Lecture
This lecture covers the wet etching process, including anisotropic and isotropic etching, thin membrane microfabrication, and applications in micro and nanofabrication. It explains the use of liquid baths for material removal, chemical reactions involved, and examples like etching of gold and silicon substrates. The lecture also discusses the etching of sacrificial layers, 'Piranha' wafer cleaning, and the realization of porous silicon. Various techniques such as isotropic etching of gold film, etching of a Si substrate, and etching of a thin Si membrane are explored, along with their applications in MEMS. Overall, the lecture provides insights into the fundamental principles and practical aspects of wet etching in microfabrication.