Semiempirical model of carrier mobility in silicon carbide for analyzing its dependence on temperature and doping level

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.…”

Temperature and Stress Simulation of 4H-SiC during Laser-Induced Silicidation for Ohmic Contact Generation

“…These advantages, compared to those of electronics based on silicon substrates, result from the higher band gap, higher thermal conductivity, higher dielectric disruptive strength, and higher saturation electron drift velocity of SiC [1,2]. Unfortunately, however, some important process steps for silicon carbide-based devices are not yet well established, e.g., the deposition of ohmic contacts, which has continuously been a topic of current research [3][4][5][6].…”

“…To generate ohmic contacts on SiC, metals such as nickel, tungsten, or titanium are deposited on the wafer using physical vapor deposition (PVD) [3] followed by a so-called rapid thermal process (RTP) to transform the contact's Schottky behavior into an ohmic one. This RTP process is usually performed for several minutes at temperatures between 900 and 1000 • C to generate silicides at the metal to semiconductor boundary such as Ni 2 Si or TiSi 2 [7,8]. For n-type contacts, the thus generated contact resistance is typically between 10 −7 and 10 −5 Ω·cm 2 .…”