Conventional n-type doping in diamond: state of the art and recent progress

Abstract

Recent progress in chemical vapour deposition (CVD) diamond technology has enabled the preparation of high-quality n-type CVD diamond layers using phosphorus as a dopant. CVD diamond can therefore be considered as a new interesting conventional wide-gap semiconducting material having both n- and p-type dopants, which makes it attractive for numerous applications in high-temperature, high-voltage and high-frequency devices. The concentration of phosphorus in n-type CVD diamond can be controlled in the concentration range of 1 × 1016–5 × 1019 cm-3 with a carrier mobility exceeding 600 cm2 V-1 s-1. In this review, the most relevant questions concerning the preparation of P-doped diamond are addressed and discussed in terms of future progress and novel electronic devices. We not only discuss the preparation of single crystal epitaxial diamond but also address the growth of large-area n-type polycrystalline CVD diamond, which can be useful for several applications such as for detectors or electron emitters.