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 (V_BD) 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 V_BD and the specific resistivity of the drift layer (R_drift). The measured V_BD was 1545 V, which was higher than that of the SiC theoretical limit by 670 V, and a value of R_drift (including the substrate resistance) of 1.06 mΩ·cm² was obtained.