Controlling the Electrochemical Etching of Pores with High Aspect Ratio at the Submicrometer Scale in Silicon

The controlled electrochemical etching at high anodic voltage (up to 35 V) of two-dimensional arrays of ordered pores with sub-micrometric diameter (down to 800 nm) at high depths (up to 40 µm) and high density (spacing 1.8 µm), yielding a maximum aspect ratio of 50, using low-doped (resistivity 3-8 Ωcm) n-type silicon is hereby for the first time demonstrated and discussed