Porous Si layers—Preparation, characterization and morphology

摘要: Abstract Porous silicon layers (PSL) of nano- and micro-structures were prepared by metal-assisted electroless etching in HF–oxidizing agent aqueous solutions. The effect oxidizing HF content on the characteristics formed porous was investigated. A thin Pt film deposited p-Si〈1 0 0〉 prior to immersion solution. properties morphology PSL this method investigated electrochemical impedance spectroscopy (EIS) scanning electron microscopy (SEM) energy dispersive X-ray (EDX) technique. found be affected constituents medium also, time. Potassium bromate (KBrO 3 ), potassium iodate (KIO dichromate (K 2 Cr O 7 ) have been used as agents. Pt-assisted p-Si for 1 h an solution consisting 22.0 M 0.05 M KBrO , results formation micro-pores Si surface. use KIO or K has led a deposit At relatively higher concentration [>0.05 M] surface becomes clear consist insoluble passive solid-phase SiF 6 which increases blocks structure formation. [>22 M] electrolyte is accompanied increase dissolution rate layer decrease passivity. experimental data fitted theoretical according proposed equivalent circuit model accounts mechanism at Si/electrolyte interface.