Comparative study on characteristics of Si-based AlGaN/GaN recessed MIS-HEMTs with HfO2 and Al2O3 gate insulators  

作　　者：Yao-Peng Zhao Chong Wang Xue-Feng Zheng Xiao-Hua Ma Kai Liu Ang Li Yun-Long He Yue Hao 赵垚澎;王冲;郑雪峰;马晓华;刘凯;李昂;何云龙;郝跃(Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices,School of Microelectronics,Xidian University,Xi'an 710071,China)

机构地区：[1]Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices,School of Microelectronics,Xidian University,Xi'an 710071,China

出　　处：《Chinese Physics B》2020年第8期445-450,共6页中国物理B（英文版）

基　　金：the National Natural Science Foundation of China(Grant Nos.61974111,11690042,and 61974115);the National Pre-research Foundation of China(Grant No.31512050402);the Fund of Innovation Center of Radiation Application,China(Grant No.KFZC2018040202).

摘　　要：Two types of enhancement-mode(E-mode)AlGaN/GaN metal-insulator-semiconductor high-electron-mobility transistors(MIS-HEMTs)with different gate insulators are fabricated on Si substrates.The HfO2 gate insulator and the Al2O3 gate insulator each with a thickness of 30 nm are grown by the plasma-enhanced atomic layer deposition(PEALD).The energy band diagrams of two types of dielectric MIS-HEMTs are compared.The breakdown voltage(VBR)of HfO2 dielectric layer and Al2O3 dielectric layer are 9.4 V and 15.9 V,respectively.With the same barrier thickness,the transconductance of MIS-HEMT with HfO2 is larger.The threshold voltage(Vth)of the HfO2 and Al2O3 MIS-HEMT are 2.0 V and 2.4 V,respectively,when the barrier layer thickness is 0 nm.The C-V characteristics are in good agreement with the Vth's transfer characteristics.As the barrier layer becomes thinner,the drain current density decreases sharply.Due to the dielectric/AlGaN interface is very close to the channel,the scattering of interface states will lead the electron mobility to decrease.The current collapse and the Ron of Al2O3 MIS-HEMT are smaller at the maximum gate voltage.As Al2O3 has excellent thermal stability and chemical stability,the interface state density of Al2O3/AlGaN is less than that of HfO2/AlGaN.

关 键 词：ALGAN/GAN ENHANCEMENT-MODE MIS-HEMT HFO2 AL2O3 

分 类 号：TN386[电子电信—物理电子学]