Design and Fabrication of black silicon based on porous silicon

초록

Silicon is a widely used semiconductor material in microelectronic industry. Because of the high refractive index of silicon, the reflectance losses up to 40% severely limiting the performance of silicon-based photon sensitive devices. In recent years, much attention has been directed toward porous silicon as a anti-reflection layer for solar cells. The minimization of reflection losses is very important for solar cells. Many texturing techniques for fabricating anti-reflective silicon surfaces have been proposed, including mechanical diamond saw cutting, optical interference lithography, reactive ion etching, and wet etching using catalysis of metal. However, most of the textured surfaces have a limited at wavelength range. In this paper, We report on the Design and fabrication of black silicon based on multilayer porous silicon. The fabricated structure was made of multilayer porous silicon possessing gradient indices from air to substrate. One of the main advantages of PS for fabrication of multi-layer structure is modulation of refractive index from 1.3 to 3.1. The porosity can be modulated by changing current density. Anti-reflective porous silicon were fabricated by using electrochemical etching. The detailed characteristics, such as the reflectance, will be discussed in presentation.