AlN/β-Ga_(2)O_(3)HEMT直流特性仿真  

Simulation on DC Characteristics of AlN/ β -Ga_(2) O_(3) HEMT

作　　者：贺小敏[1] 唐佩正 张宏伟 张昭 胡继超 李群 蒲红斌[1] HE Xiaomin;TANG Peizheng;ZHANG Hongwei;ZHANG Zhao;HU Jichao;LI Qun;PU Hongbin(School of Automation and Information Engineering,Xi’an University of Technology,Xi’an 710048,China)

机构地区：[1]西安理工大学自动化与信息工程学院,西安710048

出　　处：《人工晶体学报》2024年第5期766-772,共7页Journal of Synthetic Crystals

基　　金：国家自然科学基金青年科学基金(62104190,61904146);西安市科技局项目(2023JH-GXRC-0122)。

摘　　要：本文利用器件仿真软件对AlN/β-Ga_(2)O_(3)高电子迁移率晶体管(HEMT)器件的直流特性进行研究。由于AlN具有很强的极化效应,在AlN/β-Ga_(2)O_(3)异质结界面处产生高浓度二维电子气(2DEG),使AlN/β-Ga_(2)O_(3)异质结基HEMT具有更加优越的器件性能。理论计算得到AlN/β-Ga_(2)O_(3)异质结界面处产生的面电荷密度为2.75×10^(13) cm^(-2)。通过分析器件的能带结构、沟道电子浓度分布,研究AlN势垒层厚度、栅极长度、栅漏间距,以及金属功函数等参数对器件转移特性和输出特性的影响。结果表明:随着AlN势垒层厚度的增大,阈值电压减小,最大跨导减小,沟道电子浓度增大使饱和漏电流增大;随着栅极长度缩短,跨导增大,当栅极长度缩短至0.1μm时,器件出现了短沟道效应,并且随着栅极长度的缩短,栅下沟道区电子浓度增大,而电子速度基本不变,导致饱和漏电流增大,导通电阻减小,并且器件的饱和特性变差;随着栅漏间距的增大,跨导增大,沟道区电子浓度不变,而电子速度略有增加,导致饱和漏电流增大;肖特基栅金属功函数的增加会增大阈值电压,不会改变器件跨导,沟道电子浓度减小导致饱和漏电流减小。上述结论为后面的器件的优化改进提供了理论依据。DC characteristics of AlN/β-Ga_(2) O_(3) high-electron-mobility-transistor(HEMT)was studied in this paper by using the device simulation software.Due to the strong polarization effect of AlN,a high concentration of two-dimensional electron gas(2DEG)is generated at the interface of AlN/β-Ga_(2) O_(3) heterojunction,resulting in AlN/β-Ga_(2) O_(3) heterojunction based HEMT exhibits superior device performance.Theoretical calculation shows that the surface charge density generated at the interface of AlN/β-Ga_(2) O_(3) heterojunction is_(2).75×10^(13) cm^(-2).By analyzing the energy band structure and channel electron concentration distribution of the device,the effects of parameters such as AlN barrier layer thickness,gate length,gate drain spacing,and metal work function on the transfer and output characteristics of the device were studied.The following results were obtained.As the thickness of AlN barrier layer increases,the threshold voltage decreases,the maximum transconductance decreases,and the drain saturation current increases with the increase of channel electron concentration.As the gate length shortens,the transconductance increases,and the gate length shortens to 0.1μm,the device experienced a short channel effect.And as the gate length decreases,the electron concentration in the channel area under the gate increases,while the electron velocity remains basically unchanged,resulting in an increase in drain saturation current,a decrease in conduction resistance,and a deterioration in the saturation characteristics of the device.As the distance between the gate and drain increases,the transconductance increases,and the electron concentration in the channel region remains unchanged,while the electron velocity slightly increases,resulting in an increase in saturated leakage current.An increase in the Schottky gate metal work function will increase the threshold voltage without changing the device transconductance.The decrease in channel electron concentration will lead to a decrease in drain saturation

关 键 词：β-Ga_(2)O_(3) ALN HEMT 阈值电压 跨导 饱和漏电流 

分 类 号：TN248.4[电子电信—物理电子学] TN312