SEMICONDUCTING DIAMONDS MADE IN THE USSR

p- and n-type diamond films (DF) were grown by vapour chemical transport method and from DC are discharge plasma. Maximum contents of doping elements in epitaxial DF (EDF) were 2.5, 1 and 0.02 wt% for B-, P- and S-doped EDF, respectively. Specific resistances of the EDF were 10-3, 101 and 103 Ω cm, respectively. The doping changes the growth rate and chemical properties of EDF. Doped EDF were investigated by spark mass-spectrometry, X-ray spectrometry, Rutherford backscattering and Hall-effect measurements. Electroabsorption and cathodoluminescence spectra were studied. DF with a highly distorted structure and dislocation p-type conductivity were grown from glow discharge plasma. B- and As-doped 1 mm size crystals were obtained by an ultra-high-pressure method. As produces multicharged donor centres with two energy levels. The crystals are prospective for sensors. Doping of diamond with B, C, P, Sb and Li was realised by ion implantation. The best p- and n-type layers doped with B and Li have carrier mobility of about 1000 cm2/V s. Acceptor dislocation centres can also be created by plastic deformation of diamond crystals. Specific resistance of such crystals can fall by up to 102 Ω cm. Combining the above-mentioned methods seems to be the most prospective way. © 1992.