Low Temperature Deposition of Silicon Nitride by Reactive Ion‐Beam Sputtering

The deposition mechanism of reactive ion beam sputtered silicon nitride was studied. Using RBS analysis, the composition of Si x N y layers deposited at room temperature has been investigated as a function of different parameters. Irrespective of the nitrogen partial pressure, ranging from 10 −4 to 0.2 Pa, the stoichiometry of the film depends only on the sputtering yield of silicon in the range 0.4–20 keV. Si 3 N 4 layers can be obtained at low voltage, but only with a low deposition rate (typically 1 nm/min at our experimental conditions). In order to obtain Si 3 N 4 films with higher deposition rates, we increased the nitridation of deposited silicon, either by introducing in the deposition chamber a highly reactive molecule such as NH 3 , or by using electronic bombardment, which stimulates the adsorption of N 2 on the growing film.