The physical vapor deposition (PVD) or vacuum sputtering process mainly includes the following steps:
Surface pretreatment: Firstly, clean the substrate to ensure that the surface is free of impurities and dust, which usually includes the use of cleaning agents, chemical solvents, ultrasonic cleaning, and other methods.
Vacuum pumping inside the vacuum chamber: Place the substrate into the vacuum chamber and use a mechanical pump and diffusion pump to extract the gas inside the vacuum chamber to achieve the desired vacuum degree (usually 1 × 10 ^ -3 Pa).
Filling inert gas: Fill the vacuum chamber with inert gas such as argon for the sputtering process.
Plasma generation under high voltage electric field: Applying a high voltage electric field in a vacuum chamber to ionize argon gas and produce plasma.
Plasma bombardment of target material: Plasma bombardment of target material causes atoms or molecules on the surface of the target material to be sputtered out.
Atomic deposition on substrate surface: Sputtered atoms deposit on the substrate surface, forming a thin film.
Temperature and time control of film thickness and properties: By controlling the sputtering time and temperature, the thickness and properties of the film can be adjusted.
Cooling and removal of finished products: After sputtering is completed, the substrate is cooled in a vacuum chamber, then removed and subjected to quality inspection.
Advantages and disadvantages of vacuum sputtering:
Advantages:
Strong adhesion: Sputtering coating usually has stronger adhesion than other methods.
Wide applicability: Almost all materials can be coated by sputtering, including high melting point materials.
High film quality: The sputtered coating has a dense and uniform film layer, with good mechanical properties and corrosion resistance.
Disadvantages:
Complex equipment: Sputtering equipment is relatively complex and has high maintenance costs.
High cost: Due to high equipment and technical requirements, production costs are relatively high.
