dc.description.abstract | The plasma fabrication process attracts more and more attentions in the semiconductor industry in recent years. In the metallization process, the sputtering rate and deposition rate of the Planer DC Sputtering process is not enough to satisfy the semiconductor industry. It’s more necessary to develop the high density plasma system to improve the sputtering rate and deposition rate.
In the DC Magnetron Sputtering, an external magnetic field is applied to enhance the plasma density around the target. The sputtering rate and deposition rate will rise by additional ion bombardment, but it still has the problem that the ion bombardment flux distribution is not smooth along the target. It causes the non-uniformity of target erosion and the surface deposition. It is very important to have an appropriate design of the magnetic fields.
In this thesis, we numerically study the discharge phenomena of a DC Magnetron Sputtering system, including the effects of different magnet plate design and how it affects the plasma density. The plasma distributions and the relationships of ion bombardment on the target are discussed for the one-ring magnet plate and the multi-ring magnet plate.
In the plasma simulation, we use the fluid model method to reduce the computational time and make it more convenient to set up the plasma parameters. To make the plasma simulations more close to the reality, we also consider the effects of the gas temperature and the argon metastable atoms. When the gas temperature and the electron temperature increase, it causes the plasma density decreasing. The electron temperature distribution is same as the magnet line of force distribution. When the electron temperature in the region of 40 eV ~ 70 eV, it causes the maximal ionization rate and excitation rate. Considering the argon metastable atoms contribution, it makes the simulation more close to the real situation and causes the plasma density increasing.
In the result of this thesis, we find out that the plasma species follow the magnet lines of force and concentrate near the target surface, where the magnet lines of force are parallel to the electrode in the one-ring magnet situation. In the case of the seven-magnet plasma distribution, there are two concentration picks of ion bombardment near the edge of the target, while in the case of the six-magnet plasma distribution, the ion bombardment picks are located near the center of the target. Finally, we calculate the sputtering rates and the target erosion profiles. A special case with magnetic isolated boundary is discussed, which enhances the plasma density and the uniformity of target erosion.
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