Carrier concentration variety over multisectoral boron-doped HPHT diamond

Abstract

A set of multisectoral boron-doped diamond plates cut from a 10-ct high pressure high temperature single crystal was thoroughly studied. The plates' morphologies were examined by atomic-force microscopy, it showed the average roughness of 5-10 nm. For electrical measurements, ohmic and rectifying platinum contacts were deposited by magnetron sputtering. Schottky diodes arrays were investigated by admittance spectroscopy; current-voltage (I-V) and capacitance-voltage (C-V) characteristics were obtained and analysed. Frequency dispersion of C-V characteristics was registered. Blue (111) and white (100) faces of samples showed a drastic difference in I-V and C-V behaviour. Mathematical processing of the obtained data was performed and the depth distributions of apparent charge carriers were obtained for all diodes. The registered concentration for the white sector is in the range (1-3)•10 17 cm −3 , and for the blue sector it is one order more. Charge carrier distribution over the sample surface was obtained and it showed a fine correlation with sectors' colour and growth direction with appropriate discussion.