Exploring the resolution limit of electron-beam lithography is of great interest both scientifically and technologically. However, when electron-beam lithography approaches its resolution limit, imaging and metrology of the fabricated structures by using standard scanning electron microscopy become difficult. In this work, the authors adopted transmission-electron and atomic-force microscopies to improve the metrological accuracy and to analyze the resolution limit of electron-beam lithography. With these metrological methods, the authors found that sub-5 nm sparse features could be readily fabricated by electron-beam lithography, but dense 16 nm pitch structures were difficult to yield. Measurements of point- and line-spread functions suggested that the resolution in fabricating sub-10 nm half-pitch structures was primarily limited by the resist-development processes, meaning that the development rates depended on pattern density and/or length scale.
|Original language||English (US)|
|Journal||Journal of Vacuum Science and Technology B:Nanotechnology and Microelectronics|
|State||Published - Nov 2010|
Bibliographical noteFunding Information:
The authors thank Henry I. Smith, James M. Daley, and Mark K. Mondol for helpful discussions and Juan Ferrera for providing PSF Monte Carlo simulation codes. Electron-beam lithography was done in MIT’s shared scanning-electron-beam-lithography facility in the Research Laboratory of Electronics. H.D. would like to acknowledge his partial fellowship from China Scholarship Council. V.R.M. was supported as part of the Center for Excitonics, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award No. DE-SC0001088. This work was also supported in part by the Information Storage Industry Consortium, Nanoelectronics Research Initiative, the NSF.