Electron beam lithography simulation for sub-10 nm patterning

Molecular dynamics simulation of sub-10 nm pattern formation in electron beam lithography is performed for the poly(methyl methacrylate) (PMMA) resist. The effect of electron exposure is modeled by the chain scission of the polymer molecule, and the small segments of polymer molecules are removed from the resist structure in the development process. The acceleration voltage dependence, shot noise, and proximity effects are studied with the simulation. Under the conditions wherein the electron scattering and shot noise effects are suppressed, the line edge roughness becomes close to the size of the resist molecule segment. The structure of the resist molecule also affects the proximity effect.