Atomikerroskasvatusta

Atomikerroskasvatusta, commonly known as Atomic Layer Deposition (ALD), is a thin-film deposition technique that enables the coating of surfaces with highly conformal and precise atomic-scale layers. It is based on a self-limiting surface adsorption process that allows for sequential, layer-by-layer growth of materials. Unlike chemical vapor deposition (CVD), ALD utilizes discrete, sequential pulsing of gaseous precursor materials. Each precursor reacts with the surface in a self-limiting manner, meaning that the reaction stops once a monolayer or a fraction of a monolayer has been formed. After each precursor pulse, a purge step with an inert gas is employed to remove any unreacted precursors or gaseous byproducts before the next precursor is introduced. This cyclic process is repeated until the desired film thickness is achieved. The self-limiting nature of the reactions ensures excellent control over film thickness and composition, down to the atomic level, and results in highly uniform and conformal coatings even on complex three-dimensional structures. ALD finds applications in various fields, including microelectronics for gate dielectrics and barrier layers, catalysis for creating high-surface-area catalysts, optics for anti-reflective coatings, and biomedical devices for biocompatible coatings. Its ability to deposit a wide range of materials, including oxides, nitrides, metals, and sulfides, makes it a versatile tool for advanced material fabrication.