Atomic Layer Deposition (ALD) is a thin-film deposition technique used to create ultra-thin layers of material on a substrate. It works by alternating between two or more chemical precursors, which react on the surface to form a single atomic layer at a time. This precise control allows for uniform coatings, even on complex shapes. ALD is widely used in various industries, including semiconductors, solar cells, and nanotechnology. Its ability to produce high-quality films with excellent conformality makes it essential for applications requiring precise material properties, such as in microelectronics and catalysis.