An Analytical Model With 2-D Effects for 4H-SiC Trenched Junction Barrier Schottky Diodes

This paper presents an analytical model with 2-D effects for 1200 V 4H-silicon carbide trenched junction barrier Schottky (TJBS) diodes. Energy band diagrams of junction barrier Schottky and TJBS diodes in reverse biases are analyzed in detail. An analytical model of potential and electric field distributions with 2-D effects is proposed. Based on the modeling results of the surface electric field, a physical model accounting for three main mechanisms, namely, thermionic emission, tunneling, and avalanche multiplication is developed for the device reverse I-V characteristics. The models are verified by experimental results. Based on the physical model, optimization of the TJBS parameters including barrier height, junction depth, and junction spacing can be carried out with the target of achieving the lowest device ON-state voltage while limiting the reverse leakage current to a reasonable level. As a result, for a given breakdown voltage, an optimum set of parameters can be obtained.