Silver‐assisted electroless etching mechanism of silicon

Abstract

The morphology of metal‐assisted electroless etched n‐type silicon in HF–oxidizing agent–H2O etching system as a function of oxidizing type and etching time was studied. Three types of oxidizing agent were investigated: Na2S2O8, K2Cr2O7 and KMnO4. The layers formed on silicon were investigated by scanning electron microscopy and energy‐dispersive X‐ray analysis. It is shown that the morphology of the etched layers depends strongly on the type of oxidizing agent. The secondary ion mass spectra of the etched layers reveal that the deposited silver diffuses into the etched layers during etching. Finally, a discussion on the dissolution mechanism of silicon by silver‐assisted electroless etching is presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Porous Silicon Formation by Metal Nanoparticle-Assisted Etching

“…Other oxidizing agents such as Fe(NO 3 ) 3 (Peng et al 2005b(Peng et al , 2006b), Mg(NO 3 ) 2 (Peng et al 2006b), Na 2 S 2 O 8 (Hadjersi et al 2004(Hadjersi et al , 2005aDouani et al 2008;Hadjersi 2007), KMnO 4 (Hadjersi et al 2004(Hadjersi et al , 2005aDouani et al 2008), K 2 Cr 2 O 7 (Douani et al 2008;Hadjersi et al 2005b;Waheed et al 2010), KBrO 3 or KIO 3 (Waheed et al 2010), Co(NO 3 ) 2 (Megouda et al 2009b), molecular O 2 dissolved in H 2 O (Yae et al 2003(Yae et al , 2005(Yae et al , 2006(Yae et al , 2008a(Yae et al , b, 2010a(Yae et al , 2012Masayuki et al 2011), and electrical holes, h + by anodization (Zhao et al 2007;Chouroua et al 2010;Huang et al 2010a), are also used. The deposited metals under the form of nanoparticles or colloidal particles or patterned thin film are most generally noble metals such as Ag (Hadjersi et al 2004(Hadjersi et al , 2005bTsujino and Matsumura 2005a, 2007Peng et al 2005bPeng et al , 2006bPeng et al , 2008Huang et al 2007;Chartier et al 2008;Lee et al 2008;Douani et al 2008;Hadjersi 2007;Waheed et al 2010;Yae et al 2005;Yang ...…”

Heterojunction of poly (o-toluidine) and silicon nanowires

“…On the other hand, two broad peaks centered at 2θ ¼ 15 and 20 deg may be ascribed to the periodicity parallel to the polymer chains, while the latter peaks may be caused by the periodicity perpendicular to the polymer chains. 23 The XRD patterns may, therefore, suggest that the obtained nanostructured POT has some crystallinity. …”

Formation of aligned silicon-nanowire on silicon in aqueous HF/(AgNO3+Na2S2O8) solution

“…The generation of helical holes in silicon was attributed to the microscopical difference in etching rate of silicon on a Pt particle. Recently, we showed that cylindrical holes also were formed in HF/K 2 Cr 2 O 7 solution [1]. On the other hand, in HF/ Na 2 S 2 O 8 solution randomly propagating pores and winding pores were formed in and under the microporous layer, respectively [1].…”

“…According to the literature, the shape of the generated holes depends on several etching parameters such as the shape of the metal particle, the concentration of HF and the type of oxidant agent used in the etching solution [1,2]. Tsujino et al assumed that the shape of the generated hole and the Ag particle were related [3].…”

“…It is well known that in the process of metal-assisted electroless etching, the metal nanoparticles, which are deposited onto the substrate surface, catalyze the etching reaction, sink below the surface and leave behind holes [1]. According to the literature, the shape of the generated holes depends on several etching parameters such as the shape of the metal particle, the concentration of HF and the type of oxidant agent used in the etching solution [1,2].…”