Is sputtering same as PVD?

PVD is physical vapor deposition, which refers to the deposition of specific components of gas onto the wafer surface by physical means (electricity, magnetism, gravity) to form a thin film. Magnetron sputtering is a kind of PVD, which is one of the older thin film growth techniques. The advantages are lower cost and more kinds of films can be grown, but the disadvantages are poor film consistency, poor step coverage and lower strength.

There are four main categories of sputtering: DC sputtering, AC sputtering, reactive sputtering, and magnetron sputtering.

Principle of sputtering target

When a target is bombarded with charged particles, the accelerated ions bombard the solid surface, surface atom collisions occur and transfer of energy and momentum takes place, causing the target atoms to escape from the surface and precipitate on the substrate material in the process. The phenomenon that the atoms or molecules on the surface of the target material escape from the target surface by bombarding the target surface with charged particles (commonly positive gas ions), while the sputtering process contains momentum transfer, so the sputtered particles are directional.

Features of sputtering target

The sputtering process has the advantages of low substrate temperature, pure film quality, uniform and dense organization, good solidity and reproducibility, etc.

Application of sputtering coating technology

1. Preparation of wear-resistant oxide film for thin-film heads Sliding friction occurs between the hard disk head and the hard disk surface when reading and writing operations are performed. Insulating and protective films (i.e., AL2 O3 and SiO2 oxide films) are the main components of thin-film heads. The requirements for wear-resistant films for thin-film heads are good impact resistance, good wear resistance, proper machinability and small processing deformation, which are usually prepared by reactive sputtering. To prevent the substrate from heating up too much, the substrate is cooled during the sputter coating process.

2. Preparation of hard films A widely used hardening film is chromium plating in aqueous solution. Electroplating causes hydrogen embrittlement of the steel, and it is slow and causes environmental pollution. If a metallic Cr target is used for non-equilibrium magnetron sputtering coating in N 2 atmosphere, Cr, CrN X, etc. can be coated on the workpiece instead of aqueous solution plating for rotating shafts and other moving parts.

3. Preparation of superhard films for cutting tools and dies The preparation of TiN, TiC and other superhard coatings by ordinary chemical vapor deposition technology requires a temperature of about 1000 ℃, which is already more than the tempering temperature of high-speed steel, and may also make the coating grains grow for cemented carbide. The hardness of the TiN coating prepared by the non-equilibrium magnetron sputtering method has reached and exceeded that of other ion coatings through the hardness and critical load experiments and friction experiments.

4. Preparation of solid lubrication film Solid lubrication film such as MoS 2 film has been successfully applied in vacuum industry equipment, atomic energy equipment and aerospace field, and is indispensable for mechanical equipment working in high temperature environment. Although MoS 2 can be prepared by chemical reaction coating method, the MoS 2 film obtained by sputtering coating has good denseness and high adhesion of the film base, and the MoS 2 film with Au (5wt%) has better denseness and adhesion and lower friction coefficient.

5. Preparation of optical thin films Sputtering is a major process for the preparation of optical thin films in industrial generation. For a long time, reactive magnetron sputtering technology has been mainly used for plating superhard films such as TiN on tool surfaces and single or simple film layers such as architectural glass, automotive glass, and transparent conductive films. In recent years, the huge demand for optical thin films in optical communication, display technology, etc. has stimulated the research of using this technology for industrial production of optical thin films.