A Gallium Nitride-Based High Electron Mobility Transistor

Abstract

A gallium nitride-based high electron mobility transistor belongs to the technical field of semiconductor devices. The present invention forms a rectifying lateral Schottky diode between the gate and the drain of the traditional GaN HEMT device as a withstand voltage structure to modulate the electric field on the surface of the device and optimize the distribution of the lateral electric field, thereby increasing the breakdown voltage of the device At the same time, the existence of the lateral Schottky diode can also withstand a certain reverse voltage in the blocking state, and avoid excessive leakage current in the gate when the gate is applied with a positive voltage in the forward conduction state, ensuring that the device In addition, compared with the field plate structure, the present invention does not introduce additional parasitic capacitance, ensures the operating frequency and switching speed of the device, and improves the reliability of the device.

Description

technical field [0001] The invention belongs to the technical field of semiconductor devices, and in particular relates to a GaN-based high electron mobility transistor with a lateral Schottky diode withstand voltage structure. Background technique [0002] Gallium nitride (GaN)-based high electron mobility transistors have 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 a two-dimensional electron gas heterojunction channel with high concentration and high mobility with materials such as aluminum gallium nitride (AlGaN) or indium gallium nitride (InGaN). Therefore, gallium nitride (GaN)-based high electron Mobility transistors are especially suitable for high-voltage, high-power and high-temperature applications, and have become one of the most potential transistors for power electronics applications...

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Problems solved by technology

However, the activation rate of P-GaN is very low, and the effect of improving the withstand voltage capability of the device is limited

[0007] 3. Use AlGaN and other back barrier buffer layer structures, mentioned in the literature [Oliver Gilt et al. "Normally-offAlGaN / GaN HFET with p-type GaN Gate and AlGaN Buffer", Integrated PowerElectronics Systems, 2010], AlGaN and other back potential The use of the barrier increases the barrier height from the channel two-dimensional electron gas to the buffer layer, thereby reducing the leakage current of the device buffer layer. However, this technology also has a limited improvement in the breakdown voltage of the device and fails to fully reflect the potential of gallium nitride. The advantage of the withstand voltage of the material; at the same time, the AlGaN back barrier will not only introduce traps due to lattice mismatch between the buffer layer and the channel layer, but also because AlGaN in the buffer layer and AlGaN in the barrier layer have opposite polarization effects, On the contrary, it will reduce the two-dimensional electron gas concentration in the channel, which will lead to an increase in the on-resistance of the device.

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