Developing high-resolution resists and processes for electron-beam lithography is of great importance for high-density magnetic storage, integrated circuits, and nanoelectronic and nanophotonic devices. Until now, hydrogen silsesquioxane (HSQ) and calixarene were the only two reported negative resists that could approach sub-10-nm half-pitch resolution for electron-beam lithography. Here, the authors report that 10-nm half-pitch dense nanostructures can also be readily fabricated using the well known poly(methyl methacrylate) (PMMA) resist operating in negative tone, even at exposure energies as low as 2 keV. In addition to scanning electron microscopy metrology, transmission electron microscopy metrology was done to confirm the high-resolution capability of negative-tone PMMA. This process was compared to HSQ with salty development and showed similar ultimate resolution, so it could be used as an alternative for applications incompatible with HSQ.
|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 part fellowship from China Scholarship Council, and Erqing Xie and Li Han for their suggestions on experiments. V.R.M. was supported by the Excitonics Frontier Research Center at MIT in this research. This work was funded by the Information Storage Industry Consortium, Nanoelectronics Research Initiative, and King Abdulaziz City for Science and Technology.