A model of self-limiting residual acid diffusion for pattern doubling

Pattern doubling by cross-linking of a spacer triggered by residual acid diffusion from a previously developed primary structure into the spacer is a possible option to create the necessary structure widths for the 32 nm node with current exposure technology by pattern doubling. A particular advantage of this process step would be the self-alignment to the primary structure, which would render a second exposure step unnecessary. In the paper, we present a new prototypical model of the bake step of this process and discuss the dependency of the desired behavior on parameters of the model.