  Morphology of metal thin layers deposited on polished surfaces of LiNbO$_3$
crystal with dissimilar electric charges has been studied using various methods
of vacuum evaporation. The principal goal of the work is to optimizemethods of
thin metal coating deposition applied to polar surfaces of LiNbO$_3$ crystal.
The conducted research has demonstrated that Cr deposition on LiNbO$_3$ crystal
faces is characterized by dissimilar polarity results in growth difference
conditions of Cr films. The principal role here is played by the sign of the
electric charge on the crystal surface along with the type (thermal or
magnetron) and conditions observed during sputtering (deposition rate,
substrate temperature etc).
