Silicon surface texturing with a combination of potassium hydroxide and tetra-methyl ammonium hydroxide etching

A two step silicon surface texturing, consisting of potassium hydroxide (KOH) etching followed by tetra-methyl ammonium hydroxide etching is presented. This combined texturing results in 13.8% reflectivity at 600 nm compared to 16.1% reflectivity for KOH etching due to the modification of microstructure of etched pyramids. This combined etching also results in significantly lower flat-band voltage (VFB) (−0.19 V compared to −1.3 V) and interface trap density (Dit) (2.13 × 1012 cm−2 eV−1 compared to 3.2 × 1012 cm−2 eV−1).