High quality homoepitaxial CVD diamond for electronic devices

Recent achievements in homoepitaxial CVD diamond films for electronic devices have been discussed. We have successfully synthesized high-quality homoepitaxial diamond films with atomically flat surface by the microwave plasma chemical vapor deposition (CVD) using a low CH4 concentration of CH4/H-2 gas system less than 0.15% CH4/H-2 ratio and Ib (001) substrates with low-misorientation angle less than 1.5 degrees. These films are atomically flat over an area as large as 4 X 4 mm(2) and have shown a strong excitonic emission of 5.27 eV line, even at room temperature, with no essential emission lines in the visible Light region in the cathodoluminescence (CL) spectra. Furthermore, high-quality Schottky junctions between Al and P type high-conductivity layers near the surface of these films have been obtained. Based on this growth method, we have also successfully synthesized B-doped diamond films using trimethylboron [B(CH3)(3),TMB] gas as a B-doping source, whose Hall mobility is 1840 cm(2)/Vs at 290 K. Schottky junction fabricated by the B-doped diamond also shows excellent performances, indicating that the homoepitaxial diamond films presented here have a high potentiality for electronic devices. (C) 2001 Elsevier Science B.V. All rights reserved.