First experimental demonstration of SiC super-junction (SJ) structure by multi-epitaxial growth method

A super-junction (SJ) device has been developed to improve the trade-off relationship between the breakdown voltage (VBD) and specific on-resistance in unipolar devices. Si-SJ devices are now widely used, and the effect of the SJ structure is also expected in SiC devices. Fundamental processes for fabricating SJ structures by using a multi-epitaxial (ME) growth method have been developed, where the epitaxial growth and MeV-class implantation steps are alternately repeated. Two types of test elemental groups (TEGs) were formed on the same wafer for evaluation of VBDand the specific resistivity of the drift layer (Rdrift). The measured VBDwas 1545 V, which was higher than that of the SiC theoretical limit by 670 V, and a value of Rdrift(including the substrate resistance) of 1.06 mΩ·cm2was obtained.