Fabrication of Microholes in Silicon Wafers by Using Wet-Chemical Etching

Abstract

The presence of microholes gives materials unique physical properties through their effect on both light and matter. In particular, they can be widely used to increase the efficiency of devices such as light-emitting diodes (LEDs), organic LEDs (OLEDs), solar cells, and sensors. They also have various applications such as aiding plasmon formation on a metal surface. This work reports the quick and inexpensive formation of large amounts of microholes through wet-chemical etching. A Si(100) substrate was etched with KOH solution; the resulting holes depended on the temperature and etching duration. Reacting Si and KOH solution (20%) at 70, 80 and 90 ∘ C resulted in microholes. Field-emission scanning electron microscopy (FE-SEM) was used to investigate the mechanism and the rate of etching with respect to temperature and etching duration. The completed microholes can be finely adjusted through the deposition of a metal such as Au, Pt, Ag or Cu to give them properties suitable for various uses.