Principle of vacuum magnetron sputtering coating

In the process of electron flying to the substrate accelerate under the action of electric field, it collides with argon atoms and ionizes a large numbers of argon ions and electrons, and then the electrons fly to substrate. Under the action of electric field, argon ion accelerates to bombard the target, sputtering a large number of target atoms, as neutral target atoms (or molecules) deposited on the substrate to form films. The secondary electrons are affected by the Loren magnetic force of the magnetic field during the process of accelerating and flying to the substrate, and are bound in the plasma region close to the target surface. The plasma density in this region is very high.  The plasma density in the area is very high, secondary electron under the action of magnetic field around the target surface as a circular motion. The electrons have a long path of movement. During the movement, they continuously collide with argon atoms and ionize a large number of argon ions to bombard the target material. After multiple collisions, the energy of the electrons gradually decreases and gets rid of the constraints of the magnetic lines of force.  Away from the target, and finally deposited on the substrate. Magnetron sputtering is to confine and extend the movement path of electrons with a magnetic field, change the direction of movement of the electrons, increase the ionization rate of the working gas, and effectively uses the energy of the electrons. The fate of electrons is not only the substrate, but the inner wall of the vacuum chamber and the target anodes are also the fate of electrons. But generally the substrate, the vacuum chamber and the anode are at the same potential. The interaction between the magnetic field and the electric field (EXBdrift) makes the trajectory of a single electron appear a three-dimensional spiral instead of just moving in a circle on the target surface. As for the circular sputtering profile of the target surface, the magnetic field lines of the target source are in a circular shape. The different distribution directions of the magnetic field lines have a great influence on the film formation. The non-optical magnetron sputtering, multi-arc plating target source, ion source, plasma source, etc. that work under the EXBshift mechanism all work under the sub-principle. The difference is the direction of the electric field, the magnitude of the voltage and current. The surface of the material is bombarded with energetic particles with a kinetic energy of tens of electron volts or higher, so that the atoms gain enough energy to splash out into the gas phase. This spattered, complex particle scattering process is called sputtering.

Sputtering coating: In a vacuum chamber, the process of bombarding the surface of the material with energy particles to make the atoms get enough energy to splash out into the gas phase, and then deposit on the surface of the work piece. In sputter coating, the bombarded material is called the target.

Not only pure metal films but also multicomponent films can be obtained by sputtering. There are three representative methods for obtaining multi-component membranes. One is alloy and compound target: a target made of alloy or composite oxide; and the other is a composite target: a composite of two or more single metals with various shapes; three for multi-target: using more than two targets and rotating the substrate, each layer about one atom, through alternate deposition to obtain a compound film.