Table 1.

Feature comparisons of different etching surface advancement algorithms for the ultraviolet (UV) lithography simulation of the SU-8.

Algorithm		Main Merits	Main Disadvantages	References
String algorithm		Very fast, accurate, less memory elements	Easy to form loops, unstable, not easy to be extended to 3D simulations	[89,90,91,92,93,94]
Ray tracing algorithm		Fast, accurate, less memory usage	Unstable, unsuitable for 3D simulations	[95,96,97]
Cellular automata (CA) algorithm	Static CA algorithm (with Moore neighborhood)	Very stable, easy to be extended to 3D simulations	Very slow, not very accurate, much memory usage	[106,107]
	Dynamic CA algorithm (with von Neumann neighborhood)	Stable, easy to be extended to 3D simulations	Slow, not accurate (preferential etching)	[105,110]
	Dynamic CA algorithm (with Moore neighborhood)	Accurate, stable, easy to be extended to 3D simulations, less memory usage	Relatively slow	[38,108]
Fast marching algorithm	Original fast marching algorithm	Fast, accurate, very stable, easy to be extended to 3D simulations	Much memory usage	[111,112,115]
	Full hash fast marching algorithm	Fast, accurate, very stable, less memory usage, easy to be extended to 3D simulations	Need additional over 120 lines of computer program codes, compared with the original fast marching algorithm	[43,47]