The influence of film thickness on annealing-induced grain growth in Pt films

Pt films with thickness $h$ = 20–100 nm deposited on oxidized $с$-Si(100) substrate have been subjected to vacuum annealing at 500$^{\circ}$C for 1 h, which resulted in recrystallization and growth of grains. Simultaneously with the normal growth of grains, abnormal grain growth has been observed, as a result of which the grains have separated in normal and secondary grains. For $h$ = 20–40 nm, the secondary grains become much larger than the normal ones and the grain lateral size distribution therefore becomes bimodal. It has been shown that the abnormal grain growth rate increases with decreasing h , whereas the normal grain growth rate is independent of h . From the Pt(111) and Pt(222) X-ray diffraction peaks analysis it follows that the mean size $D$ of coherently diffracting domains increases as a result of annealing. In the annealed films, $D$ sublinearly grows with $h$, whereas in the as-prepared films, $D$ grows linearly.