Lithography simulation: modeling techniques and selected applications

Dynamic Bragg Angle Shift in the Course of Volume Hologram Formation

“…[6,7] A research challenge of considerable importance concerns the optical shrinkage in the course of hologram formation. [8,9] The photocuring is always linked to shrinkage of the volume, as a result of the shortened particle distance in the covalent bond, compared with the individual van der Waals radii prior to the curing. [9] Shrinkage during or post illumination represents a significant drawback with respect to the requirements of holographic recording, [10] which, not only in case of high capacity data storage, [11] imposes near-perfect fidelity of the reconstructed image.…”

“…[4,5] Mechanical stability gains particular importance in view of the high-resolution nanostructures achievable with material based on SU-8 photoresist [18] and with regard to further reduction of feature sizes. [8] Epoxides are used as cationically polymerizable monomer to obtain high performance in terms of inducible refractive index contrast, [4] energetic sensitivity [19] as well as mechanical stability. [20] With the aim of optimization, we consider possibilities to further reduce undesired volumetric deformations.…”

Image simulation of projection systems in photolithography

“…Parallel lithographic imaging techniques project an image of a physical mask into the photoresist on the semiconductor wafer. Advanced optical projection systems in semiconductor fabrication enable throughputs of more than 100 wafers per hour [1]. For more than 30 years optical projection lithography has been used as the standard technology for the patterning of microelectronic circuits.…”

“…The development of projection lithography for semiconductor fabrication has been accompanied by an improved understanding of the underlying physics and chemistry and by the development of predictive simulation tools. Nowadays, modeling and simulation of lithographic processes have become mandatory for the development and optimization of new processes [1]. Predictive simulation of lithographic processes requires the modeling of various physical and chemical phenomena.…”

“…Finally, a combination of empirical development rate models and surface tracking algorithms such as the fast marching method and cell removal methods is applied to describe the partial development of the photoresist. The resulting photoresist profile and its variation versus important process parameters are used for a quantitative characterization of lithographic processes [1]. Applications of lithography simulation range from training tools for researchers and engineers and comprehensive simulation studies to computational lithography for the design and optimization of new processes.…”