| Popis: |
We have developed an ultrafast lithographic 2D aerial image simulator named LithoCruiser TM . It employs a novel algorithm based on Hopkins imaging (Titanium model). Compared to currently available simulation tools, LithoCruiser has demonstrated an order of magnitude increase in computational speed. This makes it well suited for predicting the printing of sizeable 2D patterns as well as the analysis of overlapping process windows for multiple feature cut-lines. With such a high computational speed, there is a need to determine whether its accuracy has been compromised. A comprehensive set of comparisons was performed against an internal standard based on Abbe imaging (Platinum model) - one that is comparable to commercially available simulators. Analyses of CD through pitch for three 1D mask types (binary chrome, dark field, and PSM) as a function of NA, illumination, and aberrations were conducted. LithoCruiser predicted trends through pitch that agreed well with both internal standard and commercially available lithography simulators. Largest deviations were no more than 5 to 10 nm with typical values of 3 to 5 nm. As the LithoCruiser accuracy setting was increased, CD values converged to target values. The accuracy of CD values was essentially independent of simulation grid setting when less than or equal to 10 nm. |
