Research on Breakdown Mechanism and Characteristics of 4H-SiC BJT with Trench-JTE Composite Termination

The trench-JTE composite termination is designed based on the basis of 4H-SiC BJTs, and which is formed by etching the base mesa and then using ion implantation. The breakdown mechanism and characteristics of trench-JTE composite termination are researched. And combined with the actual process, the key parameters, such as trench depth and the width, concentration and junction depth of the JTE region are optimized. The simulation results, when the trench etching depth is 2 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mu \mathrm{m}$</tex>, the concentration, width and junction depth of the JTE region is <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2\times 10^{17}\text{cm}^{-3},25$</tex> um and 0.8 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mu \mathrm{m}$</tex> respectively, the breakdown voltage of 4H-SiC BJTs with trench-JTE composite termination is 1956 V, the voltage withstand efficiency is 96.31%.