Nanoforest of black silicon fabricated by AIC and RIE method

Abstract

A nanoforest of black silicon was prepared using a method combining aluminum-induced crystallization (AIC) and reactive-ion etching (RIE). During the AIC period, a rough layer, incorporating AlSix intermetallics, was formed. This layer acted as an etch mask for the RIE step. X-ray photoelectron spectroscopic (XPS) measurements were performed to further analyze the formation of black silicon. Compared to Si3N4 and polysilicon, the black silicon exhibits a high degree of infrared absorption for wavelengths of about 3 to 5μm and 8 to 14μm, respectively. In addition, black platinum overlaid on the base of black silicon further improves the infrared absorption. This nanostructure forests of black silicon could be incorporated into the fabrication process for gas detectors, photovoltaic devices, and imaging applications to improve the infrared absorption characteristics.