Simulation of shot noise effect on CD and LER of electron-beam lithography in 32 nm designs

Mask fabrication or even maskless lithography operations are performed with electron-beam lithography (EBL). The detailed understanding of the electron scattering mechanisms in resist films and multilayer substrates, as well as on substrates with topography is mandatory. Along the same track the problem of line edge roughness (LER) of created structures is emerging, because it strongly affects the device electrical behavior. Process simulation could be used for the quantification of the effects of electron-beam exposure and resist material on the produced layout. In the current work coupling between a detailed Monte-Carlo e-beam-matter interaction simulator and a stochastic resist film modeling simulator for the materials, postexposure bake, and development allows for simulation of the shot noise, resist material, and process effects on the critical dimension (CD) and LER in the 32 technology patterned by direct EBL. An example of quantification of shot noise and resist contribution to LER is provided. (C) 2009 Elsevier B.V. All rights reserved.