Characterization of diamond detectors prepared by DC plasma glow discharge CVD

We report on transport properties of CVD diamond films prepared by means of a DC plasma glow discharge method. Continuous free-standing diamond films have been obtained with good electrical properties by a proper tuning of the deposition parameters. At growth rate as low as about 10–20 μm/h we have no evidence of Raman features ascribed to non-diamond carbon phases. These films show very low leakage currents and resistivities as high as 1013 Ω cm. The high resistivity samples show a clear evidence of a signal when exposed to α radiation. The I–T analysis show that at high temperature (up to 400°C) the conduction process is dominated by an impurity level, attribuited to isolated substitutional nitrogen.