Vertical Schottky diode on (113) oriented homoepitaxial diamond

Vertical Schottky diodes were fabricated on (113) oriented diamond substrates produced from thick heavily boron doped ( N (A) - 3.5 x 10( 20 )cm (-3 )) diamond layers grown on HPHT-grown synthetic Ib diamond crystals. The p + -substrates were overgrown by a low doped p-epilayer whose surface layer was compensated up to the depth of 0.1 to 0.3 mu m. The surface was then oxygen terminated and covered by evaporated Mo/Au Schottky contacts. The bottom ohmic contact to p (+ )-substrate was formed by Ti/Au bi-layer. Current- and capacitance-voltage characteristics of the realized diodes were measured at temperatures ranging from 25 to 180( degrees) C. At room temperature, the realized diodes show high forward current densities J( F) = 100 A/cm (2) and low differential ON-state specific resistance R (on_sp) = 3.7 m Omega .cm (2) at forward voltage V- F = 4 V and a very low leakage ( J (R )< 10 -9 A/cm (2) ) in the blocking regime. At 180 degrees C, forward characteristics significantly improve ( J( F) = 5 kA/cm (2) , R (on_sp) = 0.2 m Omega .cm (2) at V- F = 4 V) while the blocking characteristics remain almost unchanged ( J( R) = 6 x 10( -8 )A/cm 2 at V (R) = 4 V). The breakdown electric field is about 3 MV/cm and the rectification ratio keeps at the level of 10 (11) . Characteristics of realized diodes, which are fully comparable to those of Schottky-pn diodes prepared on (111) oriented boron doped diamond, confirm the suitability of (113) orientation for realization of vertical diamond power devices.