Sputtering coating technology is to use ions to hit the target material appearance, and the atoms generated by sputtering pile up on the substrate appearance to form a PVD coating. Usually, gas ionization occurs by gas discharge, and its positive ions under the effect of electric field hit the cathode target at high speed, striking out the atoms or molecules of the cathode target, and then flying to the exterior of the plated substrate to accumulate into PVD coating. Magnetron sputtering coating technology is developed on the basis of sputtering coating, compared with sputtering coating, the accumulation rate is faster, the coating is dense and has good adhesion with the substrate, which is suitable for mass production of PVD coating.
1. Balanced magnetron sputtering
The traditional magnetron sputtering coating technology, is a permanent magnet or electromagnetic coil placed behind the target material, the target material will constitute a magnetic field perpendicular to the direction of the electric field. In the high-pressure effect of argon ionization into a plasma, Ar + ions accelerated by the electric field shelling cathode target, target secondary electrons are sputtered, and electrons in the perpendicular to each other under the effect of electric and magnetic fields, is bound in the cathode near the appearance of the target material, increasing the chance of collision of electrons and gases, that is, increasing the rate of ionization of argon, argon in the low-gas can be maintained under the discharge, and therefore magnetron sputtering not only reduces sputtering gas pressure, but also improve the sputtering power. Therefore, magnetron sputtering not only reduces the sputtering gas pressure, but also improves the sputtering power and stacking rate.
However, the traditional magnetron sputtering has some disadvantages, for example: low-pressure discharge of electrons and poke out the target secondary electrons are bound in the target surface near the region of about 60mm, so that the workpiece can only be placed in the target outside the range of 50~100mm. Such a small coating area constrains the scale of the workpiece to be plated, and larger workpieces are not suitable for traditional methods.
2. Non-equilibrium magnetron sputtering
This magnetron sputtering coating method to solve part of the defects of the balanced magnetron sputtering, is the target surface of the plasma lead to the target in front of the range of 200 ~ 300mm, so that the anode substrate immersed in the plasma, reducing the interval between the particles moving, the ion beam to play the role of auxiliary stacking effect. However, a separate unbalanced magnetron target on the substrate is difficult to build up a uniform thin film layer, and thus the emergence of multi-target unbalanced magnetron sputtering coating technology to make up for the defects of the single target unbalanced magnetron sputtering.
3. Reverse magnetron sputtering
With the development of appearance engineering technology, more and more use of a variety of compound thin film materials. Compound materials can be used directly to produce the target material through the sputtering to prepare compound films, but also in the sputtering of metal or alloy targets, the introduction of reactive gases to the vacuum chamber, through the chemical reaction to prepare compound films, this method is known as reverse magnetron sputtering. Generally speaking, pure metal as the target material and gas reverse easier to get high quality compound film, so most of the compound film is prepared by reverse sputtering magnetron sputtering with pure metal as the target material.
4. Intermediate frequency magnetron sputtering
This coating method is to change the magnetron sputtering power supply from the traditional DC to medium frequency AC power supply. In the sputtering process, when the system voltage in the negative half-cycle of the alternating current, the target material is positive ions shelling and sputtering, while in the positive half-cycle, the target material appearance by the plasma in the electron shelling and sputtering, at the same time, the target material appearance of the cumulative positive charge is neutralized, the phenomenon of playing the arc is suppressed. Medium frequency magnetron sputtering power supply frequency is usually between 10-80kHz, high frequency, positive ions are accelerated by a short period of time, the energy of the target is low, the sputtering accumulation rate decreases. Medium-frequency magnetron sputtering system generally has two targets, the two targets periodically rotate as the cathode and anode, on the one hand, reduce the substrate sputtering; on the other hand, also weakened the arc phenomenon.
The above broadly introduces the representative methods of magnetron sputtering coating, it can be seen that magnetron sputtering coating skills after a long time, derived from many branches, constituting different characteristics, and thus get more widely used, the preparation of PVD coating performance is better. If you need related services or want to know more, welcome to contact us to get the content you need.