3. Conclusion

Although the properties of silicon carbide now seem to be precisely known, there are still many uncertainties and grey areas. For example, ionization coefficients are given by several authors with a wide dispersion. For holes in 4H, there is a decade's difference between Raghunathan's and Konstantinov's values (figure 18 ). But the evolution of the effective mass of electrons, and a fortiori of holes, as a function of temperature is not yet known. It has to be said, moreover, that the effective mass approximation for holes is itself open to question, since according to some authors, the valence band is...