Physical Quantities

SYMBOL DESCRIPTION UNIT
     
$ a$ channel thickness cm
$ A^*$ effective Richardson constant A$ \cdot$cm $ ^{-2}\cdot$K$ ^{-2}$
$ c$ heat capacity J$ \cdot$ kg$ \cdot$K
$ C_{\nu}^{\mathrm{AU}}$ electron, hole Auger coefficient cm$ ^{6}\cdot$s$ ^{-1}$
$ D_\nu$ electron, hole diffusivity cm$ ^{2}\cdot$s$ ^{-1}$
$ E$ electric field V$ \cdot$cm$ ^{-1}$
$ E_\mathrm{B}$ breakdown/critical electric field V$ \cdot$cm$ ^{-1}$
$ E_\mathrm{a,d}$ acceptor, donor energy eV
$ E_{\mathrm{g}}$ indirect bandgap eV
$ E_\mathrm{gx}$ exciton energy gap eV
$ E_\mathrm{c,v}$ conduction, valence band energy eV
$ E_\mathrm{F}$ Fermi energy eV
$ E_\mathrm{\nu,T}$ electron, hole, trap energy eV
$ E_{i}$ intrinsic Fermi energy eV
$ E_\mathrm{x}$ exciton binding energy eV
$ \Delta E_\mathrm{a,d}$ acceptor, donor ionization energy eV
$ f$ frequency Hz
$ f_\mathrm{t}$ cutoff frequency Hz
$ f_\mathrm{max}$ maximum frequency Hz
$ f_{tp}$ occupation probability of traps 1
$ G$ generation rate cm $ ^{-3}\cdot $s$ ^{-1}$
$ \alpha _{\nu}$ electron, hole impact ionization coefficients cm$ ^{-1}$
$ g_\mathrm{m}$ conductance A$ \cdot$V$ ^{-1}$
$ g_\mathrm{A,D}$ acceptor, donor degeneracy factor 1

SYMBOL DESCRIPTION UNIT
     
$ {\mathbf{J}}$ electric current density A$ \cdot$cm$ ^{-2}$
$ j$ particle current density cm$ ^{-2}$
$ \kappa$ thermal conductivity W$ \cdot$cm $ ^{-1}\cdot $K$ ^{-1}$
$ L_\mathrm{g}$ gate length cm
$ L_{\nu}$ electron, hole diffusion length cm
$ m_{\nu}^{\ast }$ electron, hole effective mass kg
$ \mu_\nu $ carrier mobility cm$ ^{2}\cdot$V $ ^{-1}\cdot $s$ ^{-1}$
$ \mu^{\mathrm{low}}_\nu$ low field carrier mobility cm$ ^{2}\cdot$V $ ^{-1}\cdot $s$ ^{-1}$
$ \mu^{\mathrm{high}}_\nu$ high field carrier mobility cm$ ^{2}\cdot$V $ ^{-1}\cdot $s$ ^{-1}$
$ \mu^{\mathrm{max}}_\nu$ undoped material carrier mobility cm$ ^{2}\cdot$V $ ^{-1}\cdot $s$ ^{-1}$
$ \mu^{\mathrm{min}}_\nu$ highly doped material carrier mobility cm$ ^{2}\cdot$V $ ^{-1}\cdot $s$ ^{-1}$
$ _{M_\mathrm{C,V}}$ number of minima in the conduction and valence band 1
$ n$ electron density cm$ ^{-3}$
$ n_{i}$ intrinsic density cm$ ^{-3}$
$ n_{1}$ Shockley-Read-Hall parameter cm$ ^{-3}$
$ N_\mathrm{B}$ blocking layer doping concentration cm$ ^{-3}$
$ N_\mathrm{A,D}$ acceptor, donor doping concentration cm$ ^{-3}$
$ N_\mathrm{c,v}$ effective density of states cm$ ^{-3}$
$ N^+_\mathrm{D}$ ionized donor concentration cm$ ^{-3}$
$ N^-_\mathrm{A}$ ionized acceptor concentration cm$ ^{-3}$
$ N_{tp}$ density of occupied traps cm$ ^{-3}$
$ N_{tp}^{emp}$ density of empty traps cm$ ^{-3}$
$ N^{\mathrm{ref}}_\nu$ doping concentrartion at ( $ \mu_{\nu}^{\min}+\mu_{\nu}^\mathrm{max})$/2 cm$ ^{-3}$
$ p$ hole density cm$ ^{-3}$
$ p_{1}$ Shockley-Read-Hall parameter cm$ ^{-3}$
$ {\mathrm{q}}$ elementary electric charge A$ \cdot$s
$ \phi_{\nu}$ electron, hole quasi-Fermi potential V
$ \phi_{\mathrm{B}}$ barrier height V
$ \phi_{\mathrm{m}}$ metal work function V
$ \phi_{\mathrm{s}}$ semiconductor work function V
$ \phi_{\mathrm{wf}}$ work function difference V
$ \psi$ electrostatic potential eV
$ \psi_{\mathrm{bi}}$ built-in potential eV
$ \varepsilon$ relative dielectric constant 1
$ R$ recombination rate cm $ ^{-3}\cdot $s$ ^{-1}$
$ R_\mathrm{on,sp}$ specific on-resistance V$ \cdot$cm$ ^{2}\cdot$A$ ^{-1}$
$ \sigma $ electrical conductivity A$ \cdot$V $ ^{-1}\cdot $cm$ ^{-1}$
$ \varrho $ resistivity V$ \cdot$cm$ \cdot$A$ ^{-1}$
$ \rho $ charge density A$ \cdot$s$ \cdot$cm$ ^{-3}$
$ s$ entropy density eV$ \cdot$K $ ^{-1}\cdot $cm$ ^{-3}$
$ {\mathbf{S}}_\nu$ electron, hole energy flux density J$ \cdot$cm$ ^{-2}$ $ \cdot$ s$ ^{-1}$
$ T$ temperature K

SYMBOL DESCRIPTION UNIT
     
$ T_\mathrm{n,p,L}$ electron, hole, and lattice temperature K
$ T_{0}$ reference temperature (300 K) K
$ \tau_{\epsilon,\nu}$ elctron, hole energy relaxation times s
$ \tau _{R-G}$ effective lifetime of recombination or generation process s
$ \tau _{\nu}$ effective electron, hole minority carrier lifetime s
$ \tau _{\nu}^{tp}$ electron, hole minority carrier lifetime of impurity t$ _{p}$ s
$ \tau _{tp,A,D}$ trap, acceptor, donor time constant s
$ \tau_\mathrm{sc}$ space charge generation lifetime s
$ u$ total energy density eV$ \cdot$cm$ ^{-3}$
$ \nu$ substitute for electron or hole density cm$ ^{-3}$
$ v_{\nu}$ carrier velocity cm$ \cdot$s$ ^{-1}$
$ v_{\nu{\perp, \parallel}}^\mathrm{sat}$ electrons, holes, saturation velocity cm$ \cdot$s$ ^{-1}$
$ \alpha _{\nu}^\mathrm{sat}$ constant specifying how velocity goes into saturation 1
$ V_\mathrm{B}$ breakdown voltage V
$ V_{bi}$ built-in voltage V
$ V_\mathrm{D,G,S}$ drain, gate, source voltage V
$ V_\mathrm{T}$ threshold voltage V
$ W$ depletion region width cm
$ W_\mathrm{g}$ gate width cm
$ \omega $ angular frequency Hz
$ \chi$ electron affinity V
$ \xi_\mathrm{A,D}$ acceptor, donor ionization degree 1
$ \alpha_{\nu}^{\mu}$ constant measure how mobility changes from $ \mu_{\nu}^\mathrm{\min}$ to $ \mu_{\nu}^\mathrm{max}$ 1
$ \beta_{\nu}^{\mu}$ constant temperature coefficient for $ \mu_{\nu}^\mathrm{\min}$ 1
$ \gamma_{\nu}^{\mu}$ constant temperature coefficient for $ \mu_{\nu}^\mathrm{max}$ 1
$ \hbar \omega_{op}$ phonon energy eV

T. Ayalew: SiC Semiconductor Devices Technology, Modeling, and Simulation