Single Step Inverted Pyramid Texturing of n-type Silicon by Copper Assisted Chemical Etching

摘要

In this paper, we present the results of the study on the fabrication of inverted pyramids on n-type Si wafer by a single-step anisotropic copper-assisted chemical etching. The relationship between etchant composition, etching time and the surface morphology for n-type Si has been investigated. Different surface structures were obtained by adjusting molarity of H2O2, Cu(NO3)2, HF in the etching solution. Cu(NO3)2 amount promoted, while increasing H2O2 amount over optimum value reduced the etch rate. By optimizing etching duration, etching temperature and etchant composition, uniform distribution of inverted pyramids with dimensions around 2 μm was achieved. Surface average weighted reflectance was reduced to 5.67% in the wavelength range of 400-1000 nm with novel surface texturing method.