depositointi

Depositointi, in Finnish, refers to the formation of a solid material as a layer or coating on a substrate by controlled addition of material from a gas, solution, or another solid phase. It is a central concept in materials science, electronics manufacturing, optics, and surface engineering. Depositions can be chemical, physical, or electrochemical in nature and are used to create thin films with specific properties such as hardness, conductivity, or optical performance.

Physical deposition methods transfer material to a substrate through physical processes, often in vacuum or low-pressure environments. Physical vapor deposition (PVD) includes evaporation and sputtering, where atoms or molecules are deposited as a thin film. Films produced by PVD can be amorphous or crystalline and are used for protective coatings, mirrors, and semiconductor devices. Chemical deposition methods rely on chemical reactions to form the film. Chemical vapor deposition (CVD) uses gaseous precursors that react on the substrate surface, while atomic layer deposition (ALD) achieves precise thickness through sequential, self-limiting reactions.

Electrochemical deposition, or electrodeposition, uses electric current to reduce ions from a solution onto a conductive substrate, forming metallic coatings such as copper, nickel, or gold. Electroless deposition achieves metal deposition without external current, via chemical reducing agents. Deposition processes are characterized by parameters such as temperature, pressure, precursor or bath composition, current density, and deposition rate, all of which influence film quality and properties.

Applications span microelectronics, optoelectronics, protective and wear-resistant coatings, corrosion protection, and optical or reflective films. Quality control involves thickness measurement, adhesion testing, surface roughness assessment, and structural characterization (e.g., X-ray diffraction, electron microscopy).

Geological and environmental contexts also use the term deposition to describe the accumulation of sediments or minerals from fluids, forming layers over time.