Amorphous magnesium nitride films produced by reactive pulsed laser deposition

Amorphous magnesium nitride films were prepared on silicon substrates by reactive laser ablation using a magnesium target in a molecular nitrogen environment. These films were studied in situ using Auger, electron energy loss and X-ray photoelectron spectroscopies. The nitrogen content, x = [N]/[Mg], changes between 0 and 0.73 for a corresponding variation in nitrogen pressure of 4 × 10−10 Torr to 60 mTorr. By this method it is possible to achieve sub-, over- and stoichiometric films at different nitrogen pressures. The results show that the amorphous matrix keeps its metallic character for x ⩽ 0.45; x = 0.4 is a critical composition at which the material starts developing ionic characteristics; at x = 0.66 the solid is totally ionic.