摘要
研究了2100keV高能量钒注入4H-SiC制备半绝缘层的方法和特性，注入层的浓度分布用蒙特卡罗分析软件TRIM进行模拟．采用一种台面结构进行I-V测试，发现钒注入层的电阻率与4H-SiC层的初始导电类型有很大关系．常温下，钒注入p型和n型4H-SiC的电阻率分别为1．6×10^10和7．6×10^6Ω·cm．测量了不同退火温度下的电阻率，发现高温退火有利于钒的替位激活和提高电阻率，由于钒扩散的影响1700℃退火使得电阻率略有下降．测量了n型SiC钒注入层在20～140℃时的电阻率，计算出钒受主能级在4H-SiC中的激活能为0．78eV．
Vanadium ion （V^＋） implantation at a high energy （2100keV） is successfully used to form semi-insulating layers in 4H-SiC. The fabrication processes and measurements of the implanted layer are reported in detail. The profile of the ion implantation is simulated with the Monte Carlo simulator TRIM. Test patterns on semi-insulating 4H-SiC samples are processed into a mesa structure, and resistivity measurements are conducted. The resistivities of V^＊ -implanted layers are strongly dependent on the conduction type of the initial 4H-SiC samples,and they are about 1.6×10^10 and 7.6×10^6Ω·cm respectively for p- and n-type samples at room temperature. The resistivities of the as-implanted samples increase with increasing annealing temperature for both p- and n-type samples due to the introduction of compensating levels. However, they decrease slightly beyond 1700℃ due to the diffusion of vanadium. The temperature dependent resistivity behavior in V^＋ -implanted n- type 4H-SiC indicates an activation energy of 0.78eV.
基金
国家自然科学基金(批准号:60376001)
国家重点基础研究发展规划(批准号:2002CB311904)
国防基础研究计划(批准号:51327020202)资助项目~~
关键词
碳化硅
半绝缘
钒离子注入
退火
激活能
SiC
semi-insulating
vanadium ion implantation
annealing
activation energy
