Macropore formation in prepatterned p-type silicon

Abstract

The formation of ordered macropores in a prepatterned p-type silicon wafer by electrochemical anodization in HF:H2O:DMSO (dimethyl sulfoxide) and HF:DMSO solutions was investigated. The pore wall thickness in the solutions was found to be reduced with increasing current density. The pore growth rate was compared using two kinds of etch pit; one is for 2 μm lattice spacing, the other is for 5 μm. The growth rate of the macropores for 2 μm size revealed a saturation behavior, while that of 5 μm corresponded to a linear increase in the same range of current density. The big difference in morphologies of macropores between HF:H2O:DMSO and HF:DMSO solutions was accounted for based on the chemical nature of DMSO © The Electrochemical Society.