In order to construct a reliable parameter set for the physical modeling of 4H-SiC, we are collecting and examining the physical parameters. The results of mobility measurement are presented and compared with the built-in model in the device simulator. The doping dependence of the electron mobility is in agreement with the built-in model, whereas that of the hole mobility is different from the built-in model in the higher doping region. Further, the anisotropy of the electron and hole mobility is investigated. The anisotropy of the electron mobility

The conduction mechanism in heavily Al-doped or heavily Al-and N-codoped p-type 4H-SiC epilayers was investigated. In both the singly-doped and codoped samples with an Al concentration (CAl) between 4x1019 and 2x1020 cm-3, band and nearest-neighbor hopping (NNH) conductions appeared in high and low temperature ranges, respectively. The codoping of N donors makes the NNH conduction dominant at temperatures higher than in the singly-doped samples. In both the singly-doped and codoped samples with CAl between 1x1019 and 4x1019 cm-3, an unexpected conduction appeared between the regions of the band and NNH conductions.

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To reduce the resistivity of heavily Al-doped 4H-SiC epilayers, the conduction mechanisms were investigated for Al concentrations (CAl) between 2.4 × 1019 and 4.7 × 1020 cm−3 and measurement temperatures (T) between 20 and 600 K. The results elucidated the relationship between the conduction mechanisms and the values of T and CAl. For the epilayers with CAl ∼ 3 × 1019 cm−3, an unexpected additional conduction mechanism was observed between the band and nearest-neighbor-hopping conduction regions, for which two plausible conduction models are proposed. To reduce the resistivity of epilayers with CAl > 2 × 1020 cm−3, it is essential to fabricate samples with low lattice distortion.

Single-phase flat semipolar (10-13) AlN epilayers on m-plane (10-10) sapphire substrates grown by ammonia-free high-temperature metalorganic vapor phase epitaxy are firstly demonstrated. It is found that twins and basal-plane stacking faults are undetectable by X-ray diffraction and crosssectional characterization. An X-ray rocking curve (XRC) shows the full widths at half maximum (FWHM) of the (10-13) and the (0002) diffraction peaks from a ∼2.3 μm thick AlN film as narrow as 322 and 373 arcsec, respectively, indicating a high structural quality. Semipolar AlN epilayers hold great promise for high performance deep-ultraviolet (DUV) optoelectronic device applications.