Carrier mobility model for simulation of SiC-based electronic devices

Abstract

Simple analytical approximations are proposed for describing the temperature and concentration dependences of low-field mobility in the main polytypes of silicon carbide (SiC): 6H, 4H and 3C in wide ranges of temperature and concentration. The obtained results can be directly used for the computer simulation of SiC-based devices. Different approaches to the analytical approximation of SiC parameters are critically correlated and analysed.

Characterization of SiC crystals by optical and electrical means

“…The measured temperature dependence µ a ∼ T −A was found to be similar to those typical for phonon (lattice) scattering mechanism [9] and provided the index value A = 1.4 for sublimation grown epilayer and A = 1.6 for CVD grown epilayer. The similar slope values A were found in n-and p-type 4H-SiC samples in temperature range 100-300 K [10][11][12]. Our data provided µ h = 60 cm 2 /(V s) for the CVD grown sample and µ h = 40 cm 2 /(V s) for the sublimation grown one at room temperature, that was in good agreement with the Hall data in low doped 4H-SiC epilayers, which provided the hole mobility in range of 60-120 cm 2 /(V s) [12,13].…”

Temperature-dependent nonequilibrium carrier dynamics in epitaxial and bulk 4H-SiC

“…The measured temperature dependences µ ∼ T −A were found to be similar to those typical for phonon (lattice) scattering mechanism [9] and provided the index value A from 1.4 to 1.6 for nonequilibrium carrier density, varying from ∼ 5 · 10 17 to ∼ 10 19 cm −3 . The slope values of A from 1.3 to 1.9 were found for electron mobility in n-type 4H-SiC in 100-300 K range [10,11] and A from 1.5 to 2 for the hole mobility in p-type epilayer in 200-300 K range [12]. We note that our experiments differ from those in [10][11][12] as intercarrier scattering may contribute at the used nonequilibrium carrier densities [13].…”

“…The slope values of A from 1.3 to 1.9 were found for electron mobility in n-type 4H-SiC in 100-300 K range [10,11] and A from 1.5 to 2 for the hole mobility in p-type epilayer in 200-300 K range [12]. We note that our experiments differ from those in [10][11][12] as intercarrier scattering may contribute at the used nonequilibrium carrier densities [13]. Assuming that diffusion coefficient of holes is much smaller than that of electrons (D e D h ), the relationship D h = 2D h is valid and points out that the measured temperature dependence reveals nonequilibrium hole mobility at high carrier density.…”

Real-Time Measurement of Temperature Sensitive Electrical Parameters in SiC Power MOSFETs

“…Similarly to most semiconductor materials, the bandgap energy decreases as temperature increases, whilst the intrinsic concentration increases with temperature [30]. The mobility in SiC devices has a more complex dependency on temperature depending on doping levels and density of traps at the gate oxide/SiC interface resulting in bulk mobility to decrease but channel mobility to potentially increase with temperature [31]- [32]. Temperature effects on these parameters can be summarised by the empirical relations:…”