Diamond films epitaxially grown by step-flow mode

Abstract

Homoepitaxial diamond films were grown by the step-flow mode. The obtained films grown by this mode were characterized using atomic force microscopy, reflection high-energy electron diffraction (RHEED), cathodoluminescence (CL), and junction properties of Al-Schottky contacts. It is found that the surfaces of the films are covered with macroscopic steps running parallel to the [1 1 0] direction. The narrow and streaky RHEED patterns show the surfaces of the films are flat with 2 × 1 and 1 × 2 double-domain structure. From the CL spectra, strong excitonic luminescence is clearly observed in the temperature range between 120 and 300 K. The absence of the band-A emission in the CL spectra suggests a low density of dislocation in the films. The current-voltage characteristics of Al-Schottky contacts on the as-deposited diamond films show excellent junction properties with the ideality factor of 1.1. These results indicate immense potential for diamond as a semiconducting material.