GaN HEMT device capable of optimizing breakdown characteristics and reverse characteristics at same time

Abstract

The invention discloses a GaN HEMT device capable of simultaneously optimizing breakdown characteristics and reverse characteristics, which relates to the field of semiconductor devices and comprisesa GaN buffer layer, an AlGaN barrier layer, a gate electrode, an under-gate oxide layer, a source electrode, a source field plate, a reverse diode oxide layer, an Al2O3 insertion layer, an SiO2 insertion layer, a drain electrode, a drain field plate and a Si3N4 passivation layer. The reverse diode of the MIS structure surrounds the gate electrode, so that the gate electrode electric field is effectively shielded, the gate electrode leakage current is reduced, the risk that the gate electrode is broken down is reduced, and the under-grid peak value electric field is moved rightwards to the MISreverse diode oxide layer. The composite double-insertion layer further moves the peak electric field at the oxide layer of the MIS reverse diode rightwards to the drain electrode side, so that the reverse diode is effectively protected. Through the drain electrode field plate, the drain electrode side peak electric field is pulled up to the passivation layer, the electric field in the semiconductor body material of the device is reduced, the leakage current of the device is effectively reduced, and the breakdown characteristic of the device is improved.

Description

technical field [0001] The invention relates to the field of semiconductor devices, in particular to a GaNHEMT device with simultaneously optimized breakdown characteristics and reverse characteristics. Background technique [0002] The traditional GaN HEMT device is different from the Si-based MOSFET. Although its structure is simple, there is no parasitic reverse diode, so its reverse conduction characteristics are heavily dependent on the gate-source voltage in the off state, and its reverse conduction The channel voltage drop is greater than the gate threshold voltage, that is, greater than 1.5V, which is larger than the forward conduction voltage drop of most diodes, and the power consumption in reverse conduction is higher. [0003] On the other hand, GaN HEMT devices exist with areal densities as high as 10 13 / cm 2 The material defects make it produce a serious electron capture effect under high frequency and high voltage working conditions, which increases the dyn...

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Problems solved by technology

[0002] The traditional GaN HEMT device is different from the Si-based MOSFET. Although its structure is simple, there is no parasitic reverse diode, so its reverse conduction characteristics are heavily dependent on the gate-source voltage in the off state, and its reverse conduction The channel voltage drop is greater than the gate threshold voltage, that is, greater than 1.5V, which is larger than the forward conduction voltage drop of most diodes, and the power consumption of reverse conduction is higher

[0003] On the other hand, GaN HEMT devices exist with areal densities as high as 10 13 / cm 2 The material defect makes it produce a serious electron capture effect under high frequency and high voltage working conditions, which increases the dynamic conduction loss and switching loss, and the breakdown characteristics are not satisfactory

[0004] The conventional enhanced GaN HEMT device structure still has two disadvantages: one is that there is no integrated reverse diode, and when the device works in the reverse direction, the reverse conduction voltage is equal to the gate-drain threshold voltage and the gate-source off-state voltage and the device The sum of the three conduction voltage drops, so the reverse conduction voltage drop is high, and the reverse operation loss is large; the second is that the device has a strong peak electric field on the drain side under the gate, which makes the gate leakage current of the device very large. And the gate is easily broken down, so the breakdown characteristics are not good.

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