The Research On The Generation Characteristics Of Plasma And Metal Ion Implantation Technology In A Vacuum Discharge

Ion implantation technology applied to material modification has many advantages,for example,it is not limited by the solid solubility of the material,and the shape and size of material will not be affected in the process of treatment,which makes the ion implantation technology become a very important means of material modification.However,charged particles are absorbed by the anode of electrode structure of plasma source for ion implantation technology,resulting in low plasma utilization.Therefore,it is of great significance for the development of Ion implantation technology to design the electrode structure of plasma source for ion implantation technology scientifically and reasonably,and to improve the plasma density,energy and ejection performance.The coaxial discharge electrode applied to plasma source for ion implantation technology is taken as research object,and an electrode structure with an auxiliary floating potential electrode was proposed in this paper.With methods of simulation,theoretical analysis and design experiment,the discharge characteristics and generation characteristics of plasma were studied deeply.First of all,the differences in discharge characteristics and generation characteristics of plasma between the electrode structure with an auxiliary floating potential electrode and the insulated anode electrode structure were compared and analyzed,which was designed to understand the role of an auxiliary floating potential electrode in the process of discharge.Secondly,with methods of the theoretical analysis and experimental design,the influences that the thickness of the auxiliary floating potential electrode and the length of the auxiliary floating potential electrode had on space charged particle near the cathode were also discussed.Thirdly,based on the electrode structure with an auxiliary floating potential electrode,an electrode structure with a capacitor was proposed.The differences in discharge characteristics and generation characteristics of plasma between the electrode structure with a capacitor and the electrode structure with an auxiliary floating potential electrode were compared and analyzed,which was designed to understand the role of capacitor in the process of discharge.With methods of simulation analysis and experimental research,the influences that the capacitor of the electrode structure with a capacitor had on space charged particle near the cathode was discussed.Finally,based on the electrode structure with a capacitor,an electrode structure with a dc power supply was proposed.Through the method of theoretical analysis,principle of discharge for the electrode structure with a dc power supply was speculated.The experimental result shows that a lot of positive charges which the auxiliary floating potential electrode induces on its inner surface by electrostatic induction,can allow electrons of the plasma generated near the cathode to escape quickly,which makes it that the positive space potential near the cathode is increased,thus increasing the plasma density.Increasing the thickness and length of the auxiliary floating potential electrode can increase the quantities of induced positive charges on the inner surface of the auxiliary floating potential electrode,which could further improves the plasma density and energy,and reduce the plasma distribution angle.When using the electrode structure with a capacitor,the capacitor can increase the quantities of induced positive charges on the inner surface of the auxiliary floating potential electrode,increasing the plasma density and energy.The ability of the auxiliary floating potential electrode to allow electrons to escape quickly is improved by adopting a capacitor with larger capacity,further improving plasma density,energy and the directional ejection performance of plasma.The research of this paper provides a new idea and method for the development of ion implantation technology.