The breakdown mechanism of power bipolar static induction transistor (BSIT) with buried gate structure is analyzed in depth.A power BSIT sample with high voltage-resistant capability has been designed and fabricated in this paper.The technological methods for improving high voltage performances are represented.The active region of BSIT is surrounded with a deep trench to avoid any probable influences of various defects on device performances.Two field-limiting ring-shape junctions and one channel termination ring-shape junction are arranged around the gate region to reduce the electric field intensity.The gate-source breakdown voltage BV GS of power BSIT has been increased to 110 V from previous value of 50-60 V,and its blocking voltage is increased to 1700 V.The optimal geometrical dimensions for achieving the maximum breakdown voltage BV GS and blocking voltage V block are also represented in the paper. The breakdown mechanism of power bipolar static induction transistor (BSIT) with buried voltage-resistant capability has been designed and fabricated in this paper. The technological methods for improving high voltage views The active region of BSIT is surrounded with a deep trench to avoid any probable influences of various defects on device performance. Two-field ring-shape junctions and one channel termination ring-shape junction are arranged around the gate region to reduce the electric field intensity. The gate-source breakdown voltage BV GS of power BSIT has been increased to 110 V from the previous value of 50-60 V, and its blocking voltage increased to 1700 V. The optimal geometrical dimensions for achieving the maximum breakdown voltage BV GS and blocking voltage V block are also represented in the paper.