Fabrication of the pyramidal microstructure on silicon substrate using KOH solution

The texturization of monocrystalline silicon wafers using a mixture of potassium hydroxide and isopropyl alcohol solutions has been investigated. The texture morphology and pyramid size are affected by the KOH concentration, the temperature and the time together. The surface reflectance and the surface morphology were measured with a UV-Visible Spectrophotometer and a scanning electronic microscope (SEM) respectively. We reported a relatively uniform size, dense arrangement pyramid microstructure on the basement of silicon texture. According to the reflectance and SEM patterns, we got the appropriate concentration of KOH, 20wt% and 25wt%, with the corresponding reflectance were 12.049% and 14.593%. It means that either too low temperature with a long time or too high temperature with a short can damage the formation. We got the surface morphology, which was consisted of 1-1.5 mu m sized pyramids. From the pyramid dimension, the optimum process condition was found to be 20wt% KOH, 3wt% IPA, 60 degrees C and 5 min at which was reduced to 1.292 mu m. From the SEM images density and uniformity, the optimized condition is 20wt% KOH, 3wt% IPA, 70 degrees C and 15mins though its size has reached the 1.404 mu m.