Limiting factors in sub-10nm scanning-electron-beam lithography

Microelectronic Engineering

et al. 2011

Self Cite

Abstract:We fabricated 9 to 30 nm half-pitch nested Ls and 13 to 15 nm half-pitch dot arrays, using 2 keV electron-beam lithography with hydrogen silsesquioxane (HSQ) as the resist. All structures with 15 nm half-pitch and above were fully resolved. We observed that the 9 and 10-nm half-pitch nested L's and the 13-nm-half-pitch dot array contained some resist residues. We obtained good agreement between experimental and Monte-Carlo-simulated point-spread functions at energies of 1.5, 2, and 3 keV. The longrange proximity effect was minimal, as indicated by simulated and patterned 30 nm holes in negative-tone resist.

Section: Resolution Limit and Dose Requirementsmentioning

confidence: 99%

“…Electron-beam lithography (EBL) at energies 30 keV and above is a well established method of fabricating sub-20-nm-pitch structures [1,2,3,4]. However, EBL at these high energies suffers from long-range proximity effects.…”

mentioning

confidence: 99%

Sub-5keV electron-beam lithography in hydrogen silsesquioxane resist

Manfrinato

Cheong

Microelectronic Engineering

et al. 2011

Self Cite

“…Impressive high-resolution patterning of sub-20-nm pitch structures have been demonstrated using these methods. 6,10 As the resolution of HSQ-based EBL is currently thought to be limited in part by the resist performance, 11 better understanding of HSQ should enable further improvements in the resolution.…”

Section: Introductionmentioning

confidence: 99%

Understanding of hydrogen silsesquioxane electron resist for sub-5-nm-half-pitch lithography

Yang

Cord

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

et al. 2009

Self Cite

161

119

The authors, demonstrated that 4.5-nm-half-pitch structures could be achieved using electron-beam lithography, followed by salty development. They also hypothesized a development mechanism for hydrogen silsesquioxane, wherein screening of the resist surface charge is crucial in achieving a high initial development rate, which might be a more accurate assessment of developer performance than developer contrast. Finally, they showed that with a high-development-rate process, a short duration development of 15 s was sufficient to resolve high-resolution structures in 15-nm-thick resist, while a longer development degraded the quality of the structures with no improvement in the resolution.

“…However, at such small length scales, metrology becomes challenging. 15,16 For example, considering a criticaldimension control standard deviation of 10% for sub-5 nm half-pitch features implies a metrology accuracy of ϳ0.1 nm, which poses a challenge to even the best scanning electron microscopes ͑SEMs͒.…”

Section: Introductionmentioning

confidence: 99%

Metrology for electron-beam lithography and resist contrast at the sub-10 nm scale

Journal of Vacuum Science &Amp; Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phen

Manfrinato

Yang

et al. 2010

Self Cite

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.