[FTIR spectroscopic studies of inner stress on boron carbon nitride thin films].

Boron carbon nitride thin films were deposited by radio frequency (RF) magnetron sputtering technique using a 50 mm-diameter composite target consisting of h-BN and graphite in an Ar-N2 gas mixture. The composite target was composed of two semi disks: one of h-BN and the other one of graphite. The distance between the target and the substrate was kept at 50 mm. The chamber base pressure was below 5 x 10(-4) Pa. During the deposition, the mixture of Ar (80%) and N2 (20%) was injected into the vacuum chamber and the total pressure was 1.3 Pa. The films were grown on silicon substrates at different deposition parameters, including sputtering power of 80-130 W, deposition temperature of 300-500 degrees C and deposition time of 1-4 h. The chemical bonding state of the samples was characterized by Fourier transform infrared absorption spectroscopy (FTIR). The results suggested that all of the films deposited at these deposition parameters are atomic-level hybrids composed of B, C and N atoms. Besides BN and carbons bonds, the boron carbide and carbon nitride bonds were formed in the BCN thin films. And the deposition parameters have important influences on the growth and inner stress of BCN thin films. That is the higher the sputtering power, the larger the inner stress; the higher or lower the deposition temperature, the larger the inner stress; the longer the deposition time, the larger the inner stress. So changing deposition parameters properly is a feasible method to relax the inner stress between the films and substrate. In the conditions of changing one parameter each time, the optimum deposition parameters to prepare BCN thin films with lower inner stress were obtained: sputtering power of 80 W, deposition temperature of 400 degrees C and deposition time of 2 h.

[Ultraviolet transmission spectra of BC(x)N thin films].

BCN, BC2N and BC3N thin films with transmission increasing properties in the ultraviolet region were deposited by RF magnetron sputtering with different sputtering power (80-130 W). Fourier transform infrared absorption and X-ray photoelectron spectroscopy results suggested that the films were atomnic-level hybrids composed of B, 'C and N atoms. The compositions and transmission increasing properties of samples in the ultraviolet region were strongly influenced by sputtering power, which determined the transmission increasing properties in the ultraviolet region by changing compositions. And the lower the atomic number of C in the thin films, the better the transmission increasing properties in the ultraviolet region. The BCN thin films deposited at the sputtering power of 110 W possessed the lowest atonic number of C and the best transmission increasing properties in the ultraviolet region. And the increase in average transmissivity from 200 to 350 nm was about 40% compared with glass.