Uniformity Problem Of Magnetron Sputtering Film

- Jul 05, 2018-

Uniformity of magnetron sputtering film is an important index, so it is necessary to study the influencing factors affecting the uniformity of magnetron sputtering in order to better achieve uniform coatings. Simply speaking, magnetron sputtering refers to that electrons make a spiral motion around the target surface under the constraint of the closed magnetic field in an orthogonal electromagnetic field. During the motion, electrons keep striking the working gas (argon gas) to ionize a large amount of argon ions. Under the electric field, the argon ions quickly bombard the target, and the target atomic ions (or molecules) deposit on the substrate to form a thin film. 

Therefore, in order to achieve a uniform coating, it is necessary to uniformly sputter the target atom ions (or molecules), which requires that the argon ions uniformly bombard the target. Since the argon ions accelerate the bombardment of the target under the action of the electric field, the electric field is required to be uniform. The argon ions originate from the electrons bound by the closed magnetic field, and the electrons are constantly struck during the movement, which requires uniform magnetic field and uniform argon distribution. However, in actual magnetron sputtering devices, these factors are difficult to be completely uniform, and it is necessary to study the effect of their unevenness on film formation uniformity. In fact, the uniformity of the magnetic field and the uniformity of the working gas are the most important factors affecting the uniformity of film formation. Big magnetic field means large film thickness, and the direction of the magnetic field is also an important factor affecting the uniformity. In terms of air pressure, under a certain pressure, the film with a large air pressure has large thickness.