  The objective of this work was to study the RF sputtering process parameters
optimisation for deposition of Silicon Nitride thin films. The process
parameters chosen to be varied were deposition power, deposition duration, flow
rate of argon and flow rate of nitrogen. The parameters were varied at three
levels according to Taguchi L9 orthogonal array. Surface topology, film
composition, coating thickness, coating resistivity and refractive index were
determined using SEM, XRD, profilometer, Semiconductor device analyser and UV
spectrometer respectively. The measured film thickness values ranged from
127.8nm to 908.3nm with deposition rate varying from 1.47nm/min to a maximum
value of 10.1nm/min. The resistivity of the film varied between 1.53x1013ohm-m
to 7.85 x1013ohm-m. Refractive index of the film was calculated to be between
1.84 to 2.08. From the results, it was seen that film properties tend to be
poor when there is no nitrogen flow and tend to improve with small input of
nitrogen. Also, SEM images indicated amorphous structure of silicon nitride
which was confirmed by XRD pattern.
