PACVD nano-crystalline B-C-N thin films obtained by use of an organoboron precursor

Thin films of the B-C-N system deposited by use of gas mixtures composed of a boron- and nitrogen-containing organic precursor, argon and hydrogen are investigated with the aid of a radiofrequency PACVD procedure. The structure and composition of these films are found to be strongly affected by the mole ratio between the organoboron precursor and hydrogen. The films obtained at high values of this ratio are amorphous they become partially crystalline on decreasing this ratio. The deposit obtained at a relatively low value of this ratio is composed of a mixture of cubic boron nitride and boron carbide. Use of a considerable excess of hydrogen in the gas mixture is found ta allow poorly crystalline and amorphous phases in the B-C-N system to be completely removed from the deposit. (C) 1997 Elsevier Science S.A.