Alkali anisotropic chemical etching of p-silicon wafer

The surface chemistry of anisotropic etching of p-type Si-wafer ( 400) is reviewed and the anisotropic chemical etching of silicon in alkaline solution using wetting agent were discussed.The main factors which affect the production of silicon dioxide layer on crystalline silicon as a result of wet alkali anisotropic chemical etching are the concentration of etching solution (KOH) and wetting agent (n-propanol), temperature (80 °C) and time of the etching (4 hr) process.Silicon dioxide layer has found applications in many advanced areas.The synthesized silica layer was systematically characterized by XRD, SEM and FTIR spectroscopy.The XRD results revealed the amorphous nature of silica layer.FTIR spectroscopy confirmed the presence of Si-O in produced samples.SEM confirmed the addition of n-propanol to the KOH solution resulted in an improvement in the etching anisotropy in a smooth etched Si (400) surface.