Low-compensated boron-doped homoepitaxial diamond films

We have synthesized device grade B-doped homoepitaxial diamond films with low compensation using a microwave plasma chemical vapor deposition (CVD) system. This study was based on an approach in which the synthesis of device grade films was performed in a clean CVD system. Among the films studied here, Hall effect measurements showed that the highest values of Hall mobility were 1840 cm(2)/V s at 290 K. The donor (compensation) concentration N-D and compensation ratio N-D/N-Acceptor of the film mentioned above were 4 +/- 1 x 10(14) cm(-3) and about 0.4%, respectively. Furthermore, as a result of applying the two-step growth method to B-doped films, we obtained B-doped films without unepitaxial crystallites and pyramidal hillocks. We made high-quality Schottky junctions between the metal (Al, Cr, Ni, Au, or Pt) and the present B-doped diamond films. The current- voltage characteristics of these junctions indicated high-rectification properties with ideality factor n similar to 1.1 and very low leakage currents at reverse bias. In particular, the junction fabricated with Pt was operational with n similar to 1.3 at high temperature of around 731 K. (C) 2000 Elsevier Science S.A. All rights reserved.