One dimensional macropore-array formation on low doped n-type silicon

Macropores with diameters between 0.1 μm and 0.8 μm show technological significance but become difficult to obtain on low doped n-type silicons. In this study, via anodizing samples with prestructured linear defects, one dimensional (1D) densely arrayed macropores with depths up to 15 μm and diameters between 100 nm and 1 μm were produced with fast speed on low doped n-Si. The pore density increases with reduced current densities: this phenomenon was found to be largely dominated by physics rather than by chemistry. Not least, SCR effects alone were excluded as additional stabilizers of the 1D macropore arrays; the interaction between diffusion and tunneling effects was proved to play a major role instead. Simultaneously, the gradual transition from macropore to mesopore formation, not well understood to date, was experimentally displayed and theoretically interpreted.