Magnetron sputtering is a type of physical vapor deposition (pvd). The general sputtering method can be used to prepare a variety of materials such as metals, semiconductors, insulators, and has the advantages of simple equipment, convenient control, large coating area, and strong adhesion. The method developed in the 1970s achieved high speed, low temperature, and low damage. Due to the low-pressure high-speed sputtering, the ionization rate of the gas needs to be increased. It improves the plasma density and sputtering efficiency by introducing a magnetic field on the target cathode surface.
First, define a closed magnetic field that is parallel to the target surface during operation. The orthogonal electromagnetic field formed on the target surface is used to bind the secondary electrons to the specific surface area of the target surface to improve the ionization efficiency, increase the ion density and energy, and achieve a high-speed sputtering process.
Second, the working principle of magnetron sputtering The working principle is that under the action of the electric field e, the electrons collide with the argon atoms during the process of flying to the substrate, generating ar positive ions and new electrons; the new electrons fly to the substrate, The ar ion accelerates to the cathode target under the action of the electric field. Bombing the target surface with high energy causes the target to sputter. In the sputtered particles, neutral target atoms or molecules are deposited on the substrate to form a thin film. The secondary electrons generated are affected by the electric and magnetic fields, resulting in a direction shift of e (electric field) × b (magnetic field), referred to as e × b Drift, its motion trajectory is similar to cycloid. If the magnetic field is circular, the electrons move on the target surface in an approximately cycloidal form. Not only are their motion paths long, but they also have constraints on the plasma region near the target surface. In this area, a large amount of ar is ionized to bombard the target, thereby obtaining a high deposition rate. As the number of collisions increases, the energy of the secondary electrons is exhausted and gradually moves away from the target surface, and is deposited on the substrate under the action of the electric field e. Because the energy of the electrons is very low, the energy transferred to the substrate is small, and the substrate The temperature rise is low. Magnetron sputtering is a collision process between an incident particle and a target. The incident particle undergoes a complex scattering process in the target, collides with the target atom, and transfers some momentum to the target atom. The target atom collides with other target atoms to form a cascade process. In this cascading process, some target atoms near the surface gain more momentum and move outward, causing the target atoms to be sputtered out.
Third, the form of magnetron sputtering There are many forms, there are different working principles and application objects. But there is one thing in common: using the interaction of magnetic and electric fields, the electrons move in a spiral shape near the target surface, thereby increasing the probability that the electrons strike the argon to generate ions. The generated ions impinge on the surface of the target under the action of the electric field and splash out from the target.