Atomic layer deposition (ALD) is a method in which substances can be deposited layer by layer on the surface of a substrate in the form of a monoatomic film. Atomic layer deposition is similar to ordinary chemical deposition. But in the process of atomic layer deposition, the chemical reaction of the new layer of atomic film is directly related to the previous layer. This way only one layer of atoms is deposited per reaction. Atomic layer deposition is a method (technique) of forming a deposited film by passing the gas-phase precursor alternately into the reactor and chemically adsorbing and reacting on the deposition substrate. When the current drive bodies reach the surface of the deposition substrate, they will chemically adsorb on the surface and undergo surface reactions. The atomic layer deposition reactor needs to be cleaned with inert gas between precursor pulses.