Breakdown Enhancement and Current Collapse Suppression in AlGaN/GaN HEMT by NiOX/SiNX and Al2O3/SiNX as Gate Dielectric Layer and Passivation Layer

Sheng Gao,Hong Wang,Xiaoyi Liu,Quanbin Zhou

doi:10.1109/led.2019.2945175

Abstract

We propose two kinds of stacked materials that effectively yield low drain off-state leakage current, high off-state breakdown voltage and low current collapse simultaneously in AlGaN/GaN HEMT. The two kinds of stacked materials, which is NiO X /SiN X and Al 2 O 3 /SiN X respectively, act as gate dielectric layer and passivation layer for the devices. The NiO X and Al 2 O 3 are prepared through depositing Ni and Al thin film by electron beam evaporation and then annealing in O 2 ambient by rapid thermal processing. The SiN X is deposited by plasma-enhanced chemical vapor deposition. Compared to the single SiN X layer, the NiO X /SiN X stack layer and Al 2 O 3 /SiN X stack layer can distinctly reduce the drain off-state leakage current of devices. Meanwhile, high off-state breakdown voltage is also achieved. The off-state breakdown voltage in the devices with NiO X /SiN X stack layer and Al 2 O 3 /SiN X stack layer are 52% and 36% higher than that of the devices with single SiN X layer respectively. Especially, the current collapse under 200 V stress bias is reduced by 90% and 58% in the devices with NiO X /SiN X stack layer and Al 2 O 3 /SiN X stack layer compare to the devices with single SiN X layer respectively.

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