Pierre-Nicolas Volpe

Extreme dielectric strength in boron doped homoepitaxial diamond

The fabrication of Schottky diodes withstanding breakdown voltages up to 10 kV is demonstrated. A corresponding electric field of 7.7 MV/cm at the center of the diode is evaluated with the help of a two-dimensional finite elements software. These properties result from a net shallow acceptor concentration below 10(16) cm(-3) in the first micrometers of an epitaxial film with optimized crystalline quality and a special oxidizing treatment of its surface, allowing the true dielectric strength of bulk diamond to be revealed.

High hole mobility in boron doped diamond for power device applications

Low boron doped homoepitaxial diamond layers were grown on Ib (100) diamond substrates with oxygen added to the gas mixture. The acceptor density of the samples has been estimated by C(V) and Hall effect to lie close to 1016 cm−3 with a maximum low field Hall mobility value of 1870 cm2/V s at 292 K. The presence of oxygen in the gas phase is shown to be a key parameter to obtain such characteristics. The mobility parameters required to simulate the electrical behavior of devices between 300 K and 500 K are then determined for a wide doping range.