One-dimensional mesopore-array formation on low doped N-type silicon

The mechanism concerning mesopore formation remains unclear to date. In this letter, linear nuclei were pre-structured on purpose; anodizing with aqueous HF electrolyte, one-dimensional (1D) arrays of mesopores with depths up to 40 μm and diameters down to 20 nm (aspect ratios up to 1300) were fabricated in the dark. Significantly higher pore densities and markedly weaker branches occurred in comparison to randomly formed mesopores. Pore densities could increase with decreased current densities. Breakdown effects combined with current-burst-model were employed to interpret the underlying mechanism in detail; SCR (space charge region) effects were excluded as additional stabilizer of the 1D mesopore arrays.