Various types of sputtering thin film materials have been widely used in semiconductor integrated circuits (VLSI), optical disks, flat panel displays and surface coatings of workpieces. Since the 1990s, the synchronous development of sputtering target and sputtering technology has greatly satisfied the development needs of various new electronic components. For example, in the manufacturing process of semiconductor integrated circuit, copper conductor film with low resistivity replaces aluminum film wiring. In the information storage industry, the increasing storage capacity of magnetic memory and the constant innovation of new magneto-optical recording materials have put forward higher and higher requirements for the quality of sputtering target materials required, and the demand quantity also increases year by year.
An orthogonal magnetic field and electric field are added between the sputtering target pole (cathode) and the anode, and the required inert gas (usually Ar gas) is filled in the high vacuum chamber. A 250 ~ 350 gaussian magnetic field is formed on the surface of the target material by the permanent magnet, and the orthogonal electromagnetic field is formed by the high voltage electric field. Under the action of electric field, Ar gas ionization into positive ions and electrons, target and has certain negative pressure, from the action of the target from the extremely affected by magnetic field and increase of working gas ionization probability, form a high density plasma near the cathode, Ar ion under the action of lorentz force, speed up to fly to the target surface, bombarding target surface at a high speed, the target is follow the principle of momentum transfer atoms sputtering out by higher kinetic energy from the target surface to substrate deposition film. Magnetron sputtering is generally divided into two types: dc sputtering and rf sputtering. The principle of dc sputtering equipment is simple, and its rate is also fast when sputtering metal. However, rf sputtering has a wider range of application. In addition to sputtering conductive materials, non-conductive materials can also be sputtering, and reactive sputtering can also be used to prepare oxides, nitrides and carbides and other compound materials. If the frequency of rf increases, it will become microwave plasma sputtering. Nowadays, electron cyclotron resonance (ECR) type microwave plasma sputtering is commonly used.
