Correlation between Stacking Faults in Epitaxial Layers of 4H-SiC and Defects in 4H-SiC Substrate

The morphology and causes of stacking faults (SF) in homoepitaxial layers of 4H-SiC were studied. According to characteristics of PL images and morphology images of 4H-SiC five kinds of SFs have been defined. In the PL images, the morphologies of SF I and SF II-V are trapezoidal and triangular, respectively. SF II lays inside the area of SF I. In the morphology images, SF I and IV are not seen, SF II-III are carrot shaped and SF V is triangular respectively. The results show that SF I is a kind of base plane SF which originates from the base plane dislocation (BPD) lines of the substrate, parallel to <11 00> direction and moving along <112 0> direction during epitaxial growing. SF II and most of SF III-IV originate from BPDs in substrate. One BPD converts into threading dislocation during epitaxial growing and propagates to the surface along <0001> direction, while other BPDs or partial dislocations originating from threading dislocation propagate in (0001) plane to form triangular base plane SFs. The rest of SF III-IV and SF V originate from threading edge dislocation or other defects in substrate. SF II-III display carrots morphology because a 7 , : 4H-SiC