Study of electrical current reconstruction on macropore arrays etched electrochemically on lightly-doped n-Si

Abstract

Silicon macropore arrays are fabricated on lightly-doped n-Si by electrochemical etching. The opening diameter, inner diameter, and wall thickness of the macropores are observed to depend on HF concentration and current. A current reconstruction model is proposed to elucidate the formation mechanism of the macropores. Two geometric models are established for the silicon macropores according to the experimental results. The finite element method is used to simulate the electric field and current in the electrolyte-silicon system. The reconstruction of electrical current on the silicon macropore arrays is described by simulating the electric field and current. The ratio of major to minor semi-axes of the elliptical pore (b/a) decreases with increasing the ratio of diameter to wall thickness as confirmed experimentally. The results indicate that the b/a ratio is correlated with the HF concentration and applied voltage.