摘要
通过模拟的方法,研究了n型4H-SiC材料中Al离子注入深度、浓度分布与注入角度、缓冲层厚度、注入能量和剂量的关系。通过不同能量和剂量的组合进行了常温注入实验,注入深度为500 nm,注入浓度均匀分布。注入完成后,以SiC上下夹片的保护方式对SiC样品在1 650和1 750℃两种退火温度下进行激活。研究温度对激活效果的影响,观察注入条件和退火保护方式对SiC样品表面粗糙度的影响。激活完成后,在SiC样品上生长了一层Ni,并进行退火,研究激活浓度对Ni与Al注入形成的p-SiC欧姆接触的影响。实验中用喇曼谱表征注入损伤,用原子力显微镜(AFM)监测退火后表面粗糙度,用霍尔测试表征激活效果。实验结果表明,以4°偏角掠射,用100 nm SiO_2作为缓冲层进行注入,以1 750℃用SiC上下夹片保护进行退火,可以得到表面粗糙度为0.862 nm、激活浓度为4.25×1019 cm^(-3)的p-SiC样品。该方法可用于指导pin二极管、JBS、MOSFET、JFET和BJT等器件的设计。
The Al ion implantation depth and concentration distribution in the n-type 4H-SiC ma- terial as functions of the implantation angle, buffer layer thickness, implantation energy and dose were studied by the simulation. The implantation experiment was performed with multiple ener- gies and doses at room temperature to obtain the uniform ion concentration distribution, and the implantation depth is 500 nm. The Al ions were activated by annealing at 1 650 ℃ and 1 750 ℃ with the upper and lower surfaces of the SiC samples protected by SiC wafers after the implanta- tion. The influence of the temperature on the activation effect was researched. Besides, theinfluences of the implantation condition and annealing protection method on the surface roughness of the SiC samples were investigated. After the activation, a Ni layer was deposited on the SiC samples, and then the material was annealed. The effect of the activation concentration on the p-SiC Ohmic contact formed by Ni and Al implantations was studied. In the experiment, the damage induced by the implantation was characterized by Raman spectrum, the surface roughness after annealing was inspected by the atomic force microscope （AFM） and the activation effect was characterized by Hall test, respectively. The experimental results show that with a SiO2 film of 100 nm thickness as the buffer layer and the implantation tilt angle of 4°, the p-SiC samples with the surface roughness of 0. 862 nm and the activation concentration of 4.25 ×10^19 cm-3 can be obtained by annealing at 1 750℃ with the upper and lower surfaces protected by SiC wafers. The method can provide a reference for the design of SiC-based devices including pin diodes, JBS, MOSFET, JFET, BJT and so on.
出处
《微纳电子技术》
北大核心
2017年第2期125-130,141,共7页
Micronanoelectronic Technology
基金
江苏省基础研究计划青年基金项目(BK20150370)
江苏省科技支撑计划(工业)项目(SBE2014000517)
