect the current and power output characteristics of the device

[0008]The fifth is to make the source-drain electrodes directly on the surface of the AlGaN barrier layer. The ohmic contact resistance of the source-drain area is very high, which affects the current and power output characteristics of the device

[0009] Sixth, the increase of Al composition in the AlGaN barrier layer causes the increase of lattice mismatch, the critical relaxation thickness of the material decreases sharply, and it faces technical challenges in material growth

Images