On the origin of dissimilar pore evolution on patterned and unpatterned (100) n-type silicon

Via systematic investigation of the anodization of both patterned and unpatterned specimens, phenomena of pronounced discrepancy with respect to pore size, pore density and pore etch-rate were evidenced. Based on the detailed analysis of scanning electron microscope (SEM) micrographs and current-voltage curves, the competition between physical and chemical elements was found to be crucial to understanding the observations. The results indicate that the size, density and growth-speed of pores may act as an evident function of the initial morphology of the sample surface, despite a nearly fixed width of the space charge region. Electric-field effect as well as current-burst-model (CBM) was employed to interpret the underlying mechanism.