Gallium nitride-based high electron mobility transistor

Abstract

The invention discloses a gallium nitride-based high electron mobility transistor, and belongs to the technical field of semiconductor devices. According to the transistor, a transverse schottky diodewith a rectifying effect is formed between a grid electrode and a drain electrode of a conventional GaN HEMT device to be used as a voltage-resistant structure, so that the surface electric field ofa component is modulated, and the distribution of a transverse electric field is optimized, thereby achieving the purpose of improving the breakdown voltage of the device; meanwhile, the existence ofthe transverse schottky diode can also bear certain reverse voltage in a blocking state, and the grid electrode is prevented from generating too large leakage current when the grid electrode is subjected to positive voltage under the positive conducting state, so that the forward current capability of the device is guaranteed; and in addition, compared with a field plate structure, additional parasitic capacitance is not introduced, so that the working frequency and the switching speed of the device are ensured, and the reliability of the device is improved.

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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