Threshold voltage control by gate oxide thickness in fluorinated GaN metal-oxide-semiconductor high-electron-mobility transistors
Threshold voltage control by gate oxide thickness in fluorinated GaN metal-oxide-semiconductor high-electron-mobility transistors
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DOI：
10.1063/1.4815923
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发表时间：
2013-07-15
影响因子：
4
通讯作者：
Palacios, Tomas
中科院分区：
文献类型：
--
作者：
Zhang, Yuhao;Sun, Min;Palacios, Tomas
研究了GaN金属氧化物半导体高电子迁移率晶体管（MOS-HEMT）中氟离子对Al 2 O3栅介质中本征正电荷的补偿作用。在250摄氏度的原子层沉积过程中，从AlGaN势垒扩散到氧化物中的带负电荷的氟离子补偿了Al 2 O3中存在的本征正电荷。这种补偿是控制增强型（E-mode）晶体管的阈值电压（V-th）的关键。建立了一个全面的氟化MOS-HEMT的V-th解析模型，并通过实验数据进行了验证。该模型允许计算不同的电荷分量，以优化E模式操作的晶体管结构。使用所提出的电荷补偿，Vth随栅极电介质厚度增加，对于25 nm厚的栅极，Vth超过3.5V。(C)2013 AIP Publishing LLC.
This paper demonstrates the compensation of the intrinsic positive charges in Al2O3 gate dielectric by fluorine ions in GaN metal-oxide-semiconductor high-electron-mobility transistors (MOS-HEMTs). Negatively-charged fluorine ions diffused into the oxide from the AlGaN barrier during the 250 degrees C atomic layer deposition compensate the intrinsic positive charge present in the Al2O3. This compensation is key to control the threshold voltage (V-th) of enhancement-mode (E-mode) transistors. A comprehensive analytical model for the V-th of fluorinated MOS-HEMTs was established and verified by experimental data. This model allows the calculation of the different charge components in order to optimize the transistor structure for E-mode operation. Using the proposed charge compensation, the Vth increases with gate dielectric thickness, exceeding 3.5V for gate dielectrics 25 nm thick. (C) 2013 AIP Publishing LLC.