Electrical Properties of High-Quality Synthetic Boron-Doped Diamond Single Crystals and Schottky Barrier Diodes on Their Basis

摘要： The temperature dependences of the specific resistance and Hall coefficient of high-quality synthetic boron-doped diamond single crystals grown via a high-pressure high-temperature method are studied. The concentration of acceptors in the (001) cut plates was varied in a range of 2 × 1015–3 × 1017 cm–3 by varying the concentration of boron in the growth mixture (0.0004–0.04 at %). Thin rectangular plates with the uniform concentration of boron and free from extended structural defects are cut out by a laser after the X-ray topography and mapping of UV luminescence. The concentrations of donors and acceptors in the samples are calculated from the data of the Hall effect and capacitance–voltage characteristics. The obtained results correlate with the concentration of boron in the growth mixture. The minimum compensation ratio of acceptors with donors (below 1%) is observed in the crystals grown with the concentration of boron in the growth mixture of 0.002 at %. The ratio increases when the amount of boron is increased or decreased. The samples grown at such a concentration of boron have the maximum mobility of charge carriers (2200 cm2/(V s) at T = 300 K and 7200 cm2/(V s) at T = 180 K). The phonon scattering of holes dominates throughout the range of temperatures (180–800 K), while the scattering by point defects (neutral and ionized atoms of the impurity) is insignificant. The diamond crystals which are grown from a mixture containing 0.0005–0.002 at % boron and have perfect quality and a lattice mechanism of scattering can be considered as a reference semiconductor.