Accurate TCAD Simulation Model for High-Performance 4H-SiC Alpha-Particle Detectors

A systematic calibration procedure is carried out to accurately model the state-of-the-art experimental I–V and charge collection efficiency (CCE) of a 4-hexagonal silicon carbide (4H-SiC) Schottky barrier diode (SBD) alpha-particle detector in the technology computer-aided design (TCAD) simulator. At first, the simulated forward I–V is validated by adjusting the Schottky metal work function, mobility, and saturation velocity. The conventional models, such as barrier lowering (BL) and nonlocal tunneling (NLT), underestimate the reverse I–V. After several iterations, the reverse I–V is perfectly matched by activating the nonlocal trap-assisted tunneling (TAT) model with the deep-level acceptor trap ${Z} _{1/2}$ at ${E} _{C}$ –0.73 eV. On the other hand, employing the TAT model with other omnipresent Ti traps at ${E} _{C}$ –0.19 eV overestimates the leakage current, indicating that the proper trap selection is necessary to model the TAT current. The linear energy transfer (LET) data extracted from the stopping and range of ions in matter (SRIM) tool is incorporated in the heavy-ion (HI) TCAD model for simulating CCE. The default HI model predominantly predicts only drift-induced charge contributions in the detector and underestimates the diffusion component of CCE at low voltages. Thus, a novel HI TCAD model is considered to match the CCE in the entire voltage range, which includes both drift- and diffusion-induced transient currents contributing to the CCE. The temperature-induced variations in the CCE are also reported.