Results
1. Model with grain boundary
To simulate the increase in surface roughness, grain boundary was applied in this model. As can be seen in Figure 1, both groove depth and RMS showed similar trends. At high annealing temperature, surface roughness increased rapidly. This might be due to exponential increase in diffusion coefficient. Figure 2 shows surface roughness of a thin film after 30 minutes of annealing at various temperatures. Both groove depth and annealing temperature increased at higher annealing temperature.
Movie 1. Grain boundary model (annealing at 400 K for 30 min)
Figure 1. Simulation results from the model with grain boundary: a) change in groove depth at various annealing temperature, b) change in RMS at various annealing temperature
Figure 2. The effect of annealing temperature on surface roughness of a thin film with grain boundary
2. Model without grain boundary
To simulate the surface healing, grain boundary was removed in this model. Figure 3 shows evolution of surface roughness at various annealing temperatures. Both groove depth and RMS showed similar decreasing trends. At high annealing temperature, surface roughness changed rapidly due to high diffusion coefficient. Figure 4 shows surface roughness of a thin film after 30 minutes of annealing at various temperatures. High annealing temperature showed significant decrease in surface roughness.
Movie 2. No grain boundary model (annealing at 400 K for 30 min)
Figure 3. Simulation results from the model without grain boundary: a) change in groove depth at various annealing temperature, b) change in RMS at various annealing temperature
Figure 4. The effect of annealing temperature on surface roughness of a thin film without grain boundary
