KOH anisotropic etching of Si wafers for light-emitting diode electrode arrays

The formation of Si trenches with anisotropic wet etching of (100) Si wafers for light-emitting diode electrode arrays has been investigated. An alkali etchant, potassium hydroxide (KOH), was used as the anisotropic etchant for the Si etching in this study. 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, were produced with well-controlled anisotropy. Finally, Silvaco TCAD software was used to simulate the thermal power variation of the LED die in the Si trench. Heat distribution simulation analysis showed that this design improves the heat dissipation problem in subsequent manufacturing processes, such as assembly and packaging.