Nitrogenated diamond produced by introducing ammonia into the gas feed in hot-filament CVD

Nitrogenated diamond and carbon nitride films have been produced using ammn onia as the source of atomic nitrogen. A feed mixture of C2H5OH + NH3 + H-2 was used in a hot filament CVD reactor. The deposition parameters were opt imized for the growth of well-faceted crystals onto either SiO2 or undoped diamond substrates. Film structure and morphology were studied using optica l and atomic force microscopies, and Raman and photoluminescence spectrosco pies. Three types of film, according to the deposition substrate used and t he nitrogen doping, have been identified. All films presented semiconductor characteristics and their deep and shallow activation energies have been d etermined from resistance versus temperature measurements. (C) 1999 Elsevie r Science S.A. All rights reserved.