Magnetron sputtering mainly includes discharge plasma transport, target etching, thin film deposition and other processes, the magnetic field on the magnetron sputtering process will have an impact. In the magnetron sputtering system plus orthogonal magnetic field, the electrons are subject to the role of the Lorentz force and do spiral trajectory movement, must undergo constant collision to gradually move to the anode, due to the collision makes part of the electrons to reach the anode after the energy is small, the heat of bombardment on the substrate is also not big. In addition, because of the electron by the target magnetic field constraints, in the target surface of the magnetic effect of the region that is within the discharge runway this local small range of electron concentration is very high, and in the magnetic effect of the region outside the substrate surface, especially away from the magnetic field near the surface, the electron concentration due to the dispersion of much lower and relatively uniform distribution, and even lower than the dipole sputtering conditions (because of the two working gas pressure difference of an order of magnitude). The low density of electrons bombarding the surface of the substrate, so that the bombardment of the substrate caused by the lower temperature rise, which is the main mechanism of magnetron sputtering substrate temperature rise is low. In addition, if there is only an electric field, the electrons reach the anode after a very short distance, and the probability of collision with the working gas is only 63.8%. And add the magnetic field, electrons in the process of moving to the anode to do spiral motion, the magnetic field bound and extend the trajectory of electrons, greatly improving the probability of collision of electrons and working gases, which greatly promotes the occurrence of ionization, ionization and then again produce electrons also join the process of collision, the probability of collision can be increased by several orders of magnitude, the effective use of the energy of the electrons, and thus in the formation of high-density The plasma density increases in the anomalous glow discharge of the plasma. The rate of sputtering out atoms from the target is also increased, and target sputtering caused by bombardment of the target by positive ions is more effective, which is the reason for the high rate of magnetron sputtering deposition. In addition, the presence of the magnetic field can also make the sputtering system operating at lower air pressure, low 1 for air pressure can make ions in the sheath layer region to reduce the collision, bombardment of the target with a relatively large kinetic energy, and the day to be able to reduce the sputtered target atoms and neutral gas collision, to prevent the target atoms from being scattered to the wall of the device or bounced back to the target surface, to improve the rate and quality of the thin film deposition.
The target magnetic field can effectively constrain the trajectory of electrons, which in turn affects the plasma properties and the etching of ions on the target.
Trace: increase the uniformity of the target magnetic field can increase the uniformity of the target surface etching, thus improving the utilization of the target material; reasonable electromagnetic field distribution can also effectively improve the stability of the sputtering process. Therefore, for magnetron sputtering target, the size and distribution of the magnetic field is extremely important.
–This article is released by vacuum coating machine manufacturer Guangdong Zhenhua
Post time: Dec-14-2023