Ald (Atomic Layer Deposition) is a thin film deposition technique in which thin films are prepared by depositing materials on the surface of the material, atom by atom. This method is highly controlled and homogeneous, allowing precise control of the thickness and composition of the material on the micro and nano scale. Below are some basic principles, uses and parameters of the Ald system:
Principle:
Atomic Layer Control: the Ald allows layer-by-layer deposition of thin film material on the surface by alternately injecting two or more precursor gases into the substrate surface, with each gas forming a chemical reaction from molecular layer to molecular layer.
REACTION CONTROL: The uniformity and integrity of each film layer is ensured by precisely controlling parameters such as time, temperature and air pressure of each layer reaction.
Uses:
Nanoelectronics: preparation of insulating layers with high dielectric constant and low loss.
Optoelectronics: preparation of optical films, optical waveguides and other devices.
Energy storage devices: preparation of electrode materials for lithium-ion batteries, supercapacitors, etc.
Biomedicine: preparation of biosensors, medical coatings, etc.
Parameters:
Deposition rate: the growth rate of each film layer, usually in terms of E/cycle (1 E = 0.1 nm) or E/min.
Precursor gas flow: the rate of injection of each precursor gas, which affects the deposition rate and film composition.
Reaction Temperature: The temperature of the reaction chamber, which affects the reaction rate and film crystallinity.
Reaction Time: The duration of the reaction for each layer, which determines film thickness and uniformity.
The design and optimization of an Ald system needs to consider the interaction of these parameters to achieve the desired film properties and quality.
