Nitrogen polar surface gallium nitride high electron mobility transistor and manufacturing method thereof

Abstract

The invention discloses a nitrogen polar surface gallium nitride high-electron-mobility transistor and a manufacturing method thereof which mainly solve the problems that an existing nitrogen polar surface gallium nitride device is low in material epitaxial quality and can generate a heat accumulation effect and current collapse during high-voltage and high-power work. The nitrogen polar surface gallium nitride high-electron-mobility transistor comprises a diamond substrate (1), a barrier layer (4), an insertion layer (5) and a channel layer (6) from bottom to top, wherein a bonding layer (2) and a supporting layer (3) are arranged between the substrate (1) and the barrier layer (4), an insulated gate dielectric layer (7) is arranged at the upper portion of the channel layer (6), and a gate electrode is arranged on the insulated gate dielectric layer (7); ohmic contact areas are arranged at the two sides of the channel layer (6), and a source electrode and a drain electrode are arranged on the ohmic contact areas respectively. The nitrogen polar surface gallium nitride high-electron-mobility transistor is high in working frequency, the self-heating effect of a device is greatly improved, the output power working reliability of the device is improved; the manufacturing process is simple, the consistency is high, and the nitrogen polar surface gallium nitride high-electron-mobility transistor can be used for a high-frequency microwave power amplifier and a monolithic microwave millimeter wave integrated circuit.

Description

technical field [0001] The invention belongs to the technical field of semiconductor devices, in particular to a gallium nitride high electron mobility transistor on a nitrogen polar surface, which can be used for making microwave power amplifiers and monolithic microwave millimeter wave integrated circuits. Background technique [0002] The performance and reliability of microwave power amplifiers and monolithic microwave and millimeter wave integrated circuits based on gallium nitride heterojunction high electron mobility transistors have been continuously improved, and they have extremely high application value in the new generation of 5G communication base stations and electronic systems. At present, gallium nitride semiconductor devices are mainly manufactured based on gallium polar surface materials, because gallium polar surface materials are easy to achieve high-quality growth and low background carrier concentration. However, gallium nitride materials with nitrogen ...

AI Technical Summary

Problems solved by technology

[0005]First, it is difficult to control the polarity of nitrogen during the epitaxy of gallium nitride materials on the nitrogen polar surface, and the polarity reversal is prone to occur, resulting in the appearance of gallium nitride on the gallium polar surface Material;

[0006]Secondly, the background carrier concentration of the grown nitrogen polar gallium nitride material is high, and it is easy to form a bulk leakage channel to reduce the breakdown voltage of the device, so iron doping is required Compensation of background carriers increases the difficulty of material epitaxy process control;

[0007]Third, the thermal conductivity of the substrate is low, and the heat in the active area of ​​the GaN device on the nitrogen polar surface cannot be dissipated immediately, and the heat accumulation effect leads to device reliability and stability performance deterioration, it is difficult to give full play to the advantages of the device in high-frequency and high-power applications;

[0008]Fourth, when transferring GaN devices with nitrogen polar surfaces to high thermal conductivity diamond substrates, the sacrificial layer used in traditional methods is mostly SiO2 and other materials, because there is still a large lattice mismatch and thermal mismatch between the sacrificial layer and the GaN epitaxial material on the nitrogen polar surface, the sacrificial layer such as SiO2 There are high-density dislocation defects in the epitaxial gallium nitride surface material on the layer. When the device works for a long time under high bias voltage, a leakage channel will be formed to reduce the breakdown voltage of the device, and at the same time, electrons will be captured to cause the current collapse of the device;

[0009] Fifth, there are problems such as large lattice mismatch and thermal mismatch between the high thermal conductivity substrate diamond and the nitrogen polar gallium nitride material. It is difficult to achieve high crystallization quality for direct heteroepitaxial growth of gallium nitride on the nitrogen polar surface;

[0010] Sixth, the stripping transfer process of GaN devices on the nitrogen polar surface is complicated, the etching process is difficult to control accurately, the stripping interface is rough and uneven, and the completeness and success rate of device stripping Low, leading to device performance degradation after lift-off transfer

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