[21p-M206-1~9] Forefront of interface science and technology of wide bandgap semiconductor MOS devices

[21p-M206-3] On the Dominant Scattering Mechanism of the Mobility in SiC MOSFETs

〇Tetsuo Hatakeyama¹, Hirohisa HIrai², MItsuru Sometani², Dai OKamoto¹, MItsuo Okamoto², Shinsuke Harada² (1.Toyama pref. Univ., 2.AIST)

Keywords:SIC, SiC/SiO2 Ingerface, mobility

At first, to examine the dominant scattering mechanism of the measured mobility at SiC MOS interfaces, we have developed a mobility calculation program based on the scattering theory of two-dimensional electron gas considering the physical properties of SiC. By the comparison between experimental results and calculated results, it has been shown that the dominant deterioration factor of the SiC MOS interface mobility is neither phonon scattering nor Coulomb scattering. Furthermore, we have also shown that the effective electric field dependence and electron concentration dependence of the measured mobility can be reproduced by calculated mobility limited by the scattering originated from the dipoles at the MOS interface. We have investigated the possible mechanism of the formation of dipoles at the interface. It has been concluded that the dominant deterioration factor of mobility at the SiC MOS interfaces is likely to be scattering by high-density of dipoles at the MOS interface.