3.5.2 Auger Recombination

In the Auger-processes three particle are involved. This process is only relevant at high carrier concentrations. The Auger recombination rate is proportional to the product of the concentrations of the respective reaction partners [104,107]

$$R^{\mathrm{AU}}=\left(C_{n}^{\mathrm{AU}}\cdot n + C_{p}^{\mathrm{AU}}\cdot p\right) \cdot \left( n\cdot p - n^2_{i,e}\right).$$ (3.109)

$R^{\mathrm{AU}}$ represents a part of the inhomogeneity of the continuity equations (3.11) and (3.12). $C_{n}^{\mathrm{AU}}$ and $C_{p}^{\mathrm{AU}}$ denote the Auger coefficient of electrons and holes, respectively. For 6H-SiC, they have been estimated to $C_{n}^{\mathrm{AU}}=C_{p}^{\mathrm{AU}}=(3.0\pm 0.5)\times 10^{-29}$ cm$^{6}$/s [151] by means of transient measurements of the stored charge of pin-diodes during switch-off.

These coefficients depend on the lattice temperature $T_\mathrm{L}$ by a power law [107]

$$C_{\nu}^{\mathrm{AU}}= Au^a_{\nu} + Au^b_{\nu}\cdot \frac{T_\math... ...cdot \left(\frac{T_\mathrm{L}}{300\ \mathrm{K}}\right)^2. \hspace{1cm}\nu = n,p$$ (3.110)

The parameters in (3.110) are not yet experimentally determined for any SiC polytype. T. Ayalew: SiC Semiconductor Devices Technology, Modeling, and Simulation