Glass Microfabrication by Wet Etching

This lecture covers the process of glass microfabrication using wet etching with hydrofluoric acid. It explains the etching mechanism, effect of etchant and glass composition, and the etching process sequence. Historical background on hydrofluoric acid etching is discussed, along with the overall reaction and etching constants. The lecture also delves into the detailed mechanisms of HF-SiO₂ etching, surface morphology, and the impact of additives like NH4F. Various factors affecting the etching rate, such as agitation and HCI addition, are explored. The lecture concludes with insights into the surface roughness effects, thermal annealing, and the application of photosensitive glass in microfabrication.