Silver-assisted electroless etching mechanism of silicon

The morphology of metal-assisted electroless etched n-type silicon in HF-oxidizing agent-H2O etching system as a function of oxidizingtype and etching time was studied. Three types of oxidizing agent were investagated: 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 presented. (C) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.