Optimization of Substitutional Phosphorus in n-Type Diamond

n-type diamond holds great potential for a wide array of technological applications, including high-power electronics, quantum computing, and biomedical applications. Phosphorus is currently the most promising n-type dopant, yet major challenges still exist such as its low incorporation rate and a tendency to form phosphorus-vacancy complexes that compensate substitutional phosphorus atoms and reduce overall conductivity [1]. Achieving controllable levels of P is an area of significant interest [2-4] and so controlled parameter studies of the growth of P-doped diamond are needed.<br/><br/>To observe the substitutional behavior of phosphorus-doped diamond, we will grow two series of single-crystal P-doped diamond samples, one isothermal series in a pressure range of 150 to 250 torr, and another isobaric series over temperature from 800 to 1050°C. The growth will be done by Microwave-Plasma Assisted Chemical Vapor Deposition (MPACVD) using phosphine feed gas on (111) oriented single-crystal diamond substrates. The phosphorus concentration of each sample will be determined by Hall effect measurements and samples will be fully characterized by AFM for surface analysis, XRD determination of miscut orientation, and UV-Vis and FTIR spectroscopies. We will present our findings and report the optimized growth conditions for substitutional phosphorus and n-type conductivity.<br/><br/><b>References</b><br/>R. Jones, <i>et al</i>., <i>Appl. Phys. Lett. </i><b>69</b>, (1996) 2489<br/>R. Ohtani, <i>et al</i>., <i>Appl. Phys. Lett. </i><b>105</b>, (2014) 232106<br/>H. Kato, <i>et al</i>., <i>Appl. Phys. </i><i>Lett. </i><b>109</b>, (2016) 142102<br/>T. A. Grotjohn, <i>et al</i>., Diamond Relat. Mater.<b>44</b>, (2014) 129