Several techniques are utilized in nanofabrication, each with its own set of complexities:
1. Top-Down Lithography: This method involves patterning and etching down from a larger piece of material. Techniques such as Electron-Beam Lithography and Photolithography fall under this category. They offer high precision but are often costly and time-consuming.
2. Bottom-Up Approaches: These involve assembling nanostructures atom by atom or molecule by molecule, typically using chemical methods. Examples include Self-Assembly and Chemical Vapor Deposition (CVD). These methods can create highly ordered structures but controlling the assembly process can be difficult.
3. Molecular Beam Epitaxy: This technique is used to grow crystalline layers to form semiconductor devices. It allows precise control over the thickness and composition of layers but requires ultra-high vacuum conditions.
