n‐Type doping of diamond

Abstract n‐Type diamond formation is one of the most important issues for the electronic application of diamond. Phosphorus is the best n‐type dopant candidate at the moment. We have succeeded in growing high‐quality phosphorus‐doped diamond thin films on {111} diamond substrates. Although the ionization energy of the phosphorus donor is large (0.57 eV), the n‐type conductivity is clearly observed by Hall measurements. The Hall mobility is as high as 660 cm 2 /(V s) at room temperature. In this paper, the current status of n‐type diamond research is mentioned with focus mainly on the growth of high‐mobility n‐type diamond and its electrical properties. The Hall measurements performed over a wide temperature range give detailed information about the nature of the n‐type conductivity. Current–voltage and capacitance–voltage measurements of a Schottky diode formed by nickel contacts on an n‐type diamond layer show unique characteristics of semiconducting diamond. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)