Highly anisotropic room-temperature sub-half-micron Si reactive ion etching using fluorine only containing gases

Reduction of loading effects with the sufficient vertical profile for deep trench silicon etching by using decoupled plasma sources

“…To reduce the macroscopic loading effect, silicon trench etching was performed by using chlorine (Cl) and/or bromine (Br) groups rather than fluorine (F) groups, which generally perform spontaneous etching (Burtsev et al, 1998). However, several advanced methods with F-containing plasmas were investigated for the enhancement of anisotropy by using cryogenic etching in high density SF 6 plasmas or F-containing gas mixtures such as SF 6 /C 2 Cl 3 F 3 , SF 6 /CHF 3 and SF 6 /O 2 /CHF 3 because Cl-or Brcontaining plasma has some problems such as sharp trench corners, surface roughness, and black silicon or lower etch rate, respectively (Burtsev et al, 1998;Yunkin et al, 1995;Gogolides et al, 1995;Jansen et al, 1995). Recently, the advances in silicon etching have been also performed by CH 2 F 2 /SF 6 chemistry which is one of the promising chemistries where spontaneous etching by F is counterbalanced by fluoro-carbon polymer formation on the sidewalls of an etched structure (Shamiryan et al, 2009;Luere et al, 2009;Paraschiv et al, 2009).…”

Nanostructure fabrication process for optoelectronic applications

“…As can be seen from the SEM micrographs, there are three different pillar shapes: straight sidewalls, conical and overcutting. It was reported that anisotropy can be estimated by means of aspect ratio H/D (where H and D are height and diameter of pillar) [7] or anisotropy coefficient 1-(D-d)IH (where d is minimal pillar diameter) [8]. However, aspect ratio is usable only for ideal straight pillars.…”

Wet silylation and oxygen plasma development of photoresists: A mature and versatile lithographic process for microelectronics and microfabrication

“…We have used a very anisotropic selective to the resist SF 6 /CHF 3 plasma to transfer these structures to Si. 60 Figures 6 and 7 show nanowires and nanopillars produced with this method, and used to observe the Si light emission from these nanostructures, 61,62 as an imitation of light emission from porous Si. …”