Skip to content

Power Diode Structures Realized on (113) oriented Boron Doped Diamond

MetadataDetails
Publication Date2023-01-01
AuthorsP. Hazdra, Alexandr Laposa, Z. Å obÔň, Vojtěch Povolný, J. Voves
InstitutionsCzech Academy of Sciences, Institute of Physics, Czech Technical University in Prague

Molybdenum, ruthenium, and platinum contacts covered by the gold capping layer were used for preparation of pseudo-vertical Schottky barrier diodes on (113) oriented homoepitaxial boron-doped diamond. After metal deposition, diodes were stabilized by annealing for 20 minutes at 300 ˚C and their IV characteristics were measured at temperatures from 30 to 180 °C. Results show that all three metals can be used to realize Schottky diodes with sufficient forward and blocking capability. Moreover, molybdenum and ruthenium can also be used to create a stable ohmic contact on heavily doped contact p ++ layer. Molybdenum provides optimum properties: a sufficient Schottky barrier height providing low leakage at a level of 10-8 A/cm2 and an acceptable forward voltage drop of 3.80V@JF=1kA/cm2 (measured at 150 °C), the rectifying ratio then reaches 1011 over the entire temperature range under study. Ruthenium contacts exhibit lower Schottky barrier, their forward voltage drop is thus lower (2.85V@JF=1kA/cm2@150 °C), but leakage increases rapidly with temperature. Platinum provides the highest Schottky barrier and guarantees the lowest level of the leakage (<10-8 A/cm2). However, the diodes have poorer forward characteristics: their ideality factor and forward voltage is high (7.35V@JF=1kA/cm2@150 °C). Maximum realizable diode area and achievable breakdown field (0.8MV/cm) then depend on the number of crystal defects (namely threading dislocations) appearing in the diode low-doped drift region.