Transmission electron microscopy study of chemically etched porous Si

Abstract

We have developed a new, minimal damage approach for examination of luminescent porous Si (PS) layers by transmission electron microscopy (TEM). In this approach, chemically etched (CE) PS layers are fabricated after conventional plan-view TEM sample preparation. Our TEM studies show that crystalline, polycrystalline, and amorphous phases exist in the same CE sample. The microstructure is believed to gradually change from crystalline to amorphous during chemical etching in a HF-HNO3-H2O solution. The microcrystallites in the polycrystalline region are estimated to be 15–100 Å, while the pore size is on the order of 400 Å.

Porous Silicon Formation by Stain Etching

“…In particular, the iodate ion IO 3 À produces extremely high etch rates when ethanol is added to the etchant to avoid the precipitation of I 2 . However, the halogens are able to react thermally with Shih et al (1992Shih et al ( , 1993, McCord et al (1992), Kidder et al (1992), Dubbelday et al (1993), Steckl et al (1994, Chandler-Henderson et al (1994), Liu et al (1994, 2007, Kalem and Rosenbauer (1995), Anaple et al (1995), Amato (1995), Schoisswohl et al (1995), Jones et al (1995), , Di Francia and Citarella (1995), Winton et al (1996Winton et al ( , 1997 Kolasinski and Gogola (2012) Si and do so in a manner that destroys por-Si films. On the other hand, Xu and Adachi (Xu and Adachi 2006) investigated etching in KIO 3 + HF solutions.…”

“…By far the most commonly used oxidant is HNO 3 , either to etch Si uniformly (Yamamura and Mitani 2008;Robbins and Schwartz 1959Schwartz and Robbins 1976;Jenkins 1977;Kooij et al 1999;Kulkarni and Erk 2000;Svetovoy et al 2006) or to form por-Si (Turner 1960;Archer 1960;Beckmann 1965;Beale et al 1986;Shih et al 1992Shih et al , 1993McCord et al 1992;Kidder et al 1992;Dubbelday et al 1993;Steckl et al 1994;Chandler-Henderson et al 1994;Liu et al 1994Liu et al , 2007Kalem and Rosenbauer 1995;Anaple et al 1995;Amato 1995;Schoisswohl et al 1995;Jones et al 1995;Di Francia and Citarella 1995;Winton et al 1996Winton et al , 1997Velasco 2003;GuerreroLemus et al 2003;González-Díaz et al 2006;Zeng et al 2005;Melnichenko et al 2005;Luchenko et al 2007;Balaguer and Matveeva 2010;Mogoda et al 2011;Lippold et al 2011Lippold et al , 2012Terheiden et al 2011). Other sources of nitrogen oxo ions such as NaNO 2 (Archer 1960;Melnikov et al 2008;Kelly et al 1994;…”

Mechanisms for incorporation of hydrogen in and on terrestrial planetary surfaces

“…Bertie and Whalley, 1964;Hardin and Harvey, 1973). Shih et al (1993). The lowest-temperature features correspond to multilayer (bulk).…”

Photoluminescence and AFM characterisation of photochemically etched highly resistive n‐type silicon

“…Then the maximum thickness of the nanoporous layer is limited [3]. In order to obtain light-emitting layers on highly resistive n-type silicon, two methods may be considered in this respect, (i) stain etching [4] and (ii) photochemical etching [5]. These two strategies are relatively simple compared to the aforementioned electrochemical method, since they require no electrodes on the back surface of crystalline Si wafers.…”