Free-standing n-type phosphorus-doped diamond

n-type diamond substrates are highly desired for diamond electronics and quantum technology based on NV centers. In this work, we investigate the high growth rates obtained using plasma with high-power densities in a commercial bell-jar chemical vapor deposition reactor equipped with a gas panel for diamond doping with phosphorus impurities. We evidence that the diamond growth rate is increased by adding phosphorus precursor in the gas mixture, up to 21.6 μm/h. We found conditions for growing extremely thick (up 580 μm) phosphorus doped (100) diamond homoepilayers keeping a n-type character as shown by optical spectroscopy. From such films we succeed in slicing a free-standing phosphorus-doped diamond plate, showing the feasibility of n-type diamond substrate fabrication for further use in optoelectronics and quantum devices. • Synthesis of a 580 μm phosphorus-doped diamond (100) homoepitaxial layer showing n-type character • 280 μm free-standing (100) diamond plate sliced from this ultra-thick homoepilayer • Potential of production of n-type (100) diamond substrate doped with phosphorus