KOH anisotropic etching of Si wafers for LED electrode arrays

This work has mainly investigated the anisotropic wet etching of (100) Si wafers for the preparation of light-emitting diode (LED) electrode arrays. The alkali etchant, potassium hydroxide (KOH), was used as the anisotropic etchant for the Si etching in this work. The experimental results show that the KOH etching process not only etches the Si surface but also etches the SiO₂ film on the wafer surface. Electrode arrays of 25 columns by 25 rows providing a total of 625 trenches in the Si wafer have been produced with well-controlled anisotropy in this work. This electrode array provides the advantages of light weight, thin thickness, and good heat dissipation for LED arrays.