Realization of black silicon layer using simple plasma fabrication process

초록

Polished flat silicon surfaces have high reflectivity in visible lays. The minimization of reflection losses is very important for solar cells. Lowering surface reflectivity of silicon by texturization is one of the most important processes for improving the conversion photovoltaic efficiency of silicon solar cells. Many texturing techniques for fabricating antireflective silicon surfaces have been proposed, including mechanical diamond saw cutting, optical interference lithography, wet etching using catalysis of metal, and reactive ion etching, to produce so-called “black silicon”. In this paper, we attempted to chlorine and oxygen based inductively coupled plasma etching for realization of black silicon. When combined with oxygen gas, self-masking effect was occurred at lower substrate temperature, and silicon pillar was grown up because of physical etching characteristic of chlorine gas. The etched silicon surface shows almost zero reflectance in the visible region. The silicon surface was covered by columnar microstructures with variable diameter, and height of microstructure depends on surface temperature. We will discuss more detail results and etching parameters in presentation.