Advanced In Situ I-V Measurements Used in the Study of Porous Structures Growth on Silicon

Abstract

The rate of oxide formation during growth of pores structures on silicon was investigated by in situ I-V measurements. The measurements were designed to get two I-V curves in a short time (total time for the two measurements was 300 seconds) taking into account the gap (in mA/cm2) for each corresponding voltage. The in situ I-V measurements were made at different pore depth/time, at the electrolyte-pore tip interface, while etching takes place based on p-type Si. The results showed increasing, decreasing, and constant I-V gap in time, for macropores, nanopores, and electropolishing regimes, respectively. This was related to the expected diffusion limitation of oxide forming (H2O) molecules reaching the electrolyte-pore tip and the anodizing current, while etching takes place. The method can be developed further and has the potential to be applied in other electrochemically etched porous semiconductor materials.