Research: Effect of System Parameters and Simulation Resolution on Island Shape

This page shows preliminary results for island formation morphology by evolution of a film. Results are given for a range of normalized characteristic length values. Larger normalized characteristic lengths can be interpreted as an increased relevance of surface free energy, while smaller values can be interpreted as an increased relevance of strain energy, relatively.

Resolution factor = 32
Normalized characteristic length = 0.22484

Resolution factor = 32
Normalized characteristic length = 0.25

Resolution factor = 32
Normalized characteristic length = 0.3

Resolution factor = 32
Normalized characteristic length = 0.35

Resolution factor = 32
Normalized characteristic length = 0.4

In addition, it is also interesting to note the effect of the resolution factor on the morphological configuration of the final island shape. Ideally, the resolution factor should be set such that there are no significant changes to the island shape with increased resolution. This may be more or less practical, depending on computational limitations. While greater resolution will provide finer feature definition, it also incurs a significant processing penalty which may not be practical.

Resolution factor = 8
Normalized characteristic length = 0.22484

Resolution factor = 16
Normalized characteristic length = 0.22484

Resolution factor = 32
Normalized characteristic length = 0.22484

Resolution factor = 8
Normalized characteristic length = 0.4

Resolution factor = 16
Normalized characteristic length = 0.4

Resolution factor = 32
Normalized characteristic length = 0.4

From the above animations, it is concluded that lower resolution factors will produce acceptable results for systems where sharp features are not developed. When sharp (i.e. high aspect ratio, small length scale) features are expected, a higher resolution factor will be required to accurately capture those effects.

Due to the second order nature of the model used to calculate the strain energy, the analysis will not be accurate for high aspect ratio features. This means that the rougher resolution analysis should be acceptable, as cases when it would not be sufficient must already be avoided.