Hall hole mobility of boron-doped homoepitaxial (100) diamond samples has been investigated in the temperature range of 100\char21{}900 K, both experimentally and theoretically. The temperature dependence of the mobility measured in high-quality and low boron-doped materials was compared with theoretical calculations to determine the phonon-hole coupling constants (deformation potential for acoustic phonons and coupling constant for optical phonons). The maximum hole mobility is found to be close to 2000$\hskip0.3em${}cm2/Vs at room temperature. For boron-doped material, the hole scattering by neutral boron atoms is shown to be important in diamond due to the high ionization energy of the boron acceptor. The doping dependence of the Hall hole mobility is established for boron-doping levels ranging between 1014 and 1020$\hskip0.3em${}cm$-${}3 at 300 and 500 K. The physical reasons which make diamond a semiconductor with a higher mobility than other semiconductors of column IV are discussed.

High-quality surface acoustic wave (SAW) filters based on aluminum nitride (AlN)/diamond layered structures were prepared using the nucleation side of polycrystalline chemical vapor deposition (CVD) diamond, removed from a silicon substrate by wet etching. Highly oriented AlN thin films with optimized piezoelectric properties and with various thicknesses were sputtered onto the nucleation side of freestanding diamond. The effect of AlN thickness on the SAW phase velocity, the coupling coefficient, and the device characteristics were investigated. Experimental results show that the Rayleigh wave and the higher modes are generated. These results agree well with calculated dispersion curves and demonstrate that a high electromechanical coupling coefficient together with a high phase velocity can be obtained by using the nucleation side of freestanding CVD diamond layer.

The effects of doping concentration and temperature upon the transport properties in the channel of lateral n-channel SiC MOSFETs have been studied using current-voltage and Hall-effect measurements. To interpret the electrical measurements, numerical TCAD simulations have been performed. A simulation methodology that includes the calculation of the Hall factor in the channel of SiC MOSFETs has been developed and applied. In addition, a new model for the bulk mobility has been suggested to explain the temperature dependence of the MOSFET characteristics with different background doping concentrations. Based on the good agreement between the simulated and the measured results, scattering mechanisms in the channel of SiC MOSFETs have been studied.