A gan HEMT device and its manufacturing process with simultaneous optimization of breakdown characteristics and reverse characteristics

Abstract

The invention discloses a GaN HEMT device with optimized breakdown characteristics and reverse characteristics at the same time, relates to the field of semiconductor devices, and includes a GaN buffer layer, an AlGaN barrier layer, a gate electrode, an oxide layer under the gate, a source electrode, a source field Plate, Reverse Diode Oxide, Al 2 O 3 Insertion layer, SiO 2 Insertion layer, drain electrode, drain field plate, and Si 3 N 4 passivation layer. The reverse diode of the MIS structure surrounds the gate, so that the gate electric field is effectively shielded, the gate leakage current is reduced, the risk of gate breakdown is reduced, and the peak electric field under the gate is shifted to the right to the MIS reverse diode oxidation. layer. The composite double insertion layer shifts the peak electric field at the oxide layer of the MIS reverse diode further to the right to the drain side, effectively protecting the reverse diode. Through the drain field plate, the peak electric field on the drain side is pulled up into the passivation layer, which reduces the electric field inside the semiconductor body material of the device, effectively reduces the leakage current of the device, and improves the breakdown characteristics of the device.

Description

technical field [0001] The invention relates to the field of semiconductor devices, in particular to a GaNHEMT device and a manufacturing process for simultaneously optimizing 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 conditi...

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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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