Pressure effect of growing with electron beam-induced deposition with tungsten hexafluoride and tetraethylorthosilicate precursor
Article first published online: 14 MAR 2007
Copyright © 2006 Wiley Periodicals, Inc.
Volume 28, Issue 6, pages 311–318, November/December 2006
How to Cite
Choi, Y. R., Rack, P. D., Randolph, S. J., Smith, D. A. and Joy, D. C. (2006), Pressure effect of growing with electron beam-induced deposition with tungsten hexafluoride and tetraethylorthosilicate precursor. Scanning, 28: 311–318. doi: 10.1002/sca.4950280603
- Issue published online: 14 MAR 2007
- Article first published online: 14 MAR 2007
- Manuscript Accepted: 11 SEP 2006
- Manuscript Received: 31 MAY 2006
- electron beam-induced deposition;
- interaction volume;
- scanning electron microscope;
- precursor gas;
- extreme ultraviolet mask
Electron beam-induced deposition (EBID) provides a simple way to fabricate submicron- or nanometerscale structures from various elements in a scanning electron microscope (SEM). The growth rate and shape of the deposits are influenced by many factors. We have studied the growth rate and morphology of EBID-deposited nanostructures as a function of the tungsten hexafluoride (WF6) and tetraethylorthosilicate (TEOS) precursor gas pressure and growth time, and we have used Monte Carlo simulations to model the growth of tungsten and silicon oxide to elucidate the mechanisms involved in the EBID growth. The lateral radius of the deposit decreases with increasing pressure because of the enhanced vertical growth rate which limits competing lateral broadening produced by secondary and forward-scattered electrons. The morphology difference between the conical SiOx and the cylindrical W nanopillars is related to the difference in interaction volume between the two materials. A key parameter is the residence time of the precursor gas molecules. This is an exponential function of the surface temperature; it changes during nanopillar growth and is a function of the nanopillar material and the beam conditions.