SCALPEL technology challenges

In a related manner, most of the energy of the 100-keV electrons used in SCALPEL technology is deposited into the silicon wafer, which can cause temperature rises of up to several degrees (in Celsius). This wafer heating can result in mechanical distortions that depend significantly on how the wafers are 

Another challenge faced by SCALPEL technology is related to the fact that the SCALPEL mask is not protected by pellicles, making particulate and airborne molecular contamination a major issue. In particular, many components of the SCALPEL tool are sensitive to the presence of charged particulates these include electrostatic chucks, electrostatic optics, and apertures. The fact that the SCALPEL tool is designed to operate in a vacuum environment (10 torr) has been reasonably effective in limiting the amount of particulate and molecular contamination, but has not eliminated them entirely. 

Liddle, L.R. Harriot, A.E. Novembre, and W.K. Waskiewicz, SCALPEL a projection electron beam approach to sub optical lithography, http //www.bel labs.com/proJect/SCALPEL. Levinson, Principles of Lithography, 2nd ed., p. 396, SPIE Press, Bellingham, WA (2005). 

Levinson, Principles of Lithography, 2nd ed., p. 396, SPIE Press, Bellingham, WA (2005). 

To properly expose a resist, /Ne should therefore be large. The foregoing analyses lead to the conclusion that resist sensitivity sets the minimum resolution that can be written in the resist with electrons. 

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