AlN/β-Ga_(2)O_(3)HEMT频率特性仿真研究  

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

作　　者：贺小敏[1] 唐佩正 刘若琪 宋欣洋 胡继超 苏汉 HE Xiaomin;TANG Peizheng;LIU Ruoqi;SONG Xinyang;HU Jichao;SU Han(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8期1361-1368,共8页Journal of Synthetic Crystals

基　　金：国家自然科学青年基金(62104190,61904146);西安市科技局项目(2023JH-GXRC-0122);陕西省自然科学基础研究计划(2024JC-YBQN-0655)。

摘　　要：器件的频率特性影响较为复杂,本文利用Sentaurus TCAD研究了AlN势垒层厚度、栅长、栅漏间距和功函数对AlN/β-Ga_(2)O_(3)高电子迁移率晶体管(HEMT)频率特性的影响,得到以下结论:随着AlN势垒层厚度从10 nm增加到25 nm,截止频率(f_(T))和最高振荡频率(f_(max))分别增加了18和17 GHz,栅电容减小是f_(T)增加的主要原因,同时研究表明势垒层厚度减小有利于增强栅极对沟道电子的控制。栅长从0.9μm减小到0.1μm,f_(T)和f_(max)分别增加了84和98 GHz,其对频率特性的影响远远超过了势垒层厚度;栅长小于0.1μm时,发生短沟道效应。栅漏间距增大时,f_(T)微弱减小,在源电阻和f_(T)共同减小作用下,器件仅在栅源电压(V_(GS))大于-1.2 V时,f_(max)与f_(T)的变化趋势相同。功函数几乎不会影响器件的f_(T)和f_(max),但是功函数的增加改善了器件的夹断特性。本文研究表明,在栅长缩短的同时,增加AlN势垒层厚度、栅漏间距和功函数可以在提高频率特性的同时改善器件的夹断特性,对AlN/β-Ga_(2)O_(3) HEMT器件的设计有一定的指导意义。The influence of frequency characteristics of devices is complex.The effects of AlN barrier thickness,gate length,gate-drain spacing and work function on the frequency characteristics of AlN/β-Ga_(2)O_(3) high electron mobility transistor(HEMT) were studied by Sentaurus TCAD in this paper.The following conclusions are obtained:as the thickness of the AlN barrier layer increases from 10 nm to 25 nm,the cutoff frequency(f_T) and maximum oscillation frequency(f_(max)) rise by 18 and 17 GHz respectively.The decrease of gate capacitance is the main reason for the increase of f_T.Furthermore,it was found that the thinner barrier layer enhanced the gate's ability to control the channel electrons.When the gate length is scaled down from 0.9 μm to 0.1 μm,f_(T) and f_(max) increase by 84 and 98 GHz,respectively,representing a far more profound influence on frequency characteristics than the barrier layer thickness.However,when the gate length fell below 0.1 μm,short-channel effects emerged.As the gate-drain spacing increase,f_(T) exhibits a slight decrease.Coupled with the concurrent reduction in source resistance,this led to a synchronized trend in f_(max) and f_(T) only when the gate-source voltage(V_(GS)) exceeds-1.2 V.The work function,on the other hand,has minimal impacts on f_(T) and f_(max),but an increase in the work function positively influenced the device's pinch-off characteristics.In summary,this paper indicates that by shortening the gate length while concurrently augmenting the thickness of the AlN barrier layer,gate-drain spacing,and work function,one can enhance the frequency characteristics while also improving the pinch-off characteristics of the device,which has certain guiding significance for the design of HEMT devices.

关 键 词：β-Ga_(2)O_(3) ALN HEMT 截止频率 最高振荡频率 

分 类 号：TN248.4[电子电信—物理电子学] TN312