Heteroepitaxial Growth and Heterojunction Characteristics of Voids-Free n-3C-SiC on p-Si(100)

Highly oriented voids-free 3C-SiC heteroepitaxial layers are grown onφ50mm Si (100) substrates by low pressure chemical vapor deposition (LPCVD).The initial stage of carbonization and the surface morphology of carbonization layers of Si (100) are studied using reflection high energy electron diffraction (RHEED) and scanning electron microscopy (SEM).It is shown that the optimized carbonization temperature for the growth of voids-free 3C-SiC on Si (100) substrates is 1100℃.The electrical properties of SiC layers are characterized using Van der Pauw method.The I-V,C-V,and the temperature dependence of I-V characteristics in n-3C-SiC/p-Si heterojunctions with AuGeNi and Al electrical pads are investigated.It is shown that the maximum reverse breakdown voltage of the n-3C-SiC/p-Si heterojunction diodes reaches to 220V at room temperature.These results indicate that the SiC/Si heterojunction diode can be used to fabricate the wide bandgap emitter SiC/Si heterojunction bipolar transistors (HBT's).

Si(100)衬底上n-3C-SiC/p-Si异质结构研究

利用LPCVD方法在Si(100)衬底上获得了3C SiC外延膜,扫描电子显微镜(SEM)研究表明3C SiC/p Si界面平整、光滑,无明显的坑洞形成。研究了以In和Al为接触电极的3C SiC/p Si异质结的I V,C V特性及I V特性的温度依赖关系,比较了In电极的3C SiC/p Si异质结构和以SiGe作为缓冲层的3C SiC/SiGe/p Si异质结构的I V特性,实验发现引入SiGe缓冲层后,器件的反向击穿电压由40V提高到70V以上。室温下Al电极3C SiC/p Si二极管的最大反向击穿电压接近100V,品质因子为1 95。