Amorphous hydrogenated silicon nitride ($textit{a}$-SiN$_mathrm{textit{x}}$:H) thin films irradiated with 100 MeV Ni$^{7+}$ results in the formation of continuous ion track structures at the lower fluence of $5times{10^{12}}$ ions/cm$^2$ whereas at higher fluence of $1times{10^{14}}$ ions/cm$^2$ the track structures fragment into discontinuous ion track like structures . The observation of the discontinuous ion track like structures at the high fluence of $1times{10^{14}}$ ions/cm$^2$ shows clearly that higher fluence irradiation may not always lead to dissolution of the microstructure formed at lower fluence. The results are understood on the basis of a dynamic electronic energy loss (S$_{e}$) in the course of irradiation resulting from the out-diffusion of hydrogen from the films and a continuous increase in density of $textit{a}$-SiN$_mathrm{textit{x}}$:H films.
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