1. Ensure the uniformity and direction of the magnetic field as much as possible to form a relatively uniform spatial magnetic field.
2. Ensure the uniformity of the upper and lower pressures, the vacuum chamber should be designed in consideration of the installation position of the vacuum pump, the process gas intake mode and the layout of the process gas tubes in the cavity.
3. Since neither the magnetic field nor the air pressure is absolutely ideal, the unevenness of the air pressure can be used to compensate for the uneven magnetic field and make the final film uniform.
4. Distance between target and substrate is also an important factor that affects film uniformity.