Etch rates and morphology of silicon (h k l) surfaces etched in KOH and KOH saturated with isopropanol solutions

Impact of alcohol additives concentration on etch rate and surface morphology of (100) and (110) Si substrates etched in KOH solutions

“…The appearance of the minima on etch rate curves versus alcohol concentration is difficult to explain. It is well known that saturation of the KOH solution with alcohol considerably reduces the (110) etch rate whereas the reduction of (100) etch rate is relatively low Zubel and Kramkowska 2004). The effect could be explained by preferential adsorption of alcohol molecules on the (110) plane.…”

“…The etching processes were usually carried out in TMAH or KOH aqueous solutions, optionally with addition of surfactants or alcohols. The KOH solution saturated with isopropyl alcohol (also called isopropanol or IPA) was often used, because it provides high etch rate ratio R(100)/R(110), smooth (100) surface and reduction of convex corner undercut (Backlund and Rosengren 1992;Zubel 2001;Zubel and Kramkowska 2004). However, the {110} planes are patterned with stripes after etching in this solution (Backlund and Rosengren 1992;Zubel and Kramkowska 2004).…”

“…The KOH solution saturated with isopropyl alcohol (also called isopropanol or IPA) was often used, because it provides high etch rate ratio R(100)/R(110), smooth (100) surface and reduction of convex corner undercut (Backlund and Rosengren 1992;Zubel 2001;Zubel and Kramkowska 2004). However, the {110} planes are patterned with stripes after etching in this solution (Backlund and Rosengren 1992;Zubel and Kramkowska 2004). Although smooth {110} planes can be obtained in TMAH-based solution (Resnik et al 2005;Yagyu et al 2010;Xu et al 2011), it is quite expensive and usually provides lower etch rates than KOH.…”

Anisotropic etching of diamond by molten Ni particles

“…10,11 Etch pit phenomena in general are known and it has been reported that etch pit morphologies on a crystallographic face are strongly dependent on various parameters such as concentration of the etchant, the composition, e.g., additive impurities or the temperature. [12][13][14][15] These experiments have shown that the form and morphology of etched crystal faces invariably bear the symmetry of their crystallographic orientations. Owing to this behavior and choosing a diamond crystal with a given orientation, it was possible to etch well oriented pores and channels with a tunable size distribution and control of shape in diamond substrates without any need for lithographic processes.…”

Purification of Peptides in High-Complexity Arrays

“…KOH/2-propanol etching was not applied to CMOS chips and Si (100) wafers because these smaller surfaces could be efficiently cleaned and activated by UV irradiation as discussed in II.2.1 and described in V.3.1.1. However, if no UV equipment is available, homogenous etching of Si(100) wafers should be possible with 3 M KOH + 2 M 2-propanol or 5 M KOH + 1 M 2-propanol in water as reported by ZUBEL et al [126][127] Throughout this work, all polymeric films synthesized on CMOS chips or Si(100) wafers were stable independent of their subsequent use. The polymer coatings typically reached a thickness of 50 nm and did not exceed a thickness of 80 nm.…”