The sputtering process of vacuum coating machine is mainly used for sputtering etching and film deposition. During sputtering etching, the material to be etched is placed at the target electrode position and etched by argon ion bombardment. The etching rate is related to the sputtering yield of the target material, the ion current density and the vacuum degree of the sputtering chamber. During sputtering etching, the sputtering target atoms should be removed from the sputtering chamber as far as possible

 The common method is to introduce reactive gas to react with the sputtered target atoms to generate volatile gas, which is discharged from the sputtering chamber through the vacuum system. When depositing thin films, the sputtering source is placed on the target electrode, and sputtering occurs after being bombarded by argon ion. If the target material is a simple substance, a simple substance film of the target material is generated on the substrate; If the reactive gas is consciously introduced into the sputtering chamber to make it react with the sputtered target atoms and deposit on the substrate, the compound film of the target material can be formed. Generally, compound or alloy films are prepared by direct sputtering of compound or alloy targets. In sputtering, the sputtered atoms are splashed out after exchanging energy with high-energy ions with thousands of electron volts. Their energy is higher, often 1-2 orders of magnitude higher than the evaporated atoms. Therefore, the adhesion between the film formed by sputtering and the substrate is better than evaporation. If a proper bias voltage is applied to the substrate during sputtering, the cleaning treatment of the substrate can be considered, which is also beneficial to the step coverage of the film. In addition, the material film with high melting point and low vapor pressure that cannot be prepared by evaporation process can be prepared by sputtering method, which is convenient for preparing the film of compound or alloy. There are two main methods of sputtering: ion beam sputtering and plasma sputtering. In the ion beam sputtering device, the targeted ion beam with certain energy provided by the ion gun bombards the target electrode to produce sputtering. The ion gun can also be used for cleaning the substrate and sputtering the target. In order to avoid the accumulation of charges on the solid surface of insulation, the sputtering of charged neutral beam can be used. The neutral beam is caused by the neutralization of charged positive ions by electrons before leaving the ion gun. Ion beam sputtering is widely used in surface analysis instruments to clean or peel samples. Due to the limited size of the beam spot, it is still difficult to use for rapid thin film deposition on large-area substrates. Plasma sputtering is also called glow discharge sputtering. The positive ions needed to produce sputtering come from the plasma region in the glow discharge. The surface of the target electrode must be a high negative potential, and the positive ion will be accelerated by this electric field to obtain kinetic energy to bombard the target electrode to produce sputtering, and the electron bombardment on the substrate will inevitably occur.
The magnetron sputtering process of vacuum coating machine can also be divided into several types, mainly including two-stage sputtering, three-stage or four-stage sputtering, magnetron sputtering, target-to-target sputtering, RF sputtering, bias sputtering, asymmetric AC RF sputtering, ion beam sputtering and reactive sputtering. The choice of sputtering method depends on the workpiece, the material of the workpiece and the coating.