Abstract: According to the avalanche ionization theory, a computer-based analysis is performed to analyze the structural parameters of single- and multiple-zone junction termination extension (JTE) structures for 4H-SiC bipolar junction transistors (BJTs) with mesa structure. The calculation results show that a single-zone JTE can yield high breakdown voltages if the activated JTE dose and the implantation width are controlled precisely and a multiple-zone JTE method can decrease the peak surface field while still maintaining a high blocking capability. The influences of the positive and negative surface or interface states on the blocking capability are also shown. These conclusions have a realistic meaning in optimizing the design of a mesa power device.

Key words: 4H-SiC