Modeling projection printing of positive photoresists

Length scale and manufacturability in density-based topology optimization

“…The development phase consists of several steps and can be modeled with different levels of complexity [40]. The simplest model assumes constant threshold [26], i.e., for positive resist the material exposed to a level above a certain level E cl is etched away.…”

“…The threshold projection is assumed to be uniform and the threshold is modeled as a random variable η ∈ P (η d , η e ), where P is an unspecified random distribution with support [η d , η e ]. The compliance is given as (40) where u depends on the physical density and on the threshold η though the state equation. The compliance is positive and for E j (x) ≥ E i (x) , ∀x ∈ Ω the compliance J j is always smaller or equal to the compliance J i , i.e.…”

Computer Simulation of Processes at Electron and Ion Beam Lithography, Part 2: Simulation of Resist Developed Images at Electron and Ion Beam Lithography

“…In the CARs this radiation product (an acid) works as a catalytic agent and modifies the base component solubility rate. The models of the conversion of the solubility rate through the RAC concentration and the solubility rate modification products are described (Dill et al, 1975;Kim et al, 1984;Ferguson et al, 1990;Glezos et al, 1996). In these models various descriptions of the diffusion and loss of the catalytic species (acid) and of the kinetics of the de-protection (switching resist solubility) reaction are used.…”

“…Several algorithms have been suggested in the former years (Greeneich, 1974;Dill et al, 1975;Jewett et al, 1977;Hatzakis et al, 1974;Neureuther et al, 1979;Jones & Paraszczak, 1981;Matsuzawa, 1985;Ferguson et al, 1990;Fukuda & Okazaki, 1990;Vutova & Mladenov, 1991;Weiβ et al, 1995;Glezsos et al, 1996) based on these models. The result of the computer simulation is a profile of the developed simple topological patterns, during their formation under particular processing conditions.…”

“…In this model the required development time of each element is determined by summing up the time for reaching its depth and the time of dissolution of its radial distance. Other authors (Dill et al, 1975;Hatzakis et al, 1974) describe a model, where the resist is partitioned in small elements (cells), coinciding with those, for which the absorbed energy is modeled. Within these elements the solubility rate value is taken to be a constant.…”