Spatial uniformity of Schottky contacts between aluminum and hydrogenated homoepitaxial diamond films

Homoepitaxial diamond films prepared under low CH4concentration conditions CH4rH2-0.15%.show atomically flat surfaces over the whole area 4=4 mm2. of the substrate. Using these diamond films, Schottky contacts between Al and the high-conductivity layer near the surface of as-grown film have been successfully made with an excellent uniformity with ideal properties. For example, in the film grown at low CH4concentration of 0.016% CH4rH2, the ideality factor n value. and the barrier heights of the Schottky junctions fb.were close to unity n-1.1.and 1.5–1.6 eV, respectively, for nearly all junctions )42 dots.prepared on the same film. This result indicates that the quality of the films with atomically flat surfaces over the whole area of the substrate is actually excellent in a viewpoint of chemical stability as well as electrical characteristic. q2000 Elsevier Science B.V. All rights reserved.