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 compos ed of a boron- and nitrogen-containing organic precursor, argon and hy drogen are investigated with the aid of a radiofrequency PACVD procedu re. The structure and composition of these films are found to be stron gly affected by the mole ratio between the organoboron precursor and h ydrogen. The films obtained at high values of this ratio are amorphous they become partially crystalline on decreasing this ratio. The depos it obtained at a relatively low value of this ratio is composed of a m ixture of cubic boron nitride and boron carbide. Use of a considerable excess of hydrogen in the gas mixture is found ta allow poorly crysta lline and amorphous phases in the B-C-N system to be completely remove d from the deposit. (C) 1997 Elsevier Science S.A.