Structural and chemical study of a-BC, a-CN, and a-BCN thin films prepared by reactive RF sputtering

摘要

Amorphous boron-carbon (a-BC), amorphous carbon-nitrogen (a-CN), and amorphous boron-carbon-nitrogen (a-BCN) thin films were deposited by reactive radio-frequency (RF) sputtering at room temperature. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were used for structural and chemical characterization of the films. These spectroscopy techniques revealed the formation of different chemical bonds such as C = N and B-N in the a-BCN, C = N and C N bonds in the a-CN, and finally B-C bonds in the a-BC thin films. When nitrogen gas is introduced into the chamber to deposit a-BCN films, the carbon atoms are preferentially bonded to nitrogen atoms forming especially sp(2) C = N rather than sp(3) C-N bonds. In the a-CN films, the content of the C N bonds is found to be more important than that of the C = N double bonds. Carbon clusters are always present in the deposited films as observed by XPS.