Development of SiC super-junction (SJ) devices by multi-epitaxial growth

Super-junction (SJ) devices have been developed to improve the trade-off relationship between the blocking voltage (V-BD) and specific on-resistance in unipolar power devices. This SJ structure effect is expected in SIC unipolar devices. Multi-epitaxial growth is a known fabrication method for SJ structures where epitaxial growth and ion implantation are repeated alternately until a certain drift-layer thickness is achieved. In this study, we fabricated two types of test elemental groups with an SJ structure to evaluate the breakdown voltage (V-BD) and specific resistivity of the drift layer (R-drift). Experimental results show that V-BD exceeded the theoretical limit of the 4H-SiC by 300V, and R-drift agreed well with the estimated value from the device simulation. The beneficial effects of the SJ structure in the SiC material on V-BD and R-drift were confirmed for the first time.