Multistep Exposure in Photolithography

Hierarchical PMMA pattern fabricated by superposition of two embossing steps (h, i). ((a,b) Reproduced with permission from [49]. Copyright (2007) Institute of Physics (c-e) Reproduced with permission from [50]. Copyright (2009) American Chemical Society (f, g) Reproduced with permission from [57]. Copyright (2006) Elsevier (h, i) Reproduced with permission from [32]. Copyright (2006) American Chemical Society.) 

American Chemical Society (d) Reproduced with permission from [55]. Copyright (2009) National Academy of Sciences, USA.) 

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