Enhanced Electrical Performance in SiC Double-Trench MOSFETs through Optimization Techniques

Single-trench SiC MOSFETs structures offer lower on-resistance but reduce the breakdown voltage. To overcome this limitation, double-trench SiC power MOSFETs have been developed. In this study, Baliga's Figure of Merit (BFOM) was improved by adjusting the drift region doping concentration, as well as the depth and angle of the source trench. The simulation results demonstrate that as the doping concentration in the drift region increases, the BFOM reaches its peak at a value of 1.02GW/cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> when the doping concentration in the drift region is 4 × 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">15</sup> cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup>, before subsequently decreasing. Additionally, increasing the source trench depth to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$1.8 \mu \mathrm{m}$</tex> shifts the doping concentration at which the BFOM reaches its maximum to 6 × 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">15</sup> cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup>, resulting in an improved BFOM of 2.4GW/cm2. When the source trench angle is adjusted to 94 degrees, with a doping concentration of 6 × 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">15</sup> cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup>and a source trench depth of 1.8 μm, the BFOM further increases to 2.72GW/cm2.