基于机械剥离β-Ga2O3的Ni/Au垂直结构肖特基器件的温度特性  

Temperature dependent characteristics of Ni/Au vertical Schottky diode based on mechanically exfoliated beta-Ga2O3 single crystal

作　　者：龙泽 夏晓川[1] 石建军 刘俊[1] 耿昕蕾 张赫之[1] 梁红伟[1] Long Ze;Xia Xiao-Chuan;Shi Jian-Jun;Liu Jun;Geng Xin-Lei;Zhang He-Zhi;Liang Hong-Wei(School of Microelectronics,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]大连理工大学微电子学院,大连116024

出　　处：《物理学报》2020年第13期282-291,共10页Acta Physica Sinica

基　　金：大连市科技创新基金(批准号:2018J12GX060);国家重点研发计划(批准号:2016YFB0400600,2016YFB0400601)资助的课题.

摘　　要：本文制备了基于机械剥离β-Ga2O3的Ni/Au垂直结构肖特基器件,对该器件进行了温度特性I-V曲线测试.器件表现出了良好的二极管特性,随着温度从300 K升高至473 K,势垒高度从1.08 e V上升至1.35 e V,理想因子从1.32降低至1.19,二者表现出了较强的温度依赖特性,这表明器件的肖特基势垒存在势垒高度不均匀的问题.串联电阻随温度升高而降低,这主要是热激发载流子浓度升高导致的.本文利用势垒高度的高斯分布对器件的温度特性进行了修正,修正后的势垒高度为1.54 e V,理查孙常数为26.35 A·cm–2·K–2,更接近理论值,这表明利用高斯分布势垒高度的热电子发射模型能够很好地解释Au/Ni/β-Ga2O3肖特基二极管的I-V温度特性问题,这种方法更适合用来测量β-Ga2O3肖特基二极管的电学参数.In this paper,a Ni/Au vertical structure Schottky diode based on mechanically exfoliated b-Ga2O3 is fabricated.The temperature dependent characteristics of I-V curves are measured.The device shows a good rectifying behavior.As the temperature increases from 300 K to 473 K,the barrier height increases from 1.08 eV to 1.35 eV,and the ideal factor decreases from 1.32 to 1.19.Both of them show strong temperature dependence,which indicates that the Schottky barrier of the device is inhomogeneous.The device has a double exponential forward I-V characteristic curve,which may be related to crystal defects,surface states,surface energy band bending and the effect of mechanical exfoliation from the crystal surface.Through Cheung's method and Norde's method,the series resistances and barrier heights of the device at different temperatures are extracted.It is found that the parameters extracted by the Norde's method are in good agreement with the values obtained from the forward I-V curve.The series resistance decreases with temperature increasing,which is mainly caused by the increase of the concentration of thermally excited carriers.In this paper,the temperature characteristics of the device are modified by the Gauss distribution of the barrier height.The corrected barrier height is 1.54 eV and Richardson's constant is 26.35 A·cm–2·K–2,which is closer to the theoretical value.It shows that the I-V temperature characteristics of Au/Ni/b-Ga2O3 Schottky diodes can be described by the thermionic emission model of the Gauss distribution barrier height accurately.There are a lot of surface states on the surface of Ga2O3 single crystal obtained by Mechanical exfoliation,which has a great influence on the Schottky contact of the device and may lead to the inhomogeneity of Schottky barriers.At the same time,due to mechanical exploiation,the surface of gallium oxide single crystal material is not completely continuous,and the single crystal surface has layered or island structure.This will also cause the inhomogeneous Schottk

关 键 词：氧化镓 机械剥离 肖特基二极管 温度特性 

分 类 号：TN311.7[电子电信—物理电子学]