P-i-n diodes enabled by homoepitaxially grown phosphorus doped diamond with breakdown electric field >1.25 MV/cm

Owing to its rich material properties, such as high critical electric field, superior thermal conductivity and high electron and hole mobility, diamond has the potential of becoming the material of choice for high power electronic applications. In spite of superior bulk electrical and thermal properties, the only well-known use of diamond in power electronics has been as a heat sink. This is because of the lack of good quality homoepitaxially grown n-type diamond and also the difficulty involved in achieving ohmic contacts due to its very low-work function ( 0.9 eV). Although several approaches have been explored to obtain highly doped n-type diamond very few have been successful. In this presentation we report the successful fabrication and characterization of a p-i-n diode enabled by the development of low-resistance contacts to n-type diamond using Ti/Pt/Au metal contacts. This was made possible by a novel growth scheme where highly P-doped homoepitaxial diamond could be grown consistently.