6英寸高纯半绝缘4H-SiC单晶电阻率均匀性  

Resistivity Uniformity of 6-inch High-purity Semi-insulating 4H-SiC Crystals

作　　者：樊元东 毛开礼 戴鑫 魏汝省 李天 李斌 FAN Yuandong;MAO Kaili;DAI Xin;WEI Rusheng;LI Tian;LI Bin(The 13th Research Institute of CETC,Shijiazhuang 050051,China;Shanxi Semisic Crystal Co.,Ltd.,Taiyuan 030062,China)

机构地区：[1]中国电子科技集团公司第十三研究所,石家庄050051 [2]山西烁科晶体有限公司,太原030062

出　　处：《电子工艺技术》2023年第3期42-46,共5页Electronics Process Technology

基　　金：山西省科技重大专项计划资助项目(20201102012)。

摘　　要：GaN射频器件在通信基建上的大幅应用,推进了6英寸高纯半绝缘4H-SiC单晶的产业化需求。随着晶体直径增大,6英寸高纯半绝缘4H-SiC单晶存在易开裂、电阻率分布不匀的问题。利用有限元仿真设计,优化了热场分布,降低了晶体内热应力聚集,减少了晶体开裂。采用SIMS、拉曼光谱等手段分析了影响6英寸4H-SiC单晶内电阻率分布不均匀的因素,发现主要原因为正向SiC晶体小面生长机制导致N元素分布不均。采用分区高能粒子辐照处理工艺,进行分区深能级点缺陷调控,电阻率可控制在1011Ω·cm以上,可将片内和片间电阻率最大值与最小值的比值控制在1个量级内,大幅提升电阻率均匀性。The demand for 6-inch high-purity semi-insulated 4H-SiC single crystals has been promoted by the significant application of GaN RF devices in communication infrastructure.As the crystal diameter increases,the crystal cracking and the resistivity nonuniform issues become more signifi cant for 6-inch highpurity semi-insulating 4H-SiC single crystals.The finite element simulation design is used to optimize the thermal fi eld distribution,the crystal cracking problem is cut down by reducing the accumulation of thermal stress inside the crystal.The SIMS and Raman spectroscopy are used to analyze the factors affecting the electrical resistivity nonuniform in 6-inch 4H-SiC single crystals.It is found that the primary reason is that the concentration of the nitrogen element in the facet of the SiC crystal was different from the outside area.Through the partitioned high-energy particle irradiation process,the deep level point defect concentration can be controlled by adjusting irradiation dose and time,and the average resistivity of wafer is over 1011Ω·cm.The proportion value of maximum and minimum resistivity can be controlled within one order of magnitude,which signifi cantly improves the uniformity of resistivity by this method.

关 键 词：高纯半绝缘 碳化硅单晶 有限元仿真 电阻率均匀性 

分 类 号：TN304[电子电信—物理电子学]