Dielectric thin films for GaN-based high-electron-mobility transistors
来源期刊：Rare Metals2015年第6期
论文作者：Yan-Rong Li Xing-Zhao Liu Jun Zhu Ji-Hua Zhang Lin-Xuan Qian Wan-Li Zhang
文章页码：371 - 380
摘 要：The effects of dielectric thin films on the performance of Ga N-based high-electron-mobility transistors（HEMTs） were reviewed in this work. Firstly, the nonpolar dielectric thin films which act as both the surface passivation layers and the gate insulators of the high-frequency Ga N-based high-electron-mobility transistors were presented. Furthermore, the influences of dielectric thin films on the electrical properties of two-dimensional electron gas（2DEG） in the Al Ga N/Ga N hetero-structures were analyzed. It was found that the additional in-plane biaxial tensile stress was another important factor besides the change in surface potential profile for the device performance improvement of the Al Ga N/Ga N HEMTs with dielectric thin films as both passivation layers and gate dielectrics. Then, two kinds of polar gate dielectric thin films, the ferroelectric LiNbO3 and the fluorinated Al2O3,were compared for the enhancement-mode Ga N-based HEMTs, and an innovative process was proposed. At last,high-permittivity dielectric thin films were adopted as passivation layers to modulate the electric field and accordingly increase the breakdown voltage of Ga N-based HEMTs. Moreover, the polyimide embedded with Cr particles effectively increased the breakdown voltage of Ga Nbased HEMTs. Finally, the effects of high-permittivity dielectric thin films on the potential distribution in the driftregion were simulated, which showed an expanded electric field peak at the drain-side edge of gate electrode.
Yan-Rong Li，Xing-Zhao Liu，Jun Zhu，Ji-Hua Zhang，Lin-Xuan Qian，Wan-Li Zhang
State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Microelectronics and Solid-State Electronics, University of Electronic Science and Technology of China
摘 要：The effects of dielectric thin films on the performance of Ga N-based high-electron-mobility transistors（HEMTs） were reviewed in this work. Firstly, the nonpolar dielectric thin films which act as both the surface passivation layers and the gate insulators of the high-frequency Ga N-based high-electron-mobility transistors were presented. Furthermore, the influences of dielectric thin films on the electrical properties of two-dimensional electron gas（2DEG） in the Al Ga N/Ga N hetero-structures were analyzed. It was found that the additional in-plane biaxial tensile stress was another important factor besides the change in surface potential profile for the device performance improvement of the Al Ga N/Ga N HEMTs with dielectric thin films as both passivation layers and gate dielectrics. Then, two kinds of polar gate dielectric thin films, the ferroelectric LiNbO3 and the fluorinated Al2O3,were compared for the enhancement-mode Ga N-based HEMTs, and an innovative process was proposed. At last,high-permittivity dielectric thin films were adopted as passivation layers to modulate the electric field and accordingly increase the breakdown voltage of Ga N-based HEMTs. Moreover, the polyimide embedded with Cr particles effectively increased the breakdown voltage of Ga Nbased HEMTs. Finally, the effects of high-permittivity dielectric thin films on the potential distribution in the driftregion were simulated, which showed an expanded electric field peak at the drain-side edge of gate electrode.
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