Investigation of the thermal stability of nitrogen-rich amorphous carbon nitride films

The thermal stability of nitrogen-rich amorphous carbon nitride films (N/C greater than or equal to 1) is investigated from room temperature up to 600 degreesC. The films were deposited by three different methods, namely puls ed laser deposition (PLD), inductively coupled plasma chemical vapour depos ition (ICP-CVD) with gaseous precursors, and ICP-CVD utilizing transport re actions. As-deposited and annealed films were characterized with respect to their thickness, composition and bonding structure by a variety of methods including wavelength dispersive X-ray analysis (WDX), Auger electron spect roscopy (AES), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy a nd Fourier transform infrared spectroscopy (FTIR). Annealing at 200 degrees C leads to desorption of surface contaminants while in the range between 20 0 and 400 degreesC a significant densification is observed. Above 400 degre esC a drastic loss of film material, especially nitrogen-rich groups, sets on, leading to the total destruction of the films at 600-700 degreesC. Thes e observations are compared with the annealing behaviour of films with lowe r nitrogen content. (C) 2000 Elsevier Science B.V. All rights reserved.