Formation of High Aspect Ratio Macropore Array on N-Type Silicon

Abstract

The fabrication of high aspect ratio macropore silicon arrays (MSA) on n-type silicon under optimum photo-electrochemical (PEC) etching (anodization) conditions was demonstrated. The depth of the MSA can reach 350 μm with an aspect ratio of more than 100. With the presence of AOS (a type of anionic surfactant) in the electrolyte, the pore walls solution is slowest, and is more suitable for the preparation of high aspect ratio n-type MSA. The etching voltage is critical for the formation of high aspect ratio MSA on n-type silicon. The relative spectral response curve was measured for silicon photo-electrochemical etching. An IR-LEDs (850 nm) array was proposed as light source for illumination of whole silicon wafers, which was proved available.