Hall mobility and scattering mechanism of holes in boron-doped homoepitaxial chemical vapor deposition diamond thin films

The temperature dependence of the Hall mobility mu(H) has been measured from 140 to 870 K for nine boron-doped homoepitaxial chemical vapor deposition (CVD) diamond thin films. The experimental An data are compared with their theoretical An values that are calculated by an iterative technique, assuming scattering by ionized impurities, acoustic deformation potential and nonpolar optical phonons. The donor concentration No, the acoustic deformation potential constant E-1 and the coupling constant of nonpolar optical phonons D-npo are used as fitting parameters. The experimental data of the hole concentration p are also analyzed by a fitting procedure. The acceptor concentration N-A, the donor concentration N-D, and the acceptor ionization energy E-A are used as fitting parameters. The fitting analyses of mu(H) yielded an average D-npo = (1.2 +/- 0.2) x 10(12) eV/m. Considerable differences were observed between ND values estimated from the fitting analyses of mu(H) and those from the p-analyses. The average E-1 for the samples with little difference between the two types of N-D is 14.5 eV, which is in agreement with that of a natural diamond of high quality. The average E-A for the samples with a low or medium doping level is 0.365 eV, which is in good agreement with those in the literature. Some indications of the contribution of hopping conduction in the low-temperature range were observed.