An optimized termination extension tutorial is reported for a small area (≈ 1mm2 ) 4H-SiC NPN BJT. The extension system is based on a parametric JTE with isolation rings. Additional aspects such as (1) MESA angle, (2) relieving electric field on the base-drift junction, and (3) blocking the electric field from reaching border structure are investigated. A breakdown voltage greater than 10 kV is recorded, when drift region is n-doped to 8x1014 cm-3.