Electrically active traps in 4H-silicon carbide (4H-SiC) PiN power diodes

The electrically active traps in 4H-silicon carbide (4H-SiC) PiN power diodes are identified by deep-level transient Fourier spectroscopy (DLTFS). The junction termination extension (JTE) and floating JTE rings (periphery protections) are realized using the Al⁺ ion-implantation process in the PiN diode structure, to mitigate the electric field crowding at the junction edges and obtain the theoretically projected off-state performance. The 4H-SiC PiN diode exhibits forward voltage drop of ~ 2.6 V at 1 mA, ideality factor of ~ 1.6, series resistance of ~ 1.2 Ω, low reverse leakage current < 0.5 nA at 200 V, blocking voltage > 200 V, built-in barrier potential of ~ 2.1 V, and effective doping concentration for the drift layer of ~ 7.9 × 10¹⁴ cm⁻³. The temperature-induced changes in the forward I–V characteristics are investigated from 25 to 150 °C. From the DLTFS results, three hole traps H1 at E _V + 0.16 eV, H2 at E _V + 0.3 eV, and H3 at E _V + 0.63 eV, and two electron traps E1 at E_C − 0.19 eV and E2 at E_C − 0.67 eV are identified in the 4H-SiC PiN diodes. The current-mode DLTFS (I-DLTFS) and thermally stimulated capacitance (TSCAP) spectroscopy measurements are also carried out to acquire further information about the traps in the 4H-SiC PiN diodes.