1 January 2008 High-dose exposure of silicon in electron beam
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Nowadays, features with sizes smaller than 10 nm can be obtained with electron beam lithography. For such small structures, high exposure doses are required to stay away from the shot noise limit. We investigated the effect of high-dose electron exposure of silicon substrates and subsequent dry development by reactive ion etching. We found that silicon can be directly patterned at electron doses ranging from 0.05 to 3.06 C/cm2. The effect of backscattered electrons is seen as a halo around the patterns. In the given dose range, a gradual transition from positive tone low-dose to negative tone high-dose behavior is observed. It is demonstrated that the patterning is likely to be caused by structural changes of the silicon substrate, resulting in different etch rates in exposed and unexposed areas. X-ray photoelectron spectroscopy analysis has been applied to determine if the thickness of the native oxide in the irradiated areas is different from the thickness at a reference position not irradiated. Small but significant differences have been observed, the largest increase being 0.3 nm.
© (2008) Society of Photo-Optical Instrumentation Engineers (SPIE)
Anda Elena Grigorescu, Anda Elena Grigorescu, Marco C. van der Krogt, Marco C. van der Krogt, Emile W. J. M. van der Drift, Emile W. J. M. van der Drift, Cees W. Hagen, Cees W. Hagen, } "High-dose exposure of silicon in electron beam," Journal of Micro/Nanolithography, MEMS, and MOEMS 7(1), 013005 (1 January 2008). https://doi.org/10.1117/1.2841716 . Submission:


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