Journal
MICROELECTRONIC ENGINEERING
Volume 77, Issue 3-4, Pages 327-336Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/j.mee.2004.12.002
Keywords
silicon etching; cryogenic; SF6/O-2; undercut; high aspect ratio trenches
Ask authors/readers for more resources
The aim of this work is to demonstrate the ability of our system to etch deep high aspect ratio trenches (HART's) with a high etch rate (> 5 mu m/min), high selectivity, no local bowing [M. Boufnichel, Gravure profonde cryogenique du silicium dans un reacteur ICP utilisant une chimie SF6/O-2. Application pour la mise an point d'un procede d'isolation electrique sur plaquette Sol, Thesis of the University of Orleans in France, defended on December 2002; M. Boufnichel, S. Aachboun, F. Grangeon, P. Lefaucheux, P. Ranson, J. Vac. Sci. Technol. B 20 (4) (2002) 1508-1512; M. Boufnichel, S. Aachboun, P. Lefaucheux, P. Ranson, J. Vac. Sci. Technol. B 21 (1) (2003) 267-273] and with a perfect mask pattern transfer on silicon, which means no undercut. The process of plasma cryogenic dry etching can be considered as the key technology for micro- and nano-engineering as in the case of, e.g., trench capacitors, and trench isolation for vertical transistors. The most important motivation of this work is advancement of the trench cryogenic technology. The basic aspects of pattern transfer of the prepared mask-patterns by plasma etching into the substrate, considering plasma chemistry, gas flow, substrate temperature, pressure, bias voltage, RF source power, mask nature and thickness will be presented. Special attention will be given to discuss the physical and/or chemical phenomena, which are involved in the generation of undercut in features with high aspect ratios. Sidewall etching of ntype silicon in ICP SF6/O-2 discharges is completely suppressed by cooling the sample to about 100 degrees C during process and using an over-passivation step at the beginning of the process. (c) 2004 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available