Step JTE, an Edge Termination for UHV SiC Power Devices With Increased Tolerances to JTE Dose and Surface Charges

An edge termination method, referred to as guard-ring-assisted multistep junction termination extension (MS-GR-JTE), is presented for ultrahigh voltage silicon carbide (SiC) power devices. In comparisonwith other JTEs, the MS-GR-JTE creates a step electric field (EF) distribution with greatly reduced peak EF at the corners and edges of the device, resulting in a superior breakdown voltage (BV) performance with wide tolerances to JTE dose and SiC surface charges. According to the numerical simulations based on a 100- $\mu \text{m}$ -thick epilayer, an optimized MS-GR-JTE shows that the 15-kV BV performance with wide tolerances of $1.3\times 10^{12}$ cm $^{-2}$ to JTE dose and $6.1\times 10^{12}$ cm $^{-2}$ to positive surface charges are obtained, respectively, both superior to other compared JTEs.