4H-SiC同质外延层的质量表征  

Characterization of 4H-SiC Homoepitaxial layers

作　　者：李佳[1] 冯志宏[1] 陈昊[1] 蔡树军[1] 

机构地区：[1]专用集成电路国家级重点实验室,石家庄050051

出　　处：《微纳电子技术》2009年第9期535-539,共5页Micronanoelectronic Technology

摘　　要：在高纯半绝缘4H-SiC偏8°衬底上同质外延生长了高质量的外延层,利用X射线双晶衍射、原子力显微镜(AFM)、汞探针C-V以及霍尔效应等测试方法,对样品的结晶质量、表面粗糙度、掺杂浓度以及电子迁移率进行了分析测试,证实外延层的结晶质量相对于衬底有着很大的改善。在同质外延7.5μm的外延层后,其半高宽从衬底的30.55arcsec减小到27.85arcsec;外延层表面10μm×10μm的粗糙度(RMS)为0.271nm;室温下,样品的掺杂浓度为1×1015cm-3时,霍尔迁移率高达987cm2/(V.s);浓度为1.5×1016cm-3时,霍尔迁移率为821cm2/(V.s)。77K时,霍耳迁移率分别为1.82×104cm2/(V.s)和1.29×104cm2/(V.s)。掺杂浓度的汞探针C-V测试结果与霍尔效应的实验数据一致。High quality 4H-SiC homoepitaxial layers were grown on 8° off-axis （0001） HP-S. I. 4H-SiC substrates. The crystalline quality and the electrical properties of the epilayers were characterized by using double-crystal X-ray diffraction （XRD）, atomic force microscopy （AFM） and hall effect, respectively. Compared with the substrates, the crystalline quality of the epilayers was improved. The FHWM of the 4H-SiC crystal is reduced from 30.55 arcsec to 27.85 arcsec after growing 4H-SiC epilayers with 7. 5/lm thickness. The RMS of the sample in the area of 10μm ×10μm is 0. 271 nm. The room-temperature electron mobility is 821 cm^2/（V, s） at 1.5×10^16 cm^-3doping concentration and 987 cm^2/（V ·s） at 1 × 10^15 cm^-3 doping concentration, respectively. The hall mobility is 1.82 × 10^4 cm^2/（V · s） and 1.29×10^4 cm^2/（V·S） at 77K, respectively. The doping concentrations measured by mercury C-V are well consisted with those measured by the hall effect.

关 键 词：4H-SIC XRD AFM 同质外延 汞探针C-V 迁移率 

分 类 号：TN304.24[电子电信—物理电子学] TN304.054